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Sample records for multipurpose tree species

  1. Vegetative and reproductive phenology of some multipurpose tree species in the homegardens of Barak Valley, northeast India

    NASA Astrophysics Data System (ADS)

    Das, Tapasi; Das, Ashesh Kumar

    2013-01-01

    Traditional homegardens are an important component of the farming systems in many rural communities and have been highlighted considerably due to their sustainability and role in the conservation of biodiversity. However, the functional aspect of the homegardens, which includes the phenological behavior of the dominant tree species in such agroforestry systems, has been undermined till date, and there is a lack of adequate data on this aspect of the traditional homegardens. As a step in this direction the present study was carried out to determine the phenological behavior of important multipurpose trees in the homegardens of the village of Dargakona, Assam, northeast India. The study revealed the dominance of periodic growth deciduous species from a total of 25 tree species selected for phenological observation. The diversity of multipurpose trees in the homegardens is represented by different plant functional types with different phenological behavior which showed significant changes in their responses to inter-annual climatic variations. The diversity of tree species with different phenological behavior has implications for the temporal partitioning of resources, especially during periods of scarcity, thereby resulting in efficient utilization of resources such as water. Also the diverse phenological behavior plays an important role in regulating the food supply for the herbivore population and the year-round availability of products, and such information can be useful in the selection of species for integration into other agroforestry systems which can be sustainable in the long run.

  2. Village agroforestry systems and tree-use practices: A case study in Sri Lanka. Multipurpose tree species network research series

    SciTech Connect

    Wickramasinghe, A.

    1992-01-01

    Village agroforestry systems in Sri Lanka have evolved through farmers' efforts to meet their survival needs. The paper examines farmers' land-use systems and their perceptions of the role of trees in the villages of Bambarabedda and Madugalla in central Sri Lanka. The benefits of village agroforestry are diverse food, fuelwood, fodder, timber, and mulch, but food products are of outstanding importance. The ability of Artocarpus heterophyllus (the jackfruit tree) and Cocos nucifera (coconut) to ensure food security during the dry season and provide traditional foods throughout the year, as well as to grow in limited space, make them popular crops in the two study villages. The study recommends that further research precede the formulation of agricultural interventions and that efforts to promote improved tree varieties recognize farmers' practices and expressed needs.

  3. Effects of species and season on chemical composition and ruminal crude protein and organic matter degradability of some multi-purpose tree species by West African dwarf rams.

    PubMed

    Arigbede, O M; Anele, U Y; Südekum, K-H; Hummel, J; Oni, A O; Olanite, J A; Isah, A O

    2012-04-01

    Seasonal chemical composition and ruminal organic matter (OM) and crude protein (CP) degradabilities were determined in four tropical multi-purpose tree species (MPTS) namely; Pterocarpus santalinoides, Grewia pubescens, Enterolobium cyclocarpum and Leucaena leucocephala. Three West African dwarf (WAD) rams fitted with permanent rumen cannula were used for the degradability trials. Foliage samples were collected four times to represent seasonal variations as follows: January--mid dry; April--late dry; July--mid rainy and October--late rainy seasons. Leaf samples were randomly collected from the trees for estimation of dry matter (DM) and chemical composition. Ruminal in sacco OM and CP degradabilities were estimated from residues in nylon bags. All samples had high CP (161-259 g/kg DM) and moderate fibre concentrations [neutral detergent fibre (without residual ash], 300-501 g/kg DM; acid detergent fibre (without residual ash), 225-409 g/kg DM and acid detergent lignin, 87-179 g/kg DM across seasons. Interaction effects of species and season on chemical composition were highly significant (p = 0.001) except for trypsin inhibitor (p = 0.614). The MPTS recorded more than 60% OM and CP degradability at 24 h, which implied that they were all highly degradable in the rumen. Their incorporation into ruminant feeding systems as dry season forage supplements is therefore recommended. PMID:21535229

  4. De novo assembly and characterization of leaf transcriptome for the development of functional molecular markers of the extremophile multipurpose tree species Prosopis alba

    PubMed Central

    2013-01-01

    Background Prosopis alba (Fabaceae) is an important native tree adapted to arid and semiarid regions of north-western Argentina which is of great value as multipurpose species. Despite its importance, the genomic resources currently available for the entire Prosopis genus are still limited. Here we describe the development of a leaf transcriptome and the identification of new molecular markers that could support functional genetic studies in natural and domesticated populations of this genus. Results Next generation DNA pyrosequencing technology applied to P. alba transcripts produced a total of 1,103,231 raw reads with an average length of 421 bp. De novo assembling generated a set of 15,814 isotigs and 71,101 non-assembled sequences (singletons) with an average of 991 bp and 288 bp respectively. A total of 39,000 unique singletons were identified after clustering natural and artificial duplicates from pyrosequencing reads. Regarding the non-redundant sequences or unigenes, 22,095 out of 54,814 were successfully annotated with Gene Ontology terms. Moreover, simple sequence repeats (SSRs) and single nucleotide polymorphisms (SNPs) were searched, resulting in 5,992 and 6,236 markers, respectively, throughout the genome. For the validation of the the predicted SSR markers, a subset of 87 SSRs selected through functional annotation evidence was successfully amplified from six DNA samples of seedlings. From this analysis, 11 of these 87 SSRs were identified as polymorphic. Additionally, another set of 123 nuclear polymorphic SSRs were determined in silico, of which 50% have the probability of being effectively polymorphic. Conclusions This study generated a successful global analysis of the P. alba leaf transcriptome after bioinformatic and wet laboratory validations of RNA-Seq data. The limited set of molecular markers currently available will be significantly increased with the thousands of new markers that were identified in this study. This information will strongly contribute to genomics resources for P. alba functional analysis and genetics. Finally, it will also potentially contribute to the development of population-based genome studies in the genera. PMID:24125525

  5. Species integrity in trees.

    PubMed

    Ortiz-Barrientos, Daniel; Baack, Eric J

    2014-09-01

    From California sequoia, to Australian eucalyptus, to the outstanding diversity of Amazonian forests, trees are fundamental to many processes in ecology and evolution. Trees define the communities that they inhabit, are host to a multiplicity of other organisms and can determine the ecological dynamics of other plants and animals. Trees are also at the heart of major patterns of biodiversity such as the latitudinal gradient of species diversity and thus are important systems for studying the origin of new plant species. Although the role of trees in community assembly and ecological succession is partially understood, the origin of tree diversity remains largely opaque. For instance, the relative importance of differing habitats and phenologies as barriers to hybridization between closely related species is still largely uncharacterized in trees. Consequently, we know very little about the origin of trees species and their integrity. Similarly, studies on the interplay between speciation and tree community assembly are in their infancy and so are studies on how processes like forest maturation modifies the context in which reproductive isolation evolves. In this issue of Molecular Ecology, Lindtke et al. (2014) and Lagache et al. (2014) overcome some traditional difficulties in studying mating systems and sexual isolation in the iconic oaks and poplars, providing novel insights about the integrity of tree species and on how ecology leads to variation in selection on reproductive isolation over time and space. PMID:25155715

  6. Breeding status of tung tree (Vernicia sp.) in China, a multipurpose oilseed crop with industrial uses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As a developing country with the world’s largest population, China faces a serious challenge in satisfying its continuously increasing energy demands. Tung trees (Vernicia sp., especially V. fordii and V. montana), are multipurpose, perennial plants belonging to the Euphorbiaceae family. The unique ...

  7. The inference of gene trees with species trees.

    PubMed

    Szöll?si, Gergely J; Tannier, Eric; Daubin, Vincent; Boussau, Bastien

    2015-01-01

    This article reviews the various models that have been used to describe the relationships between gene trees and species trees. Molecular phylogeny has focused mainly on improving models for the reconstruction of gene trees based on sequence alignments. Yet, most phylogeneticists seek to reveal the history of species. Although the histories of genes and species are tightly linked, they are seldom identical, because genes duplicate, are lost or horizontally transferred, and because alleles can coexist in populations for periods that may span several speciation events. Building models describing the relationship between gene and species trees can thus improve the reconstruction of gene trees when a species tree is known, and vice versa. Several approaches have been proposed to solve the problem in one direction or the other, but in general neither gene trees nor species trees are known. Only a few studies have attempted to jointly infer gene trees and species trees. These models account for gene duplication and loss, transfer or incomplete lineage sorting. Some of them consider several types of events together, but none exists currently that considers the full repertoire of processes that generate gene trees along the species tree. Simulations as well as empirical studies on genomic data show that combining gene tree-species tree models with models of sequence evolution improves gene tree reconstruction. In turn, these better gene trees provide a more reliable basis for studying genome evolution or reconstructing ancestral chromosomes and ancestral gene sequences. We predict that gene tree-species tree methods that can deal with genomic data sets will be instrumental to advancing our understanding of genomic evolution. PMID:25070970

  8. The Inference of Gene Trees with Species Trees

    PubMed Central

    Szöllősi, Gergely J.; Tannier, Eric; Daubin, Vincent; Boussau, Bastien

    2015-01-01

    This article reviews the various models that have been used to describe the relationships between gene trees and species trees. Molecular phylogeny has focused mainly on improving models for the reconstruction of gene trees based on sequence alignments. Yet, most phylogeneticists seek to reveal the history of species. Although the histories of genes and species are tightly linked, they are seldom identical, because genes duplicate, are lost or horizontally transferred, and because alleles can coexist in populations for periods that may span several speciation events. Building models describing the relationship between gene and species trees can thus improve the reconstruction of gene trees when a species tree is known, and vice versa. Several approaches have been proposed to solve the problem in one direction or the other, but in general neither gene trees nor species trees are known. Only a few studies have attempted to jointly infer gene trees and species trees. These models account for gene duplication and loss, transfer or incomplete lineage sorting. Some of them consider several types of events together, but none exists currently that considers the full repertoire of processes that generate gene trees along the species tree. Simulations as well as empirical studies on genomic data show that combining gene tree–species tree models with models of sequence evolution improves gene tree reconstruction. In turn, these better gene trees provide a more reliable basis for studying genome evolution or reconstructing ancestral chromosomes and ancestral gene sequences. We predict that gene tree–species tree methods that can deal with genomic data sets will be instrumental to advancing our understanding of genomic evolution. PMID:25070970

  9. Gene tree correction for reconciliation and species tree inference

    PubMed Central

    2012-01-01

    Background Reconciliation is the commonly used method for inferring the evolutionary scenario for a gene family. It consists in “embedding” inferred gene trees into a known species tree, revealing the evolution of the gene family by duplications and losses. When a species tree is not known, a natural algorithmic problem is to infer a species tree from a set of gene trees, such that the corresponding reconciliation minimizes the number of duplications and/or losses. The main drawback of reconciliation is that the inferred evolutionary scenario is strongly dependent on the considered gene trees, as few misplaced leaves may lead to a completely different history, with significantly more duplications and losses. Results In this paper, we take advantage of certain gene trees’ properties in order to preprocess them for reconciliation or species tree inference. We flag certain duplication vertices of a gene tree, the “non-apparent duplication” (NAD) vertices, as resulting from the misplacement of leaves. In the case of species tree inference, we develop a polynomial-time heuristic for removing the minimum number of species leading to a set of gene trees that exhibit no NAD vertices with respect to at least one species tree. In the case of reconciliation, we consider the optimization problem of removing the minimum number of leaves or species leading to a tree without any NAD vertex. We develop a polynomial-time algorithm that is exact for two special classes of gene trees, and show a good performance on simulated data sets in the general case. PMID:23167951

  10. Coalescent Histories for Lodgepole Species Trees.

    PubMed

    Disanto, Filippo; Rosenberg, Noah A

    2015-10-01

    Coalescent histories are combinatorial structures that describe for a given gene tree and species tree the possible lists of branches of the species tree on which the gene tree coalescences take place. Properties of the number of coalescent histories for gene trees and species trees affect a variety of probabilistic calculations in mathematical phylogenetics. Exact and asymptotic evaluations of the number of coalescent histories, however, are known only in a limited number of cases. Here we introduce a particular family of species trees, the lodgepole species trees (?n)n ? 0, in which tree ?n has m = 2n+1 taxa. We determine the number of coalescent histories for the lodgepole species trees, in the case that the gene tree matches the species tree, showing that this number grows with m!! in the number of taxa m. This computation demonstrates the existence of tree families in which the growth in the number of coalescent histories is faster than exponential. Further, it provides a substantial improvement on the lower bound for the ratio of the largest number of matching coalescent histories to the smallest number of matching coalescent histories for trees with m taxa, increasing a previous bound of [Formula: see text] to [Formula: see text]. We discuss the implications of our enumerative results for phylogenetic computations. PMID:25973633

  11. From event-labeled gene trees to species trees

    PubMed Central

    2012-01-01

    Background Tree reconciliation problems have long been studied in phylogenetics. A particular variant of the reconciliation problem for a gene tree T and a species tree S assumes that for each interior vertex x of T it is known whether x represents a speciation or a duplication. This problem appears in the context of analyzing orthology data. Results We show that S is a species tree for T if and only if S displays all rooted triples of T that have three distinct species as their leaves and are rooted in a speciation vertex. A valid reconciliation map can then be found in polynomial time. Simulated data shows that the event-labeled gene trees convey a large amount of information on underlying species trees, even for a large percentage of losses. Conclusions The knowledge of event labels in a gene tree strongly constrains the possible species tree and, for a given species tree, also the possible reconciliation maps. Nevertheless, many degrees of freedom remain in the space of feasible solutions. In order to disambiguate the alternative solutions additional external constraints as well as optimization criteria could be employed.

  12. Multipurpose Dissociation Cell for Enhanced ETD of Intact Protein Species

    PubMed Central

    Rose, Christopher M.; Russell, Jason D.; Ledvina, Aaron R.; McAlister, Graeme C.; Westphall, Michael S.; Griep-Raming, Jens; Schwartz, Jae C.; Coon, Joshua J.; Syka, John E.P.

    2013-01-01

    We describe and characterize an improved implementation of ETD on a modified hybrid linear ion trap-Orbitrap instrument. Instead of performing ETD in the mass-analyzing quadrupole linear ion trap (A-QLT), the instrument collision cell was modified to enable ETD. We partitioned the collision cell into a multi-section RF ion storage and transfer device to enable injection and simultaneous separate storage of precursor and reagent ions. Application of a secondary (axial) confinement voltage to the cell end lens electrodes enables charge-sign independent trapping for ion-ion reactions. The approximately two-fold higher quadrupole field frequency of this cell relative to that of the A-QLT, enables higher reagent ion densities and correspondingly faster ETD reactions, and, with the collision cell’s longer axial dimensions, larger populations of precursor ions may be reacted. The higher ion capacity of the collision cell permits the accumulation and reaction of multiple full loads of precursor ions from the A-QLT followed by FT Orbitrap m/z analysis of the ETD product ions. This extends the intra-scan dynamic range by increasing the maximum number of product ions in a single MS/MS event. For analyses of large peptide/small protein precursor cations, this reduces or eliminates the need for spectral averaging to achieve acceptable ETD product ion signal-to-noise levels. Using larger ion populations, we demonstrate improvements in protein sequence coverage and aggregate protein identifications in LC-MS/MS analysis of intact protein species as compared to the standard ETD implementation. PMID:23609185

  13. Species Tree Inference Using a Mixture Model.

    PubMed

    Ullah, Ikram; Parviainen, Pekka; Lagergren, Jens

    2015-09-01

    Species tree reconstruction has been a subject of substantial research due to its central role across biology and medicine. A species tree is often reconstructed using a set of gene trees or by directly using sequence data. In either of these cases, one of the main confounding phenomena is the discordance between a species tree and a gene tree due to evolutionary events such as duplications and losses. Probabilistic methods can resolve the discordance by coestimating gene trees and the species tree but this approach poses a scalability problem for larger data sets. We present MixTreEM-DLRS: A two-phase approach for reconstructing a species tree in the presence of gene duplications and losses. In the first phase, MixTreEM, a novel structural expectation maximization algorithm based on a mixture model is used to reconstruct a set of candidate species trees, given sequence data for monocopy gene families from the genomes under study. In the second phase, PrIME-DLRS, a method based on the DLRS model (Åkerborg O, Sennblad B, Arvestad L, Lagergren J. 2009. Simultaneous Bayesian gene tree reconstruction and reconciliation analysis. Proc Natl Acad Sci U S A. 106(14):5714-5719), is used for selecting the best species tree. PrIME-DLRS can handle multicopy gene families since DLRS, apart from modeling sequence evolution, models gene duplication and loss using a gene evolution model (Arvestad L, Lagergren J, Sennblad B. 2009. The gene evolution model and computing its associated probabilities. J ACM. 56(2):1-44). We evaluate MixTreEM-DLRS using synthetic and biological data, and compare its performance with a recent genome-scale species tree reconstruction method PHYLDOG (Boussau B, Szöll?si GJ, Duret L, Gouy M, Tannier E, Daubin V. 2013. Genome-scale coestimation of species and gene trees. Genome Res. 23(2):323-330) as well as with a fast parsimony-based algorithm Duptree (Wehe A, Bansal MS, Burleigh JG, Eulenstein O. 2008. Duptree: a program for large-scale phylogenetic analyses using gene tree parsimony. Bioinformatics 24(13):1540-1541). Our method is competitive with PHYLDOG in terms of accuracy and runs significantly faster and our method outperforms Duptree in accuracy. The analysis constituted by MixTreEM without DLRS may also be used for selecting the target species tree, yielding a fast and yet accurate algorithm for larger data sets. MixTreEM is freely available at http://prime.scilifelab.se/mixtreem/. PMID:25963975

  14. ASTRID: Accurate Species TRees from Internode Distances

    PubMed Central

    2015-01-01

    Background Incomplete lineage sorting (ILS), modelled by the multi-species coalescent (MSC), is known to create discordance between gene trees and species trees, and lead to inaccurate species tree estimations unless appropriate methods are used to estimate the species tree. While many statistically consistent methods have been developed to estimate the species tree in the presence of ILS, only ASTRAL-2 and NJst have been shown to have good accuracy on large datasets. Yet, NJst is generally slower and less accurate than ASTRAL-2, and cannot run on some datasets. Results We have redesigned NJst to enable it to run on all datasets, and we have expanded its design space so that it can be used with different distance-based tree estimation methods. The resultant method, ASTRID, is statistically consistent under the MSC model, and has accuracy that is competitive with ASTRAL-2. Furthermore, ASTRID is much faster than ASTRAL-2, completing in minutes on some datasets for which ASTRAL-2 used hours. Conclusions ASTRID is a new coalescent-based method for species tree estimation that is competitive with the best current method in terms of accuracy, while being much faster. ASTRID is available in open source form on github. PMID:26449326

  15. Pushing the pace of tree species migration.

    PubMed

    Lazarus, Eli D; McGill, Brian J

    2014-01-01

    Plants and animals have responded to past climate changes by migrating with habitable environments, sometimes shifting the boundaries of their geographic ranges by tens of kilometers per year or more. Species migrating in response to present climate conditions, however, must contend with landscapes fragmented by anthropogenic disturbance. We consider this problem in the context of wind-dispersed tree species. Mechanisms of long-distance seed dispersal make these species capable of rapid migration rates. Models of species-front migration suggest that even tree species with the capacity for long-distance dispersal will be unable to keep pace with future spatial changes in temperature gradients, exclusive of habitat fragmentation effects. Here we present a numerical model that captures the salient dynamics of migration by long-distance dispersal for a generic tree species. We then use the model to explore the possible effects of assisted colonization within a fragmented landscape under a simulated tree-planting scheme. Our results suggest that an assisted-colonization program could accelerate species-front migration rates enough to match the speed of climate change, but such a program would involve an environmental-sustainability intervention at a massive scale. PMID:25162663

  16. Pushing the Pace of Tree Species Migration

    PubMed Central

    Lazarus, Eli D.; McGill, Brian J.

    2014-01-01

    Plants and animals have responded to past climate changes by migrating with habitable environments, sometimes shifting the boundaries of their geographic ranges by tens of kilometers per year or more. Species migrating in response to present climate conditions, however, must contend with landscapes fragmented by anthropogenic disturbance. We consider this problem in the context of wind-dispersed tree species. Mechanisms of long-distance seed dispersal make these species capable of rapid migration rates. Models of species-front migration suggest that even tree species with the capacity for long-distance dispersal will be unable to keep pace with future spatial changes in temperature gradients, exclusive of habitat fragmentation effects. Here we present a numerical model that captures the salient dynamics of migration by long-distance dispersal for a generic tree species. We then use the model to explore the possible effects of assisted colonization within a fragmented landscape under a simulated tree-planting scheme. Our results suggest that an assisted-colonization program could accelerate species-front migration rates enough to match the speed of climate change, but such a program would involve an environmental-sustainability intervention at a massive scale. PMID:25162663

  17. Region effects influence local tree species diversity.

    PubMed

    Ricklefs, Robert E; He, Fangliang

    2016-01-19

    Global patterns of biodiversity reflect both regional and local processes, but the relative importance of local ecological limits to species coexistence, as influenced by the physical environment, in contrast to regional processes including species production, dispersal, and extinction, is poorly understood. Failure to distinguish regional influences from local effects has been due, in part, to sampling limitations at small scales, environmental heterogeneity within local or regional samples, and incomplete geographic sampling of species. Here, we use a global dataset comprising 47 forest plots to demonstrate significant region effects on diversity, beyond the influence of local climate, which together explain more than 92% of the global variation in local forest tree species richness. Significant region effects imply that large-scale processes shaping the regional diversity of forest trees exert influence down to the local scale, where they interact with local processes to determine the number of coexisting species. PMID:26733680

  18. A tree species inventory over Europe

    NASA Astrophysics Data System (ADS)

    Ambelas Skjøth, C.; Geels, C.; Hvidberg, M.; Hertel, O.; Brandt, J.; Frohn, L. M.; Hansen, K. M.; Hedegaard, G. B.; Christensen, J. H.; Moseholm, L.

    2009-04-01

    Atmospheric transport models are used in studies of atmospheric chemistry as well as aerobiology. Atmospheric transport models in general needs accurate emissions inventories, which includes biogenic emissions such as Volatile Organic Compounds (VOCs) and pollen. Trees are important VOC and pollen sources and a needed requirement is specie distribution which takes into account important species such as Betula and Alnus. We present here a detailed tree species inventory covering Europe, parts of Africa and parts of Asia. Forest inventories have been obtained for each European country, parts of Asia and parts of Africa. The national inventories vary with respect to number of species as well as the number of sub-regions each nation is divided into. The inventories are therefore harmonised within a GIS system and afterwards gridded to the model grid defined by the EMEP model: 50 km x 50 km. The inventory is designed to be used with existing land-use data, which separates forest cover into broad leaved, mixed and conifer forests. This will be exemplified by using two different remote sensing products with different grid resolution such as GLC2000 and CLC2000 in selected areas. The final inventory includes 16 conifer species and 23 broadleaved species that are important for biogenic VOCs or pollen emission calculations. For example: Oak (Quercus), poplar (Populus), pines (Pinus), spruce (Picea), birch (Betula) and alder (Alnus). 774 regions with forest inventories are included, mainly on sub-national level. The coverage of each specie ranges from national to European scale, where the latter includes VOC and allergy relevant species such as Quercus, Alnus and Betula. The inventory is gridded to the model grid defined by the EMEP model, which is also the basis for many emissions inventories throughout Europe. The inventory is therefore prepared for easy implementation into atmospheric transport models by providing an extension to already applied land use data such as the Corine Land Cover (CLC2000) or Global Land Cover (GLC2000). Possible applications of the inventory include emissions of VOCs and pollen, CO2 fluxes and dry deposition - in general calculations which are tree specie dependent.

  19. Liana competition with tropical trees varies seasonally but not with tree species identity.

    PubMed

    Leonor, Alvarez-Cansino; Schnitzer, Stefan A; Reid, Joseph P; Powers, Jennifer S

    2015-01-01

    Lianas in tropical forests compete intensely with trees for above- and belowground resources and limit tree growth and regeneration. Liana competition with adult canopy trees may be particularly strong, and, if lianas compete more intensely with some tree species than others, they may influence tree species composition. We performed the first systematic, large-scale liana removal experiment to assess the competitive effects of lianas on multiple tropical tree species by measuring sap velocity and growth in a lowland tropical forest in Panama. Tree sap velocity increased 60% soon after liana removal compared to control trees, and tree diameter growth increased 25% after one year. Although tree species varied in their response to lianas, this variation was not significant, suggesting that lianas competed similarly with all tree species examined. The effect of lianas on tree sap velocity was particularly strong during the dry season, when soil moisture was low, suggesting that lianas compete intensely with trees for water. Under the predicted global change scenario of increased temperature and drought intensity, competition from lianas may become more prevalent in seasonal tropical forests, which, according to our data, should have a negative effect on most tropical tree species. PMID:26236888

  20. Tree species diversity in commercially logged bornean rainforest

    PubMed

    Cannon; Peart; Leighton

    1998-08-28

    The effects of commercial logging on tree diversity in tropical rainforest are largely unknown. In this study, selectively logged tropical rainforest in Indonesian Borneo is shown to contain high tree species richness, despite severe structural damage. Plots logged 8 years before sampling contained fewer species of trees greater than 20 centimeters in diameter than did similar-sized unlogged plots. However, in samples of the same numbers of trees (requiring a 50 percent larger area), logged forest contained as many tree species as unlogged forest. These findings warrant reassessment of the conservation potential of large tracts of commercially logged tropical rainforest. PMID:9721105

  1. An estimate of the number of tropical tree species.

    PubMed

    Slik, J W Ferry; Arroyo-Rodríguez, Víctor; Aiba, Shin-Ichiro; Alvarez-Loayza, Patricia; Alves, Luciana F; Ashton, Peter; Balvanera, Patricia; Bastian, Meredith L; Bellingham, Peter J; van den Berg, Eduardo; Bernacci, Luis; da Conceição Bispo, Polyanna; Blanc, Lilian; Böhning-Gaese, Katrin; Boeckx, Pascal; Bongers, Frans; Boyle, Brad; Bradford, Matt; Brearley, Francis Q; Breuer-Ndoundou Hockemba, Mireille; Bunyavejchewin, Sarayudh; Calderado Leal Matos, Darley; Castillo-Santiago, Miguel; Catharino, Eduardo L M; Chai, Shauna-Lee; Chen, Yukai; Colwell, Robert K; Chazdon, Robin L; Robin, Chazdon L; Clark, Connie; Clark, David B; Clark, Deborah A; Culmsee, Heike; Damas, Kipiro; Dattaraja, Handanakere S; Dauby, Gilles; Davidar, Priya; DeWalt, Saara J; Doucet, Jean-Louis; Duque, Alvaro; Durigan, Giselda; Eichhorn, Karl A O; Eisenlohr, Pedro V; Eler, Eduardo; Ewango, Corneille; Farwig, Nina; Feeley, Kenneth J; Ferreira, Leandro; Field, Richard; de Oliveira Filho, Ary T; Fletcher, Christine; Forshed, Olle; Franco, Geraldo; Fredriksson, Gabriella; Gillespie, Thomas; Gillet, Jean-François; Amarnath, Giriraj; Griffith, Daniel M; Grogan, James; Gunatilleke, Nimal; Harris, David; Harrison, Rhett; Hector, Andy; Homeier, Jürgen; Imai, Nobuo; Itoh, Akira; Jansen, Patrick A; Joly, Carlos A; de Jong, Bernardus H J; Kartawinata, Kuswata; Kearsley, Elizabeth; Kelly, Daniel L; Kenfack, David; Kessler, Michael; Kitayama, Kanehiro; Kooyman, Robert; Larney, Eileen; Laumonier, Yves; Laurance, Susan; Laurance, William F; Lawes, Michael J; Amaral, Ieda Leao do; Letcher, Susan G; Lindsell, Jeremy; Lu, Xinghui; Mansor, Asyraf; Marjokorpi, Antti; Martin, Emanuel H; Meilby, Henrik; Melo, Felipe P L; Metcalfe, Daniel J; Medjibe, Vincent P; Metzger, Jean Paul; Millet, Jerome; Mohandass, D; Montero, Juan C; de Morisson Valeriano, Márcio; Mugerwa, Badru; Nagamasu, Hidetoshi; Nilus, Reuben; Ochoa-Gaona, Susana; Onrizal; Page, Navendu; Parolin, Pia; Parren, Marc; Parthasarathy, Narayanaswamy; Paudel, Ekananda; Permana, Andrea; Piedade, Maria T F; Pitman, Nigel C A; Poorter, Lourens; Poulsen, Axel D; Poulsen, John; Powers, Jennifer; Prasad, Rama C; Puyravaud, Jean-Philippe; Razafimahaimodison, Jean-Claude; Reitsma, Jan; Dos Santos, João Roberto; Roberto Spironello, Wilson; Romero-Saltos, Hugo; Rovero, Francesco; Rozak, Andes Hamuraby; Ruokolainen, Kalle; Rutishauser, Ervan; Saiter, Felipe; Saner, Philippe; Santos, Braulio A; Santos, Fernanda; Sarker, Swapan K; Satdichanh, Manichanh; Schmitt, Christine B; Schöngart, Jochen; Schulze, Mark; Suganuma, Marcio S; Sheil, Douglas; da Silva Pinheiro, Eduardo; Sist, Plinio; Stevart, Tariq; Sukumar, Raman; Sun, I-Fang; Sunderland, Terry; Sunderand, Terry; Suresh, H S; Suzuki, Eizi; Tabarelli, Marcelo; Tang, Jangwei; Targhetta, Natália; Theilade, Ida; Thomas, Duncan W; Tchouto, Peguy; Hurtado, Johanna; Valencia, Renato; van Valkenburg, Johan L C H; Van Do, Tran; Vasquez, Rodolfo; Verbeeck, Hans; Adekunle, Victor; Vieira, Simone A; Webb, Campbell O; Whitfeld, Timothy; Wich, Serge A; Williams, John; Wittmann, Florian; Wöll, Hannsjoerg; Yang, Xiaobo; Adou Yao, C Yves; Yap, Sandra L; Yoneda, Tsuyoshi; Zahawi, Rakan A; Zakaria, Rahmad; Zang, Runguo; de Assis, Rafael L; Garcia Luize, Bruno; Venticinque, Eduardo M

    2015-06-16

    The high species richness of tropical forests has long been recognized, yet there remains substantial uncertainty regarding the actual number of tropical tree species. Using a pantropical tree inventory database from closed canopy forests, consisting of 657,630 trees belonging to 11,371 species, we use a fitted value of Fisher's alpha and an approximate pantropical stem total to estimate the minimum number of tropical forest tree species to fall between ∼ 40,000 and ∼ 53,000, i.e., at the high end of previous estimates. Contrary to common assumption, the Indo-Pacific region was found to be as species-rich as the Neotropics, with both regions having a minimum of ∼ 19,000-25,000 tree species. Continental Africa is relatively depauperate with a minimum of ∼ 4,500-6,000 tree species. Very few species are shared among the African, American, and the Indo-Pacific regions. We provide a methodological framework for estimating species richness in trees that may help refine species richness estimates of tree-dependent taxa. PMID:26034279

  2. An estimate of the number of tropical tree species

    PubMed Central

    Slik, J. W. Ferry; Arroyo-Rodríguez, Víctor; Aiba, Shin-Ichiro; Alvarez-Loayza, Patricia; Alves, Luciana F.; Ashton, Peter; Balvanera, Patricia; Bastian, Meredith L.; Bellingham, Peter J.; van den Berg, Eduardo; Bernacci, Luis; da Conceição Bispo, Polyanna; Blanc, Lilian; Böhning-Gaese, Katrin; Boeckx, Pascal; Bongers, Frans; Boyle, Brad; Bradford, Matt; Brearley, Francis Q.; Breuer-Ndoundou Hockemba, Mireille; Bunyavejchewin, Sarayudh; Calderado Leal Matos, Darley; Castillo-Santiago, Miguel; Catharino, Eduardo L. M.; Chai, Shauna-Lee; Chen, Yukai; Colwell, Robert K.; Chazdon, Robin L.; Clark, Connie; Clark, David B.; Clark, Deborah A.; Culmsee, Heike; Damas, Kipiro; Dattaraja, Handanakere S.; Dauby, Gilles; Davidar, Priya; DeWalt, Saara J.; Doucet, Jean-Louis; Duque, Alvaro; Durigan, Giselda; Eichhorn, Karl A. O.; Eisenlohr, Pedro V.; Eler, Eduardo; Ewango, Corneille; Farwig, Nina; Feeley, Kenneth J.; Ferreira, Leandro; Field, Richard; de Oliveira Filho, Ary T.; Fletcher, Christine; Forshed, Olle; Franco, Geraldo; Fredriksson, Gabriella; Gillespie, Thomas; Gillet, Jean-François; Amarnath, Giriraj; Griffith, Daniel M.; Grogan, James; Gunatilleke, Nimal; Harris, David; Harrison, Rhett; Hector, Andy; Homeier, Jürgen; Imai, Nobuo; Itoh, Akira; Jansen, Patrick A.; Joly, Carlos A.; de Jong, Bernardus H. J.; Kartawinata, Kuswata; Kearsley, Elizabeth; Kelly, Daniel L.; Kenfack, David; Kessler, Michael; Kitayama, Kanehiro; Kooyman, Robert; Larney, Eileen; Laumonier, Yves; Laurance, Susan; Laurance, William F.; Lawes, Michael J.; do Amaral, Ieda Leao; Letcher, Susan G.; Lindsell, Jeremy; Lu, Xinghui; Mansor, Asyraf; Marjokorpi, Antti; Martin, Emanuel H.; Meilby, Henrik; Melo, Felipe P. L.; Metcalfe, Daniel J.; Medjibe, Vincent P.; Metzger, Jean Paul; Millet, Jerome; Mohandass, D.; Montero, Juan C.; de Morisson Valeriano, Márcio; Mugerwa, Badru; Nagamasu, Hidetoshi; Nilus, Reuben; Ochoa-Gaona, Susana; Onrizal; Page, Navendu; Parolin, Pia; Parren, Marc; Parthasarathy, Narayanaswamy; Paudel, Ekananda; Permana, Andrea; Piedade, Maria T. F.; Pitman, Nigel C. A.; Poorter, Lourens; Poulsen, Axel D.; Poulsen, John; Powers, Jennifer; Prasad, Rama C.; Puyravaud, Jean-Philippe; Razafimahaimodison, Jean-Claude; Reitsma, Jan; dos Santos, João Roberto; Roberto Spironello, Wilson; Romero-Saltos, Hugo; Rovero, Francesco; Rozak, Andes Hamuraby; Ruokolainen, Kalle; Rutishauser, Ervan; Saiter, Felipe; Saner, Philippe; Santos, Braulio A.; Santos, Fernanda; Sarker, Swapan K.; Satdichanh, Manichanh; Schmitt, Christine B.; Schöngart, Jochen; Schulze, Mark; Suganuma, Marcio S.; Sheil, Douglas; da Silva Pinheiro, Eduardo; Sist, Plinio; Stevart, Tariq; Sukumar, Raman; Sun, I.-Fang; Sunderland, Terry; Suresh, H. S.; Suzuki, Eizi; Tabarelli, Marcelo; Tang, Jangwei; Targhetta, Natália; Theilade, Ida; Thomas, Duncan W.; Tchouto, Peguy; Hurtado, Johanna; Valencia, Renato; van Valkenburg, Johan L. C. H.; Van Do, Tran; Vasquez, Rodolfo; Verbeeck, Hans; Adekunle, Victor; Vieira, Simone A.; Webb, Campbell O.; Whitfeld, Timothy; Wich, Serge A.; Williams, John; Wittmann, Florian; Wöll, Hannsjoerg; Yang, Xiaobo; Adou Yao, C. Yves; Yap, Sandra L.; Yoneda, Tsuyoshi; Zahawi, Rakan A.; Zakaria, Rahmad; Zang, Runguo; de Assis, Rafael L.; Garcia Luize, Bruno; Venticinque, Eduardo M.

    2015-01-01

    The high species richness of tropical forests has long been recognized, yet there remains substantial uncertainty regarding the actual number of tropical tree species. Using a pantropical tree inventory database from closed canopy forests, consisting of 657,630 trees belonging to 11,371 species, we use a fitted value of Fisher’s alpha and an approximate pantropical stem total to estimate the minimum number of tropical forest tree species to fall between ∼40,000 and ∼53,000, i.e., at the high end of previous estimates. Contrary to common assumption, the Indo-Pacific region was found to be as species-rich as the Neotropics, with both regions having a minimum of ∼19,000–25,000 tree species. Continental Africa is relatively depauperate with a minimum of ∼4,500–6,000 tree species. Very few species are shared among the African, American, and the Indo-Pacific regions. We provide a methodological framework for estimating species richness in trees that may help refine species richness estimates of tree-dependent taxa. PMID:26034279

  3. Full modeling versus summarizing gene-tree uncertainty: method choice and species-tree accuracy.

    PubMed

    Knowles, L Lacey; Lanier, Hayley C; Klimov, Pavel B; He, Qixin

    2012-11-01

    With the proliferation of species-tree methods, empiricists now have to confront the daunting task of method choice. Such decisions might be made based on theoretical considerations alone. However, the messiness of real data means that theoretical ideals may not hold in practice (e.g., with convergence of complicated MCMC algorithms and computational times that limit analyses to small data sets). On the other hand, simplifying assumptions made by some approaches may compromise the accuracy of species-tree estimates. Here we examine the purported tradeoff between accuracy and computational simplicity for species-tree analysis, focusing on the different ways the approaches treat gene-tree uncertainty. By considering a diversity of species trees, as well as different sampling designs and total sampling efforts, we not only compare the accuracy of species-tree estimates across methods, but we also partition the variation in accuracy across factors to identify their relative importance. This analysis shows that although the method of analysis affects accuracy, other factors - namely, the history of species divergence and aspects of the sampling design - have a larger impact. Despite a full modeling of gene tree uncertainty (e.g., using a Bayesian framework), species-tree estimates may not be accurate, particularly for recent diversification histories. Nevertheless, we demonstrate how factors within the control of the empirical investigator (e.g., decisions about sampling) improve the accuracy of species tree estimates, and more so than the method of analysis. Lastly, with much of the attention on species-tree analyses focused on the discord among loci arising from the coalescent, this work also highlights a previously overlooked key determinant of species-tree accuracy for recent divergences - the level of genetic variation at a locus, which has important implications for improving species-tree estimates in practice. PMID:22835380

  4. Identifying a species tree subject to random lateral gene transfer.

    PubMed

    Steel, Mike; Linz, Simone; Huson, Daniel H; Sanderson, Michael J

    2013-04-01

    A major problem for inferring species trees from gene trees is that evolutionary processes can sometimes favor gene tree topologies that conflict with an underlying species tree. In the case of incomplete lineage sorting, this phenomenon has recently been well-studied, and some elegant solutions for species tree reconstruction have been proposed. One particularly simple and statistically consistent estimator of the species tree under incomplete lineage sorting is to combine three-taxon analyses, which are phylogenetically robust to incomplete lineage sorting. In this paper, we consider whether such an approach will also work under lateral gene transfer (LGT). By providing an exact analysis of some cases of this model, we show that there is a zone of inconsistency when majority-rule three-taxon gene trees are used to reconstruct species trees under LGT. However, a triplet-based approach will consistently reconstruct a species tree under models of LGT, provided that the expected number of LGT transfers is not too high. Our analysis involves a novel connection between the LGT problem and random walks on cyclic graphs. We have implemented a procedure for reconstructing trees subject to LGT or lineage sorting in settings where taxon coverage may be patchy and illustrate its use on two sample data sets. PMID:23340439

  5. Multipurpose Spaces.

    ERIC Educational Resources Information Center

    Butin, Dan

    This paper examines the emerging trend of multipurpose class spaces, including educational trends influencing multipurpose classroom use, and key issues when using these spaces. Issues discussed include room location, technology integration, food services, acoustics, lighting, outdoor space, capacity, and storage. Design principles emphasized…

  6. STBase: One Million Species Trees for Comparative Biology

    PubMed Central

    McMahon, Michelle M.; Deepak, Akshay; Fernández-Baca, David; Boss, Darren; Sanderson, Michael J.

    2015-01-01

    Comprehensively sampled phylogenetic trees provide the most compelling foundations for strong inferences in comparative evolutionary biology. Mismatches are common, however, between the taxa for which comparative data are available and the taxa sampled by published phylogenetic analyses. Moreover, many published phylogenies are gene trees, which cannot always be adapted immediately for species level comparisons because of discordance, gene duplication, and other confounding biological processes. A new database, STBase, lets comparative biologists quickly retrieve species level phylogenetic hypotheses in response to a query list of species names. The database consists of 1 million single- and multi-locus data sets, each with a confidence set of 1000 putative species trees, computed from GenBank sequence data for 413,000 eukaryotic taxa. Two bodies of theoretical work are leveraged to aid in the assembly of multi-locus concatenated data sets for species tree construction. First, multiply labeled gene trees are pruned to conflict-free singly-labeled species-level trees that can be combined between loci. Second, impacts of missing data in multi-locus data sets are ameliorated by assembling only decisive data sets. Data sets overlapping with the user’s query are ranked using a scheme that depends on user-provided weights for tree quality and for taxonomic overlap of the tree with the query. Retrieval times are independent of the size of the database, typically a few seconds. Tree quality is assessed by a real-time evaluation of bootstrap support on just the overlapping subtree. Associated sequence alignments, tree files and metadata can be downloaded for subsequent analysis. STBase provides a tool for comparative biologists interested in exploiting the most relevant sequence data available for the taxa of interest. It may also serve as a prototype for future species tree oriented databases and as a resource for assembly of larger species phylogenies from precomputed trees. PMID:25679219

  7. STBase: one million species trees for comparative biology.

    PubMed

    McMahon, Michelle M; Deepak, Akshay; Fernández-Baca, David; Boss, Darren; Sanderson, Michael J

    2015-01-01

    Comprehensively sampled phylogenetic trees provide the most compelling foundations for strong inferences in comparative evolutionary biology. Mismatches are common, however, between the taxa for which comparative data are available and the taxa sampled by published phylogenetic analyses. Moreover, many published phylogenies are gene trees, which cannot always be adapted immediately for species level comparisons because of discordance, gene duplication, and other confounding biological processes. A new database, STBase, lets comparative biologists quickly retrieve species level phylogenetic hypotheses in response to a query list of species names. The database consists of 1 million single- and multi-locus data sets, each with a confidence set of 1000 putative species trees, computed from GenBank sequence data for 413,000 eukaryotic taxa. Two bodies of theoretical work are leveraged to aid in the assembly of multi-locus concatenated data sets for species tree construction. First, multiply labeled gene trees are pruned to conflict-free singly-labeled species-level trees that can be combined between loci. Second, impacts of missing data in multi-locus data sets are ameliorated by assembling only decisive data sets. Data sets overlapping with the user's query are ranked using a scheme that depends on user-provided weights for tree quality and for taxonomic overlap of the tree with the query. Retrieval times are independent of the size of the database, typically a few seconds. Tree quality is assessed by a real-time evaluation of bootstrap support on just the overlapping subtree. Associated sequence alignments, tree files and metadata can be downloaded for subsequent analysis. STBase provides a tool for comparative biologists interested in exploiting the most relevant sequence data available for the taxa of interest. It may also serve as a prototype for future species tree oriented databases and as a resource for assembly of larger species phylogenies from precomputed trees. PMID:25679219

  8. The ghosts of trees past: savanna trees create enduring legacies in plant species composition.

    PubMed

    Stahlheber, Karen A; Crispin, Kimberly L; Anton, Cassidy; D'Antonio, Carla M

    2015-09-01

    Isolated trees in savannas worldwide are known to modify their local environment and interact directly with neighboring plants. Less is known about how related tree species differ in their impacts on surrounding communities, how the effects of trees vary between years, and how composition might change following loss of the tree. To address these knowledge gaps, we explored the following questions: How do savanna trees influence the surrounding composition of herbaceous plants? Is the influence of trees consistent across different species and years? How does this change following the death of the tree? We surveyed herbaceous species composition and environmental attributes surrounding living and dead evergreen and deciduous Quercus trees in California (USA) savannas across several years that differed in their total precipitation. Oak trees of all species created distinct, homogenous understory communities dominated by exotic grasses across several sites. The composition of the low-diversity understory communities showed less interannual variation than open grassland, despite a two-fold difference in precipitation between the driest and wettest year. Vegetation composition was correlated with variation in soil properties, which were strongly affected by trees. Oaks also influenced the communities beyond the edge of the crown, but this depended on site and oak species. Low-diversity understory communities persisted up to 43 years following the death of the tree. A gradual decline in the effect of trees on the physical, environment following death did not result in vegetation becoming more similar to open grassland over time. The presence of long-lasting legacies of past tree crowns highlights the difficulty of assigning control of the current distribution of herbaceous species in grassland to their contemporary environment. PMID:26594707

  9. Inferring Species Trees Directly from Biallelic Genetic Markers: Bypassing Gene Trees in a Full Coalescent Analysis

    PubMed Central

    Bryant, David; Bouckaert, Remco; Felsenstein, Joseph; Rosenberg, Noah A.; RoyChoudhury, Arindam

    2012-01-01

    The multispecies coalescent provides an elegant theoretical framework for estimating species trees and species demographics from genetic markers. However, practical applications of the multispecies coalescent model are limited by the need to integrate or sample over all gene trees possible for each genetic marker. Here we describe a polynomial-time algorithm that computes the likelihood of a species tree directly from the markers under a finite-sites model of mutation effectively integrating over all possible gene trees. The method applies to independent (unlinked) biallelic markers such as well-spaced single nucleotide polymorphisms, and we have implemented it in SNAPP, a Markov chain Monte Carlo sampler for inferring species trees, divergence dates, and population sizes. We report results from simulation experiments and from an analysis of 1997 amplified fragment length polymorphism loci in 69 individuals sampled from six species of Ourisia (New Zealand native foxglove). PMID:22422763

  10. Inferring species trees directly from biallelic genetic markers: bypassing gene trees in a full coalescent analysis.

    PubMed

    Bryant, David; Bouckaert, Remco; Felsenstein, Joseph; Rosenberg, Noah A; RoyChoudhury, Arindam

    2012-08-01

    The multispecies coalescent provides an elegant theoretical framework for estimating species trees and species demographics from genetic markers. However, practical applications of the multispecies coalescent model are limited by the need to integrate or sample over all gene trees possible for each genetic marker. Here we describe a polynomial-time algorithm that computes the likelihood of a species tree directly from the markers under a finite-sites model of mutation effectively integrating over all possible gene trees. The method applies to independent (unlinked) biallelic markers such as well-spaced single nucleotide polymorphisms, and we have implemented it in SNAPP, a Markov chain Monte Carlo sampler for inferring species trees, divergence dates, and population sizes. We report results from simulation experiments and from an analysis of 1997 amplified fragment length polymorphism loci in 69 individuals sampled from six species of Ourisia (New Zealand native foxglove). PMID:22422763

  11. Factors affecting the concordance between orthologous gene trees and species tree in bacteria

    PubMed Central

    2008-01-01

    Background As originally defined, orthologous genes implied a reflection of the history of the species. In recent years, many studies have examined the concordance between orthologous gene trees and species trees in bacteria. These studies have produced contradictory results that may have been influenced by orthologous gene misidentification and artefactual phylogenetic reconstructions. Here, using a method that allows the detection and exclusion of false positives during identification of orthologous genes, we address the question of whether putative orthologous genes within bacteria really reflect the history of the species. Results We identified a set of 370 orthologous genes from the bacterial order Rhizobiales. Although manifesting strong vertical signal, almost every orthologous gene had a distinct phylogeny, and the most common topology among the orthologous gene trees did not correspond with the best estimate of the species tree. However, each orthologous gene tree shared an average of 70% of its bipartitions with the best estimate of the species tree. Stochastic error related to gene size affected the concordance between the best estimated of the species tree and the orthologous gene trees, although this effect was weak and distributed unevenly among the functional categories. The nodes showing the greatest discordance were those defined by the shortest internal branches in the best estimated of the species tree. Moreover, a clear bias was evident with respect to the function of the orthologous genes, and the degree of divergence among the orthologous genes appeared to be related to their functional classification. Conclusion Orthologous genes do not reflect the history of the species when taken as individual markers, but they do when taken as a whole. Stochastic error affected the concordance of orthologous genes with the species tree, albeit weakly. We conclude that two important biological causes of discordance among orthologous genes are incomplete lineage sorting and functional restriction. PMID:18973688

  12. Indirect interactions among tropical tree species through shared rodent seed predators: a novel mechanism of tree species coexistence.

    PubMed

    Garzon-Lopez, Carol X; Ballesteros-Mejia, Liliana; Ordoñez, Alejandro; Bohlman, Stephanie A; Olff, Han; Jansen, Patrick A

    2015-08-01

    The coexistence of numerous tree species in tropical forests is commonly explained by negative dependence of recruitment on the conspecific seed and tree density due to specialist natural enemies that attack seeds and seedlings ('Janzen-Connell' effects). Less known is whether guilds of shared seed predators can induce a negative dependence of recruitment on the density of different species of the same plant functional group. We studied 54 plots in tropical forest on Barro Colorado Island, Panama, with contrasting mature tree densities of three coexisting large seeded tree species with shared seed predators. Levels of seed predation were far better explained by incorporating seed densities of all three focal species than by conspecific seed density alone. Both positive and negative density dependencies were observed for different species combinations. Thus, indirect interactions via shared seed predators can either promote or reduce the coexistence of different plant functional groups in tropical forest. PMID:25939379

  13. Exploring the Taxonomy of Oaks and Related Tree Species

    ERIC Educational Resources Information Center

    McMaster, Robert T.

    2004-01-01

    A lab in Eastern North America conducted a study to determine the taxonomic relationship between deciduous trees and several species of oaks by calculating the similarity index of all species to be studied. The study enabled students to classify the different species of oaks according to their distinct characteristics.

  14. Mapping urban forest tree species using IKONOS imagery: preliminary results.

    PubMed

    Pu, Ruiliang

    2011-01-01

    A stepwise masking system with high-resolution IKONOS imagery was developed to identify and map urban forest tree species/groups in the City of Tampa, Florida, USA. The eight species/groups consist of sand live oak (Quercus geminata), laurel oak (Quercus laurifolia), live oak (Quercus virginiana), magnolia (Magnolia grandiflora), pine (species group), palm (species group), camphor (Cinnamomum camphora), and red maple (Acer rubrum). The system was implemented with soil-adjusted vegetation index (SAVI) threshold, textural information after running a low-pass filter, and brightness threshold of NIR band to separate tree canopies from non-vegetated areas from other vegetation types (e.g., grass/lawn) and to separate the tree canopies into sunlit and shadow areas. A maximum likelihood classifier was used to identify and map forest type and species. After IKONOS imagery was preprocessed, a total of nine spectral features were generated, including four spectral bands, three hue-intensity-saturation indices, one SAVI, and one texture image. The identified and mapped results were examined with independent ground survey data. The experimental results indicate that when classifying all the eight tree species/ groups with the high-resolution IKONOS image data, the identifying accuracy was very low and could not satisfy a practical application level, and when merging the eight species/groups into four major species/groups, the average accuracy is still low (average accuracy = 73%, overall accuracy = 86%, and ? = 0.76 with sunlit test samples). Such a low accuracy of identifying and mapping the urban tree species/groups is attributable to low spatial resolution IKONOS image data relative to tree crown size, to complex and variable background spectrum impact on crown spectra, and to shadow/shaded impact. The preliminary results imply that to improve the tree species identification accuracy and achieve a practical application level in urban area, multi-temporal (multi-seasonal) or hyperspectral data image data should be considered for use in the future. PMID:20140503

  15. Multipurpose Spaces

    ERIC Educational Resources Information Center

    Gordon, Douglas

    2010-01-01

    The concept of multipurpose spaces in schools is certainly not new. Especially in elementary schools, the combination of cafeteria and auditorium (and sometimes indoor physical activity space as well) is a well-established approach to maximizing the use of school space and a school district's budget. Nonetheless, there continue to be refinements…

  16. Soil nutrients influence spatial distributions of tropical trees species

    USGS Publications Warehouse

    John, R.; Dalling, J.W.; Harms, K.E.; Yavitt, J.B.; Stallard, R.F.; Mirabello, M.; Hubbell, S.P.; Valencia, R.; Navarrete, H.; Vallejo, M.; Foster, R.B.

    2007-01-01

    The importance of niche vs. neutral assembly mechanisms in structuring tropical tree communities remains an important unsettled question in community ecology [Bell G (2005) Ecology 86:1757-1770]. There is ample evidence that species distributions are determined by soils and habitat factors at landscape (0.5 million individual trees of 1,400 species and 10 essential plant nutrients, we used Monte Carlo simulations of species distributions to test plant-soil associations against null expectations based on dispersal assembly. We found that the spatial distributions of 36-51% of tree species at these sites show strong associations to soil nutrient distributions. Neutral dispersal assembly cannot account for these plant-soil associations or the observed niche breadths of these species. These results indicate that belowground resource availability plays an important role in the assembly of tropical tree communities at local scales and provide the basis for future investigations on the mechanisms of resource competition among tropical tree species. ?? 2007 by The National Academy of Sciences of the USA.

  17. Phylogenomics-Based Reconstruction of Protozoan Species Tree

    PubMed Central

    Ocaña, Kary A.C.S.; Dávila, Alberto M.R.

    2011-01-01

    We have developed a semi-automatic methodology to reconstruct the phylogenetic species tree in Protozoa, integrating different phylogenetic algorithms and programs, and demonstrating the utility of a supermatrix approach to construct phylogenomics-based trees using 31 universal orthologs (UO). The species tree obtained was formed by three major clades that were related to three groups of data: i) Species containing at least 80% of UO (25/31) in the concatenated multiple alignment or supermatrix, this clade was called C1, ii) Species containing between 50%–79% (15–24/31) of UO called C2, and iii) Species containing less than 50% (1–14/31) of UO called C3. C1 was composed by only protozoan species, C2 was composed by species related to Protozoa, and C3 was composed by some species of C1 (Protozoa) and C2 (related to Protozoa). Our phylogenomics-based methodology using a supermatrix approach proved to be reliable with protozoan genome data and using at least 25 UO, suggesting that (a) the more UO used the better, (b) using the entire UO sequence or just a conserved block of it for the supermatrix produced similar phylogenomic trees. PMID:21863127

  18. Species tree estimation and the historical biogeography of heroine cichlids.

    PubMed

    Hulsey, C Darrin; Keck, Benjamin P; Hollingsworth, Phillip R

    2011-01-01

    Heroine cichlids are major components of the fish faunas in both Central America and the Caribbean. To examine the evolutionary patterns of how cichlids colonized both of these regions, we reconstructed the phylogenetic relationships among 23 cichlid lineages. We used three phylogenetically novel nuclear markers (Dystropin b, Myomesin1, and Wnt7b) in combination with sequence data from seven other gene regions (Nd2, Rag1, Enc1, Sreb2, Ptr, Plagl2, and Zic1) to elucidate the species tree of these cichlids. The species examined represent major heroine lineages in South America, Central America, and the Greater Antilles. The individual gene trees of these groups were topologically quite discordant. Therefore, we combined the genetic partitions and inferred the species tree using both concatenation and a coalescent-based Bayesian method. The two resulting phylogenetic topologies were largely concordant but differed in two fundamental ways. First, more nodes in the concatenated tree were supported with substantial or 100% Bayesian posterior support than in the coalescent-based tree. Second, there was a minor, but biogeographically critical, topological difference between the concatenated and coalescent-based trees. Nevertheless, both analyses recovered topologies consistent with the Greater Antillean heroines being phylogenetically nested within the largely Central American heroine radiation. This study suggests that reconstructions of cichlid phylogeny and historical biogeography should account for the vagaries of individual gene histories. PMID:21112406

  19. Why abundant tropical tree species are phylogenetically old.

    PubMed

    Wang, Shaopeng; Chen, Anping; Fang, Jingyun; Pacala, Stephen W

    2013-10-01

    Neutral models of species diversity predict patterns of abundance for communities in which all individuals are ecologically equivalent. These models were originally developed for Panamanian trees and successfully reproduce observed distributions of abundance. Neutral models also make macroevolutionary predictions that have rarely been evaluated or tested. Here we show that neutral models predict a humped or flat relationship between species age and population size. In contrast, ages and abundances of tree species in the Panamanian Canal watershed are found to be positively correlated, which falsifies the models. Speciation rates vary among phylogenetic lineages and are partially heritable from mother to daughter species. Variable speciation rates in an otherwise neutral model lead to a demographic advantage for species with low speciation rate. This demographic advantage results in a positive correlation between species age and abundance, as found in the Panamanian tropical forest community. PMID:24043767

  20. Micropropagation of Pithecellobium dulce (Roxb.) Benth-a multipurpose leguminous tree and assessment of genetic fidelity of micropropagated plants using molecular markers.

    PubMed

    Goyal, Pooja; Kachhwaha, Sumita; Kothari, S L

    2012-04-01

    An efficient and reproducible protocol has been developed for in vitro propagation of Pithecellobium dulce (Roxb.) Benth (a multipurpose leguminous tree) from field grown nodal segments (axillary bud). Shoot bud induction occurred from nodal explants of 15-years-old tree on Murashige and Skoog (MS) basal medium supplemented with 4.4 ?M 6-benzyladenine (BA) and multiplication was achieved on MS medium supplemented with 4.4 ?M BA + 0.73 ?M phenylacetic acid (PAA) i.e. up to 7 shoot buds in the period of 5-6 weeks. Addition of adenine sulphate (AdS) to this medium further enhanced the number of shoot buds up to 10. Proliferating shoot cultures were established by repeatedly subculturing primary culture on fresh medium (MS + 4.4 ?M BA + 0.73 ?M PAA) after every 25 days. In vitro rooting was achieved on MS medium supplemented with 2.46 ?M Indole-3-butyric acid (IBA) + 41.63 ?M activated charcoal (AC). The micropropagated shoots with well developed roots were acclimatized in green house in pots containing sand, soil and manure (1:1:1). Genetic stability of micropropagated clones was evaluated using Random amplified polymorphic DNA (RAPD) and Inter simple sequence repeat (ISSR) markers. The amplification products were monomorphic in micropropagated plants and similar to those of mother plant. No polymorphism was detected revealing the genetic uniformity of micropropagated plants. This is the first report of an efficient protocol for regeneration of P. dulce through organogenesis, which can be used for further genetic transformation and pharmaceutical purposes. PMID:23573054

  1. A polynomial time algorithm for calculating the probability of a ranked gene tree given a species tree

    PubMed Central

    2012-01-01

    Background The ancestries of genes form gene trees which do not necessarily have the same topology as the species tree due to incomplete lineage sorting. Available algorithms determining the probability of a gene tree given a species tree require exponential computational runtime. Results In this paper, we provide a polynomial time algorithm to calculate the probability of a ranked gene tree topology for a given species tree, where a ranked tree topology is a tree topology with the internal vertices being ordered. The probability of a gene tree topology can thus be calculated in polynomial time if the number of orderings of the internal vertices is a polynomial number. However, the complexity of calculating the probability of a gene tree topology with an exponential number of rankings for a given species tree remains unknown. Conclusions Polynomial algorithms for calculating ranked gene tree probabilities may become useful in developing methodology to infer species trees based on a collection of gene trees, leading to a more accurate reconstruction of ancestral species relationships. PMID:22546066

  2. Regional assessment of ozone sensitive tree species using bioindicator plants.

    PubMed

    Coulston, John W; Smith, Gretchen C; Smith, William D

    2003-04-01

    Tropospheric ozone occurs at phytotoxic levels in the northeastern and mid-Atlantic regions of the United States. Quantifying possible regional-scale impacts of ambient ozone on forest tree species is difficult and is confounded by other factors, such as moisture and light, which influence the uptake of ozone by plants. Biomonitoring provides an approach to document direct foliar injury irrespective of direct measure of ozone uptake. We used bioindicator and field plot data from the USDA Forest Service to identify tree species likely to exhibit regional-scale ozone impacts. Approximately 24% of sampled sweetgum (Liquidambar styraciflua), 15% of sampled loblolly pine (Pinus taeda), and 12% of sampled black cherry (Prunus serotina) trees were in the highest risk category. Sweetgum and loblolly pine trees were at risk on the coastal plain of Maryland, Virginia and Delaware. Black cherry trees were at risk on the Allegheny Plateau (Pennsylvania), in the Allegheny Mountains (Pennsylvania, West Virginia, and Maryland) as well as coastal plain areas of Maryland and Virginia. Our findings indicate a need for more in-depth study of actual impacts on growth and reproduction of these three species. PMID:12691526

  3. New heuristic methods for joint species delimitation and species tree inference.

    PubMed

    O'Meara, Brian C

    2010-01-01

    Species delimitation and species tree inference are difficult problems in cases of recent divergence, especially when different loci have different histories. This paper quantifies the difficulty of jointly finding the division of samples to species and estimating a species tree without constraining the possible assignments a priori. It introduces a parametric and a nonparametric method, including new heuristic search strategies, to do this delimitation and tree inference using individual gene trees as input. The new methods were evaluated using thousands of simulations and 4 empirical data sets. These analyses suggest that the new methods, especially the nonparametric one, may provide useful insights for systematists working at the species level with molecular data. However, they still often return incorrect results. PMID:20525620

  4. tropiTree: An NGS-Based EST-SSR Resource for 24 Tropical Tree Species

    PubMed Central

    Russell, Joanne R.; Hedley, Peter E.; Cardle, Linda; Dancey, Siobhan; Morris, Jenny; Booth, Allan; Odee, David; Mwaura, Lucy; Omondi, William; Angaine, Peter; Machua, Joseph; Muchugi, Alice; Milne, Iain; Kindt, Roeland; Jamnadass, Ramni; Dawson, Ian K.

    2014-01-01

    The development of genetic tools for non-model organisms has been hampered by cost, but advances in next-generation sequencing (NGS) have created new opportunities. In ecological research, this raises the prospect for developing molecular markers to simultaneously study important genetic processes such as gene flow in multiple non-model plant species within complex natural and anthropogenic landscapes. Here, we report the use of bar-coded multiplexed paired-end Illumina NGS for the de novo development of expressed sequence tag-derived simple sequence repeat (EST-SSR) markers at low cost for a range of 24 tree species. Each chosen tree species is important in complex tropical agroforestry systems where little is currently known about many genetic processes. An average of more than 5,000 EST-SSRs was identified for each of the 24 sequenced species, whereas prior to analysis 20 of the species had fewer than 100 nucleotide sequence citations. To make results available to potential users in a suitable format, we have developed an open-access, interactive online database, tropiTree (http://bioinf.hutton.ac.uk/tropiTree), which has a range of visualisation and search facilities, and which is a model for the efficient presentation and application of NGS data. PMID:25025376

  5. Early positive effects of tree species richness on herbivory in a large-scale forest biodiversity experiment influence tree growth

    PubMed Central

    Schuldt, Andreas; Bruelheide, Helge; Härdtle, Werner; Assmann, Thorsten; Li, Ying; Ma, Keping; von Oheimb, Goddert; Zhang, Jiayong

    2015-01-01

    Despite the importance of herbivory for the structure and functioning of species-rich forests, little is known about how herbivory is affected by tree species richness, and more specifically by random vs. non-random species loss. We assessed herbivore damage and its effects on tree growth in the early stage of a large-scale forest biodiversity experiment in subtropical China that features random and non-random extinction scenarios of tree mixtures numbering between one and 24 species. In contrast to random species loss, the non-random extinction scenarios were based on the tree species’ local rarity and specific leaf area – traits that may strongly influence the way herbivory is affected by plant species richness. Herbivory increased with tree species richness across all scenarios and was unaffected by the different species compositions in the random and non-random extinction scenarios. Whereas tree growth rates were positively related to herbivory on plots with smaller trees, growth rates significantly declined with increasing herbivory on plots with larger trees. Our results suggest that the effects of herbivory on growth rates increase from monocultures to the most species-rich plant communities and that negative effects with increasing tree species richness become more pronounced with time as trees grow larger. Synthesis. Our results indicate that key trophic interactions can be quick to become established in forest plantations (i.e. already 2.5 years after tree planting). Stronger herbivory effects on tree growth with increasing tree species richness suggest a potentially important role of herbivory in regulating ecosystem functions and the structural development of species-rich forests from the very start of secondary forest succession. The lack of significant differences between the extinction scenarios, however, contrasts with findings from natural forests of higher successional age, where rarity had negative effects on herbivory. This indicates that the effects of non-random species loss could change with forest succession. PMID:26690688

  6. Complementary resource use by tree species in a rain forest tree plantation.

    PubMed

    Richards, Anna E; Schmidt, Susanne

    2010-07-01

    Mixed-species tree plantations, composed of high-value native rain forest timbers, are potential forestry systems for the subtropics and tropics that can provide ecological and production benefits. Choices of rain forest tree species for mixtures are generally based on the concept that assemblages of fast-growing and light-demanding species are less productive than assemblages of species with different shade tolerances. We examined the hypothesis that mixtures of two fast-growing species compete for resources, while mixtures of shade-tolerant and shade-intolerant species are complementary. Ecophysiological characteristics of young trees were determined and analyzed with a physiology-based canopy model (MAESTRA) to test species interactions. Contrary to predictions, there was evidence for complementary interactions between two fast-growing species with respect to nutrient uptake, nutrient use efficiency, and nutrient cycling. Fast-growing Elaeocarpus angustifolius had maximum demand for soil nutrients in summer, the most efficient internal recycling of N, and low P use efficiency at the leaf and whole-plant level and produced a large amount of nutrient-rich litter. In contrast, fast-growing Grevillea robusta had maximum demand for soil nutrients in spring and highest leaf nutrient use efficiency for N and P and produced low-nutrient litter. Thus, mixtures of fast-growing G. robusta and E. angustifolius or G. robusta and slow-growing, shade-tolerant Castanospermum australe may have similar or even greater productivity than monocultures, as light requirement is just one of several factors affecting performance of mixed-species plantations. We conclude that the knowledge gained here will be useful for designing large-scale experimental mixtures and commercial forestry systems in subtropical Australia and elsewhere. PMID:20666247

  7. Impact of gene family evolutionary histories on phylogenetic species tree inference by gene tree parsimony.

    PubMed

    Shi, Tao

    2016-03-01

    Complicated history of gene duplication and loss brings challenge to molecular phylogenetic inference, especially in deep phylogenies. However, phylogenomic approaches, such as gene tree parsimony (GTP), show advantage over some other approaches in its ability to use gene families with duplications. GTP searches the 'optimal' species tree by minimizing the total cost of biological events such as duplications, but accuracy of GTP and phylogenetic signal in the context of different gene families with distinct histories of duplication and loss are unclear. To evaluate how different evolutionary properties of different gene families can impact on species tree inference, 3900 gene families from seven angiosperms encompassing a wide range of gene content, lineage-specific expansions and contractions were analyzed. It was found that the gene content and total duplication number in a gene family strongly influence species tree inference accuracy, with the highest accuracy achieved at either very low or very high gene content (or duplication number) and lowest accuracy centered in intermediate gene content (or duplication number), as the relationship can fit a binomial regression. Besides, for gene families of similar level of average gene content, those with relatively higher lineage-specific expansion or duplication rates tend to show lower accuracy. Additional correlation tests support that high accuracy for those gene families with large gene content may rely on abundant ancestral copies to provide many subtrees to resolve conflicts, whereas high accuracy for single or low copy gene families are just subject to sequence substitution per se. Very low accuracy reached by gene families of intermediate gene content or duplication number can be due to insufficient subtrees to resolve the conflicts from loss of alternative copies. As these evolutionary properties can significantly influence species tree accuracy, I discussed the potential weighting of the duplication cost by evolutionary properties of gene families in future GTP analyses. PMID:26702957

  8. Widespread Discordance of Gene Trees with Species Tree inDrosophila: Evidence for Incomplete Lineage Sorting

    SciTech Connect

    Pollard, Daniel A.; Iyer, Venky N.; Moses, Alan M.; Eisen,Michael B.

    2006-08-28

    The phylogenetic relationship of the now fully sequencedspecies Drosophila erecta and D. yakuba with respect to the D.melanogaster species complex has been a subject of controversy. All threepossible groupings of the species have been reported in the past, thoughrecent multi-gene studies suggest that D. erecta and D. yakuba are sisterspecies. Using the whole genomes of each of these species as well as thefour other fully sequenced species in the subgenus Sophophora, we set outto investigate the placement of D. erecta and D. yakuba in the D.melanogaster species group and to understand the cause of the pastincongruence. Though we find that the phylogeny grouping D. erecta and D.yakuba together is the best supported, we also find widespreadincongruence in nucleotide and amino acid substitutions, insertions anddeletions, and gene trees. The time inferred to span the two keyspeciation events is short enough that under the coalescent model, theincongruence could be the result of incomplete lineage sorting.Consistent with the lineage-sorting hypothesis, substitutions supportingthe same tree were spatially clustered. Support for the different treeswas found to be linked to recombination such that adjacent genes supportthe same tree most often in regions of low recombination andsubstitutions supporting the same tree are most enriched roughly on thesame scale as linkage disequilibrium, also consistent with lineagesorting. The incongruence was found to be statistically significant androbust to model and species choice. No systematic biases were found. Weconclude that phylogenetic incongruence in the D. melanogaster speciescomplex is the result, at least in part, of incomplete lineage sorting.Incomplete lineage sorting will likely cause phylogenetic incongruence inmany comparative genomics datasets. Methods to infer the correct speciestree, the history of every base in the genome, and comparative methodsthat control for and/or utilize this information will be valuableadvancements for the field of comparative genomics.

  9. Climatic extremes improve predictions of spatial patterns of tree species

    USGS Publications Warehouse

    Zimmermann, N.E.; Yoccoz, N.G.; Edwards, T.C., Jr.; Meier, E.S.; Thuiller, W.; Guisan, A.; Schmatz, D.R.; Pearman, P.B.

    2009-01-01

    Understanding niche evolution, dynamics, and the response of species to climate change requires knowledge of the determinants of the environmental niche and species range limits. Mean values of climatic variables are often used in such analyses. In contrast, the increasing frequency of climate extremes suggests the importance of understanding their additional influence on range limits. Here, we assess how measures representing climate extremes (i.e., interannual variability in climate parameters) explain and predict spatial patterns of 11 tree species in Switzerland. We find clear, although comparably small, improvement (+20% in adjusted D2, +8% and +3% in cross-validated True Skill Statistic and area under the receiver operating characteristics curve values) in models that use measures of extremes in addition to means. The primary effect of including information on climate extremes is a correction of local overprediction and underprediction. Our results demonstrate that measures of climate extremes are important for understanding the climatic limits of tree species and assessing species niche characteristics. The inclusion of climate variability likely will improve models of species range limits under future conditions, where changes in mean climate and increased variability are expected.

  10. Efficient algorithms for reconciling gene trees and species networks via duplication and loss events

    PubMed Central

    2015-01-01

    Reconciliation methods explain topology differences between a species tree and a gene tree by evolutionary events other than speciations. However, not all phylogenies are trees: hybridization can occur and create new species and this results into reticulate phylogenies. Here, we consider the problem of reconciling a gene tree with a species network via duplication and loss events. Two variants are proposed and solved with effcient algorithms: the first one finds the best tree in the network with which to reconcile the gene tree, and the second one finds the best reconciliation between the gene tree and the whole network. PMID:26449687

  11. Semi-supervised SVM for individual tree crown species classification

    NASA Astrophysics Data System (ADS)

    Dalponte, Michele; Ene, Liviu Theodor; Marconcini, Mattia; Gobakken, Terje; Næsset, Erik

    2015-12-01

    In this paper a novel semi-supervised SVM classifier is presented, specifically developed for tree species classification at individual tree crown (ITC) level. In ITC tree species classification, all the pixels belonging to an ITC should have the same label. This assumption is used in the learning of the proposed semi-supervised SVM classifier (ITC-S3VM). This method exploits the information contained in the unlabeled ITC samples in order to improve the classification accuracy of a standard SVM. The ITC-S3VM method can be easily implemented using freely available software libraries. The datasets used in this study include hyperspectral imagery and laser scanning data acquired over two boreal forest areas characterized by the presence of three information classes (Pine, Spruce, and Broadleaves). The experimental results quantify the effectiveness of the proposed approach, which provides classification accuracies significantly higher (from 2% to above 27%) than those obtained by the standard supervised SVM and by a state-of-the-art semi-supervised SVM (S3VM). Particularly, by reducing the number of training samples (i.e. from 100% to 25%, and from 100% to 5% for the two datasets, respectively) the proposed method still exhibits results comparable to the ones of a supervised SVM trained with the full available training set. This property of the method makes it particularly suitable for practical forest inventory applications in which collection of in situ information can be very expensive both in terms of cost and time.

  12. Native tree species regulate nitrous oxide fluxes in tropical plantations.

    PubMed

    Weintraub, Samantha R; Russell, Ann E; Townsend, Alan R

    2014-06-01

    Secondary and managed plantation forests comprise a rapidly increasing portion of the humid tropical forest biome, a region that, in turn, is a major source of nitrous oxide (N2O) emissions to the atmosphere. Previous work has demonstrated reduced N2O emissions in regenerating secondary stands compared to mature forests, yet the importance of species composition in regulating N2O production in young forests remains unclear. We measured N2O fluxes beneath four native tree species planted in replicated, 21-yr-old monodominant stands in the Caribbean lowlands of Costa Rica in comparison with nearby mature forest and abandoned pasture sites at two time points (wetter and drier seasons). We found that species differed eight-fold in their production of N2O, with slower growing, late-successional species (including one legume) promoting high N2O fluxes similar to mature forest, and faster growing, early successional species maintaining low N2O fluxes similar to abandoned pasture. Across all species, N2O flux was positively correlated with soil nitrate concentration in the wetter season and with soil water-filled pore space (WFPS) in the drier season. However, the strongest predictor of N2O fluxes was fine-root growth rate, which was negatively correlated with N2O emissions at both time points. We suggest that tree-specific variation in growth habits creates differences in both N demand and soil water conditions that may exert significant control on N2O fluxes from tropical forests. With the advent of REDD+ and related strategies for fostering climate mitigation via tropical forest regrowth and plantations, we note that species-specific traits as they relate to N2O fluxes may be an important consideration in estimating overall climate benefits. PMID:24988773

  13. Inferring Species Trees from Gene Trees in a Radiation of California Trapdoor Spiders (Araneae, Antrodiaetidae, Aliatypus)

    PubMed Central

    Satler, Jordan D.; Starrett, James; Hayashi, Cheryl Y.; Hedin, Marshal

    2011-01-01

    Background The California Floristic Province is a biodiversity hotspot, reflecting a complex geologic history, strong selective gradients, and a heterogeneous landscape. These factors have led to high endemic diversity across many lifeforms within this region, including the richest diversity of mygalomorph spiders (tarantulas, trapdoor spiders, and kin) in North America. The trapdoor spider genus Aliatypus encompasses twelve described species, eleven of which are endemic to California. Several Aliatypus species show disjunct distributional patterns in California (some are found on both sides of the vast Central Valley), and the genus as a whole occupies an impressive variety of habitats. Methodology/Principal Findings We collected specimens from 89 populations representing all described species. DNA sequence data were collected from seven gene regions, including two newly developed for spider systematics. Bayesian inference (in individual gene tree and species tree approaches) recovered a general “3 clade” structure for the genus (A. gulosus, californicus group, erebus group), with three other phylogenetically isolated species differing slightly in position across different phylogenetic analyses. Because of extremely high intraspecific divergences in mitochondrial COI sequences, the relatively slowly evolving 28S rRNA gene was found to be more useful than mitochondrial data for identification of morphologically indistinguishable immatures. For multiple species spanning the Central Valley, explicit hypothesis testing suggests a lack of monophyly for regional populations (e.g., western Coast Range populations). Phylogenetic evidence clearly shows that syntopy is restricted to distant phylogenetic relatives, consistent with ecological niche conservatism. Conclusions/Significance This study provides fundamental insight into a radiation of trapdoor spiders found in the biodiversity hotspot of California. Species relationships are clarified and undescribed lineages are discovered, with more geographic sampling likely to lead to additional species diversity. These dispersal-limited taxa provide novel insight into the biogeography and Earth history processes of California. PMID:21966507

  14. Urban Tree Species Show the Same Hydraulic Response to Vapor Pressure Deficit across Varying Tree Size and Environmental Conditions

    PubMed Central

    Chen, Lixin; Zhang, Zhiqiang; Ewers, Brent E.

    2012-01-01

    Background The functional convergence of tree transpiration has rarely been tested for tree species growing under urban conditions even though it is of significance to elucidate the relationship between functional convergence and species differences of urban trees for establishing sustainable urban forests in the context of forest water relations. Methodology/Principal Findings We measured sap flux of four urban tree species including Cedrus deodara, Zelkova schneideriana, Euonymus bungeanus and Metasequoia glyptostroboides in an urban park by using thermal dissipation probes (TDP). The concurrent microclimate conditions and soil moisture content were also measured. Our objectives were to examine 1) the influence of tree species and size on transpiration, and 2) the hydraulic control of urban trees under different environmental conditions over the transpiration in response to VPD as represented by canopy conductance. The results showed that the functional convergence between tree diameter at breast height (DBH) and tree canopy transpiration amount (Ec) was not reliable to predict stand transpiration and there were species differences within same DBH class. Species differed in transpiration patterns to seasonal weather progression and soil water stress as a result of varied sensitivity to water availability. Species differences were also found in their potential maximum transpiration rate and reaction to light. However, a same theoretical hydraulic relationship between Gc at VPD = 1 kPa (Gcref) and the Gc sensitivity to VPD (−dGc/dlnVPD) across studied species as well as under contrasting soil water and Rs conditions in the urban area. Conclusions/Significance We concluded that urban trees show the same hydraulic regulation over response to VPD across varying tree size and environmental conditions and thus tree transpiration could be predicted with appropriate assessment of Gcref. PMID:23118904

  15. The influence of gene flow on species tree estimation: a simulation study.

    PubMed

    Leaché, Adam D; Harris, Rebecca B; Rannala, Bruce; Yang, Ziheng

    2014-01-01

    Gene flow among populations or species and incomplete lineage sorting (ILS) are two evolutionary processes responsible for generating gene tree discordance and therefore hindering species tree estimation. Numerous studies have evaluated the impacts of ILS on species tree inference, yet the ramifications of gene flow on species trees remain less studied. Here, we simulate and analyse multilocus sequence data generated with ILS and gene flow to quantify their impacts on species tree inference. We characterize species tree estimation errors under various models of gene flow, such as the isolation-migration model, the n-island model, and gene flow between non-sister species or involving ancestral species, and species boundaries crossed by a single gene copy (allelic introgression) or by a single migrant individual. These patterns of gene flow are explored on species trees of different sizes (4 vs. 10 species), at different time scales (shallow vs. deep), and with different migration rates. Species trees are estimated with the multispecies coalescent model using Bayesian methods (BEST and *BEAST) and with a summary statistic approach (MPEST) that facilitates phylogenomic-scale analysis. Even in cases where the topology of the species tree is estimated with high accuracy, we find that gene flow can result in overestimates of population sizes (species tree dilation) and underestimates of species divergence times (species tree compression). Signatures of migration events remain present in the distribution of coalescent times for gene trees, and with sufficient data it is possible to identify those loci that have crossed species boundaries. These results highlight the need for careful sampling design in phylogeographic and species delimitation studies as gene flow, introgression, or incorrect sample assignments can bias the estimation of the species tree topology and of parameter estimates such as population sizes and divergence times. PMID:23945075

  16. Tree diversity and the role of non-host neighbour tree species in reducing fungal pathogen infestation

    PubMed Central

    Hantsch, Lydia; Bien, Steffen; Radatz, Stine; Braun, Uwe; Auge, Harald; Bruelheide, Helge

    2014-01-01

    The degree to which plant pathogen infestation occurs in a host plant is expected to be strongly influenced by the level of species diversity among neighbouring host and non-host plant species. Since pathogen infestation can negatively affect host plant performance, it can mediate the effects of local biodiversity on ecosystem functioning. We tested the effects of tree diversity and the proportion of neighbouring host and non-host species with respect to the foliar fungal pathogens of Tilia cordata and Quercus petraea in the Kreinitz tree diversity experiment in Germany. We hypothesized that fungal pathogen richness increases while infestation decreases with increasing local tree diversity. In addition, we tested whether fungal pathogen richness and infestation are dependent on the proportion of host plant species present or on the proportion of particular non-host neighbouring tree species. Leaves of the two target species were sampled across three consecutive years with visible foliar fungal pathogens on the leaf surface being identified macro- and microscopically. Effects of diversity among neighbouring trees were analysed: (i) for total fungal species richness and fungal infestation on host trees and (ii) for infestation by individual fungal species. We detected four and five fungal species on T. cordata and Q. petraea, respectively. High local tree diversity reduced (i) total fungal species richness and infestation of T. cordata and fungal infestation of Q. petraea and (ii) infestation by three host-specialized fungal pathogen species. These effects were brought about by local tree diversity and were independent of host species proportion. In general, host species proportion had almost no effect on fungal species richness and infestation. Strong effects associated with the proportion of particular non-host neighbouring tree species on fungal species richness and infestation were, however, recorded. Synthesis. For the first time, we experimentally demonstrated that for two common forestry tree species, foliar fungal pathogen richness and infestation depend on local biodiversity. Thus, local tree diversity can have positive impacts on ecosystem functioning in managed forests by decreasing the level of fungal pathogen infestation. PMID:25558092

  17. The Impact of Missing Data on Species Tree Estimation.

    PubMed

    Xi, Zhenxiang; Liu, Liang; Davis, Charles C

    2016-03-01

    Phylogeneticists are increasingly assembling genome-scale data sets that include hundreds of genes to resolve their focal clades. Although these data sets commonly include a moderate to high amount of missing data, there remains no consensus on their impact to species tree estimation. Here, using several simulated and empirical data sets, we assess the effects of missing data on species tree estimation under varying degrees of incomplete lineage sorting (ILS) and gene rate heterogeneity. We demonstrate that concatenation (RAxML), gene-tree-based coalescent (ASTRAL, MP-EST, and STAR), and supertree (matrix representation with parsimony [MRP]) methods perform reliably, so long as missing data are randomly distributed (by gene and/or by species) and that a sufficiently large number of genes are sampled. When data sets are indecisive sensu Sanderson et al. (2010. Phylogenomics with incomplete taxon coverage: the limits to inference. BMC Evol Biol. 10:155) and/or ILS is high, however, high amounts of missing data that are randomly distributed require exhaustive levels of gene sampling, likely exceeding most empirical studies to date. Moreover, missing data become especially problematic when they are nonrandomly distributed. We demonstrate that STAR produces inconsistent results when the amount of nonrandom missing data is high, regardless of the degree of ILS and gene rate heterogeneity. Similarly, concatenation methods using maximum likelihood can be misled by nonrandom missing data in the presence of gene rate heterogeneity, which becomes further exacerbated when combined with high ILS. In contrast, ASTRAL, MP-EST, and MRP are more robust under all of these scenarios. These results underscore the importance of understanding the influence of missing data in the phylogenomics era. PMID:26589995

  18. Interannual Variation in Stand Transpiration is Dependent Upon Tree Species

    NASA Astrophysics Data System (ADS)

    Ewers, B. E.; Mackay, D. S.; Burrows, S. N.; Ahl, D. E.; Samanta, S.

    2003-12-01

    In order to successfully predict transpirational water fluxes from forested watersheds, interannual variability in transpiration must be quantified and understood. In a heterogeneous forested landscape in northern Wisconsin, we quantified stand transpiration across four forest cover types representing more than 80 percent of the land area in order to 1) quantify differences in stand transpiration and leaf area over two years and 2) determine the mechanisms governing the changes in transpiration over two years. We measured sap flux in eight trees of each tree species in the four cover types. We found that in northern hardwoods, the leaf area of sugar maple increased between the two measurement years with transpiration per unit ground area increasing even more than could be explained by leaf area. In an aspen stand, tent caterpillars completely defoliated the stand for approximately a month until a new set of leaves flushed out. The new set of leaves resulted in a lower leaf area but the same transpiration per unit leaf area indicating there was no physiological compensation for the lower leaf area. At the same time, balsam fir growing underneath the aspen increased their transpiration rate in response to greater light penetration through the dominant aspen canopy Red pine had a thirty percent change in leaf area within a growing season due to multiple cohorts of leaves and transpiration followed this leaf area dynamic. In a forested wetland, white cedar transpiration was proportional to surface water depth between the two years. Despite the specific tree species' effects on stand transpiration, all species displayed a minimum water potential regulation resulting in a saturating response of transpiration to vapor pressure deficit that did not vary across the two years. This physiological set point will allow future water flux models to explain mechanistically interannual variability in transpiration of this and similar forests.

  19. Nitrogen and phosphorus additions negatively affect tree species diversity in tropical forest regrowth trajectories.

    PubMed

    Siddique, Ilyas; Vieira, Ima Célia Guimarães; Schmidt, Susanne; Lamb, David; Carvalho, Cláudio José Reis; Figueiredo, Ricardo de Oliveira; Blomberg, Simon; Davidson, Eric A

    2010-07-01

    Nutrient enrichment is increasingly affecting many tropical ecosystems, but there is no information on how this affects tree biodiversity. To examine dynamics in vegetation structure and tree species biomass and diversity, we annually remeasured tree species before and for six years after repeated additions of nitrogen (N) and phosphorus (P) in permanent plots of abandoned pasture in Amazonia. Nitrogen and, to a lesser extent, phosphorus addition shifted growth among woody species. Nitrogen stimulated growth of two common pioneer tree species and one common tree species adaptable to both high- and low-light environments, while P stimulated growth only of the dominant pioneer tree Rollinia exsucca (Annonaceae). Overall, N or P addition reduced tree assemblage evenness and delayed tree species accrual over time, likely due to competitive monopolization of other resources by the few tree species responding to nutrient enrichment with enhanced establishment and/or growth rates. Absolute tree growth rates were elevated for two years after nutrient addition. However, nutrient-induced shifts in relative tree species growth and reduced assemblage evenness persisted for more than three years after nutrient addition, favoring two nutrient-responsive pioneers and one early-secondary tree species. Surprisingly, N + P effects on tree biomass and species diversity were consistently weaker than N-only and P-only effects, because grass biomass increased dramatically in response to N + P addition. The resulting intensified competition probably prevented an expected positive N + P synergy in the tree assemblage. Thus, N or P enrichment may favor unknown tree functional response types, reduce the diversity of coexisting species, and delay species accrual during structurally and functionally complex tropical rainforest secondary succession. PMID:20715634

  20. Species tree estimation for the late blight pathogen, Phytophthora infestans, and close relatives

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To better understand the evolutionary history of a group of organisms, an accurate estimate of the species phylogeny must be known. Traditionally, gene trees have served as a proxy for the species tree, although it was acknowledged early on that these trees represented different evolutionary process...

  1. Tree Species Specific Soil Moisture Patterns and Dynamics

    NASA Astrophysics Data System (ADS)

    Heidbuechel, I.; Dreibrodt, J.; Guntner, A.; Blume, T.

    2014-12-01

    Land use has a major influence on the hydrologic processes that take place in soils. Soil compaction on pastures for example leads to infiltration patterns that differ considerably from the ones observable in forests. It is not clear, however, how different forest stands influence soil infiltration and soil moisture distributions. Factors that that vary amongst different stands and potentially affect soil moisture processes in forests are, amongst others, canopy density, throughfall patterns, the intensity and frequency of stem flow, litter type, root distributions and rooting depth. To investigate how different tree species influence the way soils partition, store and conduct incoming precipitation we selected 15 locations under different tree stands within the TERENO observatory in north-east Germany. The forest stands under investigation were mature oak, young pine, mature pine, young beech and mature beech. At each location we installed 30 FDR soil moisture sensors grouped into five depth profiles (monitoring soil moisture from 10 cm to 200 cm) and 5 additional near surface sensors. The profile locations within each forest stand covered most of the anticipated variability by ranging from minimum to maximum distance to the trees including locations under more and less dense canopy. Supplementary to the FDR sensors, throughfall measurements, tensiometers and groundwater data were available to observe dynamics of tree water availability, water fluxes within the soils and percolation towards the groundwater. To identify patterns in space and time we referred to the statistical methods of wavelet analysis and temporal stability analysis. Finally, we tried to link the results from these analyses to specific hydrologic processes at the different locations.

  2. The Light Driven Emission of Monoterpenes from Broadleaf Tree Species

    NASA Astrophysics Data System (ADS)

    Kesselmeier, J.

    2005-12-01

    Plant isoprene emissions are known to be both light and temperature dependent and are modeled accordingly. Contrasting, monoterpene emissions were regarded to underlie temperature dependence only. However, during the last decade several Mediterranean tree species were reported to emit monoterpenes triggered by light and temperature in very close relation to actual carbon fixation. Further studies with African and European plant species as well as from first studies within the Amazonian rainforest show that the release of isoprene and monoterpenes occurs under a very similar regulation. Furthermore, recent research delivered new insight into the biochemical pathways showing that both groups of isoprenoids are produced in chloroplasts within the same biochemical pathways. Immediate release under regulation of light and temperature is a common characteristic too. Additionally, compounds such as monoterpenes may be stored in plant tissues with special functions. Such storage phenomena can be regarded as special cases.

  3. Biogenic volatile organic compound emissions from nine tree species used in an urban tree-planting program

    NASA Astrophysics Data System (ADS)

    Curtis, A. J.; Helmig, D.; Baroch, C.; Daly, R.; Davis, S.

    2014-10-01

    The biogenic volatile organic compound (BVOC) emissions of nine urban tree species were studied to assess the air quality impacts from planting a large quantity of these trees in the City and County of Denver, Colorado, through the Mile High Million tree-planting initiative. The deciduous tree species studied were Sugar maple, Ohio buckeye, northern hackberry, Turkish hazelnut, London planetree, American basswood, Littleleaf linden, Valley Forge elm, and Japanese zelkova. These tree species were selected using the i-Tree Species Selector (itreetools.org). BVOC emissions from the selected tree species were investigated to evaluate the Species Selector data under the Colorado climate and environmental growing conditions. Individual tree species were subjected to branch enclosure experiments in which foliar emissions of BVOC were collected onto solid adsorbent cartridges. The cartridge samples were analyzed for monoterpenes (MT), sesquiterpenes (SQT), and other C10-C15 BVOC using thermal desorption-gas chromatography-flame ionization detection/mass spectroscopy (GC-FID/MS). Individual compounds and their emission rates (ER) were identified. MT were observed in all tree species, exhibiting the following total MT basal emission rates (BER; with a 1-σ lower bound, upper bound uncertainty window): Sugar maple, 0.07 (0.02, 0.11) μg g-1 h-1; London planetree, 0.15 (0.02, 0.27) μg g-1 h-1; northern hackberry, 0.33 (0.09, 0.57) μg g-1 h-1; Japanese zelkova, 0.42 (0.26, 0.58) μg g-1 h-1; Littleleaf linden, 0.71 (0.33, 1.09) μg g-1 h-1; Valley Forge elm, 0.96 (0.01, 1.92) μg g-1 h-1; Turkish hazelnut, 1.30 (0.32, 2.23) μg g-1 h-1; American basswood, 1.50 (0.40, 2.70) μg g-1 h-1; and Ohio buckeye, 6.61 (1.76, 11.47) μg g-1 h-1. SQT emissions were seen in five tree species with total SQT BER of: London planetree, 0.11 (0.01, 0.20) μg g-1 h-1; Japanese zelkova, 0.11 (0.05, 0.16) μg g-1 h-1; Littleleaf linden, 0.13 (0.06, 0.21) μg g-1 h-1; northern hackberry, 0.20 (0.11, 0.30) μg g-1 h-1; and Ohio buckeye, 0.44 (0.06, 0.83) μg g-1 h-1. The following trees exhibited emissions of other C10-C15 volatile organic compounds (VOC): Littleleaf linden, 0.15 (0.10, 0.20) μg g-1 h-1; Ohio buckeye, 0.39 (0.14, 0.65) μg g-1 h-1; and Turkish hazelnut, 0.72 (0.49, 0.95) μg g-1 h-1. All tree species studied in this experiment were confirmed to be low isoprene emitters. Compared to many other potential urban tree species, the selected trees can be considered low to moderate BVOC emitters under Colorado growing conditions, with total emission rates one-tenth to one-hundredth the rates of potential high-BVOC emitting trees. The emissions data were used to estimate the impact of this targeted tree planting on the urban BVOC flux and atmospheric VOC burden. Selecting the low-emitting tree species over known high BVOC emitters is equivalent to avoiding VOC emissions from nearly 500,000 cars from the inner city traffic.

  4. Recruitment in tropical tree species: revealing complex spatial patterns.

    PubMed

    Wiegand, Thorsten; Martínez, Isabel; Huth, Andreas

    2009-10-01

    Seed dispersal should leave a signature on the spatial distribution of recruits that can be quantified using sophisticated techniques of spatial pattern analysis. Here we study spatial patterns of five frugivore-dispersed tropical tree species at the Barro Colorado Island forest, Panama, to describe detailed properties of the spatial patterns of recruits and to investigate whether these patterns were produced by temporally consistent mechanisms. Our spatial point pattern analyses detected the existence of surprising spatial structures, such as double-cluster and superposition patterns, and they allowed for a detailed quantification of their properties. The spatial recruitment patterns were composed of two independent components comprising a random component and a component showing a complex spatial pattern with two critical scales of clustering. The analysis allowed an estimation of the relative contribution of scatter dispersal versus clump dispersal in effective seed dispersal for our study species. Additionally, the cluster characteristics were temporally consistent over 25 years and correlated with several species traits. We are just beginning to discover the richness of spatial patterns found at tropical forests, and we are confident that a combination of advanced point pattern analysis with field data will allow for significant advances in establishing the link between spatial patterns and processes. PMID:19691434

  5. Tree species and functional traits but not species richness affect interrill erosion processes in young subtropical forests

    NASA Astrophysics Data System (ADS)

    Seitz, S.; Goebes, P.; Song, Z.; Bruelheide, H.; Härdtle, W.; Kühn, P.; Li, Y.; Scholten, T.

    2016-01-01

    Soil erosion is seriously threatening ecosystem functioning in many parts of the world. In this context, it is assumed that tree species richness and functional diversity of tree communities can play a critical role in improving ecosystem services such as erosion control. An experiment with 170 micro-scale run-off plots was conducted to investigate the influence of tree species and tree species richness as well as functional traits on interrill erosion in a young forest ecosystem. An interrill erosion rate of 47.5 Mg ha-1 a-1 was calculated. This study provided evidence that different tree species affect interrill erosion differently, while tree species richness did not affect interrill erosion in young forest stands. Thus, different tree morphologies have to be considered, when assessing soil erosion under forest. High crown cover and leaf area index reduced interrill erosion in initial forest ecosystems, whereas rising tree height increased it. Even if a leaf litter cover was not present, the remaining soil surface cover by stones and biological soil crusts was the most important driver for soil erosion control. Furthermore, soil organic matter had a decreasing influence on interrill erosion. Long-term monitoring of soil erosion under closing tree canopies is necessary, and a wide range of functional tree traits should be considered in future research.

  6. Landscape variation in tree species richness in northern Iran forests.

    PubMed

    Bourque, Charles P-A; Bayat, Mahmoud

    2015-01-01

    Mapping landscape variation in tree species richness (SR) is essential to the long term management and conservation of forest ecosystems. The current study examines the prospect of mapping field assessments of SR in a high-elevation, deciduous forest in northern Iran as a function of 16 biophysical variables representative of the area's unique physiography, including topography and coastal placement, biophysical environment, and forests. Basic to this study is the development of moderate-resolution biophysical surfaces and associated plot-estimates for 202 permanent sampling plots. The biophysical variables include: (i) three topographic variables generated directly from the area's digital terrain model; (ii) four ecophysiologically-relevant variables derived from process models or from first principles; and (iii) seven variables of Landsat-8-acquired surface reflectance and two, of surface radiance. With symbolic regression, it was shown that only four of the 16 variables were needed to explain 85% of observed plot-level variation in SR (i.e., wind velocity, surface reflectance of blue light, and topographic wetness indices representative of soil water content), yielding mean-absolute and root-mean-squared error of 0.50 and 0.78, respectively. Overall, localised calculations of wind velocity and surface reflectance of blue light explained about 63% of observed variation in SR, with wind velocity accounting for 51% of that variation. The remaining 22% was explained by linear combinations of soil-water-related topographic indices and associated thresholds. In general, SR and diversity tended to be greatest for plots dominated by Carpinus betulus (involving ? 33% of all trees in a plot), than by Fagus orientalis (median difference of one species). This study provides a significant step towards describing landscape variation in SR as a function of modelled and satellite-based information and symbolic regression. Methods in this study are sufficiently general to be applicable to the characterisation of SR in other forested regions of the world, providing plot-scale data are available for model generation. PMID:25849029

  7. Changes in shoot allometry with increasing tree height in a tropical canopy species, Elateriospermum tapos.

    PubMed

    Osada, Noriyuki; Takeda, Hiroshi; Furukawa, Akio; Awang, Muhamad

    2002-06-01

    Allometry of shoot extension units (hereafter termed "current shoots") was analyzed in a Malaysian canopy species, Elateriospermum tapos Bl. (Euphorbiaceae). Changes in current shoot allometry with increasing tree height were related to growth and maintenance of tree crowns. Total biomass, biomass allocation ratio of non-photosynthetic to photosynthetic organs, and wood density of current shoots were unrelated to tree height. However, shoot structure changed with tree height. Compared with short trees, tall trees produced current shoots of the same mass but with thicker and shorter stems. Current shoots with thin and long stems enhanced height growth in short trees, whereas in tall trees, thick and short current shoots may reduce mechanical and hydraulic stresses. Furthermore, compared with short trees, tall trees produced current shoots with more leaves of lower dry mass, smaller area, and smaller specific leaf area (SLA). Short trees adapted to low light flux density by reducing mutual shading with large leaves having a large SLA. In contrast, tall trees reduced mutual shading within a shoot by producing more small leaves in distal than in proximal parts of the shoot stem. The production of a large number of small leaves promoted light penetration into the dense crowns of tall trees. All of these characteristics suggest that the change in current shoot structure with increasing tree height is adaptive in E. tapos, enabling short trees to maximize height growth and tall trees to maximize light capture. PMID:12069918

  8. Higher levels of multiple ecosystem services are found in forests with more tree species

    PubMed Central

    Gamfeldt, Lars; Snäll, Tord; Bagchi, Robert; Jonsson, Micael; Gustafsson, Lena; Kjellander, Petter; Ruiz-Jaen, María C.; Fröberg, Mats; Stendahl, Johan; Philipson, Christopher D.; Mikusi?ski, Grzegorz; Andersson, Erik; Westerlund, Bertil; Andrén, Henrik; Moberg, Fredrik; Moen, Jon; Bengtsson, Jan

    2013-01-01

    Forests are of major importance to human society, contributing several crucial ecosystem services. Biodiversity is suggested to positively influence multiple services but evidence from natural systems at scales relevant to management is scarce. Here, across a scale of 400,000?km2, we report that tree species richness in production forests shows positive to positively hump-shaped relationships with multiple ecosystem services. These include production of tree biomass, soil carbon storage, berry production and game production potential. For example, biomass production was approximately 50% greater with five than with one tree species. In addition, we show positive relationships between tree species richness and proxies for other biodiversity components. Importantly, no single tree species was able to promote all services, and some services were negatively correlated to each other. Management of production forests will therefore benefit from considering multiple tree species to sustain the full range of benefits that the society obtains from forests. PMID:23299890

  9. Tree species composition affects the abundance of rowan (Sorbus aucuparia L.) in urban forests in Finland.

    PubMed

    Hamberg, Leena; Lehvävirta, Susanna; Kotze, D Johan; Heikkinen, Juha

    2015-03-15

    Recent studies have shown a considerable increase in the abundance of rowan (Sorbus aucuparia) saplings in urban forests in Finland, yet the reasons for this increase are not well understood. Here we investigated whether canopy cover or tree species composition, i.e., the basal areas of different tree species in Norway spruce dominated urban forests, affects the abundances of rowan seedlings, saplings and trees. Altogether 24 urban forest patches were investigated. We sampled the number of rowan and other saplings, and calculated the basal areas of trees. We showed that rowan abundance was affected by tree species composition. The basal area of rowan trees (? 5 cm in diameter at breast height, dbh) decreased with increasing basal area of Norway spruce, while the cover of rowan seedlings increased with an increase in Norway spruce basal area. However, a decrease in the abundance of birch (Betula pendula) and an increase in the broad-leaved tree group (Acer platanoides, Alnus glutinosa, Alnus incana, Amelanchier spicata, Prunus padus, Quercus robur, Rhamnus frangula and Salix caprea) coincided with a decreasing number of rowans. Furthermore, rowan saplings were scarce in the vicinity of mature rowan trees. Although it seems that tree species composition has an effect on rowan, the relationship between rowan saplings and mature trees is complex, and therefore we conclude that regulating tree species composition is not an easy way to keep rowan thickets under control in urban forests in Finland. PMID:25588119

  10. Tree species identity and functional traits but not species richness affect interrill erosion processes in young subtropical forests

    NASA Astrophysics Data System (ADS)

    Seitz, S.; Goebes, P.; Song, Z.; Bruelheide, H.; Härdtle, W.; Kühn, P.; Li, Y.; Scholten, T.

    2015-06-01

    Soil erosion is seriously threatening ecosystem functioning in many parts of the world. In this context, it is assumed that tree species richness and functional diversity of tree communities can play a critical role in improving ecosystem services such as erosion control. An experiment with 170 micro-scale runoff plots was conducted to investigate the influence of tree species richness and identity as well as tree functional traits on interrill erosion in a young forest ecosystem. An interrill erosion rate of 47.5 t ha-1 a-1 was calculated. This study provided evidence that different tree species affect interrill erosion, but higher tree species richness did not mitigate soil losses in young forest stands. Thus, different tree morphologies have to be considered, when assessing erosion under forest. High crown cover and leaf area index reduced soil losses in initial forest ecosystems, whereas rising tree height increased them. Even if a leaf litter cover was not present, remaining soil surface cover by stones and biological soil crusts was the most important driver for soil erosion control. Furthermore, soil organic matter had a decreasing influence on soil loss. Long-term monitoring of soil erosion under closing tree canopies is necessary and a wide range of functional tree traits should be taken into consideration in future research.

  11. Species identity and neighbor size surpass the impact of tree species diversity on productivity in experimental broad-leaved tree sapling assemblages under dry and moist conditions

    PubMed Central

    Lübbe, Torben; Schuldt, Bernhard; Leuschner, Christoph

    2015-01-01

    Species diversity may increase the productivity of tree communities through complementarity (CE) and/or selection effects (SE), but it is not well known how this relationship changes under water limitation. We tested the stress-gradient hypothesis, which predicts that resource use complementarity and facilitation are more important under water-limited conditions. We conducted a growth experiment with saplings of five temperate broad-leaved tree species that were grown in assemblages of variable diversity (1, 3, or 5 species) and species composition under ample and limited water supply to examine effects of species richness and species identity on stand- and tree-level productivity. Special attention was paid to effects of neighbor identity on the growth of target trees in mixture as compared to growth in monoculture. Stand productivity was strongly influenced by species identity while a net biodiversity effect (NE) was significant in the moist treatment (mostly assignable to CE) but of minor importance. The growth performance of some of the species in the mixtures was affected by tree neighborhood characteristics with neighbor size likely being more important than neighbor species identity. Diversity and neighbor identity effects visible in the moist treatment mostly disappeared in the dry treatment, disproving the stress-gradient hypothesis. The mixtures were similarly sensitive to drought-induced growth reduction as the monocultures, which may relate to the decreased CE on growth upon drought in the mixtures. PMID:26579136

  12. Species Tree Estimation for the Late Blight Pathogen, Phytophthora infestans, and Close Relatives

    PubMed Central

    Blair, Jaime E.; Coffey, Michael D.; Martin, Frank N.

    2012-01-01

    To better understand the evolutionary history of a group of organisms, an accurate estimate of the species phylogeny must be known. Traditionally, gene trees have served as a proxy for the species tree, although it was acknowledged early on that these trees represented different evolutionary processes. Discordances among gene trees and between the gene trees and the species tree are also expected in closely related species that have rapidly diverged, due to processes such as the incomplete sorting of ancestral polymorphisms. Recently, methods have been developed for the explicit estimation of species trees, using information from multilocus gene trees while accommodating heterogeneity among them. Here we have used three distinct approaches to estimate the species tree for five Phytophthora pathogens, including P. infestans, the causal agent of late blight disease in potato and tomato. Our concatenation-based “supergene” approach was unable to resolve relationships even with data from both the nuclear and mitochondrial genomes, and from multiple isolates per species. Our multispecies coalescent approach using both Bayesian and maximum likelihood methods was able to estimate a moderately supported species tree showing a close relationship among P. infestans, P. andina, and P. ipomoeae. The topology of the species tree was also identical to the dominant phylogenetic history estimated in our third approach, Bayesian concordance analysis. Our results support previous suggestions that P. andina is a hybrid species, with P. infestans representing one parental lineage. The other parental lineage is not known, but represents an independent evolutionary lineage more closely related to P. ipomoeae. While all five species likely originated in the New World, further study is needed to determine when and under what conditions this hybridization event may have occurred. PMID:22615869

  13. Remnant Trees Affect Species Composition but Not Structure of Tropical Second-Growth Forest

    PubMed Central

    Sandor, Manette E.; Chazdon, Robin L.

    2014-01-01

    Remnant trees, spared from cutting when tropical forests are cleared for agriculture or grazing, act as nuclei of forest regeneration following field abandonment. Previous studies on remnant trees were primarily conducted in active pasture or old fields abandoned in the previous 2–3 years, and focused on structure and species richness of regenerating forest, but not species composition. Our study is among the first to investigate the effects of remnant trees on neighborhood forest structure, biodiversity, and species composition 20 years post-abandonment. We compared the woody vegetation around individual remnant trees to nearby plots without remnant trees in the same second-growth forests (“control plots”). Forest structure beneath remnant trees did not differ significantly from control plots. Species richness and species diversity were significantly higher around remnant trees. The species composition around remnant trees differed significantly from control plots and more closely resembled the species composition of nearby old-growth forest. The proportion of old-growth specialists and generalists around remnant trees was significantly greater than in control plots. Although previous studies show that remnant trees may initially accelerate secondary forest growth, we found no evidence that they locally affect stem density, basal area, and seedling density at later stages of regrowth. Remnant trees do, however, have a clear effect on the species diversity, composition, and ecological groups of the surrounding woody vegetation, even after 20 years of forest regeneration. To accelerate the return of diversity and old-growth forest species into regrowing forest on abandoned land, landowners should be encouraged to retain remnant trees in agricultural or pastoral fields. PMID:24454700

  14. Measuring and Modeling Interspecies Competition of Tree Species in Logged Boreal Mixed Forests

    NASA Astrophysics Data System (ADS)

    Martin, J.; Plaut, J.; Gower, S. T.; Weber, J.

    2001-12-01

    Forest tree species strongly affect biogeochemical cycles, and the differences are especially pronounced between evergreen and deciduous trees. Many boreal forests are mixed stands containing evergreen and deciduous species. The balance of evergreen and deciduous species changes during succession, yet most biogeochemical field studies and process models ignore mixed stands. The objective of the study was to determine the successional trends of tree species for a boreal logging age sequence in northern Manitoba. The experimental design consisted of eight replicate plots in four different-aged stands that originated from clearcut harvests in 1935 (mature), 1971, 1983, 1990. Dominant tree species were trembling aspen (Populus tremuloides), jack pine (Pinus banksiana), and black spruce (Picea mariana). Six trees of each major tree species were harvested and diameter * height growth relationships were determined by analyzing radial growth of stem disks collected every 0.25 m up the stem. Trembling aspen was the dominant tree species in the younger stands (1983, 1990) while jack pine and black spruce were the dominant tree species in the older stands (1971, mature). Annual growth rings of jack pine and trembling aspen decreased with age and annual radial growth of black spruce increased with stand age. The relationship of annual radial growth with stand age for the three species is discussed in relation to canopy architecture and biogeochemical cycles.

  15. The contribution of seed dispersers to tree species diversity in tropical rainforests.

    PubMed

    Kakishima, Satoshi; Morita, Satoru; Yoshida, Katsuhiko; Ishida, Atsushi; Hayashi, Saki; Asami, Takahiro; Ito, Hiromu; Miller, Donald G; Uehara, Takashi; Mori, Shigeta; Hasegawa, Eisuke; Matsuura, Kenji; Kasuya, Eiiti; Yoshimura, Jin

    2015-10-01

    Tropical rainforests are known for their extreme biodiversity, posing a challenging problem in tropical ecology. Many hypotheses have been proposed to explain the diversity of tree species, yet our understanding of this phenomenon remains incomplete. Here, we consider the contribution of animal seed dispersers to the species diversity of trees. We built a multi-layer lattice model of trees whose animal seed dispersers are allowed to move only in restricted areas to disperse the tree seeds. We incorporated the effects of seed dispersers in the traditional theory of allopatric speciation on a geological time scale. We modified the lattice model to explicitly examine the coexistence of new tree species and the resulting high biodiversity. The results indicate that both the coexistence and diversified evolution of tree species can be explained by the introduction of animal seed dispersers. PMID:26587246

  16. The contribution of seed dispersers to tree species diversity in tropical rainforests

    PubMed Central

    Kakishima, Satoshi; Morita, Satoru; Yoshida, Katsuhiko; Ishida, Atsushi; Hayashi, Saki; Asami, Takahiro; Ito, Hiromu; Miller, Donald G.; Uehara, Takashi; Mori, Shigeta; Hasegawa, Eisuke; Matsuura, Kenji; Kasuya, Eiiti; Yoshimura, Jin

    2015-01-01

    Tropical rainforests are known for their extreme biodiversity, posing a challenging problem in tropical ecology. Many hypotheses have been proposed to explain the diversity of tree species, yet our understanding of this phenomenon remains incomplete. Here, we consider the contribution of animal seed dispersers to the species diversity of trees. We built a multi-layer lattice model of trees whose animal seed dispersers are allowed to move only in restricted areas to disperse the tree seeds. We incorporated the effects of seed dispersers in the traditional theory of allopatric speciation on a geological time scale. We modified the lattice model to explicitly examine the coexistence of new tree species and the resulting high biodiversity. The results indicate that both the coexistence and diversified evolution of tree species can be explained by the introduction of animal seed dispersers. PMID:26587246

  17. Landscape Variation in Tree Species Richness in Northern Iran Forests

    PubMed Central

    Bourque, Charles P.-A.; Bayat, Mahmoud

    2015-01-01

    Mapping landscape variation in tree species richness (SR) is essential to the long term management and conservation of forest ecosystems. The current study examines the prospect of mapping field assessments of SR in a high-elevation, deciduous forest in northern Iran as a function of 16 biophysical variables representative of the area’s unique physiography, including topography and coastal placement, biophysical environment, and forests. Basic to this study is the development of moderate-resolution biophysical surfaces and associated plot-estimates for 202 permanent sampling plots. The biophysical variables include: (i) three topographic variables generated directly from the area’s digital terrain model; (ii) four ecophysiologically-relevant variables derived from process models or from first principles; and (iii) seven variables of Landsat-8-acquired surface reflectance and two, of surface radiance. With symbolic regression, it was shown that only four of the 16 variables were needed to explain 85% of observed plot-level variation in SR (i.e., wind velocity, surface reflectance of blue light, and topographic wetness indices representative of soil water content), yielding mean-absolute and root-mean-squared error of 0.50 and 0.78, respectively. Overall, localised calculations of wind velocity and surface reflectance of blue light explained about 63% of observed variation in SR, with wind velocity accounting for 51% of that variation. The remaining 22% was explained by linear combinations of soil-water-related topographic indices and associated thresholds. In general, SR and diversity tended to be greatest for plots dominated by Carpinus betulus (involving ? 33% of all trees in a plot), than by Fagus orientalis (median difference of one species). This study provides a significant step towards describing landscape variation in SR as a function of modelled and satellite-based information and symbolic regression. Methods in this study are sufficiently general to be applicable to the characterisation of SR in other forested regions of the world, providing plot-scale data are available for model generation. PMID:25849029

  18. The description of Paramblynotus delaneyi (Hymenoptera: Liopteridae), a new species from Joshua Tree National Park

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new species, Paramblynotus delaneyi (Hymenoptera: Liopteridae), is described and characters separating it from the Nearctic species P. zonatus Weld and P. virginianus Liu are discussed. A discussion of the insect biodiversity survey at Joshua Tree National Park is provided....

  19. ECOLOGICAL RESPONSE SURFACES FOR NORTH AMERICAN BOREAL TREE SPECIES AND THEIR USE IN FOREST CLASSIFICATION

    EPA Science Inventory

    Empirical ecological response surfaces were derived for eight dominant tree species in the boreal forest region of Canada. tepwise logistic regression was used to model species dominance as a response to five climatic predictor variables. he predictor variables (annual snowfall, ...

  20. Individual tree species identification using LIDAR-derived crown structures and intensity data

    NASA Astrophysics Data System (ADS)

    Kim, Sooyoung

    Tree species identification is important for a variety of natural resource management and monitoring activities including riparian buffer characterization, wildfire risk assessment, biodiversity monitoring, and wildlife habitat improvement. Coordinate data from airborne laser scanners can be used to detect individual trees and characterize forest biophysical attributes. Metrics computed from LIDAR point data describe tree size and crown shape characteristics. The intensity data recorded for each laser point is related to the spectral reflectance of the target material and thus may be useful for differentiating materials and ultimately tree species. The aim of this study is to test if LIDAR intensity data and crown structure metrics can be used to differentiate tree species. Leaf-on and leaf-off LIDAR were obtained in the Washington Park Arboretum. Field work was conducted to measure tree locations, heights, crown base heights, and crown diameters for eight broadleaved species and seven conifers. LIDAR points from individual trees were identified using the field-measured tree location. Points from adjacent trees were excluded. We found that intensity values for different tree species varied depending on foliage characteristics, the presence or absence of foliage, and the position of the LIDAR return within the tree crown. In terms of the intensity analysis, the classification accuracy for broadleaved and coniferous species was better using leaf-off data than using leaf-on data while in terms of the structure analysis, the accuracy was better using leaf-on data than using leaf-off data. The stepwise cluster analysis was conducted to find similar groups of species at consecutive steps using k-medoid algorithm. When using both LIDAR datasets showed the most reasonable clustering result compared with the result using either one of the datasets. The research presented in this dissertation provides a significant contribution to the understanding of how various tree species can be identified through the structural and spectral characteristics derived from LIDAR data.

  1. Population and species differences in treeline tree species germination in response to climate change

    NASA Astrophysics Data System (ADS)

    Kueppers, L. M.; Faist, A.; Castanha, C.

    2009-12-01

    The ability of plant species to recruit within and beyond their current geographic ranges in response to climate warming may be constrained by population differences in response. A number of studies have highlighted the degree to which genotype and environment are strongly linked in forest trees (i.e., provenances), but few studies have examined whether these local adaptations are at all predictive of population or species response to change. We report the results of lab germination experiments using high and low elevation populations of both limber pine (Pinus flexilis) and Engelmann spruce (Picea engelmannii), which are important treeline species in the Rocky Mountains. Seeds collected in 2008 were germinated under two different temperature regimes (ambient and +5°C) and two different moisture regimes, and followed for 17 weeks. For both species and source elevations, warmer temperatures advanced the timing of emergence by up to 20 days, whereas the effects of moisture were less consistent. At harvest, high elevation limber pine had less root and shoot biomass, and a slightly lower root:shoot ratio, under the +5°C treatment, whereas low elevation limber pine seedling mass was not sensitive to temperature. Whether these differences persist under field conditions will be tested in a field experiment now established at Niwot Ridge, CO. The ability to accurately predict tree seedling recruitment and ultimately shifts in treeline position with climate change will improve our ability to model changes in surface albedo, water cycling and carbon cycling, all of which can generate feedbacks to regional and global climate.

  2. Spatial Distribution Patterns in the Very Rare and Species-Rich Picea chihuahuana Tree Community (Mexico).

    PubMed

    Wehenkel, Christian; Brazão-Protázio, João Marcelo; Carrillo-Parra, Artemio; Martínez-Guerrero, José Hugo; Crecente-Campo, Felipe

    2015-01-01

    The very rare Mexican Picea chihuahuana tree community covers an area of no more than 300 ha in the Sierra Madre Occidental. This special tree community has been the subject of several studies aimed at learning more about the genetic structure and ecology of the species and the potential effects of climate change. The spatial distribution of trees is a result of many ecological processes and can affect the degree of competition between neighbouring trees, tree density, variability in size and distribution, regeneration, survival, growth, mortality, crown formation and the biological diversity within forest communities. Numerous scale-dependent measures have been established in order to describe spatial forest structure. The overall aim of most of these studies has been to obtain data to help design preservation and conservation strategies. In this study, we examined the spatial distribution pattern of trees in the P. chihuahuana tree community in 12 localities, in relation to i) tree stand density, ii) diameter distribution (vertical structure), iii) tree species diversity, iv) geographical latitude and v) tree dominance at a fine scale (in 0.25 ha plots), with the aim of obtaining a better understanding of the complex ecosystem processes and biological diversity. Because of the strongly mixed nature of this tree community, which often produces low population densities of each tree species and random tree fall gaps caused by tree death, we expect aggregated patterns in individual Picea chihuahuana trees and in the P. chihuahuana tree community, repulsive Picea patterns to other tree species and repulsive patterns of young to adult trees. Each location was represented by one plot of 50 x 50 m (0.25 ha) established in the centre of the tree community. The findings demonstrate that the hypothesis of aggregated tree pattern is not applicable to the mean pattern measured by Clark-Evans index, Uniform Angle index and Mean Directional index of the uneven-aged P. chihuahuana trees and P. chihuahuana tree community and but to specific spatial scales measured by the univariate L-function. The spatial distribution pattern of P. chihuahuana trees was found to be independent of patches of other tree species measured by the bivariate L-function. The spatial distribution was not significantly related to tree density, diameter distribution or tree species diversity. The index of Clark and Evans decreased significantly from the southern to northern plots containing all tree species. Self-thinning due to intra and inter-specific competition-induced mortality is probably the main cause of the decrease in aggregation intensity during the course of population development in this tree community. We recommend the use of larger sampling plots (> 0.25 ha) in uneven-aged and species-rich forest ecosystems to detect less obvious, but important, relationships between spatial tree pattern and functioning and diversity in these forests. PMID:26496189

  3. Spatial Distribution Patterns in the Very Rare and Species-Rich Picea chihuahuana Tree Community (Mexico)

    PubMed Central

    Wehenkel, Christian; Brazão-Protázio, João Marcelo; Carrillo-Parra, Artemio; Martínez-Guerrero, José Hugo; Crecente-Campo, Felipe

    2015-01-01

    The very rare Mexican Picea chihuahuana tree community covers an area of no more than 300 ha in the Sierra Madre Occidental. This special tree community has been the subject of several studies aimed at learning more about the genetic structure and ecology of the species and the potential effects of climate change. The spatial distribution of trees is a result of many ecological processes and can affect the degree of competition between neighbouring trees, tree density, variability in size and distribution, regeneration, survival, growth, mortality, crown formation and the biological diversity within forest communities. Numerous scale-dependent measures have been established in order to describe spatial forest structure. The overall aim of most of these studies has been to obtain data to help design preservation and conservation strategies. In this study, we examined the spatial distribution pattern of trees in the P. chihuahuana tree community in 12 localities, in relation to i) tree stand density, ii) diameter distribution (vertical structure), iii) tree species diversity, iv) geographical latitude and v) tree dominance at a fine scale (in 0.25 ha plots), with the aim of obtaining a better understanding of the complex ecosystem processes and biological diversity. Because of the strongly mixed nature of this tree community, which often produces low population densities of each tree species and random tree fall gaps caused by tree death, we expect aggregated patterns in individual Picea chihuahuana trees and in the P. chihuahuana tree community, repulsive Picea patterns to other tree species and repulsive patterns of young to adult trees. Each location was represented by one plot of 50 x 50 m (0.25 ha) established in the centre of the tree community. The findings demonstrate that the hypothesis of aggregated tree pattern is not applicable to the mean pattern measured by Clark-Evans index, Uniform Angle index and Mean Directional index of the uneven-aged P. chihuahuana trees and P. chihuahuana tree community and but to specific spatial scales measured by the univariate L-function. The spatial distribution pattern of P. chihuahuana trees was found to be independent of patches of other tree species measured by the bivariate L-function. The spatial distribution was not significantly related to tree density, diameter distribution or tree species diversity. The index of Clark and Evans decreased significantly from the southern to northern plots containing all tree species. Self-thinning due to intra and inter-specific competition-induced mortality is probably the main cause of the decrease in aggregation intensity during the course of population development in this tree community. We recommend the use of larger sampling plots (> 0.25 ha) in uneven-aged and species-rich forest ecosystems to detect less obvious, but important, relationships between spatial tree pattern and functioning and diversity in these forests. PMID:26496189

  4. Characterizing tropical tree species growth strategies: learning from inter-individual variability and scale invariance.

    PubMed

    Le Bec, Jimmy; Courbaud, Benoit; Le Moguédec, Gilles; Pélissier, Raphaël

    2015-01-01

    Understanding how tropical tree species differ in their growth strategies is critical to predict forest dynamics and assess species coexistence. Although tree growth is highly variable in tropical forests, species maximum growth is often considered as a major axis synthesizing species strategies, with fast-growing pioneer and slow-growing shade tolerant species as emblematic representatives. We used a hierarchical linear mixed model and 21-years long tree diameter increment series in a monsoon forest of the Western Ghats, India, to characterize species growth strategies and question whether maximum growth summarizes these strategies. We quantified both species responses to biotic and abiotic factors and individual tree effects unexplained by these factors. Growth responses to competition and tree size appeared highly variable among species which led to reversals in performance ranking along those two gradients. However, species-specific responses largely overlapped due to large unexplained variability resulting mostly from inter-individual growth differences consistent over time. On average one-third of the variability captured by our model was explained by covariates. This emphasizes the high dimensionality of the tree growth process, i.e. the fact that trees differ in many dimensions (genetics, life history) influencing their growth response to environmental gradients, some being unmeasured or unmeasurable. In addition, intraspecific variability increased as a power function of species maximum growth partly as a result of higher absolute responses of fast-growing species to competition and tree size. However, covariates explained on average the same proportion of intraspecific variability for slow- and fast-growing species, which showed the same range of relative responses to competition and tree size. These results reflect a scale invariance of the growth process, underlining that slow- and fast-growing species exhibit the same range of growth strategies. PMID:25756212

  5. Characterizing Tropical Tree Species Growth Strategies: Learning from Inter-Individual Variability and Scale Invariance

    PubMed Central

    Le Bec, Jimmy; Courbaud, Benoit; Le Moguédec, Gilles; Pélissier, Raphaël

    2015-01-01

    Understanding how tropical tree species differ in their growth strategies is critical to predict forest dynamics and assess species coexistence. Although tree growth is highly variable in tropical forests, species maximum growth is often considered as a major axis synthesizing species strategies, with fast-growing pioneer and slow-growing shade tolerant species as emblematic representatives. We used a hierarchical linear mixed model and 21-years long tree diameter increment series in a monsoon forest of the Western Ghats, India, to characterize species growth strategies and question whether maximum growth summarizes these strategies. We quantified both species responses to biotic and abiotic factors and individual tree effects unexplained by these factors. Growth responses to competition and tree size appeared highly variable among species which led to reversals in performance ranking along those two gradients. However, species-specific responses largely overlapped due to large unexplained variability resulting mostly from inter-individual growth differences consistent over time. On average one-third of the variability captured by our model was explained by covariates. This emphasizes the high dimensionality of the tree growth process, i.e. the fact that trees differ in many dimensions (genetics, life history) influencing their growth response to environmental gradients, some being unmeasured or unmeasurable. In addition, intraspecific variability increased as a power function of species maximum growth partly as a result of higher absolute responses of fast-growing species to competition and tree size. However, covariates explained on average the same proportion of intraspecific variability for slow- and fast-growing species, which showed the same range of relative responses to competition and tree size. These results reflect a scale invariance of the growth process, underlining that slow- and fast-growing species exhibit the same range of growth strategies. PMID:25756212

  6. The Relationship between Species Diversity and Genetic Structure in the Rare Picea chihuahuana Tree Species Community, Mexico

    PubMed Central

    Simental-Rodríguez, Sergio Leonel; Quiñones-Pérez, Carmen Zulema; Moya, Daniel; Hernández-Tecles, Enrique; López-Sánchez, Carlos Antonio; Wehenkel, Christian

    2014-01-01

    Species diversity and genetic diversity, the most basic elements of biodiversity, have long been treated as separate topics, although populations evolve within a community context. Recent studies on community genetics and ecology have suggested that genetic diversity is not completely independent of species diversity. The Mexican Picea chihuahuana Martínez is an endemic species listed as “Endangered” on the Red List. Forty populations of Chihuahua spruce have been identified. This species is often associated with tree species of eight genera in gallery forests. This rare Picea chihuahuana tree community covers an area no more than 300 ha and has been subject of several studies involving different topics such as ecology, genetic structure and climate change. The overall aim of these studies was to obtain a dataset for developing management tools to help decision makers implement preservation and conservation strategies. However, this unique forest tree community may also represent an excellent subject for helping us to understand the interplay between ecological and evolutionary processes in determining community structure and dynamics. The AFLP technique and species composition data were used together to test the hypothesis that species diversity is related to the adaptive genetic structure of some dominant tree species (Picea chihuahuana, Pinus strobiformis, Pseudotsuga menziesii and Populus tremuloides) of the Picea chihuahuana tree community at fourteen locations. The Hill numbers were used as a diversity measure. The results revealed a significant correlation between tree species diversity and genetic structure in Populus tremuloides. Because the relationship between the two levels of diversity was found to be positive for the putative adaptive AFLP detected, genetic and species structures of the tree community were possibly simultaneously adapted to a combination of ecological or environmental factors. The present findings indicate that interactions between genetic variants and species diversity may be crucial in shaping tree communities. PMID:25375134

  7. Tree species richness promotes productivity in temperate forests through strong complementarity between species.

    PubMed

    Morin, Xavier; Fahse, Lorenz; Scherer-Lorenzen, Michael; Bugmann, Harald

    2011-12-01

    Understanding the link between biodiversity and ecosystem functioning (BEF) is pivotal in the context of global biodiversity loss. Yet, long-term effects have been explored only weakly, especially for forests, and no clear evidence has been found regarding the underlying mechanisms. We explore the long-term relationship between diversity and productivity using a forest succession model. Extensive simulations show that tree species richness promotes productivity in European temperate forests across a large climatic gradient, mostly through strong complementarity between species. We show that this biodiversity effect emerges because increasing species richness promotes higher diversity in shade tolerance and growth ability, which results in forests responding faster to small-scale mortality events. Our study generalises results from short-term experiments in grasslands to forest ecosystems and demonstrates that competition for light alone induces a positive effect of biodiversity on productivity, thus providing a new angle for explaining BEF relationships. PMID:21955682

  8. [Atmospheric Particle Retaining Function of Common Deciduous Tree Species Leaves in Beijing].

    PubMed

    Wang, Bing; Wang, Xiao-yan; Niu, Xiang; Zhang, Wei-kang; Wang, Jin-song

    2015-06-01

    In order to explore the atmospheric particle-retaining function of common deciduous tree species leaves in Beijing, six typical tree species (Populus, Robinia pseudoacacia, Koelreuteria paniculata, Salix babylonica, Acer truncatum, Ginkgo biloba) were chosen to measure retaining amount of unit leaf area of air total suspended particles (TSP), coarse particles and fine particulate with aerosol generator (QRJZFSQ-I). The results showed that (1) All six tree species leaves had a certain level of retaining ability to different sizes of atmospheric particles, and different species exhibited some differences. For different sizes of atmospheric particle, retaining amounts of unit leaf area were higher in Koelreuteria paniculata and Robinia pseudoacacia than those of other four species, and the amount of Populus was the lowest among all tree species; (2) The retaining amount of unit leaf area for different tree species was not entirely increased with sampling time. The retaining amounts of TSP and coarse particles for all tree species on the eighth day after rain were significantly higher than those on the fifth day after rain, however, the retaining amount of fine particles was not significantly different under different sampling times. In order to select deciduous tree species for ecological management of air pollution in Beijing, Koelreuteria paniculata should be considered as the priority, followed by Robinia pseudoacacia, compared with Ginkgo biloba, Salix babylonica, Acer truncatum and Populus. PMID:26387301

  9. Species-specific effects on throughfall kinetic energy below 12 subtropical tree species are related to leaf traits and tree architecture

    NASA Astrophysics Data System (ADS)

    Goebes, Philipp; Seitz, Steffen; Kühn, Peter; Kröber, Wenzel; Bruelheide, Helge; Li, Ying; von Oheimb, Goddert; Scholten, Thomas

    2015-04-01

    Soil erosion impacts environmental systems widely, especially in subtropical China where high erosion rates occur. The comprehension about the mechanisms that induce soil erosion on agricultural land is broad, but erosion processes below forests are only rarely understood. Especially throughfall kinetic energy (TKE) is influenced by forests and their structure as well as their succession in many ways. Today, many forests are monoculture tree stands due to economic reasons by providing timber, fuel and pulp wood. Therefore, this study investigates the role of different monoculture forest stands on TKE that were afforestated in 2008. The main questions are: Is TKE species-specific? What are characteristic leaf traits and tree architectural parameters that induce a species-specific effect on TKE and by what extend do they contribute to a mediation of species-specific effects on TKE? We measured TKE of 12 different species in subtropical China using sand-filled splash cups during five rainfall events in summer 2013. In addition, 14 leaf traits and tree architectural parameters were registered to link species-specific effects on TKE to vegetation parameters. Our results show that TKE is highly species-specific. Highest TKE was found below Choerospondias axillaris and Sapindus mukorossi, while Schima superba showed lowest TKE. The latter species can be regarded as key species for reduced erosion occurrence. This species effect is mediated by leaf habit, leaf area, leaf pinnation, leaf margin, tree ground diameter, crown base height, tree height, number of branches and LAI as biotic factors and rainfall amount as abiotic factor. Moreover, leaf habit, tree height and LA show high effect sizes on TKE and can be considered as major drivers evoking TKE differences below vegetation.

  10. Effect of adenine sulphate interaction on growth and development of shoot regeneration and inhibition of shoot tip necrosis under in vitro condition in adult Syzygium cumini L.--a multipurpose tree.

    PubMed

    Naaz, Afshan; Shahzad, Anwar; Anis, Mohammad

    2014-05-01

    An efficient method for cloning Syzygium cumini (above 40 years old) through mature nodal segments has been successfully developed and that could be exploited for large-scale production of this valuable multipurpose tree. Nodal segments from mature tree were taken as explants and cultured on MS basal medium with different cytokinins (BA, Kin, AdS). The application of BA proved to be the best responsive cytokinin for the induction of shoot buds and shoots, but the proliferated shoots exhibited slower and stunted growth accompanied with abscission of leaves and shoot tip necrosis (STN). The problem of leaf abscission and STN was considerably reduced by the application of an adjuvant, adenine sulphate (AdS) in the optimal medium which led to the production of a maximum of 14 shoots. Further improvement in shoot bud regeneration and improved growth pattern of the regenerating tissue was obtained on the media comprised of MS?+?BA (10 ?M)?+?GA3 (2.5 ?M). A total number of 15 shoots with mean shoot length of 5.9 cm was obtained. The healthy elongated shoots were then rooted on MS basal augmented with NAA (5 ?M). The plantlets obtained were healthy and were successfully acclimatized and transferred under field condition with 70 % survival rate. PMID:24682901

  11. Surface Water Storage Capacity of Twenty Tree Species in Davis, California.

    PubMed

    Xiao, Qingfu; McPherson, E Gregory

    2016-01-01

    Urban forestry is an important green infrastructure strategy because healthy trees can intercept rainfall, reducing stormwater runoff and pollutant loading. Surface saturation storage capacity, defined as the thin film of water that must wet tree surfaces before flow begins, is the most important variable influencing rainfall interception processes. Surface storage capacity is known to vary widely among tree species, but it is little studied. This research measured surface storage capacities of 20 urban tree species in a rainfall simulator. The measurement system included a rainfall simulator, digital balance, digital camera, and computer. Eight samples were randomly collected from each tree species. Twelve rainfall intensities (3.5-139.5 mm h) were simulated. Leaf-on and leaf-off simulations were conducted for deciduous species. Stem and foliar surface areas were estimated using an image analysis method. Results indicated that surface storage capacities varied threefold among tree species, 0.59 mm for crape myrtle ( L.) and 1.81 mm for blue spruce ( Engelm.). The mean value across all species was 0.86 mm (0.11 mm SD). To illustrate application of the storage values, interception was simulated and compared across species for a 40-yr period with different rainfall intensities and durations. By quantifying the potential for different tree species to intercept rainfall under a variety of meteorological conditions, this study provides new knowledge that is fundamental to validating the cost-effectiveness of urban forestry as a green infrastructure strategy and designing functional plantings. PMID:26828174

  12. No evidence for consistent long-term growth stimulation of 13 tropical tree species: results from tree-ring analysis.

    PubMed

    Groenendijk, Peter; van der Sleen, Peter; Vlam, Mart; Bunyavejchewin, Sarayudh; Bongers, Frans; Zuidema, Pieter A

    2015-10-01

    The important role of tropical forests in the global carbon cycle makes it imperative to assess changes in their carbon dynamics for accurate projections of future climate-vegetation feedbacks. Forest monitoring studies conducted over the past decades have found evidence for both increasing and decreasing growth rates of tropical forest trees. The limited duration of these studies restrained analyses to decadal scales, and it is still unclear whether growth changes occurred over longer time scales, as would be expected if CO2 -fertilization stimulated tree growth. Furthermore, studies have so far dealt with changes in biomass gain at forest-stand level, but insights into species-specific growth changes - that ultimately determine community-level responses - are lacking. Here, we analyse species-specific growth changes on a centennial scale, using growth data from tree-ring analysis for 13 tree species (~1300 trees), from three sites distributed across the tropics. We used an established (regional curve standardization) and a new (size-class isolation) growth-trend detection method and explicitly assessed the influence of biases on the trend detection. In addition, we assessed whether aggregated trends were present within and across study sites. We found evidence for decreasing growth rates over time for 8-10 species, whereas increases were noted for two species and one showed no trend. Additionally, we found evidence for weak aggregated growth decreases at the site in Thailand and when analysing all sites simultaneously. The observed growth reductions suggest deteriorating growth conditions, perhaps due to warming. However, other causes cannot be excluded, such as recovery from large-scale disturbances or changing forest dynamics. Our findings contrast growth patterns that would be expected if elevated CO2 would stimulate tree growth. These results suggest that commonly assumed growth increases of tropical forests may not occur, which could lead to erroneous predictions of carbon dynamics of tropical forest under climate change. PMID:25917997

  13. Seasonal variations of isoprene emissions from five oak tree species in East Asia

    NASA Astrophysics Data System (ADS)

    Lim, Yong-Jae; Armendariz, Al; Son, Youn-Suk; Kim, Jo-Chun

    2011-04-01

    Emissions of biogenic volatile organic compounds (BVOC) from trees can enhance the photochemical production of tropospheric ozone. Isoprene is one of the most environmentally important BVOCs, since its emission rate from certain tree species can be high and its chemical structure gives it high ozone forming potential. Understanding of isoprene emission rates from many tree species is limited, including influences of tree age, season, and other factors. Five oak species were studied which represent approximately 85 percent of the deciduous trees in South Korean forests. In general, there were obvious seasonal variations of isoprene emissions from five oak trees. Especially, Quercus aliena B. and Quercus mongolica F showed substantial seasonal variations of isoprene emissions; However, Quercus serrata T. and Quercus acutissima C. generally did not. It was found that Q. serrata T. showed the highest isoprene emission rates among the species tested (up to 130.5 ?gC gdw -1 h -1) and its emission rates were highest during spring followed by summer and fall. The emission rates from two ( Q. acutissima C., Quercus variabilis B.) of the other tested oak species were lower by more than 3 orders of magnitude. Besides, two oak species, Q. aliena B. and Q. mongolica F. were chosen to determine the effect of tree age on isoprene emissions. Trees at the age of 21˜30 years had significantly higher isoprene emission rates than those at the age of 41˜50.

  14. Phylogenomic species tree estimation in the presence of incomplete lineage sorting and horizontal gene transfer

    PubMed Central

    2015-01-01

    Background Species tree estimation is challenged by gene tree heterogeneity resulting from biological processes such as duplication and loss, hybridization, incomplete lineage sorting (ILS), and horizontal gene transfer (HGT). Mathematical theory about reconstructing species trees in the presence of HGT alone or ILS alone suggests that quartet-based species tree methods (known to be statistically consistent under ILS, or under bounded amounts of HGT) might be effective techniques for estimating species trees when both HGT and ILS are present. Results We evaluated several publicly available coalescent-based methods and concatenation under maximum likelihood on simulated datasets with moderate ILS and varying levels of HGT. Our study shows that two quartet-based species tree estimation methods (ASTRAL-2 and weighted Quartets MaxCut) are both highly accurate, even on datasets with high rates of HGT. In contrast, although NJst and concatenation using maximum likelihood are highly accurate under low HGT, they are less robust to high HGT rates. Conclusion Our study shows that quartet-based species-tree estimation methods can be highly accurate under the presence of both HGT and ILS. The study suggests the possibility that some quartet-based methods might be statistically consistent under phylogenomic models of gene tree heterogeneity with both HGT and ILS. PMID:26450506

  15. The paradox of great longevity in a short-lived tree species.

    PubMed

    Larson, D W

    2001-04-01

    Thuja occidentalis is a tree species that was once thought to be relatively short-lived (80 years). Up until 10 years ago maximum ages were considered to be near 400 years, but such trees were thought to be rare. Research along the cliffs of the Niagara Escarpment has altered this view. Exceptionally slow-growing trees of this species have been found with ring counts to 1653 years and estimated ages to 1890 years. Senescence is slow or absent. Injury and death is due to rockfall and sporadic severe drought that kills small sectors of the trees by exposing and killing the roots. Experiments in which colored dyes are infused into roots show that each tree is composed of hydraulically independent units that allow mortality in one part of the 'individual' with little negative effect on the remaining parts of the tree. The trees are small, so environmental loadings of ice, snow, and wind are low. Slow growth of the trees results in a much greater mechanical strength in the wood. Together these properties increase the ability of the cedars to persist on cliffs for long periods of time. The paradox of great longevity in this 'short-lived' tree species is explained by slow growth that minimizes maintenance and repair costs while maximizing durability and strength, combined with an internal architecture that creates functionally independent units within each tree. PMID:11295506

  16. Soil magnetic susceptibility reflects soil moisture regimes and the adaptability of tree species to these regimes

    USGS Publications Warehouse

    Wang, J.-S.; Grimley, D.A.; Xu, C.; Dawson, J.O.

    2008-01-01

    Flooded, saturated or poorly drained soils are frequently anaerobic, leading to dissolution of the strongly magnetic minerals, magnetite and maghemite, and a corresponding decrease in soil magnetic susceptibility (MS). In this study of five temperate deciduous forests in east-central Illinois, USA, mean surface soil MS was significantly higher adjacent to upland tree species (31 ?? 10-5 SI) than adjacent to floodplain or lowland tree species (17 ?? 10-5 SI), when comparing regional soils with similar parent material of loessal silt. Although the sites differ in average soil MS for each tree species, the relative order of soil MS means for associated tree species at different locations is similar. Lowland tree species, Celtis occidentalis L., Ulmus americana L., Acer saccharinum L., Carya laciniosa (Michx. f.) Loud., and Fraxinus pennsylvanica Marsh. were associated with the lowest measured soil MS mean values overall and at each site. Tree species' flood tolerance rankings increased significantly, as soil MS values declined, the published rankings having significant correlations with soil MS values for the same species groups. The three published classifications of tree species' flood tolerance were significantly correlated with associated soil MS values at all sites, but most strongly at Allerton Park, the site with the widest range of soil drainage classes and MS values. Using soil MS measurements in forests with soil parent material containing similar initial levels of strongly magnetic minerals can provide a simple, rapid and quantitative method to classify soils according to hydric regimes, including dry conditions, and associated plant composition. Soil MS values thus have the capacity to quantify the continuum of hydric tolerances of tree species and guide tree species selection for reforestation. ?? 2007 Elsevier B.V. All rights reserved.

  17. Seven new species of the Botryosphaeriaceae from baobab and other native trees in Western Australia.

    PubMed

    Pavlic, Draginja; Wingfield, Michael J; Barber, Paul; Slippers, Bernard; Hardy, Giles E St J; Burgess, Treena I

    2008-01-01

    In this study seven new species of the Botryosphaeriaceae are described from baobab (Adansonia gibbosa) and surrounding endemic tree species growing in the Kimberley region of northwestern Australia. Members of the Botryosphaeriaceae were predominantly endophytes isolated from apparently healthy sapwood and bark of endemic trees; others were isolated from dying branches. Phylogenetic analyses of ITS and EF1-alpha sequence data revealed seven new species: Dothiorella longicollis, Fusicoccum ramosum, Lasiodiplodia margaritacea, Neoscytalidium novaehollandiae, Pseudofusicoccum adansoniae, P. ardesiacum and P. kimberleyense. PMID:19202840

  18. [Tree species discrimination based on leaf-level hyperspectral characteristic analysis].

    PubMed

    Wang, Zhi-hui; Ding, Li-xia

    2010-07-01

    The emergence of hyperspectral remote sensing technology will provide chance for solving problems of identifying forest tree species precisely. For discrimination of tree species with hyperspectral remote sensing technology, extraction and selection of the spectral characteristics is a very important process. Compared with multispectral data, hyperspectral data have the characteristics of more bands, larger amount of data and larger redundancy degree. The method of derivative reflectance was used to deal with the original spectral data, analyze and compare curves of the original spectrum, the first derivative reflectance and second derivative reflectance of the different tree species, and the bands with bigger difference were selected to identify the different tree species. Then the Euclidean distance method was used to test the selective bands identifying different tree species, and the results showed that the selective bands could identify different tree species effectively. The bands for identifying different tree species were most near-infrared bands, and the bands with maximum difference derived from the three methods are 1,657-1,666, 1,868-1,877 and 1,868-1,877 nm respectively. PMID:20827979

  19. Phenology and recruitment of Caryocar costaricense (Caryocaceae), an endemic tree species of Southern Central America.

    PubMed

    Solís, Silvia; Lobo, Jorge; Grimaldo, Mayori

    2009-09-01

    Basic aspects of the reproductive biology are largely unknown for most tropical tree species, although they are important elements to understand the impacts of anthropogenic activities as logging and forest fragmentation on these populations. In this study, data are presented on leaf and reproductive phenology, fruit production and seedling demography of a population of an endemic tree species of Southern Central America, Caryocar costaricense. This species has been affected by selective logging and forest fragmentation of its habitat. Phenology was studied by observation of 15-22 tree crowns during two reproductive periods (2003 and 2005). Circular plots were established around 11 adult trees to count the number of fallen fruits and seedlings during three years (2003, 2004, 2005). Although reproductive phenology is restricted to the short dry season in this species, seed germination occurred year-round. Fruit and seedling production shows a strong inter-individual variation within the study populations, with two large trees producing nearly 50%-70% of the fruits and seedlings during two years. Most of the seeds that fall beneath the tree crown are covered by litterfall or removed by fauna. We found evidence that many of these seeds become part of a seed bank in the forest floor. Because of the observed reproductive dominance of few large trees in these populations, we propose that selective logging on reproductive trees can severely impact the recruitment of this species. PMID:19928470

  20. Designing Mixed Species Tree Plantations for the Tropics: Balancing Ecological Attributes of Species with Landholder Preferences in the Philippines

    PubMed Central

    Nguyen, Huong; Lamb, David; Herbohn, John; Firn, Jennifer

    2014-01-01

    A mixed species reforestation program known as the Rainforestation Farming system was undertaken in the Philippines to develop forms of farm forestry more suitable for smallholders than the simple monocultural plantations commonly used then. In this study, we describe the subsequent changes in stand structure and floristic composition of these plantations in order to learn from the experience and develop improved prescriptions for reforestation systems likely to be attractive to smallholders. We investigated stands aged from 6 to 11 years old on three successive occasions over a 6 year period. We found the number of species originally present in the plots as trees >5 cm dbh decreased from an initial total of 76 species to 65 species at the end of study period. But, at the same time, some new species reached the size class threshold and were recruited into the canopy layer. There was a substantial decline in tree density from an estimated stocking of about 5000 trees per ha at the time of planting to 1380 trees per ha at the time of the first measurement; the density declined by a further 4.9% per year. Changes in composition and stand structure were indicated by a marked shift in the Importance Value Index of species. Over six years, shade-intolerant species became less important and the native shade-tolerant species (often Dipterocarps) increased in importance. Based on how the Rainforestation Farming plantations developed in these early years, we suggest that mixed-species plantations elsewhere in the humid tropics should be around 1000 trees per ha or less, that the proportion of fast growing (and hence early maturing) trees should be about 30–40% of this initial density and that any fruit tree component should only be planted on the plantation margin where more light and space are available for crowns to develop. PMID:24751720

  1. Conspecific plant-soil feedbacks of temperate tree species in the southern Appalachians, USA.

    PubMed

    Reinhart, Kurt O; Johnson, Daniel; Clay, Keith

    2012-01-01

    Many tree species have seedling recruitment patterns suggesting that they are affected by non-competitive distance-dependent sources of mortality. We conducted an experiment, with landscape-level replication, to identify cases of negative distance-dependent effects and whether variation in these effects corresponded with tree recruitment patterns in the southern Appalachian Mountains region. Specifically, soil was collected from 14 sites and used as inocula in a 62 day growth chamber experiment determining whether tree seedling growth was less when interacting with soil from conspecific (like) than heterospecific (other) tree species. Tests were performed on six tree species. Three of the tree species had been previously described as having greater recruitment around conspecifics (i.e. facilitator species group) compared to the other half (i.e. inhibitor species group). We were then able to determine whether variation in negative distance-dependent effects corresponded with recruitment patterns in the field. Across the six species, none were negatively affected by soil inocula from conspecific relative to heterospecific sources. Most species (four of six) were unaffected by soil source. Two species (Prunus serotina and Tsuga canadensis) had enhanced growth in pots inoculated with soil from conspecific trees vs. heterospecifics. Species varied in their susceptibility to soil pathogens, but trends across all species revealed that species classified as inhibitors were not more negatively affected by conspecific than heterospecific soil inocula or more susceptible to pathogenic effects than facilitators. Although plant-soil biota interactions may be important for individual species and sites, it may be difficult to scale these interactions over space or levels of ecological organization. Generalizing the importance of plant-soil feedbacks or other factors across regional scales may be especially problematic for hyperdiverse temperate forests where interactions may be spatially variable. PMID:22808231

  2. CpDNA-based species identification and phylogeography: application to African tropical tree species.

    PubMed

    Duminil, J; Heuertz, M; Doucet, J-L; Bourland, N; Cruaud, C; Gavory, F; Doumenge, C; Navascués, M; Hardy, O J

    2010-12-01

    Despite the importance of the African tropical rainforests as a hotspot of biodiversity, their history and the processes that have structured their biodiversity are understood poorly. With respect to past demographic processes, new insights can be gained through characterizing the distribution of genetic diversity. However, few studies of this type have been conducted in Central Africa, where the identification of species in the field can be difficult. We examine here the distribution of chloroplast DNA (cpDNA) diversity in Lower Guinea in two tree species that are difficult to distinguish, Erythrophleum ivorense and Erythrophleum suaveolens (Fabaceae). By using a blind-sampling approach and comparing molecular and morphological markers, we first identified retrospectively all sampled individuals and determined the limits of the distribution of each species. We then performed a phylogeographic study using the same genetic data set. The two species displayed essentially parapatric distributions that were correlated well with the rainfall gradient, which indicated different ecological requirements. In addition, a phylogeographic structure was found for E. suaveolens and, for both species, substantially higher levels of diversity and allelic endemism were observed in the south (Gabon) than in the north (Cameroon) of the Lower Guinea region. This finding indicated different histories of population demographics for the two species, which might reflect different responses to Quaternary climate changes. We suggest that a recent period of forest perturbation, which might have been caused by humans, favoured the spread of these two species and that their poor recruitment at present results from natural succession in their forest formations. PMID:21091558

  3. Tree diversity and species identity effects on soil fungi, protists and animals are context dependent.

    PubMed

    Tedersoo, Leho; Bahram, Mohammad; Cajthaml, Tomáš; Põlme, Sergei; Hiiesalu, Indrek; Anslan, Sten; Harend, Helery; Buegger, Franz; Pritsch, Karin; Koricheva, Julia; Abarenkov, Kessy

    2016-02-01

    Plant species richness and the presence of certain influential species (sampling effect) drive the stability and functionality of ecosystems as well as primary production and biomass of consumers. However, little is known about these floristic effects on richness and community composition of soil biota in forest habitats owing to methodological constraints. We developed a DNA metabarcoding approach to identify the major eukaryote groups directly from soil with roughly species-level resolution. Using this method, we examined the effects of tree diversity and individual tree species on soil microbial biomass and taxonomic richness of soil biota in two experimental study systems in Finland and Estonia and accounted for edaphic variables and spatial autocorrelation. Our analyses revealed that the effects of tree diversity and individual species on soil biota are largely context dependent. Multiple regression and structural equation modelling suggested that biomass, soil pH, nutrients and tree species directly affect richness of different taxonomic groups. The community composition of most soil organisms was strongly correlated due to similar response to environmental predictors rather than causal relationships. On a local scale, soil resources and tree species have stronger effect on diversity of soil biota than tree species richness per se. PMID:26172210

  4. Leapfrogging of tree species provenances? Interaction of microclimate and genetics on upward shifts in tree species' range limits

    NASA Astrophysics Data System (ADS)

    Reinhardt, K.; Castanha, C.; Germino, M. J.; Kueppers, L. M.

    2011-12-01

    The elevation limit of tree growth (alpine treeline) is considered to be constrained by environmental (i.e., thermal) and genetic (i.e., inability to adapt to climatic conditions) limitations to growth. Warming conditions due to climate change are predicted to cause upward shifts in the elevation of alpine treelines, through relief of cold-induced physiological limitations on seedling recruitment beyond current treeline boundaries. To determine how genetics and climate may interact to affect seedling establishment, we transplanted recently germinated seedlings from high- and low-elevation provenances (HI and LO, respectively) of Pinus flexilis in common gardens arrayed along an elevation and canopy gradient from subalpine forest into the alpine zone at Niwot Ridge, CO. We compared differences in microclimate and seedling ecophysiology among sites and between provenances. During the first summer of growth, frequently cloudy skies resulted in similar solar radiation incidence and air and soil temperatures among sites, despite nearly a 500 m-span in elevation across all sites. Preliminary findings suggest that survival of seedlings was similar between the lowest and highest elevations, with greater survival of LO (60%) compared to HI (40%) seedlings at each of these sites. Photosynthesis, carbon balance (photosynthesis/respiration), and conductance increased more than 2X with elevation for both provenances, and were 35-77% greater in LO seedlings compared to HI seedlings. There were no differences in dark-adapted chlorophyll fluorescence (Fv/Fm) among sites or between provenances. However, in a common-garden study at low elevation, we observed no differences in carbon or water relations between two naturally-germinated mitochondrial haplotypes of P. flexilis (of narrow and wide-ranging distributions). We did observe water-related thresholds on seedling carbon balance and survival that occurred when soil volumetric water content dropped below 10% and seedling water potentials went below -4 MPa. Our preliminary results suggest that for high-elevation conifer seedlings such as P. flexilis: 1) individuals can survive and even have enhanced physiological performance at and above treeline when/where clouds or other conditions minimize factors like cold-induced photoinhibition; 2) in the field, provenances selected for aboveground growth may out-perform those selected for stress-resistance in the absence of harsh climatic conditions, even well above the species' range limits in the alpine; 3) water, and not thermal, limitations might explain treeline altitude in this particular mountain range; 4) forest genetics may be important to understanding and managing species' range adjustments due to climate change.

  5. Assessing the potential of native tree species for carbon sequestration forestry in Northeast China.

    PubMed

    Thomas, S C; Malczewski, G; Saprunoff, M

    2007-11-01

    Although the native forests of China are exceptionally diverse, only a small number of tree species have been widely utilized in forest plantations and reforestation efforts. We used dendrochronological sampling methods to assess the potential growth and carbon sequestration of native tree species in Jilin Province, Northeast China. Trees were sampled in and near the Changbaishan Biosphere Reserve, with samples encompassing old-growth, disturbed forest, and plantations. To approximate conditions for planted trees, sampling focused on trees with exposed crowns (dominant and co-dominant individuals). A log-linear relationship was found between diameter increment and tree diameter, with a linear decrease in increment with increasing local basal area; no significant differences in these patterns between plantations and natural stands were detected for two commonly planted species (Pinus koraiensis and Larix olgensis). A growth model that incorporates observed feedbacks with individual tree size and local basal area (in conjunction with allometric models for tree biomass), was used to project stand-level biomass increment. Predicted growth trajectories were then linked to the carbon process model InTEC to provide estimates of carbon sequestration potential. Results indicate substantial differences among species, and suggest that certain native hardwoods (in particular Fraxinus mandshurica and Phellodendron amurense), have high potential for use in carbon forestry applications. Increased use of native hardwoods in carbon forestry in China is likely to have additional benefits in terms of economic diversification and enhanced provision of "ecosystem services", including biodiversity protection. PMID:17188419

  6. SIMULATION OF OZONE EFFECTS ON EIGHT TREE SPECIES AT SHENANDOAH NATIONAL PARK

    EPA Science Inventory

    As part of an assessment of potential effects of air pollutants on the vegetation of Shenandoah National Park (SHEN), we simulated the growth of eight important tree species using TREGRO, a mechanistic model of individual tree growth. Published TREGRO parameters for black cherry...

  7. Species divergence and phylogenetic variation of ecophysiological traits in lianas and trees.

    PubMed

    Rios, Rodrigo S; Salgado-Luarte, Cristian; Gianoli, Ernesto

    2014-01-01

    The climbing habit is an evolutionary key innovation in plants because it is associated with enhanced clade diversification. We tested whether patterns of species divergence and variation of three ecophysiological traits that are fundamental for plant adaptation to light environments (maximum photosynthetic rate [A(max)], dark respiration rate [R(d)], and specific leaf area [SLA]) are consistent with this key innovation. Using data reported from four tropical forests and three temperate forests, we compared phylogenetic distance among species as well as the evolutionary rate, phylogenetic distance and phylogenetic signal of those traits in lianas and trees. Estimates of evolutionary rates showed that R(d) evolved faster in lianas, while SLA evolved faster in trees. The mean phylogenetic distance was 1.2 times greater among liana species than among tree species. Likewise, estimates of phylogenetic distance indicated that lianas were less related than by chance alone (phylogenetic evenness across 63 species), and trees were more related than expected by chance (phylogenetic clustering across 71 species). Lianas showed evenness for R(d), while trees showed phylogenetic clustering for this trait. In contrast, for SLA, lianas exhibited phylogenetic clustering and trees showed phylogenetic evenness. Lianas and trees showed patterns of ecophysiological trait variation among species that were independent of phylogenetic relatedness. We found support for the expected pattern of greater species divergence in lianas, but did not find consistent patterns regarding ecophysiological trait evolution and divergence. R(d) followed the species-level pattern, i.e., greater divergence/evolution in lianas compared to trees, while the opposite occurred for SLA and no pattern was detected for A(max). R(d) may have driven lianas' divergence across forest environments, and might contribute to diversification in climber clades. PMID:24914958

  8. New flux based dose-response relationships for ozone for European forest tree species.

    TOXLINE Toxicology Bibliographic Information

    Büker P; Feng Z; Uddling J; Briolat A; Alonso R; Braun S; Elvira S; Gerosa G; Karlsson PE; Le Thiec D; Marzuoli R; Mills G; Oksanen E; Wieser G; Wilkinson M; Emberson LD

    2015-11-01

    To derive O3 dose-response relationships (DRR) for five European forest trees species and broadleaf deciduous and needleleaf tree plant functional types (PFTs), phytotoxic O3 doses (PODy) were related to biomass reductions. PODy was calculated using a stomatal flux model with a range of cut-off thresholds (y) indicative of varying detoxification capacities. Linear regression analysis showed that DRR for PFT and individual tree species differed in their robustness. A simplified parameterisation of the flux model was tested and showed that for most non-Mediterranean tree species, this simplified model led to similarly robust DRR as compared to a species- and climate region-specific parameterisation. Experimentally induced soil water stress was not found to substantially reduce PODy, mainly due to the short duration of soil water stress periods. This study validates the stomatal O3 flux concept and represents a step forward in predicting O3 damage to forests in a spatially and temporally varying climate.

  9. Pythium species Associated with Forest Tree Nurseries of Oregon and Washington

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pythium species are one of several pathogen genera responsible for damping off of conifer seedlings in forest tree nurseries. Species identification has been traditionally based on morphology. However, DNA-based identification methods may allow more accurate identification of species associated wi...

  10. Herbs versus Trees: Influences on Teenagers' Knowledge of Plant Species

    ERIC Educational Resources Information Center

    Lückmann, Katrin; Menzel, Susanne

    2014-01-01

    The study reports on species knowledge among German adolescents (n = 507) as: (1) self-assessed evaluation of one's species knowledge; and (2) factual knowledge about popular local herbs and trees. Besides assessing species knowledge, we were interested in whether selected demographic factors, environmental attitude (as measured through the…

  11. Herbs versus Trees: Influences on Teenagers' Knowledge of Plant Species

    ERIC Educational Resources Information Center

    Lückmann, Katrin; Menzel, Susanne

    2014-01-01

    The study reports on species knowledge among German adolescents (n = 507) as: (1) self-assessed evaluation of one's species knowledge; and (2) factual knowledge about popular local herbs and trees. Besides assessing species knowledge, we were interested in whether selected demographic factors, environmental attitude (as measured through the…

  12. Multipurpose anthropometric facial anglemeter.

    PubMed

    Venkatadri, G; Farkas, L G; Kooiman, J

    1992-09-01

    We have developed a multipurpose anglemeter for measuring the face that enables us to determine accurately the size of six profile angles by both direct and indirect anthropometry in markedly reduced time. PMID:1513900

  13. Predicting spatial variations of tree species richness in tropical forests from high-resolution remote sensing.

    PubMed

    Fricker, Geoffrey A; Wolf, Jeffrey A; Saatchi, Sassan S; Gillespie, Thomas W

    2015-10-01

    There is an increasing interest in identifying theories, empirical data sets, and remote-sensing metrics that can quantify tropical forest alpha diversity at a landscape scale. Quantifying patterns of tree species richness in the field is time consuming, especially in regions with over 100 tree species/ha. We examine species richness in a 50-ha plot in Barro Colorado Island in Panama and test if biophysical measurements of canopy reflectance from high-resolution satellite imagery and detailed vertical forest structure and topography from light detection and ranging (lidar) are associated with species richness across four tree size classes (>1, 1-10, >10, and >20 cm dbh) and three spatial scales (1, 0.25, and 0.04 ha). We use the 2010 tree inventory, including 204,757 individuals belonging to 301 species of freestanding woody plants or 166 ± 1.5 species/ha (mean ± SE), to compare with remote-sensing data. All remote-sensing metrics became less correlated with species richness as spatial resolution decreased from 1.0 ha to 0.04 ha and tree size increased from 1 cm to 20 cm dbh. When all stems with dbh > 1 cm in 1-ha plots were compared to remote-sensing metrics, standard deviation in canopy reflectance explained 13% of the variance in species richness. The standard deviations of canopy height and the topographic wetness index (TWI) derived from lidar were the best metrics to explain the spatial variance in species richness (15% and 24%, respectively). Using multiple regression models, we made predictions of species richness across Barro Colorado Island (BCI) at the 1-ha spatial scale for different tree size classes. We predicted variation in tree species richness among all plants (adjusted r² = 0.35) and trees with dbh > 10 cm (adjusted r² = 0.25). However, the best model results were for understory trees and shrubs (dbh 1-10 cm) (adjusted r² = 0.52) that comprise the majority of species richness in tropical forests. Our results indicate that high-resolution remote sensing can predict a large percentage of variance in species richness and potentially provide a framework to map and predict alpha diversity among trees in diverse tropical forests. PMID:26591445

  14. Supercooling Capacity Increases from Sea Level to Tree Line in the Hawaiian Tree Species Metrosideros polymorpha.

    PubMed

    Melcher; Cordell; Jones; Scowcroft; Niemczura; Giambelluca; Goldstein

    2000-05-01

    Population-specific differences in the freezing resistance of Metrosideros polymorpha leaves were studied along an elevational gradient from sea level to tree line (located at ca. 2500 m above sea level) on the east flank of the Mauna Loa volcano in Hawaii. In addition, we also studied 8-yr-old saplings grown in a common garden from seeds collected from the same field populations. Leaves of low-elevation field plants exhibited damage at -2 degrees C, before the onset of ice formation, which occurred at -5.7 degrees C. Leaves of high-elevation plants exhibited damage at ca. -8.5 degrees C, concurrent with ice formation in the leaf tissue, which is typical of plants that avoid freezing in their natural environment by supercooling. Nuclear magnetic resonance studies revealed that water molecules of both extra- and intracellular leaf water fractions from high-elevation plants had restricted mobility, which is consistent with their low water content and their high levels of osmotically active solutes. Decreased mobility of water molecules may delay ice nucleation and/or ice growth and may therefore enhance the ability of plant tissues to supercool. Leaf traits that correlated with specific differences in supercooling capacity were in part genetically determined and in part environmentally induced. Evidence indicated that lower apoplastic water content and smaller intercellular spaces were associated with the larger supercooling capacity of the plant's foliage at tree line. The irreversible tissue-damage temperature decreased by ca. 7 degrees C from sea level to tree line in leaves of field populations. However, this decrease appears to be only large enough to allow M. polymorpha trees to avoid leaf tissue damage from freezing up to a level of ca. 2500 m elevation, which is also the current tree line location on the east flank of Mauna Loa. The limited freezing resistance of M. polymorpha leaves may be partially responsible for the occurrence of tree line at a relatively low elevation in Hawaii compared with continental tree lines, which can be up to 1500 m higher. If the elevation of tree line is influenced by the inability of M. polymorpha leaves to supercool to lower subzero temperatures, then it will be the first example that freezing damage resulting from limited supercooling capacity can be a factor in tree line formation. PMID:10817972

  15. Version 5 of Forecasts; Forecasts of Climate-Associated Shifts in Tree Species

    NASA Astrophysics Data System (ADS)

    Hargrove, W. W.; Kumar, J.; Potter, K. M.; Hoffman, F. M.

    2014-12-01

    Version 5 of the ForeCASTS tree range shift atlas (www.geobabble.org/~hnw/global/treeranges5/climate_change/atlas.html) now predicts global shifts in the suitable ranges of 335 tree species (essentially all woody species measured in Forest Inventory Analysis (FIA)) under forecasts from the Parallel Climate Model, and the Hadley Model, each under future climatic scenarios A1 and B1, each at two future dates (2050 and 2100). Version 5 includes more Global Biodiversity Information Facility (GBIF) occurrence points, uses improved heuristics for occurrence training, and recovers occurrence points that fall in water. A multivariate clustering procedure was used to quantitatively delineate 30 thousand environmentally homogeneous ecoregions across present and 8 potential future global locations at once, using global maps of 17 environmental characteristics describing temperature, precipitation, soils, topography and solar insolation. Occurrence of each tree species on FIA plots and in GBIF samples was used to identify a subset of suitable ecoregions from the full set of 30 thousand. This subset of suitable ecoregions was compared to the known current present range of the tree species. Predicted present ranges correspond well with existing ranges for all but a few of the 335 tree species. The subset of suitable ecoregions can then be tracked into the future to determine whether the suitable home range remains the same, moves, grows, shrinks, or disappears under each model/scenario combination. A quantitative niche breadth analysis allows sorting of the 17 environmental variables from the narrowest, most important, to the broadest, least restrictive environmental factors limiting each tree species. Potential tree richness maps were produced, along with a quantitative potential tree endemism map for present and future CONUS. Using a new empirical imputation method which associates sparse measurements of dependent variables with particular clustered combinations of the environmental driver variables, and then estimates values for unmeasured clusters, we interpolated FIA measurements of productivity into continuous maps showing productivity across each tree's entire present and future ranges.

  16. Anonymous nuclear markers data supporting species tree phylogeny and divergence time estimates in a cactus species complex in South America.

    PubMed

    Perez, Manolo F; Carstens, Bryan C; Rodrigues, Gustavo L; Moraes, Evandro M

    2016-03-01

    Supportive data related to the article "Anonymous nuclear markers reveal taxonomic incongruence and long-term disjunction in a cactus species complex with continental-island distribution in South America" (Perez et al., 2016) [1]. Here, we present pyrosequencing results, primer sequences, a cpDNA phylogeny, and a species tree phylogeny. PMID:26900589

  17. Anonymous nuclear markers data supporting species tree phylogeny and divergence time estimates in a cactus species complex in South America

    PubMed Central

    Perez, Manolo F.; Carstens, Bryan C.; Rodrigues, Gustavo L.; Moraes, Evandro M.

    2015-01-01

    Supportive data related to the article “Anonymous nuclear markers reveal taxonomic incongruence and long-term disjunction in a cactus species complex with continental-island distribution in South America” (Perez et al., 2016) [1]. Here, we present pyrosequencing results, primer sequences, a cpDNA phylogeny, and a species tree phylogeny. PMID:26900589

  18. Long range correlations in tree ring chronologies of the USA: Variation within and across species

    NASA Astrophysics Data System (ADS)

    Bowers, M. C.; Gao, J. B.; Tung, W. W.

    2013-02-01

    Abstract <span class="hlt">Tree</span> ring width data are among the best proxies for reconstructing past temperature and precipitation records. The discovery of fractal scaling and long-memory in meteorological and hydrological signals motivates us to investigate such properties in <span class="hlt">tree</span> ring chronologies. Detrended fluctuation analysis and adaptive fractal analysis are utilized to estimate the Hurst parameter values of 697 <span class="hlt">tree</span> ring chronologies from the continental United States. We find significant differences in the Hurst parameter values across the 10 <span class="hlt">species</span> studied in the work. The long-range scaling relations found here suggest that the behavior of <span class="hlt">tree</span> ring growth observed in a short calibration period may be similar to the general behavior of <span class="hlt">tree</span> ring growth in a much longer period, and therefore, the limited calibration period may be more useful than originally thought. The variations of the long-range correlations within and across <span class="hlt">species</span> may be further explored in future to better reconstruct paleoclimatic records.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26437239','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26437239"><span id="translatedtitle">North American <span class="hlt">tree</span> squirrels and ground squirrels with overlapping ranges host different Cryptosporidium <span class="hlt">species</span> and genotypes.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Stenger, Brianna L S; Clark, Mark E; Kvá?, Martin; Khan, Eakalak; Giddings, Catherine W; Prediger, Jitka; McEvoy, John M</p> <p>2015-12-01</p> <p>Wildlife-associated Cryptosporidium are an emerging cause of cryptosporidiosis in humans. The present study was undertaken to determine the extent to which North American <span class="hlt">tree</span> squirrels and ground squirrels host zoonotic Cryptosporidium <span class="hlt">species</span> and genotypes. Fragments of the Cryptosporidium 18S rRNA and actin genes were amplified and sequenced from fecal samples obtained from three <span class="hlt">tree</span> squirrel and three ground squirrel <span class="hlt">species</span>. In <span class="hlt">tree</span> squirrels, Cryptosporidium was identified in 40.5% (17/42) of American red squirrels (Tamiasciurus hudsonicus), 40.4% (55/136) of eastern gray squirrels (Sciurus carolinensis), and 28.6% (2/7) of fox squirrels (Sciurus niger). Human-pathogenic Cryptosporidium ubiquitum and Cryptosporidium skunk genotype were the most prevalent <span class="hlt">species</span>/genotypes in <span class="hlt">tree</span> squirrels. Because <span class="hlt">tree</span> squirrels live in close proximity to humans and are frequently infected with potentially zoonotic Cryptosporidium <span class="hlt">species</span>/genotypes, they may be a significant reservoir of infection in humans. In ground squirrels, Cryptosporidium was detected in 70.2% (33/47) of 13-lined ground squirrels (Ictidomys tridecemlineatus), 35.1% (27/77) of black-tailed prairie dogs (Cynomys ludovicianus), and the only golden-mantled ground squirrel (Callospermophilus lateralis) that was sampled. Cryptosporidium rubeyi and ground squirrel genotypes I, II, and III were identified in isolates from these ground squirrel <span class="hlt">species</span>. In contrast to the Cryptosporidium infecting <span class="hlt">tree</span> squirrels, these <span class="hlt">species</span>/genotypes appear to be specific for ground squirrels and are not associated with human disease. PMID:26437239</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/21966498','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21966498"><span id="translatedtitle">Growth strategies of tropical <span class="hlt">tree</span> <span class="hlt">species</span>: disentangling light and size effects.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rüger, Nadja; Berger, Uta; Hubbell, Stephen P; Vieilledent, Ghislain; Condit, Richard</p> <p>2011-01-01</p> <p>An understanding of the drivers of <span class="hlt">tree</span> growth at the <span class="hlt">species</span> level is required to predict likely changes of carbon stocks and biodiversity when environmental conditions change. Especially in <span class="hlt">species</span>-rich tropical forests, it is largely unknown how <span class="hlt">species</span> differ in their response of growth to resource availability and individual size. We use a hierarchical bayesian approach to quantify the impact of light availability and <span class="hlt">tree</span> diameter on growth of 274 woody <span class="hlt">species</span> in a 50-ha long-term forest census plot in Barro Colorado Island, Panama. Light reaching each individual <span class="hlt">tree</span> was estimated from yearly vertical censuses of canopy density. The hierarchical bayesian approach allowed accounting for different sources of error, such as negative growth observations, and including rare <span class="hlt">species</span> correctly weighted by their abundance. All <span class="hlt">species</span> grew faster at higher light. Exponents of a power function relating growth to light were mostly between 0 and 1. This indicates that nearly all <span class="hlt">species</span> exhibit a decelerating increase of growth with light. In contrast, estimated growth rates at standardized conditions (5 cm dbh, 5% light) varied over a 9-fold range and reflect strong growth-strategy differentiation between the <span class="hlt">species</span>. As a consequence, growth rankings of the <span class="hlt">species</span> at low (2%) and high light (20%) were highly correlated. Rare <span class="hlt">species</span> tended to grow faster and showed a greater sensitivity to light than abundant <span class="hlt">species</span>. Overall, <span class="hlt">tree</span> size was less important for growth than light and about half the <span class="hlt">species</span> were predicted to grow faster in diameter when bigger or smaller, respectively. Together light availability and <span class="hlt">tree</span> diameter only explained on average 12% of the variation in growth rates. Thus, other factors such as soil characteristics, herbivory, or pathogens may contribute considerably to shaping <span class="hlt">tree</span> growth in the tropics. PMID:21966498</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_6 --> <div id="page_7" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="121"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3178650','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3178650"><span id="translatedtitle">Growth Strategies of Tropical <span class="hlt">Tree</span> <span class="hlt">Species</span>: Disentangling Light and Size Effects</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Rüger, Nadja; Berger, Uta; Hubbell, Stephen P.; Vieilledent, Ghislain; Condit, Richard</p> <p>2011-01-01</p> <p>An understanding of the drivers of <span class="hlt">tree</span> growth at the <span class="hlt">species</span> level is required to predict likely changes of carbon stocks and biodiversity when environmental conditions change. Especially in <span class="hlt">species</span>-rich tropical forests, it is largely unknown how <span class="hlt">species</span> differ in their response of growth to resource availability and individual size. We use a hierarchical Bayesian approach to quantify the impact of light availability and <span class="hlt">tree</span> diameter on growth of 274 woody <span class="hlt">species</span> in a 50-ha long-term forest census plot in Barro Colorado Island, Panama. Light reaching each individual <span class="hlt">tree</span> was estimated from yearly vertical censuses of canopy density. The hierarchical Bayesian approach allowed accounting for different sources of error, such as negative growth observations, and including rare <span class="hlt">species</span> correctly weighted by their abundance. All <span class="hlt">species</span> grew faster at higher light. Exponents of a power function relating growth to light were mostly between 0 and 1. This indicates that nearly all <span class="hlt">species</span> exhibit a decelerating increase of growth with light. In contrast, estimated growth rates at standardized conditions (5 cm dbh, 5% light) varied over a 9-fold range and reflect strong growth-strategy differentiation between the <span class="hlt">species</span>. As a consequence, growth rankings of the <span class="hlt">species</span> at low (2%) and high light (20%) were highly correlated. Rare <span class="hlt">species</span> tended to grow faster and showed a greater sensitivity to light than abundant <span class="hlt">species</span>. Overall, <span class="hlt">tree</span> size was less important for growth than light and about half the <span class="hlt">species</span> were predicted to grow faster in diameter when bigger or smaller, respectively. Together light availability and <span class="hlt">tree</span> diameter only explained on average 12% of the variation in growth rates. Thus, other factors such as soil characteristics, herbivory, or pathogens may contribute considerably to shaping <span class="hlt">tree</span> growth in the tropics. PMID:21966498</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007JPRS...61..325B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007JPRS...61..325B"><span id="translatedtitle">Classifying individual <span class="hlt">tree</span> <span class="hlt">species</span> under leaf-off and leaf-on conditions using airborne lidar</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brandtberg, Tomas</p> <p></p> <p>In this paper, a methodology for individual <span class="hlt">tree</span>-based <span class="hlt">species</span> classification using high sampling density and small footprint lidar data is clarified, corrected and improved. For this purpose, a well-defined directed graph (digraph) is introduced and it plays a fundamental role in the approach. It is argued that there exists one and only one such unique digraph that describes all four pure events and resulting disjoint sets of laser points associated with a single <span class="hlt">tree</span> in data from a two-return lidar system. However, the digraph is extendable so that it fits an n-return lidar system ( n > 2) with higher logical resolution. Furthermore, a mathematical notation for different types of groupings of the laser points is defined, and a new terminology for various types of individual <span class="hlt">tree</span>-based concepts defined by the digraph is proposed. A novel calibration technique for estimating individual <span class="hlt">tree</span> heights is evaluated. The approach replaces the unreliable maximum single laser point height of each <span class="hlt">tree</span> with a more reliable prediction based on shape characteristics of a marginal height distribution of the whole first-return point cloud of each <span class="hlt">tree</span>. The result shows a reduction of the RMSE of the <span class="hlt">tree</span> heights of about 20% (stddev = 1.1 m reduced to stddev = 0.92 m). The method improves the <span class="hlt">species</span> classification accuracy markedly, but it could also be used for reducing the sampling density at the time of data acquisition. Using the calibrated <span class="hlt">tree</span> heights, a scale-invariant rescaled space for the universal set of points for each <span class="hlt">tree</span> is defined, in which all individual <span class="hlt">tree</span>-based geometric measurements are conducted. With the corrected and improved classification methodology the total accuracy raises from 60% to 64% for classifying three leaf-off individual <span class="hlt">tree</span> deciduous <span class="hlt">species</span> ( N = 200 each) in West Virginia, USA: oaks ( Quercus spp.), red maple ( Acer rubrum), and yellow poplar ( Liriodendron tuliperifera).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2694365','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2694365"><span id="translatedtitle"><span class="hlt">Tree</span> <span class="hlt">Species</span> Traits Influence Soil Physical, Chemical, and Biological Properties in High Elevation Forests</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ayres, Edward; Steltzer, Heidi; Berg, Sarah; Wallenstein, Matthew D.; Simmons, Breana L.; Wall, Diana H.</p> <p>2009-01-01</p> <p>Background Previous studies have shown that plants often have <span class="hlt">species</span>-specific effects on soil properties. In high elevation forests in the Southern Rocky Mountains, North America, areas that are dominated by a single <span class="hlt">tree</span> <span class="hlt">species</span> are often adjacent to areas dominated by another <span class="hlt">tree</span> <span class="hlt">species</span>. Here, we assessed soil properties beneath adjacent stands of trembling aspen, lodgepole pine, and Engelmann spruce, which are dominant <span class="hlt">tree</span> <span class="hlt">species</span> in this region and are distributed widely in North America. We hypothesized that soil properties would differ among stands dominated by different <span class="hlt">tree</span> <span class="hlt">species</span> and expected that aspen stands would have higher soil temperatures due to their open structure, which, combined with higher quality litter, would result in increased soil respiration rates, nitrogen availability, and microbial biomass, and differences in soil faunal community composition. Methodology/Principal Findings We assessed soil physical, chemical, and biological properties at four sites where stands of aspen, pine, and spruce occurred in close proximity to one-another in the San Juan Mountains, Colorado. Leaf litter quality differed among the <span class="hlt">tree</span> <span class="hlt">species</span>, with the highest nitrogen (N) concentration and lowest lignin∶N in aspen litter. Nitrogen concentration was similar in pine and spruce litter, but lignin∶N was highest in pine litter. Soil temperature and moisture were highest in aspen stands, which, in combination with higher litter quality, probably contributed to faster soil respiration rates from stands of aspen. Soil carbon and N content, ammonium concentration, and microbial biomass did not differ among <span class="hlt">tree</span> <span class="hlt">species</span>, but nitrate concentration was highest in aspen soil and lowest in spruce soil. In addition, soil fungal, bacterial, and nematode community composition and rotifer, collembolan, and mesostigmatid mite abundance differed among the <span class="hlt">tree</span> <span class="hlt">species</span>, while the total abundance of nematodes, tardigrades, oribatid mites, and prostigmatid mites did not. Conclusions/Significance Although some soil characteristics were unaffected by <span class="hlt">tree</span> <span class="hlt">species</span> identity, our results clearly demonstrate that these dominant <span class="hlt">tree</span> <span class="hlt">species</span> are associated with soils that differ in several physical, chemical, and biotic properties. Ongoing environmental changes in this region, e.g. changes in fire regime, frequency of insect outbreaks, changes in precipitation patterns and snowpack, and land-use change, may alter the relative abundance of these <span class="hlt">tree</span> <span class="hlt">species</span> over coming decades, which in turn will likely alter the soils. PMID:19536334</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/20886243','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/20886243"><span id="translatedtitle">Host preferences and differential contributions of deciduous <span class="hlt">tree</span> <span class="hlt">species</span> shape mycorrhizal <span class="hlt">species</span> richness in a mixed Central European forest.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lang, Christa; Seven, Jasmin; Polle, Andrea</p> <p>2011-05-01</p> <p>Mycorrhizal <span class="hlt">species</span> richness and host ranges were investigated in mixed deciduous stands composed of Fagus sylvatica, Tilia spp., Carpinus betulus, Acer spp., and Fraxinus excelsior. Acer and Fraxinus were colonized by arbuscular mycorrhizas and contributed 5% to total stand mycorrhizal fungal <span class="hlt">species</span> richness. Tilia hosted similar and Carpinus half the number of ectomycorrhizal (EM) fungal taxa compared with Fagus (75 putative taxa). The relative abundance of the host <span class="hlt">tree</span> the EM fungal richness decreased in the order Fagus?>?Tilia?>?Carpinus. After correction for similar sampling intensities, EM fungal <span class="hlt">species</span> richness of Carpinus was still about 30-40% lower than that of Fagus and Tilia. About 10% of the mycorrhizal <span class="hlt">species</span> were shared among the EM forming <span class="hlt">trees</span>; 29% were associated with two host <span class="hlt">tree</span> <span class="hlt">species</span> and 61% with only one of the hosts. The latter group consisted mainly of rare EM fungal <span class="hlt">species</span> colonizing about 20% of the root tips and included known specialists but also putative non-host associations such as conifer or shrub mycorrhizas. Our data indicate that EM fungal <span class="hlt">species</span> richness was associated with <span class="hlt">tree</span> identity and suggest that Fagus secures EM fungal diversity in an ecosystem since it shared more common EM fungi with Tilia and Carpinus than the latter two among each other. PMID:20886243</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=64306&keyword=Taxonomy&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=55621171&CFTOKEN=96919780','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=64306&keyword=Taxonomy&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=55621171&CFTOKEN=96919780"><span id="translatedtitle">ISOPRENE EMISSION CAPACITY FOR U.S. <span class="hlt">TREE</span> <span class="hlt">SPECIES</span></span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Isoprene emission capacity measurements are presented from 18 North American oak <I>(Quercus)</I> <span class="hlt">species</span> and <span class="hlt">species</span> from six other genera previously found to emit significant quantities of isoprene. Sampling was conducted at physiographically diverse locations in North Carolina...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26353356','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26353356"><span id="translatedtitle">Hierarchical Learning of <span class="hlt">Tree</span> Classifiers for Large-Scale Plant <span class="hlt">Species</span> Identification.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fan, Jianping; Zhou, Ning; Peng, Jinye; Gao, Ling</p> <p>2015-11-01</p> <p>In this paper, a hierarchical multi-task structural learning algorithm is developed to support large-scale plant <span class="hlt">species</span> identification, where a visual <span class="hlt">tree</span> is constructed for organizing large numbers of plant <span class="hlt">species</span> in a coarse-to-fine fashion and determining the inter-related learning tasks automatically. For a given parent node on the visual <span class="hlt">tree</span>, it contains a set of sibling coarse-grained categories of plant <span class="hlt">species</span> or sibling fine-grained plant <span class="hlt">species</span>, and a multi-task structural learning algorithm is developed to train their inter-related classifiers jointly for enhancing their discrimination power. The inter-level relationship constraint, e.g., a plant image must first be assigned to a parent node (high-level non-leaf node) correctly if it can further be assigned to the most relevant child node (low-level non-leaf node or leaf node) on the visual <span class="hlt">tree</span>, is formally defined and leveraged to learn more discriminative <span class="hlt">tree</span> classifiers over the visual <span class="hlt">tree</span>. Our experimental results have demonstrated the effectiveness of our hierarchical multi-task structural learning algorithm on training more discriminative <span class="hlt">tree</span> classifiers for large-scale plant <span class="hlt">species</span> identification. PMID:26353356</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/1015692','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/1015692"><span id="translatedtitle">Relationships among environmental variables and distribution of <span class="hlt">tree</span> <span class="hlt">species</span> at high elevation in the Olympic Mountains</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Woodward, Andrea</p> <p>1998-01-01</p> <p>Relationships among environmental variables and occurrence of <span class="hlt">tree</span> <span class="hlt">species</span> were investigated at Hurricane Ridge in Olympic National Park, Washington, USA. A transect consisting of three plots was established down one north-and one south-facing slope in stands representing the typical elevational sequence of <span class="hlt">tree</span> <span class="hlt">species</span>. <span class="hlt">Tree</span> <span class="hlt">species</span> included subalpine fir (Abies lasiocarpa), Douglas-fir (Pseudotsuga menziesii), mountain hemlock (Tsuga mertensiana), and Pacific silver fir (Abies amabilis). Air and soil temperature, precipitation, and soil moisture were measured during three growing seasons. Snowmelt patterns, soil carbon and moisture release curves were also determined. The plots represented a wide range in soil water potential, a major determinant of <span class="hlt">tree</span> <span class="hlt">species</span> distribution (range of minimum values = -1.1 to -8.0 MPa for Pacific silver fir and Douglas-fir plots, respectively). Precipitation intercepted at plots depended on topographic location, storm direction and storm type. Differences in soil moisture among plots was related to soil properties, while annual differences at each plot were most often related to early season precipitation. Changes in climate due to a doubling of atmospheric CO2 will likely shift <span class="hlt">tree</span> <span class="hlt">species</span> distributions within, but not among aspects. Change will be buffered by innate tolerance of adult <span class="hlt">trees</span> and the inertia of soil properties.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25761711','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25761711"><span id="translatedtitle">Glacial refugia and modern genetic diversity of 22 western North American <span class="hlt">tree</span> <span class="hlt">species</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Roberts, David R; Hamann, Andreas</p> <p>2015-04-01</p> <p>North American <span class="hlt">tree</span> <span class="hlt">species</span>, subspecies and genetic varieties have primarily evolved in a landscape of extensive continental ice and restricted temperate climate environments. Here, we reconstruct the refugial history of western North American <span class="hlt">trees</span> since the last glacial maximum using <span class="hlt">species</span> distribution models, validated against 3571 palaeoecological records. We investigate how modern subspecies structure and genetic diversity corresponds to modelled glacial refugia, based on a meta-analysis of allelic richness and expected heterozygosity for 473 populations of 22 <span class="hlt">tree</span> <span class="hlt">species</span>. We find that <span class="hlt">species</span> with strong genetic differentiation into subspecies had widespread and large glacial refugia, whereas <span class="hlt">species</span> with restricted refugia show no differentiation among populations and little genetic diversity, despite being common over a wide range of environments today. In addition, a strong relationship between allelic richness and the size of modelled glacial refugia (r(2) = 0.55) suggest that population bottlenecks during glacial periods had a pronounced effect on the presence of rare alleles. PMID:25761711</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.8279L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.8279L"><span id="translatedtitle">Temporal and Spatial Dynamics of <span class="hlt">Tree</span> <span class="hlt">Species</span> Composition in Temperate Mountains of South Korea</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lee, Boknam; Park, Juhan; Cho, Sungsik; Ryu, Daun; Zaw Wynn, Khine; Park, Minji; Cho, Sunhee; Yoon, Jongguk; Park, Jongyoung; Kim, Hyun Seok</p> <p>2015-04-01</p> <p>Long term studies on vegetation dynamics are important to identify changes of ecosystem-level responses to climate change. To learn how <span class="hlt">tree</span> <span class="hlt">species</span> composition and stand structure change across temperate mountains, the temporal and spatial variations in <span class="hlt">tree</span> <span class="hlt">species</span> diversity and structure were investigated using the <span class="hlt">species</span> composition and DBH size collected over the fourteen-year period across 134 sites in Jiri and Baekoon Mountains, South Korea. The overall temporal changes over fourteen years showed significant increase in stand density, <span class="hlt">species</span> diversity and evenness according to the indices of Shannon-Weiner diversity, Bray-Curtis dissimilarity, and Pielou's evenness, contributing to the increase of basal area and biomass growth. The change of <span class="hlt">tree</span> <span class="hlt">species</span> composition could be categorized into five <span class="hlt">species</span> communities, representing gradual increase or decrease, establishment, extinction, fluctuation of <span class="hlt">species</span> population. However, in general, the change in <span class="hlt">species</span> composition appeared to have consistent and directional patterns of increase in the annual rate of change in the mean <span class="hlt">species</span> traits including <span class="hlt">species</span> richness, pole growth rate, adult growth rate, and adult stature with five common dominant <span class="hlt">species</span> (Quercus mongolica, Quercus variabilis, Quercus serrata, Carpinus laxiflora, and Styrax japonicus). The spatial patterns of <span class="hlt">species</span> composition appeared to have a higher stand density and <span class="hlt">species</span> diversity along with the low latitude and high slope ecosystem. The climate change was another main driver to vary the distribution of <span class="hlt">species</span> abundance. Overall, both temporal and spatial changes of composition in <span class="hlt">tree</span> <span class="hlt">species</span> community was clear and further analysis to clarify the reasons for such fast and <span class="hlt">species</span>-specific changes is underway especially to separate the effect of successional change and climate change. Keywords <span class="hlt">species</span> composition; climate change; temporal and spatial variation ; forest structure; temperate forest</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25712048','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25712048"><span id="translatedtitle">Regional-scale directional changes in abundance of <span class="hlt">tree</span> <span class="hlt">species</span> along a temperature gradient in Japan.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Suzuki, Satoshi N; Ishihara, Masae I; Hidaka, Amane</p> <p>2015-09-01</p> <p>Climate changes are assumed to shift the ranges of <span class="hlt">tree</span> <span class="hlt">species</span> and forest biomes. Such range shifts result from changes in abundances of <span class="hlt">tree</span> <span class="hlt">species</span> or functional types. Owing to global warming, the abundance of a <span class="hlt">tree</span> <span class="hlt">species</span> or functional type is expected to increase near the colder edge of its range and decrease near the warmer edge. This study examined directional changes in abundance and demographic parameters of forest <span class="hlt">trees</span> along a temperature gradient, as well as a successional gradient, in Japan. Changes in the relative abundance of each of four functional types (evergreen broad-leaved, deciduous broad-leaved, evergreen temperate conifer, and evergreen boreal conifer) and the demography of each <span class="hlt">species</span> (recruitment rate, mortality, and population growth rate) were analyzed in 39 permanent forest plots across the Japanese archipelago. Directional changes in the relative abundance of functional types were detected along the temperature gradient. Relative abundance of evergreen broad-leaved <span class="hlt">trees</span> increased near their colder range boundaries, especially in secondary forests, coinciding with the decrease in deciduous broad-leaved <span class="hlt">trees</span>. Similarly, relative abundance of deciduous broad-leaved <span class="hlt">trees</span> increased near their colder range boundaries, coinciding with the decrease in boreal conifers. These functional-type-level changes were mainly due to higher recruitment rates and partly to the lower mortality of individual <span class="hlt">species</span> at colder sites. This is the first report to show that <span class="hlt">tree</span> <span class="hlt">species</span> abundances in temperate forests are changing directionally along a temperature gradient, which might be due to current or past climate changes as well as recovery from past disturbances. PMID:25712048</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1712601J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1712601J"><span id="translatedtitle">Does deciduous <span class="hlt">tree</span> <span class="hlt">species</span> identity affect carbon storage in temperate soils?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jungkunst, Hermann; Schleuß, Per; Heitkamp, Felix</p> <p>2015-04-01</p> <p>Forest soils contribute roughly 70 % to the global terrestrial soil organic carbon (SOC) pool and thus play a vital role in the global carbon cycle. It is less clear, however, whether temperate <span class="hlt">tree</span> <span class="hlt">species</span> identity affects SOC storage beyond the coarse differentiation between coniferous and deciduous <span class="hlt">trees</span>. The most important driver for soil SOC storage definitely is the fine mineral fraction (clay and fine silt) because of its high sorption ability. It is difficult to disentangle any additional biotic effects since clay and silt vary considerably in nature. For experimental approaches, the process of soil carbon accumulation is too slow and, therefore, sound results cannot be expected for decades. Here we will present our success to distinguish between the effects of fine particle content (abiotic) and <span class="hlt">tree</span> <span class="hlt">species</span> composition (biotic) on the SOC pool in an old-growth broad-leaved forest plots along a <span class="hlt">tree</span> diversity gradient , i.e., 1- (beech), 3- (plus ash and lime <span class="hlt">tree</span>)- and 5-(plus maple and hornbeam) <span class="hlt">species</span>. The particle size fractions were separated first and then the carbon concentrations of each fraction was measured. Hence, the carbon content per unit clay was not calculated, as usually done, but directly measured. As expected, the variation in SOC content was mainly explained by the variations in clay content but not entirely. We found that the carbon concentration per unit clay and fine silt in the subsoil was by 30-35% higher in mixed than in monospecific stands indicating a significant <span class="hlt">species</span> identity or <span class="hlt">species</span> diversity effect on C stabilization. In contrast to the subsoil, no <span class="hlt">tree</span> <span class="hlt">species</span> effects was identified for the topsoil. Indications are given that the mineral phase was already carbon saturated and thus left no more room for a possible biotic effect. Underlying processes must remain speculative, but we will additionally present our latest microcosm results, including isotopic signatures, to underpin the proposed deciduous <span class="hlt">tree</span> <span class="hlt">species</span> identity effect on initial soil carbon accumulation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..1212532W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..1212532W"><span id="translatedtitle">How <span class="hlt">tree</span> <span class="hlt">species</span>-specific drought responses influence the carbon-water interaction in temperate forests</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wolf, Annett; Leuzinger, Sebastian; Bugmann, Harald</p> <p>2010-05-01</p> <p>Climate-change-induced differences in soil moisture conditions will influence the carbon uptake of <span class="hlt">tree</span> <span class="hlt">species</span> and hence the carbon budget of ecosystems. Experimental data showed that in a mature deciduous forest <span class="hlt">tree</span> transpiration during a prolonged drought was reduced in a <span class="hlt">species</span>-specific manner (Leuzinger et al. 2005). We implemented such a differential drought responses using the ecosystem model LPJ-GUESS. We simulated forest ecosystems in central Europe, using mixed forests and single <span class="hlt">species</span> stands. The model showed that one result of the <span class="hlt">species</span> specific drought response are differences in <span class="hlt">tree</span> <span class="hlt">species</span> diversity in the long run. At the intra-annual scale, we showed that a reduction in ecosystem evapotranspiration at an early stage during the drought period resulted in lower water stress later on in the drought. A consequence was that drought sensitive <span class="hlt">tree</span> <span class="hlt">species</span> could maintain a positive carbon balance during longer drought periods. As drought periods are likely to become more frequent and/or longer in many parts of the world, projections of ecosystem responses will be sensitive to the processes investigated here, and therefore ecosystem models should be upgraded to take them into account. Leuzinger et al. (2005) <span class="hlt">Tree</span> physiology 25: 641-650.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3799400','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3799400"><span id="translatedtitle">Flowering and Fruiting Phenology of <span class="hlt">Tree</span> <span class="hlt">Species</span> in Mount Papandayan Nature Reserve, West Java, Indonesia</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Sulistyawati, Endah; Mashita, Nusa; Setiawan, Nuri Nurlaila; Choesin, Devi N; Suryana, Pipin</p> <p>2012-01-01</p> <p>Mount Papandayan Nature Reserve (MPNR) is an area highly rich in biodiversity, however deforestation has left a vast area urgently in need of reforestation. When reforestation is designed to restore some level of biodiversity, it is imperative that native <span class="hlt">tree</span> <span class="hlt">species</span> are used for planting. This research aimed to provide information on the flowering and fruiting phenology of native <span class="hlt">trees</span>. Such information can be useful to plan seed collection and mass seedling production in the nursery. The observations were conducted each month during August 2009–July 2010 by recording flowering and fruiting <span class="hlt">trees</span> along two survey track passing through the middle of the mixed forest of MPNR. Data gathered were used to construct a simple phenology calendar. During the study, there were 155 <span class="hlt">trees</span> of 43 <span class="hlt">species</span> found flowering or fruiting along the survey track. The peak time of flowering and fruiting was in July (13 <span class="hlt">species</span> flowering and 19 <span class="hlt">species</span> fruiting), while the lowest level was in October (1 <span class="hlt">species</span> flowering and 3 <span class="hlt">species</span> fruiting). According to the phenology calendar constructed, March to July were considered to be the appropriate time to collect seeds of native <span class="hlt">trees</span> in Mount Papandayan. PMID:24575236</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/861330','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/861330"><span id="translatedtitle">Ambrosia Beetle (Coleoptera: Scolytidae) <span class="hlt">Species</span>, Flight, and Attack on Living Eastern Cottonwood <span class="hlt">Trees</span>.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Coyle, D R; D.C. Booth: M.S. Wallace</p> <p>2005-12-01</p> <p>ABSTRACT In spring 2002, ambrosia beetles (Coleoptera: Scolytidae) infested an intensively managed 22-ha <span class="hlt">tree</span> plantation on the upper coastal plain of South Carolina. Nearly 3,500 scolytids representing 28 <span class="hlt">species</span> were captured in ethanol-baited traps from 18 June 2002 to 18 April 2004. More than 88% of total captures were exotic <span class="hlt">species</span>. Five <span class="hlt">species</span> [Dryoxylon onoharaensum (Murayama), Euwallacea validus (Eichhoff), Pseudopityophthorus minutissimus (Zimmermann), Xyleborus atratus Eichhoff, and Xyleborus impressus Eichhoff]) were collected in South Carolina for the first time. Of four <span class="hlt">tree</span> <span class="hlt">species</span> in the plantation, eastern cottonwood, Populus deltoides Bartram, was the only one attacked, with nearly 40% of the <span class="hlt">trees</span> sustaining ambrosia beetle damage. Clone ST66 sustained more damage than clone S7C15. ST66 <span class="hlt">trees</span> receiving fertilization were attacked more frequently than <span class="hlt">trees</span> receiving irrigation, irrigation_fertilization, or controls, although the number of S7C15 <span class="hlt">trees</span> attacked did not differ among treatments. The study location is near major shipping ports; our results demonstrate the necessity for intensive monitoring programs to determine the arrival, spread, ecology, and impact of exotic scolytids.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.B13B0476R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.B13B0476R"><span id="translatedtitle">Wind Disturbance Produced Changes in <span class="hlt">Tree</span> <span class="hlt">Species</span> Assemblage in the Peruvian Amazon</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rifai, S. W.; Chambers, J. Q.; Negron Juarez, R. I.; Ramirez, F.; Tello, R.; Alegria Muñoz, W.</p> <p>2010-12-01</p> <p>Wind disturbance has been a frequently overlooked abiotic cause of mass <span class="hlt">tree</span> mortality in the Amazon basin. In the Peruvian Amazon these wind disturbances are produced by meteorological events such as convective systems. Downbursts for example produce short term descendent wind speeds that can be in excess of 30 m s-1. These are capable of producing <span class="hlt">tree</span> blowdowns which have been reported to be as large as 33 km2 in the Amazon basin. We used the chronosequence of Landsat Satellite imagery to find and locate where these blowdowns have occurred in the Loreto region of the Peruvian Amazon. Spectral Mixture Analysis was used to estimate the proportion landcover of green vegetation, non-photosynthetic vegetation (NPV), soil and shade in each pixel. The change in NPV was calculated by subtracting the NPV signal in the Landsat image prior to the blowdown occurrence, from the image following the disturbance. Our prior research has established a linear relationship between <span class="hlt">tree</span> mortality and change in NPV. It is hypothesized that these mass <span class="hlt">tree</span> mortality events result in changes in the <span class="hlt">tree</span> <span class="hlt">species</span> assemblage of affected forests. Here we present preliminary <span class="hlt">tree</span> <span class="hlt">species</span> assemblage data from two sites in the Peruvian Amazon near Iquitos, Peru. The site (ALP) at the Allpahuayo Mishana reserve (3.945 S, 73.455 W) is 30 km south of Iquitos, Peru, and hosts the remnants of a 50 ha blowdown that occurred in either 1992 or 1993. Another site (NAPO) on the Napo river about 60 km north of Iquitos, is the location of an approximately 300 ha blowdown that occurred in 1998. At each site, a 3000 m x 10 m transect encompassing non disturbed and disturbed areas was installed, and <span class="hlt">trees</span> greater than 10 cm diameter at breast height were measured for diameter, height and were identified to the <span class="hlt">species</span>. Stem density of <span class="hlt">trees</span> with diameter at breast height > 10 cm, and <span class="hlt">tree</span> height appear to be similar both inside and outside the blowdown affected areas of the forests at both sites. At the ALP and NAPO sites the most dramatic change in the <span class="hlt">tree</span> <span class="hlt">species</span> assemblage has been a three and an eleven fold increase in the pioneer <span class="hlt">tree</span> family, Cecropiaceae, respectively. This preliminary data suggests that wind disturbance is capable of producing large shifts in the <span class="hlt">tree</span> <span class="hlt">species</span> assemblage of affected Amazon forests.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20010004212','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20010004212"><span id="translatedtitle">BOREAS TE-4 Branch Bag Data From Boreal <span class="hlt">Tree</span> <span class="hlt">Species</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hall, Forrest G. (Editor); Papagno, Andrea (Editor); Berry, Joseph A.; Fu, Wei; Fredeen, Art; Gamon, John</p> <p>2000-01-01</p> <p>The BOREAS TE-4 team collected continuous records of gas exchange under ambient conditions from intact boreal forest <span class="hlt">trees</span> in the BOREAS NSA from 23-Jul-1996 until 14-Aug-1996. These measurements can be used to test models of photosynthesis, stomatal conductance, and leaf respiration, such as SiB2 (Sellers et al., 1996) or the leaf model (Collatz et al., 1991), and programs can be obtained from the investigators. The data are stored in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/Publications.htm?seq_no_115=238475','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/Publications.htm?seq_no_115=238475"><span id="translatedtitle">Impact of Fumigation on Pythium <span class="hlt">Species</span> Associated with Forest <span class="hlt">Tree</span> Nurseries of Oregon and Washington</span></a></p> <p><a target="_blank" href="http://www.ars.usda.gov/services/TekTran.htm">Technology Transfer Automated Retrieval System (TEKTRAN)</a></p> <p></p> <p></p> <p>Pythium <span class="hlt">species</span> cause damping off of conifer seedlings in forest <span class="hlt">tree</span> nurseries. Identification of the <span class="hlt">species</span> responsible for the disease has been traditionally based on morphology. However, newer DNA-based identification methods may allow more accurate identification and assessment of soil popul...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26936241','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26936241"><span id="translatedtitle">Selective logging in tropical forests decreases the robustness of liana-<span class="hlt">tree</span> interaction networks to the loss of host <span class="hlt">tree</span> <span class="hlt">species</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Magrach, Ainhoa; Senior, Rebecca A; Rogers, Andrew; Nurdin, Deddy; Benedick, Suzan; Laurance, William F; Santamaria, Luis; Edwards, David P</p> <p>2016-03-16</p> <p>Selective logging is one of the major drivers of tropical forest degradation, causing important shifts in <span class="hlt">species</span> composition. Whether such changes modify interactions between <span class="hlt">species</span> and the networks in which they are embedded remain fundamental questions to assess the 'health' and ecosystem functionality of logged forests. We focus on interactions between lianas and their <span class="hlt">tree</span> hosts within primary and selectively logged forests in the biodiversity hotspot of Malaysian Borneo. We found that lianas were more abundant, had higher <span class="hlt">species</span> richness, and different <span class="hlt">species</span> compositions in logged than in primary forests. Logged forests showed heavier liana loads disparately affecting slow-growing <span class="hlt">tree</span> <span class="hlt">species</span>, which could exacerbate the loss of timber value and carbon storage already associated with logging. Moreover, simulation scenarios of host <span class="hlt">tree</span> local <span class="hlt">species</span> loss indicated that logging might decrease the robustness of liana-<span class="hlt">tree</span> interaction networks if heavily infested <span class="hlt">trees</span> (i.e. the most connected ones) were more likely to disappear. This effect is partially mitigated in the short term by the colonization of host <span class="hlt">trees</span> by a greater diversity of liana <span class="hlt">species</span> within logged forests, yet this might not compensate for the loss of preferred <span class="hlt">tree</span> hosts in the long term. As a consequence, <span class="hlt">species</span> interaction networks may show a lagged response to disturbance, which may trigger sudden collapses in <span class="hlt">species</span> richness and ecosystem function in response to additional disturbances, representing a new type of 'extinction debt'. PMID:26936241</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4476806','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4476806"><span id="translatedtitle">Phylogenetic Structure of <span class="hlt">Tree</span> <span class="hlt">Species</span> across Different Life Stages from Seedlings to Canopy <span class="hlt">Trees</span> in a Subtropical Evergreen Broad-Leaved Forest</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Jin, Yi; Qian, Hong; Yu, Mingjian</p> <p>2015-01-01</p> <p>Investigating patterns of phylogenetic structure across different life stages of <span class="hlt">tree</span> <span class="hlt">species</span> in forests is crucial to understanding forest community assembly, and investigating forest gap influence on the phylogenetic structure of forest regeneration is necessary for understanding forest community assembly. Here, we examine the phylogenetic structure of <span class="hlt">tree</span> <span class="hlt">species</span> across life stages from seedlings to canopy <span class="hlt">trees</span>, as well as forest gap influence on the phylogenetic structure of forest regeneration in a forest of the subtropical region in China. We investigate changes in phylogenetic relatedness (measured as NRI) of <span class="hlt">tree</span> <span class="hlt">species</span> from seedlings, saplings, treelets to canopy <span class="hlt">trees</span>; we compare the phylogenetic turnover (measured as ?NRI) between canopy <span class="hlt">trees</span> and seedlings in forest understory with that between canopy <span class="hlt">trees</span> and seedlings in forest gaps. We found that phylogenetic relatedness generally increases from seedlings through saplings and treelets up to canopy <span class="hlt">trees</span>, and that phylogenetic relatedness does not differ between seedlings in forest understory and those in forest gaps, but phylogenetic turnover between canopy <span class="hlt">trees</span> and seedlings in forest understory is lower than that between canopy <span class="hlt">trees</span> and seedlings in forest gaps. We conclude that <span class="hlt">tree</span> <span class="hlt">species</span> tend to be more closely related from seedling to canopy layers, and that forest gaps alter the seedling phylogenetic turnover of the studied forest. It is likely that the increasing trend of phylogenetic clustering as <span class="hlt">tree</span> stem size increases observed in this subtropical forest is primarily driven by abiotic filtering processes, which select a set of closely related evergreen broad-leaved <span class="hlt">tree</span> <span class="hlt">species</span> whose regeneration has adapted to the closed canopy environments of the subtropical forest developed under the regional monsoon climate. PMID:26098916</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3460976','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3460976"><span id="translatedtitle">Spatial Distribution and Interspecific Associations of <span class="hlt">Tree</span> <span class="hlt">Species</span> in a Tropical Seasonal Rain Forest of China</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Lan, Guoyu; Getzin, Stephan; Wiegand, Thorsten; Hu, Yuehua; Xie, Guishui; Zhu, Hua; Cao, Min</p> <p>2012-01-01</p> <p>Studying the spatial pattern and interspecific associations of plant <span class="hlt">species</span> may provide valuable insights into processes and mechanisms that maintain <span class="hlt">species</span> coexistence. Point pattern analysis was used to analyze the spatial distribution patterns of twenty dominant <span class="hlt">tree</span> <span class="hlt">species</span>, their interspecific spatial associations and changes across life stages in a 20-ha permanent plot of seasonal tropical rainforest in Xishuangbanna, China, to test mechanisms maintaining <span class="hlt">species</span> coexistence. Torus-translation tests were used to quantify positive or negative associations of the <span class="hlt">species</span> to topographic habitats. The results showed: (1) fourteen of the twenty <span class="hlt">tree</span> <span class="hlt">species</span> were negatively (or positively) associated with one or two of the topographic variables, which evidences that the niche contributes to the spatial pattern of these <span class="hlt">species</span>. (2) Most saplings of the study <span class="hlt">species</span> showed a significantly clumped distribution at small scales (0–10 m) which was lost at larger scales (10–30 m). (3) The degree of spatial clumping deceases from saplings, to poles, to adults indicates that density-dependent mortality of the offspring is ubiquitous in <span class="hlt">species</span>. (4) It is notable that a high number of positive small-scale interactions were found among the twenty <span class="hlt">species</span>. For saplings, 42.6% of all combinations of <span class="hlt">species</span> pairs showed positive associations at neighborhood scales up to five meters, but only 38.4% were negative. For poles and adults, positive associations at these distances still made up 45.5% and 29.5%, respectively. In conclusion, there is considerable evidence for the presence of positive interactions among the <span class="hlt">tree</span> <span class="hlt">species</span>, which suggests that <span class="hlt">species</span> herd protection may occur in our plot. In addition, niche assembly and limited dispersal (likely) contribute to the spatial patterns of <span class="hlt">tree</span> <span class="hlt">species</span> in the tropical seasonal rain forest in Xishuangbanna, China. PMID:23029394</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_7 --> <div id="page_8" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="141"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25315885','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25315885"><span id="translatedtitle">When do <span class="hlt">species-tree</span> and concatenated estimates disagree? An empirical analysis with higher-level scincid lizard phylogeny.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lambert, Shea M; Reeder, Tod W; Wiens, John J</p> <p>2015-01-01</p> <p>Simulation studies suggest that coalescent-based <span class="hlt">species-tree</span> methods are generally more accurate than concatenated analyses. However, these <span class="hlt">species-tree</span> methods remain impractical for many large datasets. Thus, a critical but unresolved issue is when and why concatenated and coalescent <span class="hlt">species-tree</span> estimates will differ. We predict such differences for branches in concatenated <span class="hlt">trees</span> that are short, weakly supported, and have conflicting gene <span class="hlt">trees</span>. We test these predictions in Scincidae, the largest lizard family, with data from 10 nuclear genes for 17 ingroup taxa and 44 genes for 12 taxa. We support our initial predictions, andsuggest that simply considering uncertainty in concatenated <span class="hlt">trees</span> may sometimes encompass the differences between these methods. We also found that relaxed-clock concatenated <span class="hlt">trees</span> can be surprisingly similar to the <span class="hlt">species-tree</span> estimate. Remarkably, the coalescent <span class="hlt">species-tree</span> estimates had slightly lower support values when based on many more genes (44 vs. 10) and a small (∼30%) reduction in taxon sampling. Thus, taxon sampling may be more important than gene sampling when applying <span class="hlt">species-tree</span> methods to deep phylogenetic questions. Finally, our coalescent <span class="hlt">species-tree</span> estimates tentatively support division of Scincidae into three monophyletic subfamilies, a result otherwise found only in concatenated analyses with extensive <span class="hlt">species</span> sampling. PMID:25315885</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26364482','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26364482"><span id="translatedtitle">Fuel wood properties of some oak <span class="hlt">tree</span> <span class="hlt">species</span> of Manipur, India.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Meetei, Shougrakpam Bijen; Singh, E J; Das, Ashesh Kumar</p> <p>2015-07-01</p> <p>Five indigenous oak <span class="hlt">tree</span> <span class="hlt">species</span>, i.e., Castanopsis indica (Roxb. ex Lindl.) A.DC., Lithocarpus fenestratus (Roxb.) Rehder, Lithocarpus pachyphyllus (Kurz) Rehder, Lithocarpus polystachyus (Wall. ex A.DC.) Rehder and Quercus serrata Murray were estimated for their wood properties such as calorific value, density, moisture content and ash content from a sub-tropical forest of Haraothel hill, Senapati District, Manipur. Wood biomass components were found to have higher calorific value (kJ g(-)) than bark components. The calorific values for <span class="hlt">tree</span> <span class="hlt">species</span> were found highest in L. pachyphyllus (17.99 kJ g(-1)) followed by C. indica (17.98 kJ g1), L. fenestratus (17.96 kJ g"), L. polystachyus (17.80 kJ g(-1)) and Q. serrata (17.49 kJ g(-1)). Calorific values for bole bark, bole wood and branch bark were found significantly different (F > 3.48 at p = 0.05) in five oak <span class="hlt">tree</span> <span class="hlt">species</span>. Percentage of ash on dry weight basis was found to be highest in Q. serrata (4.73%) and lowest in C. indica (2.19%). Ash content of <span class="hlt">tree</span> components gives a singnificant factor in determining fuelwood value index (FVI). Of all the five oak <span class="hlt">tree</span> <span class="hlt">species</span>, Q. serrata exhibited highest value of wood density (0.78 g cm-) and lowest was observed in C. indica (0.63 g cm(-3)). There was significant correlation between wood density (p<0.05), ash content (p<0.01) with calorific value in oak <span class="hlt">tree</span> <span class="hlt">species</span>. Fuelwood value index (FVI) was in the following order: C. indica (1109.70) > L. pachyphyllus (898.41)> L. polystachyus (879.02)> L. fenestratus (824.61)> Q. serrata (792.50). Thus, the present study suggests that C. indica may be considered as a fuelwood oak <span class="hlt">tree</span> <span class="hlt">species</span> in Manipur. PMID:26364482</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25881439','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25881439"><span id="translatedtitle">[Mahalanobis distance based hyperspectral characteristic discrimination of leaves of different desert <span class="hlt">tree</span> <span class="hlt">species</span>].</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lin, Hai-jun; Zhang, Hui-fang; Gao, Ya-qi; Li, Xia; Yang, Fan; Zhou, Yan-fei</p> <p>2014-12-01</p> <p>The hyperspectral reflectance of Populus euphratica, Tamarix hispida, Haloxylon ammodendron and Calligonum mongolicum in the lower reaches of Tarim River and Turpan Desert Botanical Garden was measured by using the HR-768 field-portable spectroradiometer. The method of continuum removal, first derivative reflectance and second derivative reflectance were used to deal with the original spectral data of four <span class="hlt">tree</span> <span class="hlt">species</span>. The method of Mahalanobis Distance was used to select the bands with significant differences in the original spectral data and transform spectral data to identify the different <span class="hlt">tree</span> <span class="hlt">species</span>. The progressive discrimination analyses were used to test the selective bands used to identify different <span class="hlt">tree</span> <span class="hlt">species</span>. The results showed that The Mahalanobis Distance method was an effective method in feature band extraction. The bands for identifying different <span class="hlt">tree</span> <span class="hlt">species</span> were most near-infrared bands. The recognition accuracy of four methods was 85%, 93.8%, 92.4% and 95.5% respectively. Spectrum transform could improve the recognition accuracy. The recognition accuracy of different research objects and different spectrum transform methods were different. The research provided evidence for desert <span class="hlt">tree</span> <span class="hlt">species</span> classification, monitoring biodiversity and the analysis of area in desert by using large scale remote sensing method. PMID:25881439</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/21910838','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21910838"><span id="translatedtitle">Fruit availability, frugivore satiation and seed removal in 2 primate-dispersed <span class="hlt">tree</span> <span class="hlt">species</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ratiarison, Sandra; Forget, Pierre-Michel</p> <p>2011-09-01</p> <p>During a mast-fruiting event we investigated spatial variability in fruit availability, consumption, and seed removal at two sympatric <span class="hlt">tree</span> <span class="hlt">species</span>, Manilkara bidentata and M. huberi (Sapotaceae) at Nouragues Natural Reserve, French Guiana. We addressed the question of how Manilkara density and fruits at the community level might be major causes of variability in feeding assemblages between <span class="hlt">tree</span> <span class="hlt">species</span>. We thus explored how the frugivore assemblages differed between forest patches with contrasting relative Manilkara density and fruiting context. During the daytime, Alouatta seniculus was more often observed in M. huberi crowns at Petit Plateau (PP) with the greatest density of Manilkara spp. and the lowest fruit diversity and availability, whereas Cebus apella and Saguinus midas were more often observed in M. bidentata crowns at both Grand Plateau (GP), with a lowest density of M. bidentata and overall greater fruit supply, and PP. Overall, nearly 53% and 15% of the M. bidentata seed crop at GP and PP, respectively, and about 47% of the M. huberi seed crop were removed, otherwise either spit out or defecated beneath <span class="hlt">trees</span>, or dropped in fruits. Small-bodied primates concentrated fallen seeds beneath parent <span class="hlt">trees</span> while large-bodied primate <span class="hlt">species</span> removed and dispersed more seeds away from parents. However, among the latter, satiated A. seniculus wasted seeds under conspecific <span class="hlt">trees</span> at PP. Variations in feeding assemblages, seed removal rates and fates possibly reflected interactions with extra-generic fruit <span class="hlt">species</span> at the community level, according to feeding choice, habitat preferences and ranging patterns of primate <span class="hlt">species</span>. PMID:21910838</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26600422','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26600422"><span id="translatedtitle">Discrimination of Deciduous <span class="hlt">Tree</span> <span class="hlt">Species</span> from Time Series of Unmanned Aerial System Imagery.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lisein, Jonathan; Michez, Adrien; Claessens, Hugues; Lejeune, Philippe</p> <p>2015-01-01</p> <p>Technology advances can revolutionize Precision Forestry by providing accurate and fine forest information at <span class="hlt">tree</span> level. This paper addresses the question of how and particularly when Unmanned Aerial System (UAS) should be used in order to efficiently discriminate deciduous <span class="hlt">tree</span> <span class="hlt">species</span>. The goal of this research is to determine when is the best time window to achieve an optimal <span class="hlt">species</span> discrimination. A time series of high resolution UAS imagery was collected to cover the growing season from leaf flush to leaf fall. Full benefit was taken of the temporal resolution of UAS acquisition, one of the most promising features of small drones. The disparity in forest <span class="hlt">tree</span> phenology is at the maximum during early spring and late autumn. But the phenology state that optimized the classification result is the one that minimizes the spectral variation within <span class="hlt">tree</span> <span class="hlt">species</span> groups and, at the same time, maximizes the phenologic differences between <span class="hlt">species</span>. Sunlit <span class="hlt">tree</span> crowns (5 deciduous <span class="hlt">species</span> groups) were classified using a Random Forest approach for monotemporal, two-date and three-date combinations. The end of leaf flushing was the most efficient single-date time window. Multitemporal datasets definitely improve the overall classification accuracy. But single-date high resolution orthophotomosaics, acquired on optimal time-windows, result in a very good classification accuracy (overall out of bag error of 16%). PMID:26600422</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4657984','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4657984"><span id="translatedtitle">Discrimination of Deciduous <span class="hlt">Tree</span> <span class="hlt">Species</span> from Time Series of Unmanned Aerial System Imagery</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Lisein, Jonathan; Michez, Adrien; Claessens, Hugues; Lejeune, Philippe</p> <p>2015-01-01</p> <p>Technology advances can revolutionize Precision Forestry by providing accurate and fine forest information at <span class="hlt">tree</span> level. This paper addresses the question of how and particularly when Unmanned Aerial System (UAS) should be used in order to efficiently discriminate deciduous <span class="hlt">tree</span> <span class="hlt">species</span>. The goal of this research is to determine when is the best time window to achieve an optimal <span class="hlt">species</span> discrimination. A time series of high resolution UAS imagery was collected to cover the growing season from leaf flush to leaf fall. Full benefit was taken of the temporal resolution of UAS acquisition, one of the most promising features of small drones. The disparity in forest <span class="hlt">tree</span> phenology is at the maximum during early spring and late autumn. But the phenology state that optimized the classification result is the one that minimizes the spectral variation within <span class="hlt">tree</span> <span class="hlt">species</span> groups and, at the same time, maximizes the phenologic differences between <span class="hlt">species</span>. Sunlit <span class="hlt">tree</span> crowns (5 deciduous <span class="hlt">species</span> groups) were classified using a Random Forest approach for monotemporal, two-date and three-date combinations. The end of leaf flushing was the most efficient single-date time window. Multitemporal datasets definitely improve the overall classification accuracy. But single-date high resolution orthophotomosaics, acquired on optimal time-windows, result in a very good classification accuracy (overall out of bag error of 16%). PMID:26600422</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26209413','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26209413"><span id="translatedtitle">PoMo: An Allele Frequency-Based Approach for <span class="hlt">Species</span> <span class="hlt">Tree</span> Estimation.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>De Maio, Nicola; Schrempf, Dominik; Kosiol, Carolin</p> <p>2015-11-01</p> <p>Incomplete lineage sorting can cause incongruencies of the overall <span class="hlt">species</span>-level phylogenetic <span class="hlt">tree</span> with the phylogenetic <span class="hlt">trees</span> for individual genes or genomic segments. If these incongruencies are not accounted for, it is possible to incur several biases in <span class="hlt">species</span> <span class="hlt">tree</span> estimation. Here, we present a simple maximum likelihood approach that accounts for ancestral variation and incomplete lineage sorting. We use a POlymorphisms-aware phylogenetic MOdel (PoMo) that we have recently shown to efficiently estimate mutation rates and fixation biases from within and between-<span class="hlt">species</span> variation data. We extend this model to perform efficient estimation of <span class="hlt">species</span> <span class="hlt">trees</span>. We test the performance of PoMo in several different scenarios of incomplete lineage sorting using simulations and compare it with existing methods both in accuracy and computational speed. In contrast to other approaches, our model does not use coalescent theory but is allele frequency based. We show that PoMo is well suited for genome-wide <span class="hlt">species</span> <span class="hlt">tree</span> estimation and that on such data it is more accurate than previous approaches. PMID:26209413</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4240985','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4240985"><span id="translatedtitle">Multiple <span class="hlt">species</span> of wild <span class="hlt">tree</span> peonies gave rise to the ‘king of flowers’, Paeonia suffruticosa Andrews</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Zhou, Shi-Liang; Zou, Xin-Hui; Zhou, Zhi-Qin; Liu, Jing; Xu, Chao; Yu, Jing; Wang, Qiang; Zhang, Da-Ming; Wang, Xiao-Quan; Ge, Song; Sang, Tao; Pan, Kai-Yu; Hong, De-Yuan</p> <p>2014-01-01</p> <p>The origin of cultivated <span class="hlt">tree</span> peonies, known as the ‘king of flowers' in China for more than 1000 years, has attracted considerable interest, but remained unsolved. Here, we conducted phylogenetic analyses of explicitly sampled traditional cultivars of <span class="hlt">tree</span> peonies and all wild <span class="hlt">species</span> from the shrubby section Moutan of the genus Paeonia based on sequences of 14 fast-evolved chloroplast regions and 25 presumably single-copy nuclear markers identified from RNA-seq data. The phylogeny of the wild <span class="hlt">species</span> inferred from the nuclear markers was fully resolved and largely congruent with morphology and classification. The incongruence between the nuclear and chloroplast <span class="hlt">trees</span> suggested that there had been gene flow between the wild <span class="hlt">species</span>. The comparison of nuclear and chloroplast phylogenies including cultivars showed that the cultivated <span class="hlt">tree</span> peonies originated from homoploid hybridization among five wild <span class="hlt">species</span>. Since the origin, thousands of cultivated varieties have spread worldwide, whereas four parental <span class="hlt">species</span> are currently endangered or on the verge of extinction. The documentation of extensive homoploid hybridization involved in <span class="hlt">tree</span> peony domestication provides new insights into the mechanisms underlying the origins of garden ornamentals and the way of preserving natural genetic resources through domestication. PMID:25377453</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/949520','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/949520"><span id="translatedtitle">Strategy space and the disturbance spectrum : a model for <span class="hlt">tree</span> <span class="hlt">species</span> coexistence.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Loehle, C.; Environmental Research</p> <p>2000-07-01</p> <p>The disturbance spectrum consists of disturbance patterns differing in type, size, intensity, and frequency. It is proposed that <span class="hlt">tree</span> life-history traits are adaptations to particular disturbance regimes. Four independent axes are proposed to define the dominant dimensions of <span class="hlt">tree</span> strategy space: shade tolerance, <span class="hlt">tree</span> height, capacity for vegetative reproduction, and seed dispersal distance. A fitness model was developed to elucidate interactions between the proposed life-history traits. The model shows how alternate life-history sets can coexist when disturbance patterns fluctuate in space and time. Variable disturbance regimes were shown, based on data and simulation results, to enhance <span class="hlt">species</span> coexistence, as predicted. The strategy space model accurately predicts the number of common <span class="hlt">tree</span> <span class="hlt">species</span> for the eastern United States, boreal Canada, and southwestern pinon-juniper woodlands. The model also provides an explanation for latitudinal gradients in <span class="hlt">tree</span> <span class="hlt">species</span> richness in North America and Europe. The proposed model predicts a relationship between disturbance characteristics and the <span class="hlt">species</span> composition of a forest that allows for the coexistence of large numbers of <span class="hlt">species</span>. The life-history traits of size, growth rate, life span, shade tolerance, age of reproduction, seed dispersal distance, and vegetative reproduction are all incorporated into the model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/949422','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/949422"><span id="translatedtitle">Strategy space and the disturbance spectrum : a life history model for <span class="hlt">tree</span> <span class="hlt">species</span> coexistence.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Loehle, C.; Environmental Research</p> <p>2000-07-01</p> <p>The disturbance spectrum consists of disturbance patterns differing in type, size, intensity, and frequency. It is proposed that <span class="hlt">tree</span> life-history traits are adaptations to particular disturbance regimes. Four independent axes are proposed to define the dominant dimensions of <span class="hlt">tree</span> strategy space: shade tolerance, <span class="hlt">tree</span> height, capacity for vegetative reproduction, and seed dispersal distance. A fitness model was developed to elucidate interactions between the proposed life-history traits. The model shows how alternate life-history sets can coexist when disturbance patterns fluctuate in space and time. Variable disturbance regimes were shown, based on data and simulation results, to enhance <span class="hlt">species</span> coexistence, as predicted. The strategy space model accurately predicts the number of common <span class="hlt">tree</span> <span class="hlt">species</span> for the eastern United States, boreal Canada, and southwestern pinon-juniper woodlands. The model also provides an explanation for latitudinal gradients in <span class="hlt">tree</span> <span class="hlt">species</span> richness in North America and Europe. The proposed model predicts a relationship between disturbance characteristics and the <span class="hlt">species</span> composition of a forest that allows for the coexistence of large numbers of <span class="hlt">species</span>. The life-history traits of size, growth rate, life span, shade tolerance, age of reproduction, seed dispersal distance, and vegetative reproduction are all incorporated into the model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4604832','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4604832"><span id="translatedtitle">PoMo: An Allele Frequency-Based Approach for <span class="hlt">Species</span> <span class="hlt">Tree</span> Estimation</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>De Maio, Nicola; Schrempf, Dominik; Kosiol, Carolin</p> <p>2015-01-01</p> <p>Incomplete lineage sorting can cause incongruencies of the overall <span class="hlt">species</span>-level phylogenetic <span class="hlt">tree</span> with the phylogenetic <span class="hlt">trees</span> for individual genes or genomic segments. If these incongruencies are not accounted for, it is possible to incur several biases in <span class="hlt">species</span> <span class="hlt">tree</span> estimation. Here, we present a simple maximum likelihood approach that accounts for ancestral variation and incomplete lineage sorting. We use a POlymorphisms-aware phylogenetic MOdel (PoMo) that we have recently shown to efficiently estimate mutation rates and fixation biases from within and between-<span class="hlt">species</span> variation data. We extend this model to perform efficient estimation of <span class="hlt">species</span> <span class="hlt">trees</span>. We test the performance of PoMo in several different scenarios of incomplete lineage sorting using simulations and compare it with existing methods both in accuracy and computational speed. In contrast to other approaches, our model does not use coalescent theory but is allele frequency based. We show that PoMo is well suited for genome-wide <span class="hlt">species</span> <span class="hlt">tree</span> estimation and that on such data it is more accurate than previous approaches. PMID:26209413</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24588709','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24588709"><span id="translatedtitle">Interpreting <span class="hlt">species</span>-specific variation in <span class="hlt">tree</span>-ring oxygen isotope ratios among three temperate forest <span class="hlt">trees</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Song, Xin; Clark, Kenneth S; Helliker, Brent R</p> <p>2014-09-01</p> <p>Although considerable variation has been documented in <span class="hlt">tree</span>-ring cellulose oxygen isotope ratios (?(18)O(cell)) among co-occurring <span class="hlt">species</span>, the underlying causes are unknown. Here, we used a combination of field measurements and modelling to investigate the mechanisms behind variations in late-wood ?(18) O(cell) (?(18)O(lc)) among three co-occurring <span class="hlt">species</span> (chestnut oak, black oak and pitch pine) in a temperate forest. For two growing seasons, we quantified among-<span class="hlt">species</span> variation in ?(18)O(lc), as well as several variables that could potentially cause the ?(18)O(lc) variation. Data analysis based on the ?(18) O(cell) model rules out leaf water enrichment (?(18)O(lw)) and <span class="hlt">tree</span>-ring formation period (?t), but highlights source water ?(18) O (?(18) O(sw)) as an important driver for the measured difference in ?(18)O(lc) between black and chestnut oak. However, the enriched ?(18)O(lc) in pitch pine relative to the oaks could not be sufficiently explained by consideration of the above three variables only, but rather, we show that differences in the proportion of oxygen exchange during cellulose synthesis (p(ex)) is most likely a key mechanism. Our demonstration of the relevance of some <span class="hlt">species</span>-specific features (or lack thereof) to ?(18)O(cell) has important implications for isotope based ecophysiological/paleoclimate studies. PMID:24588709</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/12650343','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/12650343"><span id="translatedtitle">Survival and development of Lymantria monacha (Lepidoptera: Lymantriidae) on North American and introduced Eurasian <span class="hlt">tree</span> <span class="hlt">species</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Keena, M A</p> <p>2003-02-01</p> <p>Lymantria monacha (L.) (Lepidoptera: Lymantriidae), the nun moth, is a Eurasian pest of conifers that has potential for accidental introduction into North America. To project the potential host range of this insect if introduced into North America, survival and development of L. monacha on 26 North American and eight introduced Eurasian <span class="hlt">tree</span> <span class="hlt">species</span> were examined. Seven conifer <span class="hlt">species</span> (Abies concolor, Picea abies, P. glauca, P. pungens, Pinus sylvestris with male cones, P. menziesii variety glance, and Tsuga canadensis) and six broadleaf <span class="hlt">species</span> (Betula populifolia, Malus x domestica, Prunus serotiaa, Quercus lobata, Q. rubra, and Q. velutina) were suitable for L. monacha survival and development. Eleven of the host <span class="hlt">species</span> tested were rated as intermediate in suitability, four conifer <span class="hlt">species</span> (Larix occidentalis, P. nigra, P. ponderosa, P. strobus, and Pseudotsuga menziesii variety menziesii) and six broadleaf <span class="hlt">species</span> (Carpinus caroliniana, Carya ovata, Fagus grandifolia, Populus grandidentata, Q. alba, and Tilia cordata) and the remaining 10 <span class="hlt">species</span> tested were rated as poor (Acer rubrum, A. platanoidies, A. saccharum, F. americana, Juniperus virginiana, Larix kaempferi, Liriodendron tulipfera, Morus alba, P. taeda, and P. deltoides). The phenological state of the <span class="hlt">trees</span> had a major impact on establishment, survival, and development of L. monacha on many of the <span class="hlt">tree</span> <span class="hlt">species</span> tested. Several of the deciduous <span class="hlt">tree</span> <span class="hlt">species</span> that are suitable for L. monacha also are suitable for L. dispar (L.) and L. mathura Moore. Establishment of L. monacha in North America would be catastrophic because of the large number of economically important <span class="hlt">tree</span> <span class="hlt">species</span> on which it can survive and develop, and the ability of mated females to fly and colonize new areas. PMID:12650343</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4496029','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4496029"><span id="translatedtitle">Operational <span class="hlt">Tree</span> <span class="hlt">Species</span> Mapping in a Diverse Tropical Forest with Airborne Imaging Spectroscopy</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Baldeck, Claire A.; Asner, Gregory P.; Martin, Robin E.; Anderson, Christopher B.; Knapp, David E.; Kellner, James R.; Wright, S. Joseph</p> <p>2015-01-01</p> <p>Remote identification and mapping of canopy <span class="hlt">tree</span> <span class="hlt">species</span> can contribute valuable information towards our understanding of ecosystem biodiversity and function over large spatial scales. However, the extreme challenges posed by highly diverse, closed-canopy tropical forests have prevented automated remote <span class="hlt">species</span> mapping of non-flowering <span class="hlt">tree</span> crowns in these ecosystems. We set out to identify individuals of three focal canopy <span class="hlt">tree</span> <span class="hlt">species</span> amongst a diverse background of <span class="hlt">tree</span> and liana <span class="hlt">species</span> on Barro Colorado Island, Panama, using airborne imaging spectroscopy data. First, we compared two leading single-class classification methods—binary support vector machine (SVM) and biased SVM—for their performance in identifying pixels of a single focal <span class="hlt">species</span>. From this comparison we determined that biased SVM was more precise and created a multi-<span class="hlt">species</span> classification model by combining the three biased SVM models. This model was applied to the imagery to identify pixels belonging to the three focal <span class="hlt">species</span> and the prediction results were then processed to create a map of focal <span class="hlt">species</span> crown objects. Crown-level cross-validation of the training data indicated that the multi-<span class="hlt">species</span> classification model had pixel-level producer’s accuracies of 94–97% for the three focal <span class="hlt">species</span>, and field validation of the predicted crown objects indicated that these had user’s accuracies of 94–100%. Our results demonstrate the ability of high spatial and spectral resolution remote sensing to accurately detect non-flowering crowns of focal <span class="hlt">species</span> within a diverse tropical forest. We attribute the success of our model to recent classification and mapping techniques adapted to <span class="hlt">species</span> detection in diverse closed-canopy forests, which can pave the way for remote <span class="hlt">species</span> mapping in a wider variety of ecosystems. PMID:26153693</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26153693','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26153693"><span id="translatedtitle">Operational <span class="hlt">Tree</span> <span class="hlt">Species</span> Mapping in a Diverse Tropical Forest with Airborne Imaging Spectroscopy.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Baldeck, Claire A; Asner, Gregory P; Martin, Robin E; Anderson, Christopher B; Knapp, David E; Kellner, James R; Wright, S Joseph</p> <p>2015-01-01</p> <p>Remote identification and mapping of canopy <span class="hlt">tree</span> <span class="hlt">species</span> can contribute valuable information towards our understanding of ecosystem biodiversity and function over large spatial scales. However, the extreme challenges posed by highly diverse, closed-canopy tropical forests have prevented automated remote <span class="hlt">species</span> mapping of non-flowering <span class="hlt">tree</span> crowns in these ecosystems. We set out to identify individuals of three focal canopy <span class="hlt">tree</span> <span class="hlt">species</span> amongst a diverse background of <span class="hlt">tree</span> and liana <span class="hlt">species</span> on Barro Colorado Island, Panama, using airborne imaging spectroscopy data. First, we compared two leading single-class classification methods--binary support vector machine (SVM) and biased SVM--for their performance in identifying pixels of a single focal <span class="hlt">species</span>. From this comparison we determined that biased SVM was more precise and created a multi-<span class="hlt">species</span> classification model by combining the three biased SVM models. This model was applied to the imagery to identify pixels belonging to the three focal <span class="hlt">species</span> and the prediction results were then processed to create a map of focal <span class="hlt">species</span> crown objects. Crown-level cross-validation of the training data indicated that the multi-<span class="hlt">species</span> classification model had pixel-level producer's accuracies of 94-97% for the three focal <span class="hlt">species</span>, and field validation of the predicted crown objects indicated that these had user's accuracies of 94-100%. Our results demonstrate the ability of high spatial and spectral resolution remote sensing to accurately detect non-flowering crowns of focal <span class="hlt">species</span> within a diverse tropical forest. We attribute the success of our model to recent classification and mapping techniques adapted to <span class="hlt">species</span> detection in diverse closed-canopy forests, which can pave the way for remote <span class="hlt">species</span> mapping in a wider variety of ecosystems. PMID:26153693</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70041741','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70041741"><span id="translatedtitle">Quantifying <span class="hlt">tree</span> mortality in a mixed <span class="hlt">species</span> woodland using multitemporal high spatial resolution satellite imagery</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Garrity, Steven R.; Allen, Craig D.; Brumby, Steven P.; Gangodagamage, Chandana; McDowell, Nate G.; Cai, D. Michael</p> <p>2013-01-01</p> <p>Widespread <span class="hlt">tree</span> mortality events have recently been observed in several biomes. To effectively quantify the severity and extent of these events, tools that allow for rapid assessment at the landscape scale are required. Past studies using high spatial resolution satellite imagery have primarily focused on detecting green, red, and gray <span class="hlt">tree</span> canopies during and shortly after <span class="hlt">tree</span> damage or mortality has occurred. However, detecting <span class="hlt">trees</span> in various stages of death is not always possible due to limited availability of archived satellite imagery. Here we assess the capability of high spatial resolution satellite imagery for <span class="hlt">tree</span> mortality detection in a southwestern U.S. mixed <span class="hlt">species</span> woodland using archived satellite images acquired prior to mortality and well after dead <span class="hlt">trees</span> had dropped their leaves. We developed a multistep classification approach that uses: supervised masking of non-<span class="hlt">tree</span> image elements; bi-temporal (pre- and post-mortality) differencing of normalized difference vegetation index (NDVI) and red:green ratio (RGI); and unsupervised multivariate clustering of pixels into live and dead <span class="hlt">tree</span> classes using a Gaussian mixture model. Classification accuracies were improved in a final step by tuning the rules of pixel classification using the posterior probabilities of class membership obtained from the Gaussian mixture model. Classifications were produced for two images acquired post-mortality with overall accuracies of 97.9% and 98.5%, respectively. Classified images were combined with land cover data to characterize the spatiotemporal characteristics of <span class="hlt">tree</span> mortality across areas with differences in <span class="hlt">tree</span> <span class="hlt">species</span> composition. We found that 38% of <span class="hlt">tree</span> crown area was lost during the drought period between 2002 and 2006. The majority of <span class="hlt">tree</span> mortality during this period was concentrated in piñon-juniper (Pinus edulis-Juniperus monosperma) woodlands. An additional 20% of the <span class="hlt">tree</span> canopy died or was removed between 2006 and 2011, primarily in areas experiencing wildfire and management activity. -Our results demonstrate that unsupervised clustering of bi-temporal NDVI and RGI differences can be used to detect <span class="hlt">tree</span> mortality resulting from numerous causes and in several forest cover types.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25988872','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25988872"><span id="translatedtitle">Dominant <span class="hlt">tree</span> <span class="hlt">species</span> are at risk from exaggerated drought under climate change.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fensham, Roderick J; Fraser, Josie; MacDermott, Harry J; Firn, Jenifer</p> <p>2015-10-01</p> <p>Predicting the consequences of climate change on forest systems is difficult because <span class="hlt">trees</span> may display <span class="hlt">species</span>-specific responses to exaggerated droughts that may not be reflected by the climatic envelope of their geographic range. Furthermore, few studies have examined the postdrought recovery potential of drought-susceptible <span class="hlt">tree</span> <span class="hlt">species</span>. This study develops a robust ranking of the drought susceptibility of 21 <span class="hlt">tree</span> <span class="hlt">species</span> based on their mortality after two droughts (1990s and 2000s) in the savanna of north-eastern Australia. Drought-induced mortality was positively related to <span class="hlt">species</span> dominance, negatively related to the ratio of postdrought seedlings to adults and had no relationship to the magnitude of extreme drought within the <span class="hlt">species</span> current geographic ranges. These results suggest that predicting the consequences of exaggerated drought on <span class="hlt">species</span>' geographic ranges is difficult, but that dominant <span class="hlt">species</span> like Eucalyptus with relatively slow rates of population recovery and dispersal are the most susceptible. The implications for savanna ecosystems are lower <span class="hlt">tree</span> densities and basal area. PMID:25988872</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ISPAnII22..175M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ISPAnII22..175M"><span id="translatedtitle">Identification and Mapping of <span class="hlt">Tree</span> <span class="hlt">Species</span> in Urban Areas Using WORLDVIEW-2 Imagery</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mustafa, Y. T.; Habeeb, H. N.; Stein, A.; Sulaiman, F. Y.</p> <p>2015-10-01</p> <p>Monitoring and mapping of urban <span class="hlt">trees</span> are essential to provide urban forestry authorities with timely and consistent information. Modern techniques increasingly facilitate these tasks, but require the development of semi-automatic <span class="hlt">tree</span> detection and classification methods. In this article, we propose an approach to delineate and map the crown of 15 <span class="hlt">tree</span> <span class="hlt">species</span> in the city of Duhok, Kurdistan Region of Iraq using WorldView-2 (WV-2) imagery. A <span class="hlt">tree</span> crown object is identified first and is subsequently delineated as an image object (IO) using vegetation indices and texture measurements. Next, three classification methods: Maximum Likelihood, Neural Network, and Support Vector Machine were used to classify IOs using selected IO features. The best results are obtained with Support Vector Machine classification that gives the best map of urban <span class="hlt">tree</span> <span class="hlt">species</span> in Duhok. The overall accuracy was between 60.93% to 88.92% and ?-coefficient was between 0.57 to 0.75. We conclude that fifteen <span class="hlt">tree</span> <span class="hlt">species</span> were identified and mapped at a satisfactory accuracy in urban areas of this study.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.9592I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.9592I"><span id="translatedtitle">The response of European <span class="hlt">tree</span> <span class="hlt">species</span> to drought: a meta-analysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Irschick, C.; Mayr, S.; Wohlfahrt, G.</p> <p>2012-04-01</p> <p>Here we provide first results of a meta-analysis of the response of European <span class="hlt">tree</span> <span class="hlt">species</span> to drought. A literature search was conducted in order to collect available studies of the response of the gas exchange of European <span class="hlt">tree</span> <span class="hlt">species</span> to either natural or imposed water shortage. The resulting publications were screened and parameters at organ (e.g. leaf or shoot), individual (i.e. <span class="hlt">tree</span>) and ecosystem scale were transferred to a data base. Here we present preliminary results from queries of the data base aiming at identifying differences in the drought response between <span class="hlt">species</span> that may have implications for forest productivity and composition under likely future warmer and drier conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4021425','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4021425"><span id="translatedtitle">An empirical evaluation of two-stage <span class="hlt">species</span> <span class="hlt">tree</span> inference strategies using a multilocus dataset from North American pines</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2014-01-01</p> <p>Background As it becomes increasingly possible to obtain DNA sequences of orthologous genes from diverse sets of taxa, <span class="hlt">species</span> <span class="hlt">trees</span> are frequently being inferred from multilocus data. However, the behavior of many methods for performing this inference has remained largely unexplored. Some methods have been proven to be consistent given certain evolutionary models, whereas others rely on criteria that, although appropriate for many parameter values, have peculiar zones of the parameter space in which they fail to converge on the correct estimate as data sets increase in size. Results Here, using North American pines, we empirically evaluate the behavior of 24 strategies for <span class="hlt">species</span> <span class="hlt">tree</span> inference using three alternative outgroups (72 strategies total). The data consist of 120 individuals sampled in eight ingroup <span class="hlt">species</span> from subsection Strobus and three outgroup <span class="hlt">species</span> from subsection Gerardianae, spanning ∼47 kilobases of sequence at 121 loci. Each “strategy” for inferring <span class="hlt">species</span> <span class="hlt">trees</span> consists of three features: a <span class="hlt">species</span> <span class="hlt">tree</span> construction method, a gene <span class="hlt">tree</span> inference method, and a choice of outgroup. We use multivariate analysis techniques such as principal components analysis and hierarchical clustering to identify <span class="hlt">tree</span> characteristics that are robustly observed across strategies, as well as to identify groups of strategies that produce <span class="hlt">trees</span> with similar features. We find that strategies that construct <span class="hlt">species</span> <span class="hlt">trees</span> using only topological information cluster together and that strategies that use additional non-topological information (e.g., branch lengths) also cluster together. Strategies that utilize more than one individual within a <span class="hlt">species</span> to infer gene <span class="hlt">trees</span> tend to produce estimates of <span class="hlt">species</span> <span class="hlt">trees</span> that contain clades present in <span class="hlt">trees</span> estimated by other strategies. Strategies that use the minimize-deep-coalescences criterion to construct <span class="hlt">species</span> <span class="hlt">trees</span> tend to produce <span class="hlt">species</span> <span class="hlt">tree</span> estimates that contain clades that are not present in <span class="hlt">trees</span> estimated by the Concatenation, RTC, SMRT, STAR, and STEAC methods, and that in general are more balanced than those inferred by these other strategies. Conclusions When constructing a <span class="hlt">species</span> <span class="hlt">tree</span> from a multilocus set of sequences, our observations provide a basis for interpreting differences in <span class="hlt">species</span> <span class="hlt">tree</span> estimates obtained via different approaches that have a two-stage structure in common, one step for gene <span class="hlt">tree</span> estimation and a second step for <span class="hlt">species</span> <span class="hlt">tree</span> estimation. The methods explored here employ a number of distinct features of the data, and our analysis suggests that recovery of the same results from multiple methods that tend to differ in their patterns of inference can be a valuable tool for obtaining reliable estimates. PMID:24678701</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_8 --> <div id="page_9" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="161"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/20576853','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/20576853"><span id="translatedtitle">Asymmetric density dependence shapes <span class="hlt">species</span> abundances in a tropical <span class="hlt">tree</span> community.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Comita, Liza S; Muller-Landau, Helene C; Aguilar, Salomón; Hubbell, Stephen P</p> <p>2010-07-16</p> <p>The factors determining <span class="hlt">species</span> commonness and rarity are poorly understood, particularly in highly diverse communities. Theory predicts that interactions with neighbors of the same (conspecific) and other (heterospecific) <span class="hlt">species</span> can influence a <span class="hlt">species</span>' relative abundance, but empirical tests are lacking. By using a hierarchical model of survival for more than 30,000 seedlings of 180 tropical <span class="hlt">tree</span> <span class="hlt">species</span> on Barro Colorado Island, Panama, we tested whether <span class="hlt">species</span>' sensitivity to neighboring individuals relates to their relative abundance in the community. We found wide variation among <span class="hlt">species</span> in the effect of conspecific, but not heterospecific, neighbors on survival, and we found a significant relationship between the strength of conspecific neighbor effects and <span class="hlt">species</span> abundance. Specifically, rare <span class="hlt">species</span> suffered more from the presence of conspecific neighbors than common <span class="hlt">species</span> did, suggesting that conspecific density dependence shapes <span class="hlt">species</span> abundances in diverse communities. PMID:20576853</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2954149','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2954149"><span id="translatedtitle">Influences of Forest Structure, Climate and <span class="hlt">Species</span> Composition on <span class="hlt">Tree</span> Mortality across the Eastern US</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Lines, Emily R.; Coomes, David A.; Purves, Drew W.</p> <p>2010-01-01</p> <p>Few studies have quantified regional variation in <span class="hlt">tree</span> mortality, or explored whether <span class="hlt">species</span> compositional changes or within-<span class="hlt">species</span> variation are responsible for regional patterns, despite the fact that mortality has direct effects on the dynamics of woody biomass, <span class="hlt">species</span> composition, stand structure, wood production and forest response to climate change. Using Bayesian analysis of over 430,000 <span class="hlt">tree</span> records from a large eastern US forest database we characterised <span class="hlt">tree</span> mortality as a function of climate, soils, <span class="hlt">species</span> and size (stem diameter). We found (1) mortality is U-shaped vs. stem diameter for all 21 <span class="hlt">species</span> examined; (2) mortality is hump-shaped vs. plot basal area for most <span class="hlt">species</span>; (3) geographical variation in mortality is substantial, and correlated with several environmental factors; and (4) individual <span class="hlt">species</span> vary substantially from the combined average in the nature and magnitude of their mortality responses to environmental variation. Regional variation in mortality is therefore the product of variation in <span class="hlt">species</span> composition combined with highly varied mortality-environment correlations within <span class="hlt">species</span>. The results imply that variation in mortality is a crucial part of variation in the forest carbon cycle, such that including this variation in models of the global carbon cycle could significantly narrow uncertainty in climate change predictions. PMID:20967250</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013SPIE.8921E..07D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013SPIE.8921E..07D"><span id="translatedtitle">Forest <span class="hlt">tree</span> <span class="hlt">species</span> clssification based on airborne hyper-spectral imagery</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dian, Yuanyong; Li, Zengyuan; Pang, Yong</p> <p>2013-10-01</p> <p>Forest precision classification products were the basic data for surveying of forest resource, updating forest subplot information, logging and design of forest. However, due to the diversity of stand structure, complexity of the forest growth environment, it's difficult to discriminate forest <span class="hlt">tree</span> <span class="hlt">species</span> using multi-spectral image. The airborne hyperspectral images can achieve the high spatial and spectral resolution imagery of forest canopy, so it will good for <span class="hlt">tree</span> <span class="hlt">species</span> level classification. The aim of this paper was to test the effective of combining spatial and spectral features in airborne hyper-spectral image classification. The CASI hyper spectral image data were acquired from Liangshui natural reserves area. Firstly, we use the MNF (minimum noise fraction) transform method for to reduce the hyperspectral image dimensionality and highlighting variation. And secondly, we use the grey level co-occurrence matrix (GLCM) to extract the texture features of forest <span class="hlt">tree</span> canopy from the hyper-spectral image, and thirdly we fused the texture and the spectral features of forest canopy to classify the <span class="hlt">trees</span> <span class="hlt">species</span> using support vector machine (SVM) with different kernel functions. The results showed that when using the SVM classifier, MNF and texture-based features combined with linear kernel function can achieve the best overall accuracy which was 85.92%. It was also confirm that combine the spatial and spectral information can improve the accuracy of <span class="hlt">tree</span> <span class="hlt">species</span> classification.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25083408','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25083408"><span id="translatedtitle">New Phaeoacremonium <span class="hlt">species</span> isolated from sandalwood <span class="hlt">trees</span> in Western Australia.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gramaje, David; León, Maela; Pérez-Sierra, Ana; Burgess, Treena; Armengol, Josep</p> <p>2014-06-01</p> <p>Thirty-eight Phaeoacremonium isolates collected from pruning wounds of tropical sandalwood in Western Australia were studied with morphological and cultural characteristics as well as phylogenetic analyses of combined DNA sequences of the actin and ?-tubulin genes. Three known Phaeoacremonium <span class="hlt">species</span> were found, namely P. alvesii, P. parasiticum, and P. venezuelense. Phaeoacremonium venezuelense represents a new record for Australia. Two new <span class="hlt">species</span> are described: P. luteum sp. nov. can be identified by the ability to produce yellow pigment on MEA, PDA, and OA, the predominance of subcylindrical to subulate type II phialides, and the mycelium showing prominent exudate droplets observed as warts; and P. santali sp. nov. which can be separated from other <span class="hlt">species</span> producing pink colonies on MEA by the predominance of type I and II phialides, the distinct brownish olive colonies in OA, and slow growth. PMID:25083408</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24620581','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24620581"><span id="translatedtitle">Diversity and utilization of <span class="hlt">tree</span> <span class="hlt">species</span> in Meitei homegardens of Barak Valley, Assam.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Devi, N Linthoingambi; Das, Ashesh Kumar</p> <p>2013-03-01</p> <p>An inventory of <span class="hlt">tree</span> diversity in traditional homegardens of Meitei community was conducted in a Bontarapur village in Cachar district of Barak Valley, Assam. Meitei homegarden locally called Ingkhol exhibits a wide diversity in size, shape, location and composition. Seventy one <span class="hlt">tree</span> <span class="hlt">species</span> were enumerated from 50 homegardens belonging to 60 genus and 35 families. Among the families encountered, Rutaceae was the dominant family (4 genus and 7 <span class="hlt">species</span>) followed by Meliaceae (5 genus and 5 <span class="hlt">species</span>), Arecaceae (4 genus and 4 <span class="hlt">species</span>) and Moraceae (3 genus and 5 <span class="hlt">species</span>). Total 7946 <span class="hlt">tree</span> individuals were recorded, with the density of 831 No ha(-1) of and total basal area of 9.54 m2 ha(-1). Areco catechu was the dominant <span class="hlt">species</span> with the maximum number of individuals. Other dominant <span class="hlt">trees</span> include Mangifera indica, Artocarpus heterophyllus, Citrus grandis, Parkia timoriana, Syzygium cumini and Psidium guajava. Being a cash crop, the intensification of betel nut has been preferred in many homegardens. Homegardens form an important component of land use of Meitei community which fulfills the socio-cultural and economic needs of the family and helps in conserving plant diversity through utilization. PMID:24620581</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014IJAEO..28..140G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014IJAEO..28..140G"><span id="translatedtitle">Forest <span class="hlt">tree</span> <span class="hlt">species</span> discrimination in western Himalaya using EO-1 Hyperion</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>George, Rajee; Padalia, Hitendra; Kushwaha, S. P. S.</p> <p>2014-05-01</p> <p>The information acquired in the narrow bands of hyperspectral remote sensing data has potential to capture plant <span class="hlt">species</span> spectral variability, thereby improving forest <span class="hlt">tree</span> <span class="hlt">species</span> mapping. This study assessed the utility of spaceborne EO-1 Hyperion data in discrimination and classification of broadleaved evergreen and conifer forest <span class="hlt">tree</span> <span class="hlt">species</span> in western Himalaya. The pre-processing of 242 bands of Hyperion data resulted into 160 noise-free and vertical stripe corrected reflectance bands. Of these, 29 bands were selected through step-wise exclusion of bands (Wilk's Lambda). Spectral Angle Mapper (SAM) and Support Vector Machine (SVM) algorithms were applied to the selected bands to assess their effectiveness in classification. SVM was also applied to broadband data (Landsat TM) to compare the variation in classification accuracy. All commonly occurring six gregarious <span class="hlt">tree</span> <span class="hlt">species</span>, viz., white oak, brown oak, chir pine, blue pine, cedar and fir in western Himalaya could be effectively discriminated. SVM produced a better <span class="hlt">species</span> classification (overall accuracy 82.27%, kappa statistic 0.79) than SAM (overall accuracy 74.68%, kappa statistic 0.70). It was noticed that classification accuracy achieved with Hyperion bands was significantly higher than Landsat TM bands (overall accuracy 69.62%, kappa statistic 0.65). Study demonstrated the potential utility of narrow spectral bands of Hyperion data in discriminating <span class="hlt">tree</span> <span class="hlt">species</span> in a hilly terrain.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4110017','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4110017"><span id="translatedtitle">Negative Density Dependence Regulates Two <span class="hlt">Tree</span> <span class="hlt">Species</span> at Later Life Stage in a Temperate Forest</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Piao, Tiefeng; Chun, Jung Hwa; Yang, Hee Moon; Cheon, Kwangil</p> <p>2014-01-01</p> <p>Numerous studies have demonstrated that <span class="hlt">tree</span> survival is influenced by negative density dependence (NDD) and differences among <span class="hlt">species</span> in shade tolerance could enhance coexistence via resource partitioning, but it is still unclear how NDD affects <span class="hlt">tree</span> <span class="hlt">species</span> with different shade-tolerance guilds at later life stages. In this study, we analyzed the spatial patterns for <span class="hlt">trees</span> with dbh (diameter at breast height) ?2 cm using the pair-correlation g(r) function to test for NDD in a temperate forest in South Korea after removing the effects of habitat heterogeneity. The analyses were implemented for the most abundant shade-tolerant (Chamaecyparis obtusa) and shade-intolerant (Quercus serrata) <span class="hlt">species</span>. We found NDD existed for both <span class="hlt">species</span> at later life stages. We also found Quercus serrata experienced greater NDD compared with Chamaecyparis obtusa. This study indicates that NDD regulates the two abundant <span class="hlt">tree</span> <span class="hlt">species</span> at later life stages and it is important to consider variation in <span class="hlt">species</span>' shade tolerance in NDD study. PMID:25058660</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26094447','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26094447"><span id="translatedtitle">[Biomass allometric equations of nine common <span class="hlt">tree</span> <span class="hlt">species</span> in an evergreen broadleaved forest of subtropical China].</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zuo, Shu-di; Ren, Yin; Weng, Xian; Ding, Hong-feng; Luo, Yun-jian</p> <p>2015-02-01</p> <p>Biomass allometric equation (BAE) considered as a simple and reliable method in the estimation of forest biomass and carbon was used widely. In China, numerous studies focused on the BAEs for coniferous forest and pure broadleaved forest, and generalized BAEs were frequently used to estimate the biomass and carbon of mixed broadleaved forest, although they could induce large uncertainty in the estimates. In this study, we developed the <span class="hlt">species</span>-specific and generalized BAEs using biomass measurement for 9 common broadleaved <span class="hlt">trees</span> (Castanopsis fargesii, C. lamontii, C. tibetana, Lithocarpus glaber, Sloanea sinensis, Daphniphyllum oldhami, Alniphyllum fortunei, Manglietia yuyuanensis, and Engelhardtia fenzlii) of subtropical evergreen broadleaved forest, and compared differences in <span class="hlt">species</span>-specific and generalized BAEs. The results showed that D (diameter at breast height) was a better independent variable in estimating the biomass of branch, leaf, root, aboveground section and total <span class="hlt">tree</span> than a combined variable (D2 H) of D and H (<span class="hlt">tree</span> height) , but D2H was better than D in estimating stem biomass. R2 (coefficient of determination) values of BAEs for 6 <span class="hlt">species</span> decreased when adding H as the second independent variable into D- only BAEs, where R2 value for S. sinensis decreased by 5.6%. Compared with generalized D- and D2H-based BAEs, standard errors of estimate (SEE) of BAEs for 8 <span class="hlt">tree</span> <span class="hlt">species</span> decreased, and similar decreasing trend was observed for different components, where SEEs of the branch decreased by 13.0% and 20.3%. Therefore, the biomass carbon storage and its dynamic estimates were influenced largely by <span class="hlt">tree</span> <span class="hlt">species</span> and model types. In order to improve the accuracy of the estimates of biomass and carbon, we should consider the differences in <span class="hlt">tree</span> <span class="hlt">species</span> and model types. PMID:26094447</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70028562','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70028562"><span id="translatedtitle">Effects of sample survey design on the accuracy of classification <span class="hlt">tree</span> models in <span class="hlt">species</span> distribution models</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Edwards, T.C., Jr.; Cutler, D.R.; Zimmermann, N.E.; Geiser, L.; Moisen, G.G.</p> <p>2006-01-01</p> <p>We evaluated the effects of probabilistic (hereafter DESIGN) and non-probabilistic (PURPOSIVE) sample surveys on resultant classification <span class="hlt">tree</span> models for predicting the presence of four lichen <span class="hlt">species</span> in the Pacific Northwest, USA. Models derived from both survey forms were assessed using an independent data set (EVALUATION). Measures of accuracy as gauged by resubstitution rates were similar for each lichen <span class="hlt">species</span> irrespective of the underlying sample survey form. Cross-validation estimates of prediction accuracies were lower than resubstitution accuracies for all <span class="hlt">species</span> and both design types, and in all cases were closer to the true prediction accuracies based on the EVALUATION data set. We argue that greater emphasis should be placed on calculating and reporting cross-validation accuracy rates rather than simple resubstitution accuracy rates. Evaluation of the DESIGN and PURPOSIVE <span class="hlt">tree</span> models on the EVALUATION data set shows significantly lower prediction accuracy for the PURPOSIVE <span class="hlt">tree</span> models relative to the DESIGN models, indicating that non-probabilistic sample surveys may generate models with limited predictive capability. These differences were consistent across all four lichen <span class="hlt">species</span>, with 11 of the 12 possible <span class="hlt">species</span> and sample survey type comparisons having significantly lower accuracy rates. Some differences in accuracy were as large as 50%. The classification <span class="hlt">tree</span> structures also differed considerably both among and within the modelled <span class="hlt">species</span>, depending on the sample survey form. Overlap in the predictor variables selected by the DESIGN and PURPOSIVE <span class="hlt">tree</span> models ranged from only 20% to 38%, indicating the classification <span class="hlt">trees</span> fit the two evaluated survey forms on different sets of predictor variables. The magnitude of these differences in predictor variables throws doubt on ecological interpretation derived from prediction models based on non-probabilistic sample surveys. ?? 2006 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25371435','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25371435"><span id="translatedtitle">Toward more accurate ancestral protein genotype-phenotype reconstructions with the use of <span class="hlt">species</span> <span class="hlt">tree</span>-aware gene <span class="hlt">trees</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Groussin, Mathieu; Hobbs, Joanne K; Szöll?si, Gergely J; Gribaldo, Simonetta; Arcus, Vickery L; Gouy, Manolo</p> <p>2015-01-01</p> <p>The resurrection of ancestral proteins provides direct insight into how natural selection has shaped proteins found in nature. By tracing substitutions along a gene phylogeny, ancestral proteins can be reconstructed in silico and subsequently synthesized in vitro. This elegant strategy reveals the complex mechanisms responsible for the evolution of protein functions and structures. However, to date, all protein resurrection studies have used simplistic approaches for ancestral sequence reconstruction (ASR), including the assumption that a single sequence alignment alone is sufficient to accurately reconstruct the history of the gene family. The impact of such shortcuts on conclusions about ancestral functions has not been investigated. Here, we show with simulations that utilizing information on <span class="hlt">species</span> history using a model that accounts for the duplication, horizontal transfer, and loss (DTL) of genes statistically increases ASR accuracy. This underscores the importance of the <span class="hlt">tree</span> topology in the inference of putative ancestors. We validate our in silico predictions using in vitro resurrection of the LeuB enzyme for the ancestor of the Firmicutes, a major and ancient bacterial phylum. With this particular protein, our experimental results demonstrate that information on the <span class="hlt">species</span> phylogeny results in a biochemically more realistic and kinetically more stable ancestral protein. Additional resurrection experiments with different proteins are necessary to statistically quantify the impact of using <span class="hlt">species</span> <span class="hlt">tree</span>-aware gene <span class="hlt">trees</span> on ancestral protein phenotypes. Nonetheless, our results suggest the need for incorporating both sequence and DTL information in future studies of protein resurrections to accurately define the genotype-phenotype space in which proteins diversify. PMID:25371435</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.springerlink.com/content/g4295k8x56wj20g0/','USGSPUBS'); return false;" href="http://www.springerlink.com/content/g4295k8x56wj20g0/"><span id="translatedtitle">Complementary models of <span class="hlt">tree</span> <span class="hlt">species</span>-soil relationships in old-growth temperate forests</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Cross, Alison; Perakis, Steven S.</p> <p>2011-01-01</p> <p>Ecosystem level studies identify plant soil feed backs as important controls on soil nutrient availability,particularly for nitrogen and phosphorus. Although site and <span class="hlt">species</span> specific studies of <span class="hlt">tree</span> <span class="hlt">species</span> soil relationships are relatively common,comparatively fewer studies consider multiple coexisting speciesin old-growth forests across a range of sites that vary underlying soil fertility. We characterized patterns in forest floor and mineral soil nutrients associated with four common <span class="hlt">tree</span> <span class="hlt">species</span> across eight undisturbed old-growth forests in Oregon, USA, and used two complementary conceptual models to assess <span class="hlt">tree</span> <span class="hlt">species</span> soil relationships. Plant soil feedbacks that could reinforce sitelevel differences in nutrient availability were assessed using the context dependent relationships model, where by relative <span class="hlt">species</span> based differences in each soil nutrient divergedorconvergedas nutrient status changed across sites. <span class="hlt">Tree</span> <span class="hlt">species</span> soil relationships that did not reflect strong feedbacks were evaluated using a site independent relationships model, where by forest floor and surface mineral soil nutrient tools differed consistently by <span class="hlt">tree</span> <span class="hlt">species</span> across sites,without variation in deeper mineral soils. We found that theorganically cycled elements carbon, nitrogen, and phosphorus exhibited context-dependent differences among <span class="hlt">species</span> in both forest floor and mineral soil, and most of ten followed adivergence model,where by <span class="hlt">species</span> differences were greatest at high-nutrient sites. These patterns are consistent with the oryemphasizing biotic control of these elements through plant soil feedback mechanisms. Site independent <span class="hlt">species</span> differences were strongest for pool so if the weather able cations calcium, magnesium, potassium,as well as phosphorus, in mineral soils. Site independent <span class="hlt">species</span> differences in forest floor nutrients we reattributable too nespecies that displayed significant greater forest floor mass accumulation. Our finding confirmed that site-independent and context-dependent <span class="hlt">tree</span> <span class="hlt">species</span>-soil relationships occur simultaneouslyinold-grow the temperate forests, with context-dependent relationships strongest for organically cycled elements, and site-independent relationships strongest for weather able elements with in organic cycling phases. These models provide complementary explanations for patterns of nutrient accumulation and cycling in mixed <span class="hlt">species</span> old-growth temperate forests.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3641141','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3641141"><span id="translatedtitle">A Phylogenetic Perspective on the Individual <span class="hlt">Species</span>-Area Relationship in Temperate and Tropical <span class="hlt">Tree</span> Communities</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Yang, Jie; Swenson, Nathan G.; Cao, Min; Chuyong, George B.; Ewango, Corneille E. N.; Howe, Robert; Kenfack, David; Thomas, Duncan; Wolf, Amy; Lin, Luxiang</p> <p>2013-01-01</p> <p>Ecologists have historically used <span class="hlt">species</span>-area relationships (SARs) as a tool to understand the spatial distribution of <span class="hlt">species</span>. Recent work has extended SARs to focus on individual-level distributions to generate individual <span class="hlt">species</span> area relationships (ISARs). The ISAR approach quantifies whether individuals of a <span class="hlt">species</span> tend have more or less <span class="hlt">species</span> richness surrounding them than expected by chance. By identifying richness ‘accumulators’ and ‘repellers’, respectively, the ISAR approach has been used to infer the relative importance of abiotic and biotic interactions and neutrality. A clear limitation of the SAR and ISAR approaches is that all <span class="hlt">species</span> are treated as evolutionarily independent and that a large amount of work has now shown that local <span class="hlt">tree</span> neighborhoods exhibit non-random phylogenetic structure given the <span class="hlt">species</span> richness. Here, we use nine tropical and temperate forest dynamics plots to ask: (i) do ISARs change predictably across latitude?; (ii) is the phylogenetic diversity in the neighborhood of <span class="hlt">species</span> accumulators and repellers higher or lower than that expected given the observed <span class="hlt">species</span> richness?; and (iii) do <span class="hlt">species</span> accumulators, repellers distributed non-randomly on the community phylogenetic <span class="hlt">tree</span>? The results indicate no clear trend in ISARs from the temperate zone to the tropics and that the phylogenetic diversity surrounding the individuals of <span class="hlt">species</span> is generally only non-random on very local scales. Interestingly the distribution of <span class="hlt">species</span> accumulators and repellers was non-random on the community phylogenies suggesting the presence of phylogenetic signal in the ISAR across latitude. PMID:23650553</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25292455','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25292455"><span id="translatedtitle">Stem CO2 efflux in six co-occurring <span class="hlt">tree</span> <span class="hlt">species</span>: underlying factors and ecological implications.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rodríguez-Calcerrada, Jesús; López, Rosana; Salomón, Roberto; Gordaliza, Guillermo G; Valbuena-Carabaña, María; Oleksyn, Jacek; Gil, Luis</p> <p>2015-06-01</p> <p>Stem respiration plays a role in <span class="hlt">species</span> coexistence and forest dynamics. Here we examined the intra- and inter-specific variability of stem CO2 efflux (E) in dominant and suppressed <span class="hlt">trees</span> of six deciduous <span class="hlt">species</span> in a mixed forest stand: Fagus sylvatica L., Quercus petraea [Matt.] Liebl, Quercus pyrenaica?Willd., Prunus avium?L., Sorbus aucuparia?L. and Crataegus monogyna?Jacq. We conducted measurements in late autumn. Within <span class="hlt">species</span>, dominants had higher E per unit stem surface area (Es ) mainly because sapwood depth was higher than in suppressed <span class="hlt">trees</span>. Across <span class="hlt">species</span>, however, differences in Es corresponded with differences in the proportion of living parenchyma in sapwood and concentration of non-structural carbohydrates (NSC). Across <span class="hlt">species</span>, Es was strongly and NSC marginally positively related with an index of drought tolerance, suggesting that slow growth of drought-tolerant <span class="hlt">trees</span> is related to higher NSC concentration and Es . We conclude that, during the leafless period, E is indicative of maintenance respiration and is related with some ecological characteristics of the <span class="hlt">species</span>, such as drought resistance; that sapwood depth is the main factor explaining variability in Es within <span class="hlt">species</span>; and that the proportion of NSC in the sapwood is the main factor behind variability in Es among <span class="hlt">species</span>. PMID:25292455</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EnMan..53..783S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EnMan..53..783S"><span id="translatedtitle">The Right <span class="hlt">Tree</span> for the Job? Perceptions of <span class="hlt">Species</span> Suitability for the Provision of Ecosystem Services</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Smaill, Simeon J.; Bayne, Karen M.; Coker, Graham W. R.; Paul, Thomas S. H.; Clinton, Peter W.</p> <p>2014-04-01</p> <p>Stakeholders in plantation forestry are increasingly aware of the importance of the ecosystem services and non-market values associated with forests. In New Zealand, there is significant interest in establishing <span class="hlt">species</span> other than Pinus radiata D. Don (the dominant plantation <span class="hlt">species</span>) in the belief that alternative <span class="hlt">species</span> are better suited to deliver these services. Significant risk is associated with this position as there is little objective data to support these views. To identify which <span class="hlt">species</span> were likely to be planted to deliver ecosystem services, a survey was distributed to examine stakeholder perceptions. Stakeholders were asked which of 15 <span class="hlt">tree</span> attributes contributed to the provision of five ecosystem services (amenity value, bioenergy production, carbon capture, the diversity of native habitat, and erosion control/water quality) and to identify which of 22 candidate <span class="hlt">tree</span> <span class="hlt">species</span> possessed those attributes. These data were combined to identify the <span class="hlt">species</span> perceived most suitable for the delivery of each ecosystem service. Sequoia sempervirens (D.Don) Endl. closely matched the stakeholder derived ideotypes associated with all five ecosystem services. Comparisons to data from growth, physiological and ecological studies demonstrated that many of the opinions held by stakeholders were inaccurate, leading to erroneous assumptions regarding the suitability of most candidate <span class="hlt">species</span>. Stakeholder perceptions substantially influence <span class="hlt">tree</span> <span class="hlt">species</span> selection, and plantations established on the basis of inaccurate opinions are unlikely to deliver the desired outcomes. Attitudinal surveys associated with engagement campaigns are essential to improve stakeholder knowledge, advancing the development of fit-for-purpose forest management that provides the required ecosystem services.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/21444307','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21444307"><span id="translatedtitle">Genetic variation in a tropical <span class="hlt">tree</span> <span class="hlt">species</span> influences the associated epiphytic plant and invertebrate communities in a complex forest ecosystem.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zytynska, Sharon E; Fay, Michael F; Penney, David; Preziosi, Richard F</p> <p>2011-05-12</p> <p>Genetic differences among <span class="hlt">tree</span> <span class="hlt">species</span>, their hybrids and within <span class="hlt">tree</span> <span class="hlt">species</span> are known to influence associated ecological communities and ecosystem processes in areas of limited <span class="hlt">species</span> diversity. The extent to which this same phenomenon occurs based on genetic variation within a single <span class="hlt">tree</span> <span class="hlt">species</span>, in a diverse complex ecosystem such as a tropical forest, is unknown. The level of biodiversity and complexity of the ecosystem may reduce the impact of a single <span class="hlt">tree</span> <span class="hlt">species</span> on associated communities. We assessed the influence of within-<span class="hlt">species</span> genetic variation in the <span class="hlt">tree</span> Brosimum alicastrum (Moraceae) on associated epiphytic and invertebrate communities in a neotropical rainforest. We found a significant positive association between genetic distance of <span class="hlt">trees</span> and community difference of the epiphytic plants growing on the <span class="hlt">tree</span>, the invertebrates living among the leaf litter around the base of the <span class="hlt">tree</span>, and the invertebrates found on the <span class="hlt">tree</span> trunk. This means that the more genetically similar <span class="hlt">trees</span> are host to more similar epiphyte and invertebrate communities. Our work has implications for whole ecosystem conservation management, since maintaining sufficient genetic diversity at the primary producer level will enhance <span class="hlt">species</span> diversity of other plants and animals. PMID:21444307</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3081567','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3081567"><span id="translatedtitle">Genetic variation in a tropical <span class="hlt">tree</span> <span class="hlt">species</span> influences the associated epiphytic plant and invertebrate communities in a complex forest ecosystem</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Zytynska, Sharon E.; Fay, Michael F.; Penney, David; Preziosi, Richard F.</p> <p>2011-01-01</p> <p>Genetic differences among <span class="hlt">tree</span> <span class="hlt">species</span>, their hybrids and within <span class="hlt">tree</span> <span class="hlt">species</span> are known to influence associated ecological communities and ecosystem processes in areas of limited <span class="hlt">species</span> diversity. The extent to which this same phenomenon occurs based on genetic variation within a single <span class="hlt">tree</span> <span class="hlt">species</span>, in a diverse complex ecosystem such as a tropical forest, is unknown. The level of biodiversity and complexity of the ecosystem may reduce the impact of a single <span class="hlt">tree</span> <span class="hlt">species</span> on associated communities. We assessed the influence of within-<span class="hlt">species</span> genetic variation in the <span class="hlt">tree</span> Brosimum alicastrum (Moraceae) on associated epiphytic and invertebrate communities in a neotropical rainforest. We found a significant positive association between genetic distance of <span class="hlt">trees</span> and community difference of the epiphytic plants growing on the <span class="hlt">tree</span>, the invertebrates living among the leaf litter around the base of the <span class="hlt">tree</span>, and the invertebrates found on the <span class="hlt">tree</span> trunk. This means that the more genetically similar <span class="hlt">trees</span> are host to more similar epiphyte and invertebrate communities. Our work has implications for whole ecosystem conservation management, since maintaining sufficient genetic diversity at the primary producer level will enhance <span class="hlt">species</span> diversity of other plants and animals. PMID:21444307</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4538783','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4538783"><span id="translatedtitle"><span class="hlt">Tree</span> cover at fine and coarse spatial grains interacts with shade tolerance to shape plant <span class="hlt">species</span> distributions across the Alps</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Nieto-Lugilde, Diego; Lenoir, Jonathan; Abdulhak, Sylvain; Aeschimann, David; Dullinger, Stefan; Gégout, Jean-Claude; Guisan, Antoine; Pauli, Harald; Renaud, Julien; Theurillat, Jean-Paul; Thuiller, Wilfried; Van Es, Jérémie; Vittoz, Pascal; Willner, Wolfgang; Wohlgemuth, Thomas; Zimmermann, Niklaus E.; Svenning, Jens-Christian</p> <p>2015-01-01</p> <p>The role of competition for light among plants has long been recognised at local scales, but its importance for plant <span class="hlt">species</span> distributions at larger spatial scales has generally been ignored. <span class="hlt">Tree</span> cover modifies the local abiotic conditions below the canopy, notably by reducing light availability, and thus, also the performance of <span class="hlt">species</span> that are not adapted to low-light conditions. However, this local effect may propagate to coarser spatial grains, by affecting colonisation probabilities and local extinction risks of herbs and shrubs. To assess the effect of <span class="hlt">tree</span> cover at both the plot- and landscape-grain sizes (approximately 10-m and 1-km), we fit Generalised Linear Models (GLMs) for the plot-level distributions of 960 <span class="hlt">species</span> of herbs and shrubs using 6,935 vegetation plots across the European Alps. We ran four models with different combinations of variables (climate, soil and <span class="hlt">tree</span> cover) at both spatial grains for each <span class="hlt">species</span>. We used partial regressions to evaluate the independent effects of plot- and landscape-grain <span class="hlt">tree</span> cover on plot-level plant communities. Finally, the effects on <span class="hlt">species</span>-specific elevational range limits were assessed by simulating a removal experiment comparing the <span class="hlt">species</span> distributions under high and low <span class="hlt">tree</span> cover. Accounting for <span class="hlt">tree</span> cover improved the model performance, with the probability of the presence of shade-tolerant <span class="hlt">species</span> increasing with increasing <span class="hlt">tree</span> cover, whereas shade-intolerant <span class="hlt">species</span> showed the opposite pattern. The <span class="hlt">tree</span> cover effect occurred consistently at both the plot and landscape spatial grains, albeit most strongly at the former. Importantly, <span class="hlt">tree</span> cover at the two grain sizes had partially independent effects on plot-level plant communities. With high <span class="hlt">tree</span> cover, shade-intolerant <span class="hlt">species</span> exhibited narrower elevational ranges than with low <span class="hlt">tree</span> cover whereas shade-tolerant <span class="hlt">species</span> showed wider elevational ranges at both limits. These findings suggest that forecasts of climate-related range shifts for herb and shrub <span class="hlt">species</span> may be modified by <span class="hlt">tree</span> cover dynamics. PMID:26290621</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23572941','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23572941"><span id="translatedtitle">Improved method of in vitro regeneration in Leucaena leucocephala - a leguminous pulpwood <span class="hlt">tree</span> <span class="hlt">species</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shaik, Noor M; Arha, Manish; Nookaraju, A; Gupta, Sushim K; Srivastava, Sameer; Yadav, Arun K; Kulkarni, Pallavi S; Abhilash, O U; Vishwakarma, Rishi K; Singh, Somesh; Tatkare, Rajeshri; Chinnathambi, Kannan; Rawal, Shuban K; Khan, Bashir M</p> <p>2009-10-01</p> <p>Leucaena leucocephala is a fast growing <span class="hlt">multipurpose</span> legume <span class="hlt">tree</span> used for forage, leaf manure, paper and pulp. Lignin in Leucaena pulp adversely influences the quality of paper produced. Developing transgenic Leucaena with altered lignin by genetic engineering demands an optimized regeneration system. The present study deals with optimization of regeneration system for L. leucocephala cv. K636. Multiple shoot induction from the cotyledonary nodes of L. leucocephala was studied in response to cytokinins, thidiazuron (TDZ) and N(6)-benzyladenine (BA) supplemented in half strength MS (½-MS) medium and also their effect on in vitro rooting of the regenerated shoots. Multiple shoots were induced from cotyledonary nodes at varied frequencies depending on the type and concentration of cytokinin used in the medium. TDZ was found to induce more number of shoots per explant than BA, with a maximum of 7 shoots at an optimum concentration of 0.23 µM. Further increase in TDZ concentration resulted in reduced shoot length and fasciation of the shoots. Liquid pulse treatment of the explants with TDZ did not improve the shoot production further but improved the subsequent rooting of the shoots that regenerated. Regenerated shoots successfully rooted on ½-MS medium supplemented with 0.54 µM α-naphthaleneacetic acid (NAA). Rooted shoots of Leucaena were transferred to coco-peat and hardened plantlets showed ≥ 90 % establishment in the green house. PMID:23572941</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26828175','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26828175"><span id="translatedtitle"><span class="hlt">Tree</span> <span class="hlt">Species</span> Suitability to Bioswales and Impact on the Urban Water Budget.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Scharenbroch, Bryant C; Morgenroth, Justin; Maule, Brian</p> <p>2016-01-01</p> <p>Water movement between soil and the atmosphere is restricted by hardscapes in the urban environment. Some green infrastructure is intended to increase infiltration and storage of water, thus decreasing runoff and discharge of urban stormwater. Bioswales are a critical component of a water-sensitive urban design (or a low-impact urban design), and incorporation of <span class="hlt">trees</span> into these green infrastructural components is believed to be a novel way to return stored water to the atmosphere via transpiration. This research was conducted in The Morton Arboretum's main parking lot, which is one of the first and largest green infrastructure installations in the midwestern United States. The parking lot is constructed of permeable pavers and <span class="hlt">tree</span> bioswales. <span class="hlt">Trees</span> in bioswales were evaluated for growth and condition and for their effects on water cycling via transpiration. Our data indicate that <span class="hlt">trees</span> in bioswales accounted for 46 to 72% of total water outputs via transpiration, thereby reducing runoff and discharge from the parking lot. By evaluating the stomatal conductance, diameter growth, and condition of a variety of <span class="hlt">tree</span> <span class="hlt">species</span> in these bioswales, we found that not all <span class="hlt">species</span> are equally suited for bioswales and that not all are equivalent in their transpiration and growth rates, thereby contributing differentially to the functional capacity of bioswales. We conclude that <span class="hlt">species</span> with high stomatal conductance and large mature form are likely to contribute best to bioswale function. PMID:26828175</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EnMan..51..524M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EnMan..51..524M"><span id="translatedtitle">Certified and Uncertified Logging Concessions Compared in Gabon: Changes in Stand Structure, <span class="hlt">Tree</span> <span class="hlt">Species</span>, and Biomass</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Medjibe, V. P.; Putz, Francis E.; Romero, Claudia</p> <p>2013-03-01</p> <p>Forest management certification is assumed to promote sustainable forest management, but there is little field-based evidence to support this claim. To help fill this gap, we compared a Forest Stewardship Council (FSC)-certified with an adjacent uncertified, conventionally logged concession (CL) in Gabon on the basis of logging damage, above-ground biomass (AGB), and <span class="hlt">tree</span> <span class="hlt">species</span> diversity and composition. Before logging, we marked, mapped, and measured all <span class="hlt">trees</span> >10 cm dbh in 20 and twelve 1-ha permanent plots in the FSC and CL areas, respectively. Soil and <span class="hlt">tree</span> damage due to felling, skidding, and road-related activities was then assessed 2-3 months after the 508 ha FSC study area and the 200 ha CL study area were selectively logged at respective intensities of 5.7 m3/ha (0.39 <span class="hlt">trees</span>/ha) and 11.4 m3/ha (0.76 <span class="hlt">trees</span>/ha). For each <span class="hlt">tree</span> felled, averages of 9.1 and 20.9 other <span class="hlt">trees</span> were damaged in the FSC and CL plots, respectively; when expressed as the impacts per timber volume extracted, the values did not differ between the two treatments. Skid trails covered 2.9 % more of the CL surface, but skid trail length per unit timber volume extracted was not greater. Logging roads were wider in the CL than FSC site and disturbed 4.7 % more of the surface. Overall, logging caused declines in AGB of 7.1 and 13.4 % at the FSC and CL sites, respectively. Changes in <span class="hlt">tree</span> <span class="hlt">species</span> composition were small but greater for the CL site. Based on these findings and in light of the pseudoreplicated study design with less-than perfect counterfactual, we cautiously conclude that certification yields environmental benefits even after accounting for differences in logging intensities.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_9 --> <div id="page_10" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="181"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23277438','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23277438"><span id="translatedtitle">Certified and uncertified logging concessions compared in Gabon: changes in stand structure, <span class="hlt">tree</span> <span class="hlt">species</span>, and biomass.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Medjibe, V P; Putz, Francis E; Romero, Claudia</p> <p>2013-03-01</p> <p>Forest management certification is assumed to promote sustainable forest management, but there is little field-based evidence to support this claim. To help fill this gap, we compared a Forest Stewardship Council (FSC)-certified with an adjacent uncertified, conventionally logged concession (CL) in Gabon on the basis of logging damage, above-ground biomass (AGB), and <span class="hlt">tree</span> <span class="hlt">species</span> diversity and composition. Before logging, we marked, mapped, and measured all <span class="hlt">trees</span> >10 cm dbh in 20 and twelve 1-ha permanent plots in the FSC and CL areas, respectively. Soil and <span class="hlt">tree</span> damage due to felling, skidding, and road-related activities was then assessed 2-3 months after the 508 ha FSC study area and the 200 ha CL study area were selectively logged at respective intensities of 5.7 m(3)/ha (0.39 <span class="hlt">trees</span>/ha) and 11.4 m(3)/ha (0.76 <span class="hlt">trees</span>/ha). For each <span class="hlt">tree</span> felled, averages of 9.1 and 20.9 other <span class="hlt">trees</span> were damaged in the FSC and CL plots, respectively; when expressed as the impacts per timber volume extracted, the values did not differ between the two treatments. Skid trails covered 2.9 % more of the CL surface, but skid trail length per unit timber volume extracted was not greater. Logging roads were wider in the CL than FSC site and disturbed 4.7 % more of the surface. Overall, logging caused declines in AGB of 7.1 and 13.4 % at the FSC and CL sites, respectively. Changes in <span class="hlt">tree</span> <span class="hlt">species</span> composition were small but greater for the CL site. Based on these findings and in light of the pseudoreplicated study design with less-than perfect counterfactual, we cautiously conclude that certification yields environmental benefits even after accounting for differences in logging intensities. PMID:23277438</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70031880','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70031880"><span id="translatedtitle">Influences of calcium availability and <span class="hlt">tree</span> <span class="hlt">species</span> on Ca isotope fractionation in soil and vegetation</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Page, B.D.; Bullen, T.D.; Mitchell, M.J.</p> <p>2008-01-01</p> <p>The calcium (Ca) isotope system is potentially of great use for understanding biogeochemical processes at multiple scales in forest ecosystems, yet remains largely unexplored for this purpose. In order to further our understanding of Ca behavior in forests, we examined two nearly adjacent hardwood-dominated catchments with differing soil Ca concentrations, developed from crystalline bedrock, to determine the variability of 44Ca/ 40Ca ratios (expressed as ??44Ca) within soil and vegetation pools. For both sugar maple and American beech, the Ca isotope compositions of the measured roots and calculated bulk <span class="hlt">trees</span> were considerably lighter than those of soil pools at these sites, suggesting that the <span class="hlt">trees</span> were able to preferentially take up light Ca at the root-soil interface. The Ca isotope compositions of three of four root samples were among the lightest values yet reported for terrestrial materials (??44Ca ???-3.95???). Our results further indicate that Ca isotopes were fractionated along the transpiration streams of both <span class="hlt">tree</span> <span class="hlt">species</span> with roots having the least ??44Ca values and leaf litter the greatest. An approximately 2??? difference in ??44Ca values between roots and leaf litter of both <span class="hlt">tree</span> <span class="hlt">species</span> suggests a persistent fractionation mechanism along the transpiration stream, likely related to Ca binding in wood tissue coupled with internal ion exchange. Finally, our data indicate that differing <span class="hlt">tree</span> <span class="hlt">species</span> demand for Ca and soil Ca concentrations together may influence Ca isotope distribution within the <span class="hlt">trees</span>. Inter-catchment differences in Ca isotope distributions in soils and <span class="hlt">trees</span> were minor, indicating that the results of our study may have broad transferability to studies of forest ecosystems in catchments developed on crystalline substrates elsewhere. ?? 2008 Springer Science+Business Media B.V.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1712942H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1712942H"><span id="translatedtitle"><span class="hlt">Tree</span> <span class="hlt">species</span> specific soil moisture patterns and dynamics through the seasons</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Heidbüchel, Ingo; Dreibrodt, Janek; Simard, Sonia; Güntner, Andreas; Blume, Theresa</p> <p>2015-04-01</p> <p>Soil moisture patterns in the landscape are largely controlled by soil types (pore size distributions) and landscape position. But how strong is the influence of vegetation on patterns within a single soil type? While we would envision a clear difference in soil moisture patterns and responses between for example bare soil, a pasture and a forest, our conceptual images start to become less clear when we move on to different forest stands. Do different <span class="hlt">tree</span> <span class="hlt">species</span> cause different moisture patterns to emerge? Could it be possible to identify the dominant <span class="hlt">tree</span> <span class="hlt">species</span> of a site by classifying its soil moisture pattern? To investigate this question we analyzed data from 15 sensor clusters in the lowlands of north-eastern Germany (within the TERENO observatory) which were instrumented with soil moisture sensors (5 profiles per site), tensiometers, sap flow sensors, throughfall and stemflow gages. Data has been collected at these sites since May 2014. While the summer data has already been analyzed, the analysis of the winter data and thus the possible seasonal shifts in patterns will be carried out in the coming months. Throughout the last summer we found different dynamics of soil moisture patterns under pine <span class="hlt">trees</span> compared to beech <span class="hlt">trees</span>. While the soils under beech <span class="hlt">trees</span> were more often relatively wet and more often relatively dry, the soils under pine <span class="hlt">trees</span> showed less variability and more often average soil moisture. These differences are most likely due to differences in both throughfall patterns as well as root water uptake. Further analysis includes the use of throughfall and stemflow data as well as stable water isotope samples that were taken at different depths in the soil, in the groundwater and from the sapwood. The manifestation of <span class="hlt">tree</span> <span class="hlt">species</span> differences in soil moisture patterns and dynamics is likely to have implications for groundwater recharge, transit times and hydrologic partitioning.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25127455','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25127455"><span id="translatedtitle">Patterns of <span class="hlt">tree</span> <span class="hlt">species</span> diversity in relation to climatic factors on the Sierra Madre Occidental, Mexico.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Silva-Flores, Ramón; Pérez-Verdín, Gustavo; Wehenkel, Christian</p> <p>2014-01-01</p> <p>Biological diversity can be defined as variability among living organisms from all sources, including terrestrial organisms, marine and other aquatic ecosystems, and the ecological complexes which they are part of. This includes diversity within <span class="hlt">species</span>, between <span class="hlt">species</span>, and of ecosystems. Numerous diversity indices combine richness and evenness in a single expression, and several climate-based explanations have been proposed to explain broad-scale diversity patterns. However, climate-based water-energy dynamics appears to be an essential factor that determines patterns of diversity. The Mexican Sierra Madre Occidental occupies an area of about 29 million hectares and is located between the Neotropical and Holarctic ecozones. It shelters a high diversity of flora, including 24 different <span class="hlt">species</span> of Pinus (ca. 22% on the whole), 54 <span class="hlt">species</span> of Quercus (ca. 9-14%), 7 <span class="hlt">species</span> of Arbutus (ca. 50%) and many other <span class="hlt">trees</span> <span class="hlt">species</span>. The objectives of this study were to model how <span class="hlt">tree</span> <span class="hlt">species</span> diversity is related to climatic and geographic factors and stand density and to test the Metabolic Theory, Productivity-Diversity Hypothesis, Physiological Tolerance Hypothesis, Mid-Domain Effect, and the Water-Energy Dynamic Theory on the Sierra Madre Occidental, Durango. The results supported the Productivity-Diversity Hypothesis, Physiological Tolerance Hypothesis and Water-Energy Dynamic Theory, but not the Mid-Domain Effect or Metabolic Theory. The annual aridity index was the variable most closely related to the diversity indices analyzed. Contemporary climate was found to have moderate to strong effects on the minimum, median and maximum <span class="hlt">tree</span> <span class="hlt">species</span> diversity. Because water-energy dynamics provided a satisfactory explanation for the patterns of minimum, median and maximum diversity, an understanding of this factor is critical to future biodiversity research. Quantile regression of the data showed that the three diversity parameters of <span class="hlt">tree</span> <span class="hlt">species</span> are generally higher in cold, humid temperate climates than in dry, hot climates. PMID:25127455</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4134238','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4134238"><span id="translatedtitle">Patterns of <span class="hlt">Tree</span> <span class="hlt">Species</span> Diversity in Relation to Climatic Factors on the Sierra Madre Occidental, Mexico</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Silva-Flores, Ramón; Pérez-Verdín, Gustavo; Wehenkel, Christian</p> <p>2014-01-01</p> <p>Biological diversity can be defined as variability among living organisms from all sources, including terrestrial organisms, marine and other aquatic ecosystems, and the ecological complexes which they are part of. This includes diversity within <span class="hlt">species</span>, between <span class="hlt">species</span>, and of ecosystems. Numerous diversity indices combine richness and evenness in a single expression, and several climate-based explanations have been proposed to explain broad-scale diversity patterns. However, climate-based water-energy dynamics appears to be an essential factor that determines patterns of diversity. The Mexican Sierra Madre Occidental occupies an area of about 29 million hectares and is located between the Neotropical and Holarctic ecozones. It shelters a high diversity of flora, including 24 different <span class="hlt">species</span> of Pinus (ca. 22% on the whole), 54 <span class="hlt">species</span> of Quercus (ca. 9–14%), 7 <span class="hlt">species</span> of Arbutus (ca. 50%) and many other <span class="hlt">trees</span> <span class="hlt">species</span>. The objectives of this study were to model how <span class="hlt">tree</span> <span class="hlt">species</span> diversity is related to climatic and geographic factors and stand density and to test the Metabolic Theory, Productivity-Diversity Hypothesis, Physiological Tolerance Hypothesis, Mid-Domain Effect, and the Water-Energy Dynamic Theory on the Sierra Madre Occidental, Durango. The results supported the Productivity-Diversity Hypothesis, Physiological Tolerance Hypothesis and Water-Energy Dynamic Theory, but not the Mid-Domain Effect or Metabolic Theory. The annual aridity index was the variable most closely related to the diversity indices analyzed. Contemporary climate was found to have moderate to strong effects on the minimum, median and maximum <span class="hlt">tree</span> <span class="hlt">species</span> diversity. Because water-energy dynamics provided a satisfactory explanation for the patterns of minimum, median and maximum diversity, an understanding of this factor is critical to future biodiversity research. Quantile regression of the data showed that the three diversity parameters of <span class="hlt">tree</span> <span class="hlt">species</span> are generally higher in cold, humid temperate climates than in dry, hot climates. PMID:25127455</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/17204076','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/17204076"><span id="translatedtitle">Large variation in whole-plant water-use efficiency among tropical <span class="hlt">tree</span> <span class="hlt">species</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cernusak, Lucas A; Aranda, Jorge; Marshall, John D; Winter, Klaus</p> <p>2007-01-01</p> <p>It is well known that whole-plant water-use efficiency (transpiration efficiency of carbon gain, TE(C)) varies among plant <span class="hlt">species</span> with different photosynthetic pathways. However, less is known of such variation among <span class="hlt">tree</span> <span class="hlt">species</span> within the C(3) group. Here we measured the TE(C) of seven C(3) tropical <span class="hlt">tree</span> <span class="hlt">species</span>. Isotopic analyses (delta(13)C, delta(18)O, and delta(15)N) and elemental analyses (carbon and nitrogen) were undertaken to provide insight into sources of variation in TE(C). Plants were grown over several months in approx. 80% full sunlight in individual 38-l containers in the Republic of Panama. Soil moisture content was nonlimiting. Significant variation was observed in TE(C) among the C(3) <span class="hlt">tree</span> <span class="hlt">species</span>. Values ranged from 1.6 mmol C mol(-1) H(2)O for teak (Tectona grandis) to 4.0 mmol C mol(-1) H(2)O for a legume, Platymiscium pinnatum. Variation in TE(C) was correlated with both leaf N concentration, a proxy for photosynthetic capacity, and oxygen-isotope enrichment, a proxy for stomatal conductance. The TE(C) varied with C-isotope discrimination within <span class="hlt">species</span>, but the relationship broke down among <span class="hlt">species</span>, reflecting the existence of <span class="hlt">species</span>-specific offsets. PMID:17204076</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3586649','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3586649"><span id="translatedtitle">Epigenetic regulation of adaptive responses of forest <span class="hlt">tree</span> <span class="hlt">species</span> to the environment</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Bräutigam, Katharina; Vining, Kelly J; Lafon-Placette, Clément; Fossdal, Carl G; Mirouze, Marie; Marcos, José Gutiérrez; Fluch, Silvia; Fraga, Mario Fernández; Guevara, M Ángeles; Abarca, Dolores; Johnsen, Øystein; Maury, Stéphane; Strauss, Steven H; Campbell, Malcolm M; Rohde, Antje; Díaz-Sala, Carmen; Cervera, María-Teresa</p> <p>2013-01-01</p> <p>Epigenetic variation is likely to contribute to the phenotypic plasticity and adaptative capacity of plant <span class="hlt">species</span>, and may be especially important for long-lived organisms with complex life cycles, including forest <span class="hlt">trees</span>. Diverse environmental stresses and hybridization/polyploidization events can create reversible heritable epigenetic marks that can be transmitted to subsequent generations as a form of molecular “memory”. Epigenetic changes might also contribute to the ability of plants to colonize or persist in variable environments. In this review, we provide an overview of recent data on epigenetic mechanisms involved in developmental processes and responses to environmental cues in plant, with a focus on forest <span class="hlt">tree</span> <span class="hlt">species</span>. We consider the possible role of forest <span class="hlt">tree</span> epigenetics as a new source of adaptive traits in plant breeding, biotechnology, and ecosystem conservation under rapid climate change. PMID:23467802</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20010004211','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20010004211"><span id="translatedtitle">BOREAS TE-4 Gas Exchange Data from Boreal <span class="hlt">Tree</span> <span class="hlt">Species</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hall, Forrest G. (Editor); Curd, Shelaine (Editor); Collatz, G. James; Berry, Joseph A.; Gamon, John; Fredeen, Art; Fu, Wei</p> <p>2000-01-01</p> <p>The BOREAS TE-4 team collected steady-state gas exchange and reflectance data from several <span class="hlt">species</span> in the BOREAS SSA during 1994 and in the NSA during 1996. Measurements of light, CO2, temperature, and humidity response curves were made by the BOREAS TE-4 team during the summers of 1994 and 1996 using intact attached leaves of boreal forest <span class="hlt">species</span> located in the BOREAS SSA and NSA. These measurements were conducted to calibrate models used to predict photosynthesis, stomatal conductance, and leaf respiration. The 1994 and 1996 data can be used to construct plots of response functions or for parameterizing models. Parameter values are suitable for application in SiB2 (Sellers et al., 1996) or the leaf model of Collatz et al. (1991), and programs can be obtained from the investigators. The data are stored in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.B51B0028L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.B51B0028L"><span id="translatedtitle">Dynamics of <span class="hlt">Tree</span> <span class="hlt">Species</span> Composition in Temperate Mountains of South Korea over Fourteen Years using 880 Permanent Plots</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lee, B.; Kim, H. S.; Park, J.; Moon, M.; Cho, S.; Ryu, D.; Wynn, K. Z.; Park, J.</p> <p>2014-12-01</p> <p>The structure of forest and diversity of <span class="hlt">tree</span> <span class="hlt">species</span> in temperate mountains have been influenced by changing climate conditions as well as successional changes. To understand how <span class="hlt">tree</span> <span class="hlt">species</span> composition and stand structure change across temperate mountains, the <span class="hlt">species</span> composition, size, and environmental information were collected over the past fourteen years in 880 quadrats of 20 m x 50 m of woodland communities distributed across Jiri and Baekoon Mountains, South Korea. The preliminary investigation on variations of <span class="hlt">tree</span> <span class="hlt">species</span> revealed that overall composition of <span class="hlt">tree</span> <span class="hlt">species</span> increased in terms of both diversity and biomass growth of <span class="hlt">tree</span> <span class="hlt">species</span>, reflecting fast and wide changes in temperate forests of Korea. Among dominant <span class="hlt">trees</span>, the Quercus mongolica, Styrax japonicu, and Acer pseudosieboldianum recorded the highest increase in stand density, implying the most prosperous <span class="hlt">species</span> under current conditions, while the <span class="hlt">species</span> of Quercus variabilis and Fraxinus mandshurica appeared as fast declining <span class="hlt">species</span> in the number. In terms of biomass growth of dominant <span class="hlt">species</span>, the Stewartia pseudocamellia showed the largest increase of biomass, followed by Quercus serrata and Quercus mongolica., while the Fraxinus mandshurica appeared to have a rapid decline, followed by Alnus japonica and Quercus dentata. Overall, the fast change of composition in <span class="hlt">tree</span> <span class="hlt">species</span> is clear and further analysis to clarify the reasons for such fast and <span class="hlt">species</span>-specific changes is underway especially to separate the effect of successional change and climate change.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3892915','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3892915"><span id="translatedtitle">Eco-physiological adaptation of dominant <span class="hlt">tree</span> <span class="hlt">species</span> at two contrasting karst habitats in southwestern China</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wu, Qian; Yan, Hui; Xu, Xinwu</p> <p>2013-01-01</p> <p>The purpose of this study was to investigate the eco-physiological adaptation of indigenous woody <span class="hlt">species</span> to their habitats in karst areas of southwestern China. Two contrasting forest habitats were studied: a degraded habitat in Daxiagu and a well-developed habitat in Tianlongshan, and the eco-physiological characteristics of the <span class="hlt">trees</span> were measured for three growth seasons. Photosynthetic rate (Pn), stomatal conductance (gs), and transpiration rate (Tr) of the <span class="hlt">tree</span> <span class="hlt">species</span> in Daxiagu were 2-3 times higher than those in Tianlongshan under ambient conditions. However, this habitat effect was not significant when measurements were taken under controlled conditions. Under controlled conditions, Pn, gs, and Tr of the deciduous <span class="hlt">species</span> were markedly higher than those for the evergreen <span class="hlt">species</span>. Habitat had no significant effect on water use efficiency (WUE) or photochemical characteristics of PSII. The stomatal sensitivity of woody <span class="hlt">species</span> in the degraded habitat was much higher than that in the well-developed habitat. Similarly, the leaf total nitrogen (N) and phosphorus (P) contents expressed on the basis of either dry mass or leaf area were also much higher in Daxiagu than they were in Tianlongshan. The mass-based leaf total N content of deciduous <span class="hlt">species</span> was much higher than that of evergreen <span class="hlt">species</span>, while leaf area-based total N and P contents of evergreens were significantly higher than those of deciduous <span class="hlt">species</span>. The photosynthetic nitrogen- and phosphorus-use efficiencies (PNUE and PPUE) of deciduous <span class="hlt">species</span> were much higher than those of evergreens. Further, the PPUE of the woody <span class="hlt">species</span> in Tianlongshan was much higher than that  of the woody <span class="hlt">species</span> in Daxiagu. The results from three growth seasons imply that the <span class="hlt">tree</span> <span class="hlt">species</span> were able to adapt well to their growth habitats. Furthermore, it seems that so-called “temporary drought stress” may not occur, or may not be severe for most woody plants in karst areas of southwestern China. PMID:24555059</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25555688','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25555688"><span id="translatedtitle">Characterization of mariner-like transposons of the mauritiana Subfamily in seven <span class="hlt">tree</span> aphid <span class="hlt">species</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kharrat, Imen; Mezghani, Maha; Casse, Nathalie; Denis, Françoise; Caruso, Aurore; Makni, Hanem; Capy, Pierre; Rouault, Jacques-Deric; Chénais, Benoît; Makni, Mohamed</p> <p>2015-02-01</p> <p>Mariner-like elements (MLEs) are Class II transposons present in all eukaryotic genomes in which MLEs have been searched for. This article reports the detection of MLEs in seven of the main fruit <span class="hlt">tree</span> aphid <span class="hlt">species</span> out of eight <span class="hlt">species</span> studied. Deleted MLE sequences of 916-919 bp were characterized, using the terminal-inverted repeats (TIRs) of mariner elements belonging to the mauritiana Subfamily as primers. All the sequences detected were deleted copies of full-length elements that included the 3'- and 5'-TIRs but displayed internal deletions affecting Mos1 activity. Networks based on the mtDNA cytochrome oxidase subunit-I (CO-I) and MLE sequences were incongruent, suggesting that mutations in transposon sequences had accumulated before speciation of <span class="hlt">tree</span> aphid <span class="hlt">species</span> occurred, and that they have been maintained in this <span class="hlt">species</span> via vertical transmissions. This is the first evidence of the widespread occurrence of MLEs in aphids. PMID:25555688</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24584221','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24584221"><span id="translatedtitle">Physiological minimum temperatures for root growth in seven common European broad-leaved <span class="hlt">tree</span> <span class="hlt">species</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Schenker, Gabriela; Lenz, Armando; Körner, Christian; Hoch, Günter</p> <p>2014-03-01</p> <p>Temperature is the most important factor driving the cold edge distribution limit of temperate <span class="hlt">trees</span>. Here, we identified the minimum temperatures for root growth in seven broad-leaved <span class="hlt">tree</span> <span class="hlt">species</span>, compared them with the <span class="hlt">species</span>' natural elevational limits and identified morphological changes in roots produced near their physiological cold limit. Seedlings were exposed to a vertical soil-temperature gradient from 20 to 2 °C along the rooting zone for 18 weeks. In all <span class="hlt">species</span>, the bulk of roots was produced at temperatures above 5 °C. However, the absolute minimum temperatures for root growth differed among <span class="hlt">species</span> between 2.3 and 4.2 °C, with those <span class="hlt">species</span> that reach their natural distribution limits at higher elevations also tending to have lower thermal limits for root tissue formation. In all investigated <span class="hlt">species</span>, the roots produced at temperatures close to the thermal limit were pale, thick, unbranched and of reduced mechanical strength. Across <span class="hlt">species</span>, the specific root length (m g(-1) root) was reduced by, on average, 60% at temperatures below 7 °C. A significant correlation of minimum temperatures for root growth with the natural high elevation limits of the investigated <span class="hlt">species</span> indicates <span class="hlt">species</span>-specific thermal requirements for basic physiological processes. Although these limits are not necessarily directly causative for the upper distribution limit of a <span class="hlt">species</span>, they seem to belong to a syndrome of adaptive processes for life at low temperatures. The anatomical changes at the cold limit likely hint at the mechanisms impeding meristematic activity at low temperatures. PMID:24584221</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26164201','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26164201"><span id="translatedtitle">New flux based dose-response relationships for ozone for European forest <span class="hlt">tree</span> <span class="hlt">species</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Büker, P; Feng, Z; Uddling, J; Briolat, A; Alonso, R; Braun, S; Elvira, S; Gerosa, G; Karlsson, P E; Le Thiec, D; Marzuoli, R; Mills, G; Oksanen, E; Wieser, G; Wilkinson, M; Emberson, L D</p> <p>2015-11-01</p> <p>To derive O3 dose-response relationships (DRR) for five European forest <span class="hlt">trees</span> <span class="hlt">species</span> and broadleaf deciduous and needleleaf <span class="hlt">tree</span> plant functional types (PFTs), phytotoxic O3 doses (PODy) were related to biomass reductions. PODy was calculated using a stomatal flux model with a range of cut-off thresholds (y) indicative of varying detoxification capacities. Linear regression analysis showed that DRR for PFT and individual <span class="hlt">tree</span> <span class="hlt">species</span> differed in their robustness. A simplified parameterisation of the flux model was tested and showed that for most non-Mediterranean <span class="hlt">tree</span> <span class="hlt">species</span>, this simplified model led to similarly robust DRR as compared to a <span class="hlt">species</span>- and climate region-specific parameterisation. Experimentally induced soil water stress was not found to substantially reduce PODy, mainly due to the short duration of soil water stress periods. This study validates the stomatal O3 flux concept and represents a step forward in predicting O3 damage to forests in a spatially and temporally varying climate. PMID:26164201</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/Publications.htm?seq_no_115=276289','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/Publications.htm?seq_no_115=276289"><span id="translatedtitle">Conspecific plant-soil feedbacks of temperate <span class="hlt">tree</span> <span class="hlt">species</span> in the southern Appalachians, USA</span></a></p> <p><a target="_blank" href="http://www.ars.usda.gov/services/TekTran.htm">Technology Transfer Automated Retrieval System (TEKTRAN)</a></p> <p></p> <p></p> <p>Many <span class="hlt">tree</span> <span class="hlt">species</span> have seedling recruitment patterns suggesting that they are affected by non-competitive distance-dependent sources of mortality. We conducted an experiment, with landscape-level replication, to identify cases of negative distance-dependence effects and whether variation in these e...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005BGD.....2..303B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005BGD.....2..303B"><span id="translatedtitle">Pure stands of temperate forest <span class="hlt">tree</span> <span class="hlt">species</span> modify soil respiration and N turnover</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brüggemann, N.; Rosenkranz, P.; Papen, H.; Pilegaard, K.; Butterbach-Bahl, K.</p> <p>2005-04-01</p> <p>The effects of five different <span class="hlt">tree</span> <span class="hlt">species</span> common in the temperate zone, i.e. beech (Fagus sylvatica L.), pedunculate oak (Quercus robur L.), Norway spruce (Picea abies [L.] Karst), Japanese larch (Larix leptolepis [Sichold and Zucc.] Gordon) and mountain pine (Pinus mugo Turra), on soil respiration, gross N mineralization and gross nitrification rates were investigated. Soils were sampled in spring and summer 2002 at a forest trial in Western Jutland, Denmark, where pure stands of the five <span class="hlt">tree</span> <span class="hlt">species</span> of the same age were growing on the same soil. Soil respiration, gross rates of N mineralization and nitrification were significantly higher in the organic layers than in the Ah horizons for all <span class="hlt">tree</span> <span class="hlt">species</span> and both sampling dates. In summer (July), the highest rates of soil respiration, gross N mineralization and gross nitrification were found in the organic layer under spruce, followed by beech > larch > oak > pine. In spring (April), these rates were also higher under spruce compared to the other <span class="hlt">tree</span> <span class="hlt">species</span>, but were significantly lower than in summer. For the Ah horizons no clear seasonal trend was observed for any of the processes examined. A linear relationship between soil respiration and gross N mineralization (r2=0.77), gross N mineralization and gross nitrification rates (r2=0.72), and between soil respiration and gross nitrification (r2=0.81) was found. The results obtained underline the importance of considering the effect of forest type on soil C and N transformations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25065257','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25065257"><span id="translatedtitle">Responses of <span class="hlt">tree</span> <span class="hlt">species</span> to heat waves and extreme heat events.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Teskey, Robert; Wertin, Timothy; Bauweraerts, Ingvar; Ameye, Maarten; McGuire, Mary Anne; Steppe, Kathy</p> <p>2015-09-01</p> <p>The number and intensity of heat waves has increased, and this trend is likely to continue throughout the 21st century. Often, heat waves are accompanied by drought conditions. It is projected that the global land area experiencing heat waves will double by 2020, and quadruple by 2040. Extreme heat events can impact a wide variety of <span class="hlt">tree</span> functions. At the leaf level, photosynthesis is reduced, photooxidative stress increases, leaves abscise and the growth rate of remaining leaves decreases. In some <span class="hlt">species</span>, stomatal conductance increases at high temperatures, which may be a mechanism for leaf cooling. At the whole plant level, heat stress can decrease growth and shift biomass allocation. When drought stress accompanies heat waves, the negative effects of heat stress are exacerbated and can lead to <span class="hlt">tree</span> mortality. However, some <span class="hlt">species</span> exhibit remarkable tolerance to thermal stress. Responses include changes that minimize stress on photosynthesis and reductions in dark respiration. Although there have been few studies to date, there is evidence of within-<span class="hlt">species</span> genetic variation in thermal tolerance, which could be important to exploit in production forestry systems. Understanding the mechanisms of differing <span class="hlt">tree</span> responses to extreme temperature events may be critically important for understanding how <span class="hlt">tree</span> <span class="hlt">species</span> will be affected by climate change. PMID:25065257</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70045618','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70045618"><span id="translatedtitle">Effects of canopy <span class="hlt">tree</span> <span class="hlt">species</span> on belowground biogeochemistry in a lowland wet tropical forest</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Keller, Adrienne B.; Reed, Sasha C.; Townsend, Alan R.; Cleveland, Cory C.</p> <p>2013-01-01</p> <p>Tropical rain forests are known for their high biological diversity, but the effects of plant diversity on important ecosystem processes in this biome remain unclear. Interspecies differences in both the demand for nutrients and in foliar and litter nutrient concentrations could drive variations in both the pool sizes and fluxes of important belowground resources, yet our understanding of the effects and importance of aboveground heterogeneity on belowground biogeochemistry is poor, especially in the <span class="hlt">species</span>-rich forests of the wet tropics. To investigate the effects of individual <span class="hlt">tree</span> <span class="hlt">species</span> on belowground biogeochemical processes, we used both field and laboratory studies to examine how carbon (C), nitrogen (N), and phosphorus (P) cycles vary under nine different canopy <span class="hlt">tree</span> <span class="hlt">species</span> – including three legume and six non-legume <span class="hlt">species</span> – that vary in foliar nutrient concentrations in a wet tropical forest in southwestern Costa Rica. We found significant differences in belowground C, N and P cycling under different canopy <span class="hlt">tree</span> <span class="hlt">species</span>: total C, N and P pools in standing litter varied by <span class="hlt">species</span>, as did total soil and microbial C and N pools. Rates of soil extracellular acid phosphatase activity also varied significantly among <span class="hlt">species</span> and functional groups, with higher rates of phosphatase activity under legumes. In addition, across all <span class="hlt">tree</span> <span class="hlt">species</span>, phosphatase activity was significantly positively correlated with litter N/P ratios, suggesting a tight coupling between relative N and P inputs and resource allocation to P acquisition. Overall, our results suggest the importance of aboveground plant community composition in promoting belowground biogeochemical heterogeneity at relatively small spatial scales.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2803392','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2803392"><span id="translatedtitle">Neither Host-specific nor Random: Vascular Epiphytes on Three <span class="hlt">Tree</span> <span class="hlt">Species</span> in a Panamanian Lowland Forest</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>LAUBE, STEFAN; ZOTZ, GERHARD</p> <p>2006-01-01</p> <p>• Background and Aims A possible role of host <span class="hlt">tree</span> identity in the structuring of vascular epiphyte communities has attracted scientific attention for decades. Specifically, it has been suggested that each host <span class="hlt">tree</span> <span class="hlt">species</span> has a specific subset of the local <span class="hlt">species</span> pool according to its own set of properties, e.g. physicochemical characteristics of the bark, <span class="hlt">tree</span> architecture, or leaf phenology patterns. • Methods A novel, quantitative approach to this question is presented, taking advantage of a complete census of the vascular epiphyte community in 0·4 ha of undisturbed lowland forest in Panama. For three locally common host-<span class="hlt">tree</span> <span class="hlt">species</span> (Socratea exorrhiza, Marila laxiflora, Perebea xanthochyma) null models were created of the expected epiphyte assemblages assuming that epiphyte colonization reflected random distribution of epiphytes in the forest. • Key Results In all three <span class="hlt">tree</span> <span class="hlt">species</span>, abundances of the majority of epiphyte <span class="hlt">species</span> (69–81?%) were indistinguishable from random, while the remaining <span class="hlt">species</span> were about equally over- or under-represented compared with their occurrence in the entire forest plot. Permutations based on the number of colonized <span class="hlt">trees</span> (reflecting observed spatial patchiness) yielded similar results. Finally, a third analysis (canonical correspondence analysis) also confirmed host-specific differences in epiphyte assemblages. In spite of pronounced preferences of some epiphytes for particular host <span class="hlt">trees</span>, no epiphyte <span class="hlt">species</span> was restricted to a single host. • Conclusions The epiphytes on a given <span class="hlt">tree</span> <span class="hlt">species</span> are not simply a random sample of the local <span class="hlt">species</span> pool, but there are no indications of host specificity either. PMID:16574691</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25902148','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25902148"><span id="translatedtitle">Mapping and characterizing selected canopy <span class="hlt">tree</span> <span class="hlt">species</span> at the Angkor World Heritage site in Cambodia using aerial data.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Singh, Minerva; Evans, Damian; Tan, Boun Suy; Nin, Chan Samean</p> <p>2015-01-01</p> <p>At present, there is very limited information on the ecology, distribution, and structure of Cambodia's <span class="hlt">tree</span> <span class="hlt">species</span> to warrant suitable conservation measures. The aim of this study was to assess various methods of analysis of aerial imagery for characterization of the forest mensuration variables (i.e., <span class="hlt">tree</span> height and crown width) of selected <span class="hlt">tree</span> <span class="hlt">species</span> found in the forested region around the temples of Angkor Thom, Cambodia. Object-based image analysis (OBIA) was used (using multiresolution segmentation) to delineate individual <span class="hlt">tree</span> crowns from very-high-resolution (VHR) aerial imagery and light detection and ranging (LiDAR) data. Crown width and <span class="hlt">tree</span> height values that were extracted using multiresolution segmentation showed a high level of congruence with field-measured values of the <span class="hlt">trees</span> (Spearman's rho 0.782 and 0.589, respectively). Individual <span class="hlt">tree</span> crowns that were delineated from aerial imagery using multiresolution segmentation had a high level of segmentation accuracy (69.22%), whereas <span class="hlt">tree</span> crowns delineated using watershed segmentation underestimated the field-measured <span class="hlt">tree</span> crown widths. Both spectral angle mapper (SAM) and maximum likelihood (ML) classifications were applied to the aerial imagery for mapping of selected <span class="hlt">tree</span> <span class="hlt">species</span>. The latter was found to be more suitable for <span class="hlt">tree</span> <span class="hlt">species</span> classification. Individual <span class="hlt">tree</span> <span class="hlt">species</span> were identified with high accuracy. Inclusion of textural information further improved <span class="hlt">species</span> identification, albeit marginally. Our findings suggest that VHR aerial imagery, in conjunction with OBIA-based segmentation methods (such as multiresolution segmentation) and supervised classification techniques are useful for <span class="hlt">tree</span> <span class="hlt">species</span> mapping and for studies of the forest mensuration variables. PMID:25902148</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4406680','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4406680"><span id="translatedtitle">Mapping and Characterizing Selected Canopy <span class="hlt">Tree</span> <span class="hlt">Species</span> at the Angkor World Heritage Site in Cambodia Using Aerial Data</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Singh, Minerva; Evans, Damian; Tan, Boun Suy; Nin, Chan Samean</p> <p>2015-01-01</p> <p>At present, there is very limited information on the ecology, distribution, and structure of Cambodia’s <span class="hlt">tree</span> <span class="hlt">species</span> to warrant suitable conservation measures. The aim of this study was to assess various methods of analysis of aerial imagery for characterization of the forest mensuration variables (i.e., <span class="hlt">tree</span> height and crown width) of selected <span class="hlt">tree</span> <span class="hlt">species</span> found in the forested region around the temples of Angkor Thom, Cambodia. Object-based image analysis (OBIA) was used (using multiresolution segmentation) to delineate individual <span class="hlt">tree</span> crowns from very-high-resolution (VHR) aerial imagery and light detection and ranging (LiDAR) data. Crown width and <span class="hlt">tree</span> height values that were extracted using multiresolution segmentation showed a high level of congruence with field-measured values of the <span class="hlt">trees</span> (Spearman’s rho 0.782 and 0.589, respectively). Individual <span class="hlt">tree</span> crowns that were delineated from aerial imagery using multiresolution segmentation had a high level of segmentation accuracy (69.22%), whereas <span class="hlt">tree</span> crowns delineated using watershed segmentation underestimated the field-measured <span class="hlt">tree</span> crown widths. Both spectral angle mapper (SAM) and maximum likelihood (ML) classifications were applied to the aerial imagery for mapping of selected <span class="hlt">tree</span> <span class="hlt">species</span>. The latter was found to be more suitable for <span class="hlt">tree</span> <span class="hlt">species</span> classification. Individual <span class="hlt">tree</span> <span class="hlt">species</span> were identified with high accuracy. Inclusion of textural information further improved <span class="hlt">species</span> identification, albeit marginally. Our findings suggest that VHR aerial imagery, in conjunction with OBIA-based segmentation methods (such as multiresolution segmentation) and supervised classification techniques are useful for <span class="hlt">tree</span> <span class="hlt">species</span> mapping and for studies of the forest mensuration variables. PMID:25902148</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_10 --> <div id="page_11" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="201"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003EAEJA.....8463B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003EAEJA.....8463B"><span id="translatedtitle">Effect of temperate climate <span class="hlt">tree</span> <span class="hlt">species</span> on gross ammonification, gross nitrification and N2O formation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brüggemann, N.; Rosenkranz, P.; Papen, H.; Butterbach-Bahl, K.</p> <p>2003-04-01</p> <p>Microbial nitrogen turnover processes in the soil, like ammonification, nitrification and denitrification, play an important role in the formation of nitrous oxide (N2O): (i) ammonification, because it releases nitrogen from organic material in the form of ammonium (NH4+), which in turn can serve as substrate for nitrification; (ii) nitrification itself (i.e. the turnover of NH4+ to nitrate, NO3-), during which nitric oxide (NO) and N2O can be released as by-products at varying ratios; (iii) denitrification, in which NO3- serves as electron acceptor and is converted to molecular nitrogen (N2) via NO and N2O as intermediates, that can also be partially lost to the atmosphere. Temperate forest soils are a substantial source of atmospheric N2O contributing up to 10% to the total atmospheric N2O budget. However, this figure is afflicted with a huge uncertainty due to a number of factors governing the soil N2O formation, consumption, release and uptake, which are not fully understood at present. To one of these factors belongs the influence of the <span class="hlt">tree</span> <span class="hlt">species</span> on nitrogen turnover processes in the soil and the formation of N trace gases related with them. The aim of the present work was to analyse this <span class="hlt">tree</span> <span class="hlt">species</span> effect for the temperate climate region. For this purpose the effect of five different temperate <span class="hlt">tree</span> <span class="hlt">species</span>, having the same age and growing on the same soil in direct vicinity to each other, on gross ammonification and gross nitrification as well as on N2O formation was investigated. The <span class="hlt">trees</span> (common beech, Fagus sylvatica; pedunculate oak, Quercus robur; Norway spruce, Picea abies; Japanese larch, Larix leptolepis; mountain pine, Pinus mugo) were part of a <span class="hlt">species</span> trial in Western Jutland, Denmark, established in 1965 on a former sandy heathland. Samples from the soil under these five <span class="hlt">tree</span> <span class="hlt">species</span> were taken in spring and in summer 2002, respectively, differentiating between organic layer and mineral soil. The gross rates of ammonification as well of nitrification were significantly higher in the organic layer than in the mineral layer for all <span class="hlt">tree</span> <span class="hlt">species</span> and for both sampling dates, when expressed on a dry weight basis. In the organic layer of all <span class="hlt">tree</span> <span class="hlt">species</span> the gross rates of ammonification and nitrification were higher in summer than in spring. The highest gross ammonification rates were found in the organic layer under spruce, being significantly higher than in beech and larch, which in turn were higher than in oak and pine. Gross rates of nitrification were clearly higher in beech and spruce compared to oak, pine and larch. A linear relationship between gross ammonification and gross nitrification could be found in all samples. N2O formation was significantly different in the respective <span class="hlt">tree</span> <span class="hlt">species</span>: soil under beech showed the highest N2O formation rates of all <span class="hlt">tree</span> <span class="hlt">species</span> investigated, being significantly higher than in spruce and pine, which in turn were significantly higher than in oak and larch, which showed the lowest N2O formation rates. The results obtained underline the importance of considering the effect of <span class="hlt">tree</span> <span class="hlt">species</span> on soil nitrogen cycling and the biosphere-atmosphere exchange of N trace gases, especially with respect to forest management practices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/5224196','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/5224196"><span id="translatedtitle">Narrowing historical uncertainty: probabilistic classification of ambiguously identified <span class="hlt">tree</span> <span class="hlt">species</span> in historical forest survey data</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Mladenoff, D.J.; Dahir, S.E.; Nordheim, E.V.; Schulte, L.A.; Guntenspergen, G.R.</p> <p>2002-01-01</p> <p>Historical data have increasingly become appreciated for insight into the past conditions of ecosystems. Uses of such data include assessing the extent of ecosystem change; deriving ecological baselines for management, restoration, and modeling; and assessing the importance of past conditions on the composition and function of current systems. One historical data set of this type is the Public Land Survey (PLS) of the United States General Land Office, which contains data on multiple <span class="hlt">tree</span> <span class="hlt">species</span>, sizes, and distances recorded at each survey point, located at half-mile (0.8 km) intervals on a 1-mi (1.6 km) grid. This survey method was begun in the 1790s on US federal lands extending westward from Ohio. Thus, the data have the potential of providing a view of much of the US landscape from the mid-1800s, and they have been used extensively for this purpose. However, historical data sources, such as those describing the <span class="hlt">species</span> composition of forests, can often be limited in the detail recorded and the reliability of the data, since the information was often not originally recorded for ecological purposes. Forest <span class="hlt">trees</span> are sometimes recorded ambiguously, using generic or obscure common names. For the PLS data of northern Wisconsin, USA, we developed a method to classify ambiguously identified <span class="hlt">tree</span> <span class="hlt">species</span> using logistic regression analysis, using data on <span class="hlt">trees</span> that were clearly identified to <span class="hlt">species</span> and a set of independent predictor variables to build the models. The models were first created on partial data sets for each <span class="hlt">species</span> and then tested for fit against the remaining data. Validations were conducted using repeated, random subsets of the data. Model prediction accuracy ranged from 81% to 96% in differentiating congeneric <span class="hlt">species</span> among oak, pine, ash, maple, birch, and elm. Major predictor variables were <span class="hlt">tree</span> size, associated <span class="hlt">species</span>, landscape classes indicative of soil type, and spatial location within the study region. Results help to clarify ambiguities formerly present in maps of historic ecosystems for the region and can be applied to PLS datasets elsewhere, as well as other sources of ambiguous historical data. Mapping the newly classified data with ecological land units provides additional information on the distribution, abundance, and associations of <span class="hlt">tree</span> <span class="hlt">species</span>, as well as their relationships to environmental gradients before the industrial period, and clarifies the identities of <span class="hlt">species</span> formerly mapped only to genus. We offer some caveats on the appropriate use of data derived in this way, as well as describing their potential.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.B52C..06K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.B52C..06K"><span id="translatedtitle">Leaf nitrate assimilation during leaf expansion period: comparison of temperate and boreal <span class="hlt">tree</span> <span class="hlt">species</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Koyama, L.; Tokuchi, N.; Kielland, K.</p> <p>2011-12-01</p> <p>We examined nitrate assimilation in several <span class="hlt">tree</span> <span class="hlt">species</span> to test the hypothesis that plant N acquisition is highest in early spring due to the N demands of leaf growth and the seasonal availability of soil N. Specifically, we advance the idea that <span class="hlt">trees</span> acquire N most actively during the leaf expansion period, which serves to offset growth-dilution of foliar N. However, it has been observed that boreal <span class="hlt">species</span> expand their leaves more rapidly than do temperate <span class="hlt">species</span>, suggesting that they exhibit a different seasonal pattern of N acquisition than do temperate <span class="hlt">species</span>. To examine these relationships we measured leaf nitrate reductase activity (NRA) as a proxy for nitrate assimilation, leaf expansion rates, and foliar N concentrations on three boreal <span class="hlt">tree</span> <span class="hlt">species</span> and three temperate <span class="hlt">tree</span> <span class="hlt">species</span> throughout their leaf expansion period. An evergreen <span class="hlt">species</span> (Quercus glauca) and two deciduous <span class="hlt">species</span> (Acer palmatum and Zelkova serrata) were investigated in temperate Japan, and three deciduous <span class="hlt">species</span> Alnus crispa, Betula papyrifera and Populus tremuloides were chosen in a boreal forest in interior Alaska, US. The patterns of foliar N concentrations were very similar across all six <span class="hlt">species</span>, but the mean leaf expansion period was shorter in the boreal <span class="hlt">species</span> (about 25 days) than in temperate <span class="hlt">species</span> (about 29 days). All temperate <span class="hlt">species</span> showed clear peaks of leaf NRA in the middle of leaf expansion period, suggesting that leaves partly compensate for the N dilution during expansion via foliar nitrate assimilation, and that plant nitrate acquisition was effectively timed to coincide with soil N availability generally increased in early spring. By contrast, peak NRA in the boreal <span class="hlt">species</span> were observed in different stage of leaf expansion, but as in the temperate <span class="hlt">species</span> declined to very low levels after the leaves were fully expanded. Our results demonstrate that plant nitrate assimilation is concentrated during leaf expansion in spring and early summer, but declines to very low levels during the remaining part of the growing season. This high rate of acquisition in early spring may reflect the seasonal nature of soil nitrate dynamics as well as acquisition of N liberated over-winter in both biomes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140009601','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140009601"><span id="translatedtitle"><span class="hlt">Tree</span> Density and <span class="hlt">Species</span> Decline in the African Sahel Attributable to Climate</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gonzalez, Patrick; Tucker, Compton J.; Sy, H.</p> <p>2012-01-01</p> <p>Increased aridity and human population have reduced <span class="hlt">tree</span> cover in parts of the African Sahel and degraded resources for local people. Yet, <span class="hlt">tree</span> cover trends and the relative importance of climate and population remain unresolved. From field measurements, aerial photos, and Ikonos satellite images, we detected significant 1954-2002 <span class="hlt">tree</span> density declines in the western Sahel of 18 +/- 14% (P = 0.014, n = 204) and 17 +/- 13% (P = 0.0009, n = 187). From field observations, we detected a significant 1960-2000 <span class="hlt">species</span> richness decline of 21 +/- 11% (P = 0.0028, n = 14) across the Sahel and a southward shift of the Sahel, Sudan, and Guinea zones. Multivariate analyses of climate, soil, and population showed that temperature most significantly (P < 0.001) explained <span class="hlt">tree</span> cover changes. Multivariate and bivariate tests and field observations indicated the dominance of temperature and precipitation, supporting attribution of <span class="hlt">tree</span> cover changes to climate variability. Climate change forcing of Sahel climate variability, particularly the significant (P < 0.05) 1901-2002 temperature increases and precipitation decreases in the research areas, connects Sahel <span class="hlt">tree</span> cover changes to global climate change. This suggests roles for global action and local adaptation to address ecological change in the Sahel.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/18608895','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/18608895"><span id="translatedtitle">The expanding host <span class="hlt">tree</span> <span class="hlt">species</span> spectrum of Cryptococcus gattii and Cryptococcus neoformans and their isolations from surrounding soil in India.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Randhawa, H S; Kowshik, T; Chowdhary, Anuradha; Preeti Sinha, K; Khan, Z U; Sun, Sheng; Xu, Jianping</p> <p>2008-12-01</p> <p>This study reports the widespread prevalence of Cryptococcus neoformans and Cryptococcus gattii in decayed wood inside trunk hollows of 14 <span class="hlt">species</span> representing 12 families of <span class="hlt">trees</span> and from soil near the base of various host <span class="hlt">trees</span> from Delhi and several places in the Indian states of Uttar Pradesh, Haryana, Tamil Nadu and Chandigarh Union Territory. Of the 311 <span class="hlt">trees</span> from which samples were obtained, 64 (20.5%) were found to contain strains of the C. neoformans <span class="hlt">species</span> complex. The number of <span class="hlt">trees</span> positive for C. neoformans var grubii (serotypeA) was 51 (16.3%), for C. gattii (serotype B) 24 (7.7%) and for both C. neoformans and C. gattii 11 (3.5%). The overall prevalence of C. neoformans <span class="hlt">species</span> complex in decayed wood samples was 19.9% (111/556). There was no obvious correlation between the prevalence of these two yeast <span class="hlt">species</span> and the <span class="hlt">species</span> of host <span class="hlt">trees</span>. The data on prevalence of C. gattii (24%) and C. neoformans (26%) in soil around the base of some host <span class="hlt">trees</span> indicated that soil is another important ecologic niche for these two Cryptococcus <span class="hlt">species</span> in India. Among our sampled <span class="hlt">tree</span> <span class="hlt">species</span>, eight and six were recorded for the first time as hosts for C. neoformans var grubii and C. gattii, respectively. A longitudinal surveillance of 8 host <span class="hlt">tree</span> <span class="hlt">species</span> over 0.7 to 2.5 years indicated long term colonization of Polyalthia longifolia, Mimusops elengi and Manilkara hexandra <span class="hlt">trees</span> by C. gattii and/or C. neoformans. The mating type was determined for 153 of the isolates, including 98 strains of serotype A and 55 of serotype B and all proved to be mating type alpha (MAT alpha). Our observations document the rapidly expanding spectrum of host <span class="hlt">tree</span> <span class="hlt">species</span> for C. gattii and C. neoformans and indicate that decayed woods of many <span class="hlt">tree</span> <span class="hlt">species</span> are potentially suitable ecological niches for both pathogens. PMID:18608895</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JGRG..117.0N16Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JGRG..117.0N16Z"><span id="translatedtitle">Large difference of inhibitive effect of nitrogen deposition on soil methane oxidation between plantations with N-fixing <span class="hlt">tree</span> <span class="hlt">species</span> and non-N-fixing <span class="hlt">tree</span> <span class="hlt">species</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Wei; Zhu, Xiaomin; Liu, Lei; Fu, Shenglei; Chen, Hao; Huang, Juan; Lu, Xiankai; Liu, Zhanfeng; Mo, Jiangming</p> <p>2012-12-01</p> <p>The responses of soil methane (CH4) net fluxes to nitrogen (N) addition in a N-fixing <span class="hlt">tree</span> <span class="hlt">species</span> (Acacia auriculiformis (AA)) and a non-N-fixing <span class="hlt">tree</span> <span class="hlt">species</span> (Eucalyptus citriodora (EU)) plantation were studied in southern China. Treatments were conducted at each plantation with three N levels (0, 50, and 100 kg N ha-1 yr-1 for control, medium-N, and high-N treatment, respectively, abbreviated as C, MN, and HN). From August 2010 to July 2011, CH4 flux was measured biweekly using a static chamber and gas chromatography technique. The soils of both sites acted as sink of atmospheric CH4. The CH4 uptake rate in control of the AA site (36.3 ± 3.2 ?g CH4-C m-2 h-1) was greater than that of the EU plantation (29.9 ± 0.9 ?g CH4-C m-2 h-1). In the AA plantation, the averaged rates of CH4 uptake for the MN (28.6 ± 2.3 ?g CH4-C m-2 h-1) and HN treatment (23.8 ± 2.8 ?g CH4-C m-2 h-1) were decreased by 21% and 35%, respectively, compared to the control. However, there was no change of soil CH4 uptake between N-treated plots and the controls in the EU site. Our results indicated that there might be large difference of inhibitive effect of N deposition on soil CH4 oxidation between the AA and EU plantations. The projected increase of N deposition would weaken the capability of N-fixing <span class="hlt">tree</span> <span class="hlt">species</span> plantations for atmospheric CH4 sink in tropical and subtropical regions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2714761','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2714761"><span id="translatedtitle">Temperature dependence, spatial scale, and <span class="hlt">tree</span> <span class="hlt">species</span> diversity in eastern Asia and North America</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wang, Zhiheng; Brown, James H.; Tang, Zhiyao; Fang, Jingyun</p> <p>2009-01-01</p> <p>The increase of biodiversity from poles to equator is one of the most pervasive features of nature. For 2 centuries since von Humboldt, Wallace, and Darwin, biogeographers and ecologists have investigated the environmental and historical factors that determine the latitudinal gradient of <span class="hlt">species</span> diversity, but the underlying mechanisms remain poorly understood. The recently proposed metabolic theory of ecology (MTE) aims to explain ecological patterns and processes, including geographical patterns of <span class="hlt">species</span> richness, in terms of the effects of temperature and body size on the metabolism of organisms. Here we use 2 comparable databases of <span class="hlt">tree</span> distributions in eastern Asia and North America to investigate the roles of environmental temperature and spatial scale in shaping geographical patterns of <span class="hlt">species</span> diversity. We find that number of <span class="hlt">species</span> increases exponentially with environmental temperature as predicted by the MTE, and so does the rate of spatial turnover in <span class="hlt">species</span> composition (slope of the <span class="hlt">species</span>-area relationship). The magnitude of temperature dependence of <span class="hlt">species</span> richness increases with spatial scale. Moreover, the relationship between <span class="hlt">species</span> richness and temperature is much steeper in eastern Asia than in North America: in cold climates at high latitudes there are more <span class="hlt">tree</span> <span class="hlt">species</span> in North America, but the reverse is true in warmer climates at lower latitudes. These patterns provide evidence that the kinetics of ecological and evolutionary processes play a major role in the latitudinal pattern of biodiversity. PMID:19628692</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3626689','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3626689"><span id="translatedtitle">Winning and Losing <span class="hlt">Tree</span> <span class="hlt">Species</span> of Reassembly in Minnesota’s Mixed and Broadleaf Forests</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hanberry, Brice B.; Palik, Brian J.; He, Hong S.</p> <p>2013-01-01</p> <p>We examined reassembly of winning and losing <span class="hlt">tree</span> <span class="hlt">species</span>, <span class="hlt">species</span> traits including shade and fire tolerance, and associated disturbance filters and forest ecosystem types due to rapid forest change in the Great Lakes region since 1850. We identified winning and losing <span class="hlt">species</span> by changes in composition, distribution, and site factors between historical and current surveys in Minnesota’s mixed and broadleaf forests. In the Laurentian Mixed Forest, shade-intolerant aspen replaced shade-intolerant tamarack as the most dominant <span class="hlt">tree</span> <span class="hlt">species</span>. Fire-tolerant white pine and jack pine decreased, whereas shade-tolerant ashes, maples, and white cedar increased. In the Eastern Broadleaf Forest, fire-tolerant white oaks and red oaks decreased, while shade-tolerant ashes, American basswood, and maples increased. Tamarack, pines, and oaks have become restricted to sites with either wetter or sandier and drier soils due to increases in aspen and shade-tolerant, fire-sensitive <span class="hlt">species</span> on mesic sites. The proportion of shade-tolerant <span class="hlt">species</span> increased in both regions, but selective harvest reduced the applicability of functional groups alone to specify winners and losers. Harvest and existing forestry practices supported aspen dominance in mixed forests, although without aspen forestry and with fire suppression, mixed forests will transition to a greater composition of shade-tolerant <span class="hlt">species</span>, converging to forests similar to broadleaf forests. A functional group framework provided a perspective of winning and losing <span class="hlt">species</span> and traits, selective filters, and forest ecosystems that can be generalized to other regions, regardless of <span class="hlt">species</span> identity. PMID:23613911</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/283030','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/283030"><span id="translatedtitle">Anatomical, chemical, and ecological factors affecting <span class="hlt">tree</span> <span class="hlt">species</span> choice in dendrochemistry studies</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Cutter, B.E.; Guyette, R.P.</p> <p>1993-07-01</p> <p>Recently, element concentrations in <span class="hlt">tree</span> rings have been used to monitor metal contamination, fertilization, and the effects of acid precipitation on soils. This has stimulated interest in which <span class="hlt">tree</span> <span class="hlt">species</span> may be suitable for use in studies of long-term trends in environmental chemistry. Potential radial translocation of elements across living boundaries can be a confounding factor in assessing environmental change. The selection of <span class="hlt">species</span> which minimizes radial translocation of elements can be critical to the success of dendrochemical research. Criteria for selection of <span class="hlt">species</span> with characteristics favorable for dendrochemical analysis are categorized into (1) habitat-based factors, (2) xylem-based factors, and (3) element-based factors. A wide geographic range and ecological amplitude provide an advantage in calibration and better controls on the effects of soil chemistry. The most important xylem-based criteria are heartwood moisture content, permeability, and the nature of the sapwood-heartwood transition. The element of interest is important in determining suitable <span class="hlt">tree</span> <span class="hlt">species</span> because all elements are not equally mobile or detectable in the xylem. Ideally, the <span class="hlt">tree</span> <span class="hlt">species</span> selected for dendrochemical study will be long-lived, grow on a wide range of sites over a large geographic distribution, have a distinct heartwood with a low number of rings in the sapwood, a low heartwood moisture content, and have low radial permeability. Recommended temperate zone North American <span class="hlt">species</span> include white oak (Quercus alba L.), post oak (Q. stellate Wangenh.), eastern redcedar (funiperus virginiana L.), old-growth Douglas-fir [Pseudoaugu menziesii (Mirb.) Franco] and big sagebrush (Artemisia tridentata Nutt.). In addition, <span class="hlt">species</span> such as bristlecone pine (Pinus aristata Engelm. syn. longaeva), old-growth redwood [Sequoia sempervirens (D. Don) Endl.], and giant sequoia [S. gigantea (Lindl.) Deene] may be suitable for local purposes. 118 refs., 2 tabs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70025565','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70025565"><span id="translatedtitle">Impacts of the Brown <span class="hlt">Tree</span> Snake: Patterns of Decline and <span class="hlt">Species</span> Persistence in Guam's Avifauna</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Wiles, G.J.; Bart, J.; Beck, R.E., Jr.; Aguon, C.F.</p> <p>2003-01-01</p> <p>Predation by brown <span class="hlt">tree</span> snakes (Boiga irregularis) devastated the avifauna of Guam in the Mariana Islands during the last half of the twentieth century, causing the extirpation or serious reduction of most of the island's 25 resident bird <span class="hlt">species</span>. Past studies have provided qualitative descriptions of the decline of native forest birds but have not considered all <span class="hlt">species</span> or presented quantitative analyses. We analyzed two sets of survey data gathered in northern Guam between 1976 and 1998 and reviewed unpublished sources to provide a comprehensive account of the impact of brown <span class="hlt">tree</span> snakes on the island's birds. Our results indicate that 22 <span class="hlt">species</span>, including 17 of 18 native <span class="hlt">species</span>, were severely affected by snakes. Twelve <span class="hlt">species</span> were likely extirpated as breeding residents on the main island, 8 others experienced declines of ???90% throughout the island or at least in the north, and 2 were kept at reduced population levels during all or much of the study. Declines of ???90% occurred rapidly, averaging just 8.9 years along three roadside survey routes combined and 1.6 years at a 100-ha forested study site. Declines in northern Guam were also relatively synchronous and occurred from about 1976 to 1986 for most <span class="hlt">species</span>. The most important factor predisposing a <span class="hlt">species</span> to coexistence with brown <span class="hlt">tree</span> snakes was its ability to nest and roost at locations where snakes were uncommon. Large clutch size and large body size were also related to longer persistence times, although large body size appeared to delay, but not prevent, extirpation. Our results draw attention to the enormous detrimental impact that brown <span class="hlt">tree</span> snakes are likely to have upon invading new areas. Increased containment efforts on Guam are needed to prevent further colonizations, but a variety of additional management efforts would also benefit the island's remaining bird populations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/19495788','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/19495788"><span id="translatedtitle">Independence of stem and leaf hydraulic traits in six Euphorbiaceae <span class="hlt">tree</span> <span class="hlt">species</span> with contrasting leaf phenology.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chen, Jun-Wen; Zhang, Qiang; Li, Xiao-Shuang; Cao, Kun-Fang</p> <p>2009-08-01</p> <p>Hydraulic traits and hydraulic-related structural properties were examined in three deciduous (Hevea brasiliensis, Macaranga denticulate, and Bischofia javanica) and three evergreen (Drypetes indica, Aleurites moluccana, and Codiaeum variegatum) Euphorbiaceae <span class="hlt">tree</span> <span class="hlt">species</span> from a seasonally tropical forest in south-western China. Xylem water potential at 50% loss of stem hydraulic conductivity (P50(stem)) was more negative in the evergreen <span class="hlt">tree</span>, but leaf water potential at 50% loss of leaf hydraulic conductivity (P50(leaf)) did not function as P50(stem) did. Furthermore, P50(stem) was more negative than P50(leaf) in the evergreen <span class="hlt">tree</span>; contrarily, this pattern was not observed in the deciduous <span class="hlt">tree</span>. Leaf hydraulic conductivity overlapped considerably, but stem hydraulic conductivity diverged between the evergreen and deciduous <span class="hlt">tree</span>. Correspondingly, structural properties of leaves overlapped substantially; however, structural properties of stem diverged markedly. Consequently, leaf and stem hydraulic traits were closely correlated with leaf and stem structural properties, respectively. Additionally, stem hydraulic efficiency was significantly correlated with stem hydraulic resistance to embolism; nevertheless, such a hydraulic pattern was not found in leaf hydraulics. Thus, these results suggest: (1) that the evergreen and deciduous <span class="hlt">tree</span> mainly diverge in stem hydraulics, but not in leaf hydraulics, (2) that regardless of leaf or stem, their hydraulic traits result primarily from structural properties, and not from leaf phenology, (3) that leaves are more vulnerable to drought-induced embolism than stem in the evergreen <span class="hlt">tree</span>, but not always in the deciduous <span class="hlt">tree</span> and (4) that there exists a trade-off between hydraulic efficiency and safety for stem hydraulics, but not for leaf hydraulics. PMID:19495788</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015GPC...133..298B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GPC...133..298B"><span id="translatedtitle">Oxygen isotopes in <span class="hlt">tree</span> rings show good coherence between <span class="hlt">species</span> and sites in Bolivia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Baker, Jessica C. A.; Hunt, Sarah F. P.; Clerici, Santiago J.; Newton, Robert J.; Bottrell, Simon H.; Leng, Melanie J.; Heaton, Timothy H. E.; Helle, Gerhard; Argollo, Jaime; Gloor, Manuel; Brienen, Roel J. W.</p> <p>2015-10-01</p> <p>A <span class="hlt">tree</span> ring oxygen isotope (δ18OTR) chronology developed from one <span class="hlt">species</span> (Cedrela odorata) growing in a single site has been shown to be a sensitive proxy for rainfall over the Amazon Basin, thus allowing reconstructions of precipitation in a region where meteorological records are short and scarce. Although these results suggest that there should be large-scale (> 100 km) spatial coherence of δ18OTR records in the Amazon, this has not been tested. Furthermore, it is of interest to investigate whether other, possibly longer-lived, <span class="hlt">species</span> similarly record interannual variation of Amazon precipitation, and can be used to develop climate sensitive isotope chronologies. In this study, we measured δ18O in <span class="hlt">tree</span> rings from seven lowland and one highland <span class="hlt">tree</span> <span class="hlt">species</span> from Bolivia. We found that cross-dating with δ18OTR gave more accurate <span class="hlt">tree</span> ring dates than using ring width. Our "isotope cross-dating approach" is confirmed with radiocarbon "bomb-peak" dates, and has the potential to greatly facilitate development of δ18OTR records in the tropics, identify dating errors, and check annual ring formation in tropical <span class="hlt">trees</span>. Six of the seven lowland <span class="hlt">species</span> correlated significantly with C. odorata, showing that variation in δ18OTR has a coherent imprint across very different <span class="hlt">species</span>, most likely arising from a dominant influence of source water δ18O on δ18OTR. In addition we show that δ18OTR series cohere over large distances, within and between <span class="hlt">species</span>. Comparison of two C. odorata δ18OTR chronologies from sites several hundreds of kilometres apart showed a very strong correlation (r = 0.80, p < 0.001, 1901-2001), and a significant (but weaker) relationship was found between lowland C. odorata <span class="hlt">trees</span> and a Polylepis tarapacana <span class="hlt">tree</span> growing in the distant Altiplano (r = 0.39, p < 0.01, 1931-2001). This large-scale coherence of δ18OTR records is probably triggered by a strong spatial coherence in precipitation δ18O due to large-scale controls. These results highlight the strength of δ18OTR as a precipitation proxy, and open the way for temporal and spatial expansion of precipitation reconstructions in South America.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26663665','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26663665"><span id="translatedtitle">Drought stress limits the geographic ranges of two <span class="hlt">tree</span> <span class="hlt">species</span> via different physiological mechanisms.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Anderegg, Leander D L; HilleRisLambers, Janneke</p> <p>2016-03-01</p> <p>Range shifts are among the most ubiquitous ecological responses to anthropogenic climate change and have large consequences for ecosystems. Unfortunately, the ecophysiological forces that constrain range boundaries are poorly understood, making it difficult to mechanistically project range shifts. To explore the physiological mechanisms by which drought stress controls dry range boundaries in <span class="hlt">trees</span>, we quantified elevational variation in drought tolerance and in drought avoidance-related functional traits of a widespread gymnosperm (ponderosa pine - Pinus ponderosa) and angiosperm (trembling aspen - Populus tremuloides) <span class="hlt">tree</span> <span class="hlt">species</span> in the southwestern USA. Specifically, we quantified <span class="hlt">tree-to-tree</span> variation in growth, water stress (predawn and midday xylem tension), drought avoidance traits (branch conductivity, leaf/needle size, <span class="hlt">tree</span> height, leaf area-to-sapwood area ratio), and drought tolerance traits (xylem resistance to embolism, hydraulic safety margin, wood density) at the range margins and range center of each <span class="hlt">species</span>. Although water stress increased and growth declined strongly at lower range margins of both <span class="hlt">species</span>, ponderosa pine and aspen showed contrasting patterns of clinal trait variation. Trembling aspen increased its drought tolerance at its dry range edge by growing stronger but more carbon dense branch and leaf tissues, implying an increased cost of growth at its range boundary. By contrast, ponderosa pine showed little elevational variation in drought-related traits but avoided drought stress at low elevations by limiting transpiration through stomatal closure, such that its dry range boundary is associated with limited carbon assimilation even in average climatic conditions. Thus, the same climatic factor (drought) may drive range boundaries through different physiological mechanisms - a result that has important implications for process-based modeling approaches to <span class="hlt">tree</span> biogeography. Further, we show that comparing intraspecific patterns of trait variation across ranges, something rarely done in a range-limit context, helps elucidate a mechanistic understanding of range constraints. PMID:26663665</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AcO....34..370B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AcO....34..370B"><span id="translatedtitle">Hydraulic redistribution study in two native <span class="hlt">tree</span> <span class="hlt">species</span> of agroforestry parklands of West African dry savanna</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bayala, Jules; Heng, Lee Kheng; van Noordwijk, Meine; Ouedraogo, Sibiri Jean</p> <p>2008-11-01</p> <p>Hydraulic redistribution (HR) in karité ( Vitellaria paradoxa) and néré ( Parkia biglobosa) <span class="hlt">tree</span> <span class="hlt">species</span> was studied by monitoring the soil water potential ( ψs) using thermocouple psychrometers at four compass directions, various distances from <span class="hlt">trees</span> and at different soil depths (max depth 80 cm) during the dry seasons of 2004 and 2005. A modified WaNuLCAS model was then used to infer the amount of water redistribued based on ψs values. <span class="hlt">Tree</span> transpiration rate was also estimated from sap velocity using thermal dissipative probes (TDP) and sapwood area, and the contribution of hydraulically redistributed water in <span class="hlt">tree</span> transpiration was determined. The results revealed on average that 46% of the psychrometer readings under karité and 33% under néré showed the occurrence of HR for the two years. Soil under néré displayed significantly lower fluctuations of ψs (0.16 MPa) compared to soil under karité (0.21 MPa). The results of this study indicated that the existence of HR leads to a higher ψs in the plant rhizosphere and hence is important for soil water dynamics and plant nutrition by making more accessible the soluble elements. The simulation showed that the amount of water redistributed would be approximately 73.0 L and 247.1 L per <span class="hlt">tree</span> per day in 2005 for karité and néré, and would represent respectively 60% and 53% of the amount transpired a day. Even though the model has certainly overestimated the volume of water hydraulically redistributed by the two <span class="hlt">species</span>, this water may play a key role in maintaining fine root viability and ensuring the well adaptation of these <span class="hlt">species</span> to the dry areas. Therefore, knowledge of the extent of such transfers and of the seasonal patterns is required and is of paramount importance in parkland systems both for <span class="hlt">trees</span> and associated crops.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.2533C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.2533C"><span id="translatedtitle">Different <span class="hlt">tree</span> <span class="hlt">species</span> affect soil respiration spatial distribution in a subtropical forest of southern Taiwan</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chiang, Po-Neng; Yu, Jui-Chu; Wang, Ya-nan; Lai, Yen-Jen</p> <p>2014-05-01</p> <p>Global forests contain 69% of total carbon stored in forest soil and litter. But the carbon storage ability and release rate of warming gases of forest soil also affect global climate change. Soil carbon cycling processes are paid much attention by ecological scientists and policy makers because of the possibility of carbon being stored in soil via land use management. Soil respiration contributed large part of terrestrial carbon flux, but the relationship of soil respiration and climate change was still obscurity. Most of soil respiration researches focus on template and tropical area, little was known that in subtropical area. Afforestation is one of solutions to mitigate CO2 increase and to sequestrate CO2 in <span class="hlt">tree</span> and soil. Therefore, the objective of this study is to clarify the relationship of <span class="hlt">tree</span> <span class="hlt">species</span> and soil respiration distribution in subtropical broad-leaves plantation in southern Taiwan. The research site located on southern Taiwan was sugarcane farm before 2002. The sugarcane was removed and fourteen broadleaved <span class="hlt">tree</span> <span class="hlt">species</span> were planted in 2002-2005. Sixteen plots (250m*250m) were set on 1 km2 area, each plot contained 4 subplots (170m2). The forest biomass (i.e. <span class="hlt">tree</span> height, DBH) understory biomass, litter, and soil C were measured and analyzed at 2011 to 2012. Soil respiration measurement was sampled in each subplot in each month. The soil belongs to Entisol with over 60% of sandstone. The soil pH is 5.5 with low base cations because of high sand percentage. Soil carbon storage showed significantly negative relationship with soil bulk density (p<0.001) in research site. The differences of distribution of live <span class="hlt">tree</span> C pool among 16 plots were affected by growth characteristic of <span class="hlt">tree</span> <span class="hlt">species</span>. Data showed that the accumulation amount of litterfall was highest in December to February and lowest in June. Different <span class="hlt">tree</span> <span class="hlt">species</span> planted in 16 plots, resulting in high spatial variation of litterfall amount. It also affected total amount of litterfall temporal variation. Soil respiration was related with season variation in research site. Soil temperature and soil respiration showed highly spatial variation in 16 plots. Soil temperature showed significantly exponential related with soil respiration in research site (p<0.001).However, soil respiration showed significantly negative relationship with total amount of litterfall (p<0.001), suggesting that the <span class="hlt">tree</span> was still young and did not reach crown closure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26526427','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26526427"><span id="translatedtitle">SimPhy: Phylogenomic Simulation of Gene, Locus, and <span class="hlt">Species</span> <span class="hlt">Trees</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mallo, Diego; De Oliveira Martins, Leonardo; Posada, David</p> <p>2016-03-01</p> <p>We present a fast and flexible software package-SimPhy-for the simulation of multiple gene families evolving under incomplete lineage sorting, gene duplication and loss, horizontal gene transfer-all three potentially leading to <span class="hlt">species</span> <span class="hlt">tree</span>/gene <span class="hlt">tree</span> discordance-and gene conversion. SimPhy implements a hierarchical phylogenetic model in which the evolution of <span class="hlt">species</span>, locus, and gene <span class="hlt">trees</span> is governed by global and local parameters (e.g., genome-wide, <span class="hlt">species</span>-specific, locus-specific), that can be fixed or be sampled from a priori statistical distributions. SimPhy also incorporates comprehensive models of substitution rate variation among lineages (uncorrelated relaxed clocks) and the capability of simulating partitioned nucleotide, codon, and protein multilocus sequence alignments under a plethora of substitution models using the program INDELible. We validate SimPhy's output using theoretical expectations and other programs, and show that it scales extremely well with complex models and/or large <span class="hlt">trees</span>, being an order of magnitude faster than the most similar program (DLCoal-Sim). In addition, we demonstrate how SimPhy can be useful to understand interactions among different evolutionary processes, conducting a simulation study to characterize the systematic overestimation of the duplication time when using standard reconciliation methods. SimPhy is available at https://github.com/adamallo/SimPhy, where users can find the source code, precompiled executables, a detailed manual and example cases. PMID:26526427</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4748750','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4748750"><span id="translatedtitle">SimPhy: Phylogenomic Simulation of Gene, Locus, and <span class="hlt">Species</span> <span class="hlt">Trees</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Mallo, Diego; De Oliveira Martins, Leonardo; Posada, David</p> <p>2016-01-01</p> <p>We present a fast and flexible software package—SimPhy—for the simulation of multiple gene families evolving under incomplete lineage sorting, gene duplication and loss, horizontal gene transfer—all three potentially leading to <span class="hlt">species</span> <span class="hlt">tree</span>/gene <span class="hlt">tree</span> discordance—and gene conversion. SimPhy implements a hierarchical phylogenetic model in which the evolution of <span class="hlt">species</span>, locus, and gene <span class="hlt">trees</span> is governed by global and local parameters (e.g., genome-wide, <span class="hlt">species</span>-specific, locus-specific), that can be fixed or be sampled from a priori statistical distributions. SimPhy also incorporates comprehensive models of substitution rate variation among lineages (uncorrelated relaxed clocks) and the capability of simulating partitioned nucleotide, codon, and protein multilocus sequence alignments under a plethora of substitution models using the program INDELible. We validate SimPhy's output using theoretical expectations and other programs, and show that it scales extremely well with complex models and/or large <span class="hlt">trees</span>, being an order of magnitude faster than the most similar program (DLCoal-Sim). In addition, we demonstrate how SimPhy can be useful to understand interactions among different evolutionary processes, conducting a simulation study to characterize the systematic overestimation of the duplication time when using standard reconciliation methods. SimPhy is available at https://github.com/adamallo/SimPhy, where users can find the source code, precompiled executables, a detailed manual and example cases. PMID:26526427</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/7243571','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/7243571"><span id="translatedtitle">Sustainable <span class="hlt">multipurpose</span> <span class="hlt">tree</span> production systems for Nepal</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Shen, S.Y.; Kilpatrick, K.J.</p> <p>1988-03-01</p> <p>Argonne National Laboratory is developing methods for producing reforestation plating stock, fuel, and fodder in a sustainable manner in Nepal. This project, in cooperation with the Ministry of Forest and Soil Conservation of Nepal, is sponsored by the US Agency for International Development (AID). Several production systems are being evaluated for the Mid-Hills Region of Nepal. To provide sustainable biomass production and ecological management of the fragile Mid-Hills Region, the production systems must simultaneously satisfy the physiological requirements of the plants, the symbiotic requirements of the plant and the microorganisms in its rhizosphere, the physicochemical requirements of nutrient and water cycling, and the climatic and topographic constraints.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26702442','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26702442"><span id="translatedtitle">Estimating the global conservation status of more than 15,000 Amazonian <span class="hlt">tree</span> <span class="hlt">species</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ter Steege, Hans; Pitman, Nigel C A; Killeen, Timothy J; Laurance, William F; Peres, Carlos A; Guevara, Juan Ernesto; Salomão, Rafael P; Castilho, Carolina V; Amaral, Iêda Leão; de Almeida Matos, Francisca Dionízia; de Souza Coelho, Luiz; Magnusson, William E; Phillips, Oliver L; de Andrade Lima Filho, Diogenes; de Jesus Veiga Carim, Marcelo; Irume, Mariana Victória; Martins, Maria Pires; Molino, Jean-François; Sabatier, Daniel; Wittmann, Florian; López, Dairon Cárdenas; da Silva Guimarães, José Renan; Mendoza, Abel Monteagudo; Vargas, Percy Núñez; Manzatto, Angelo Gilberto; Reis, Neidiane Farias Costa; Terborgh, John; Casula, Katia Regina; Montero, Juan Carlos; Feldpausch, Ted R; Honorio Coronado, Euridice N; Montoya, Alvaro Javier Duque; Zartman, Charles Eugene; Mostacedo, Bonifacio; Vasquez, Rodolfo; Assis, Rafael L; Medeiros, Marcelo Brilhante; Simon, Marcelo Fragomeni; Andrade, Ana; Camargo, José Luís; Laurance, Susan G W; Nascimento, Henrique Eduardo Mendonça; Marimon, Beatriz S; Marimon, Ben-Hur; Costa, Flávia; Targhetta, Natalia; Vieira, Ima Célia Guimarães; Brienen, Roel; Castellanos, Hernán; Duivenvoorden, Joost F; Mogollón, Hugo F; Piedade, Maria Teresa Fernandez; Aymard C, Gerardo A; Comiskey, James A; Damasco, Gabriel; Dávila, Nállarett; García-Villacorta, Roosevelt; Diaz, Pablo Roberto Stevenson; Vincentini, Alberto; Emilio, Thaise; Levis, Carolina; Schietti, Juliana; Souza, Priscila; Alonso, Alfonso; Dallmeier, Francisco; Ferreira, Leandro Valle; Neill, David; Araujo-Murakami, Alejandro; Arroyo, Luzmila; Carvalho, Fernanda Antunes; Souza, Fernanda Coelho; do Amaral, Dário Dantas; Gribel, Rogerio; Luize, Bruno Garcia; Pansonato, Marcelo Petrati; Venticinque, Eduardo; Fine, Paul; Toledo, Marisol; Baraloto, Chris; Cerón, Carlos; Engel, Julien; Henkel, Terry W; Jimenez, Eliana M; Maas, Paul; Mora, Maria Cristina Peñuela; Petronelli, Pascal; Revilla, Juan David Cardenas; Silveira, Marcos; Stropp, Juliana; Thomas-Caesar, Raquel; Baker, Tim R; Daly, Doug; Paredes, Marcos Ríos; da Silva, Naara Ferreira; Fuentes, Alfredo; Jørgensen, Peter Møller; Schöngart, Jochen; Silman, Miles R; Arboleda, Nicolás Castaño; Cintra, Bruno Barçante Ladvocat; Valverde, Fernando Cornejo; Di Fiore, Anthony; Phillips, Juan Fernando; van Andel, Tinde R; von Hildebrand, Patricio; Barbosa, Edelcilio Marques; de Matos Bonates, Luiz Carlos; de Castro, Deborah; de Sousa Farias, Emanuelle; Gonzales, Therany; Guillaumet, Jean-Louis; Hoffman, Bruce; Malhi, Yadvinder; de Andrade Miranda, Ires Paula; Prieto, Adriana; Rudas, Agustín; Ruschell, Ademir R; Silva, Natalino; Vela, César I A; Vos, Vincent A; Zent, Eglée L; Zent, Stanford; Cano, Angela; Nascimento, Marcelo Trindade; Oliveira, Alexandre A; Ramirez-Angulo, Hirma; Ramos, José Ferreira; Sierra, Rodrigo; Tirado, Milton; Medina, Maria Natalia Umaña; van der Heijden, Geertje; Torre, Emilio Vilanova; Vriesendorp, Corine; Wang, Ophelia; Young, Kenneth R; Baider, Claudia; Balslev, Henrik; de Castro, Natalia; Farfan-Rios, William; Ferreira, Cid; Mendoza, Casimiro; Mesones, Italo; Torres-Lezama, Armando; Giraldo, Ligia Estela Urrego; Villarroel, Daniel; Zagt, Roderick; Alexiades, Miguel N; Garcia-Cabrera, Karina; Hernandez, Lionel; Huamantupa-Chuquimaco, Isau; Milliken, William; Cuenca, Walter Palacios; Pansini, Susamar; Pauletto, Daniela; Arevalo, Freddy Ramirez; Sampaio, Adeilza Felipe; Valderrama Sandoval, Elvis H; Gamarra, Luis Valenzuela</p> <p>2015-11-01</p> <p>Estimates of extinction risk for Amazonian plant and animal <span class="hlt">species</span> are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian <span class="hlt">tree</span> <span class="hlt">species</span> are likely to qualify as globally threatened under International Union for Conservation of Nature (IUCN) Red List criteria. If confirmed, these results would increase the number of threatened plant <span class="hlt">species</span> on Earth by 22%. We show that the trends observed in Amazonia apply to <span class="hlt">trees</span> throughout the tropics, and we predict that most of the world's >40,000 tropical <span class="hlt">tree</span> <span class="hlt">species</span> now qualify as globally threatened. A gap analysis suggests that existing Amazonian protected areas and indigenous territories will protect viable populations of most threatened <span class="hlt">species</span> if these areas suffer no further degradation, highlighting the key roles that protected areas, indigenous peoples, and improved governance can play in preventing large-scale extinctions in the tropics in this century. PMID:26702442</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4681336','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4681336"><span id="translatedtitle">Estimating the global conservation status of more than 15,000 Amazonian <span class="hlt">tree</span> <span class="hlt">species</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>ter Steege, Hans; Pitman, Nigel C. A.; Killeen, Timothy J.; Laurance, William F.; Peres, Carlos A.; Guevara, Juan Ernesto; Salomão, Rafael P.; Castilho, Carolina V.; Amaral, Iêda Leão; de Almeida Matos, Francisca Dionízia; de Souza Coelho, Luiz; Magnusson, William E.; Phillips, Oliver L.; de Andrade Lima Filho, Diogenes; de Jesus Veiga Carim, Marcelo; Irume, Mariana Victória; Martins, Maria Pires; Molino, Jean-François; Sabatier, Daniel; Wittmann, Florian; López, Dairon Cárdenas; da Silva Guimarães, José Renan; Mendoza, Abel Monteagudo; Vargas, Percy Núñez; Manzatto, Angelo Gilberto; Reis, Neidiane Farias Costa; Terborgh, John; Casula, Katia Regina; Montero, Juan Carlos; Feldpausch, Ted R.; Honorio Coronado, Euridice N.; Montoya, Alvaro Javier Duque; Zartman, Charles Eugene; Mostacedo, Bonifacio; Vasquez, Rodolfo; Assis, Rafael L.; Medeiros, Marcelo Brilhante; Simon, Marcelo Fragomeni; Andrade, Ana; Camargo, José Luís; Laurance, Susan G. W.; Nascimento, Henrique Eduardo Mendonça; Marimon, Beatriz S.; Marimon, Ben-Hur; Costa, Flávia; Targhetta, Natalia; Vieira, Ima Célia Guimarães; Brienen, Roel; Castellanos, Hernán; Duivenvoorden, Joost F.; Mogollón, Hugo F.; Piedade, Maria Teresa Fernandez; Aymard C., Gerardo A.; Comiskey, James A.; Damasco, Gabriel; Dávila, Nállarett; García-Villacorta, Roosevelt; Diaz, Pablo Roberto Stevenson; Vincentini, Alberto; Emilio, Thaise; Levis, Carolina; Schietti, Juliana; Souza, Priscila; Alonso, Alfonso; Dallmeier, Francisco; Ferreira, Leandro Valle; Neill, David; Araujo-Murakami, Alejandro; Arroyo, Luzmila; Carvalho, Fernanda Antunes; Souza, Fernanda Coelho; do Amaral, Dário Dantas; Gribel, Rogerio; Luize, Bruno Garcia; Pansonato, Marcelo Petrati; Venticinque, Eduardo; Fine, Paul; Toledo, Marisol; Baraloto, Chris; Cerón, Carlos; Engel, Julien; Henkel, Terry W.; Jimenez, Eliana M.; Maas, Paul; Mora, Maria Cristina Peñuela; Petronelli, Pascal; Revilla, Juan David Cardenas; Silveira, Marcos; Stropp, Juliana; Thomas-Caesar, Raquel; Baker, Tim R.; Daly, Doug; Paredes, Marcos Ríos; da Silva, Naara Ferreira; Fuentes, Alfredo; Jørgensen, Peter Møller; Schöngart, Jochen; Silman, Miles R.; Arboleda, Nicolás Castaño; Cintra, Bruno Barçante Ladvocat; Valverde, Fernando Cornejo; Di Fiore, Anthony; Phillips, Juan Fernando; van Andel, Tinde R.; von Hildebrand, Patricio; Barbosa, Edelcilio Marques; de Matos Bonates, Luiz Carlos; de Castro, Deborah; de Sousa Farias, Emanuelle; Gonzales, Therany; Guillaumet, Jean-Louis; Hoffman, Bruce; Malhi, Yadvinder; de Andrade Miranda, Ires Paula; Prieto, Adriana; Rudas, Agustín; Ruschell, Ademir R.; Silva, Natalino; Vela, César I. A.; Vos, Vincent A.; Zent, Eglée L.; Zent, Stanford; Cano, Angela; Nascimento, Marcelo Trindade; Oliveira, Alexandre A.; Ramirez-Angulo, Hirma; Ramos, José Ferreira; Sierra, Rodrigo; Tirado, Milton; Medina, Maria Natalia Umaña; van der Heijden, Geertje; Torre, Emilio Vilanova; Vriesendorp, Corine; Wang, Ophelia; Young, Kenneth R.; Baider, Claudia; Balslev, Henrik; de Castro, Natalia; Farfan-Rios, William; Ferreira, Cid; Mendoza, Casimiro; Mesones, Italo; Torres-Lezama, Armando; Giraldo, Ligia Estela Urrego; Villarroel, Daniel; Zagt, Roderick; Alexiades, Miguel N.; Garcia-Cabrera, Karina; Hernandez, Lionel; Huamantupa-Chuquimaco, Isau; Milliken, William; Cuenca, Walter Palacios; Pansini, Susamar; Pauletto, Daniela; Arevalo, Freddy Ramirez; Sampaio, Adeilza Felipe; Valderrama Sandoval, Elvis H.; Gamarra, Luis Valenzuela</p> <p>2015-01-01</p> <p>Estimates of extinction risk for Amazonian plant and animal <span class="hlt">species</span> are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian <span class="hlt">tree</span> <span class="hlt">species</span> are likely to qualify as globally threatened under International Union for Conservation of Nature (IUCN) Red List criteria. If confirmed, these results would increase the number of threatened plant <span class="hlt">species</span> on Earth by 22%. We show that the trends observed in Amazonia apply to <span class="hlt">trees</span> throughout the tropics, and we predict that most of the world’s >40,000 tropical <span class="hlt">tree</span> <span class="hlt">species</span> now qualify as globally threatened. A gap analysis suggests that existing Amazonian protected areas and indigenous territories will protect viable populations of most threatened <span class="hlt">species</span> if these areas suffer no further degradation, highlighting the key roles that protected areas, indigenous peoples, and improved governance can play in preventing large-scale extinctions in the tropics in this century. PMID:26702442</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/927777','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/927777"><span id="translatedtitle">Managing Commercial <span class="hlt">Tree</span> <span class="hlt">Species</span> for Timber Production and Carbon Sequestration: Management Guidelines and Financial Returns</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gary D. Kronrad</p> <p>2006-09-19</p> <p>A carbon credit market is developing in the United States. Information is needed by buyers and sellers of carbon credits so that the market functions equitably and efficiently. Analyses have been conducted to determine the optimal forest management regime to employ for each of the major commercial <span class="hlt">tree</span> <span class="hlt">species</span> so that profitability of timber production only or the combination of timber production and carbon sequestration is maximized. Because the potential of a forest ecosystem to sequester carbon depends on the <span class="hlt">tree</span> <span class="hlt">species</span>, site quality and management regimes utilized, analyses have determined how to optimize carbon sequestration by determining how to optimally manage each <span class="hlt">species</span>, given a range of site qualities, discount rates, prices of carbon credits and other economic variables. The effects of a carbon credit market on the method and profitability of forest management, the cost of sequestering carbon, the amount of carbon that can be sequestered, and the amount of timber products produced has been determined.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4255775','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4255775"><span id="translatedtitle">Multispecies Coalescent Analysis of the Early Diversification of Neotropical Primates: Phylogenetic Inference under Strong Gene <span class="hlt">Trees/Species</span> <span class="hlt">Tree</span> Conflict</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Schrago, Carlos G.; Menezes, Albert N.; Furtado, Carolina; Bonvicino, Cibele R.; Seuanez, Hector N.</p> <p>2014-01-01</p> <p>Neotropical primates (NP) are presently distributed in the New World from Mexico to northern Argentina, comprising three large families, Cebidae, Atelidae, and Pitheciidae, consequently to their diversification following their separation from Old World anthropoids near the Eocene/Oligocene boundary, some 40 Ma. The evolution of NP has been intensively investigated in the last decade by studies focusing on their phylogeny and timescale. However, despite major efforts, the phylogenetic relationship between these three major clades and the age of their last common ancestor are still controversial because these inferences were based on limited numbers of loci and dating analyses that did not consider the evolutionary variation associated with the distribution of gene <span class="hlt">trees</span> within the proposed phylogenies. We show, by multispecies coalescent analyses of selected genome segments, spanning along 92,496,904 bp that the early diversification of extant NP was marked by a 2-fold increase of their effective population size and that Atelids and Cebids are more closely related respective to Pitheciids. The molecular phylogeny of NP has been difficult to solve because of population-level phenomena at the early evolution of the lineage. The association of evolutionary variation with the distribution of gene <span class="hlt">trees</span> within proposed phylogenies is crucial for distinguishing the mean genetic divergence between <span class="hlt">species</span> (the mean coalescent time between loci) from speciation time. This approach, based on extensive genomic data provided by new generation DNA sequencing, provides more accurate reconstructions of phylogenies and timescales for all organisms. PMID:25377940</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/19324819','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/19324819"><span id="translatedtitle">The demography of range boundaries versus range cores in eastern US <span class="hlt">tree</span> <span class="hlt">species</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Purves, Drew W</p> <p>2009-04-22</p> <p>Regional <span class="hlt">species</span>-climate correlations are well documented, but little is known about the ecological processes responsible for generating these patterns. Using the data from over 690,000 individual <span class="hlt">trees</span> I estimated five demographic rates--canopy growth, understorey growth, canopy lifespan, understorey lifespan and per capita reproduction--for 19 common eastern US <span class="hlt">tree</span> <span class="hlt">species</span>, within the core and the northern and southern boundaries, of the <span class="hlt">species</span> range. Most <span class="hlt">species</span> showed statistically significant boundary versus core differences in most rates at both boundary types. Differences in canopy and understorey growth were relatively small in magnitude but consistent among <span class="hlt">species</span>, being lower at the northern (average -17%) and higher at the southern (average +12%) boundaries. Differences in lifespan were larger in magnitude but highly variable among <span class="hlt">species</span>, except for a marked trend for reduced canopy lifespan at the northern boundary (average -49%). Differences in per capita reproduction were large and statistically significant for some <span class="hlt">species</span>, but highly variable among <span class="hlt">species</span>. The rate estimates were combined to calculate two performance indices: R(0) (a measure of lifetime fitness in the absence of competition) was consistently lower at the northern boundary (average -86%) whereas Z* (a measure of competitive ability in closed forest) showed no sign of a consistent boundary-core difference at either boundary. PMID:19324819</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3419709','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3419709"><span id="translatedtitle">Avian <span class="hlt">Species</span> Richness in Relation to Intensive Forest Management Practices in Early Seral <span class="hlt">Tree</span> Plantations</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Jones, Jay E.; Kroll, Andrew J.; Giovanini, Jack; Duke, Steven D.; Ellis, Tana M.; Betts, Matthew G.</p> <p>2012-01-01</p> <p>Background Managers of landscapes dedicated to forest commodity production require information about how practices influence biological diversity. Individual <span class="hlt">species</span> and communities may be threatened if management practices truncate or simplify forest age classes that are essential for reproduction and survival. For instance, the degradation and loss of complex diverse forest in young age classes have been associated with declines in forest-associated Neotropical migrant bird populations in the Pacific Northwest, USA. These declines may be exacerbated by intensive forest management practices that reduce hardwood and broadleaf shrub cover in order to promote growth of economically valuable <span class="hlt">tree</span> <span class="hlt">species</span> in plantations. Methodology and Principal Findings We used a Bayesian hierarchical model to evaluate relationships between avian <span class="hlt">species</span> richness and vegetation variables that reflect stand management intensity (primarily via herbicide application) on 212 <span class="hlt">tree</span> plantations in the Coast Range, Oregon, USA. Specifically, we estimated the influence of broadleaf hardwood vegetation cover, which is reduced through herbicide applications, on bird <span class="hlt">species</span> richness and individual <span class="hlt">species</span> occupancy. Our model accounted for imperfect detection. We used average predictive comparisons to quantify the degree of association between vegetation variables and <span class="hlt">species</span> richness. Both conifer and hardwood cover were positively associated with total <span class="hlt">species</span> richness, suggesting that these components of forest stand composition may be important predictors of alpha diversity. Estimates of <span class="hlt">species</span> richness were 35–80% lower when imperfect detection was ignored (depending on covariate values), a result that has critical implications for previous efforts that have examined relationships between forest composition and <span class="hlt">species</span> richness. Conclusion and Significance Our results revealed that individual and community responses were positively associated with both conifer and hardwood cover. In our system, patterns of bird community assembly appear to be associated with stand management strategies that retain or increase hardwood vegetation while simultaneously regenerating the conifer cover in commercial <span class="hlt">tree</span> plantations. PMID:22905249</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/21700641','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21700641"><span id="translatedtitle">Novel <span class="hlt">species</span> of Celoporthe from Eucalyptus and Syzygium <span class="hlt">trees</span> in China and Indonesia.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chen, Shuaifei; Gryzenhout, Marieka; Roux, Jolanda; Xie, Yaojian; Wingfield, Michael J; Zhou, Xudong</p> <p>2011-01-01</p> <p>Many <span class="hlt">species</span> in the Cryphonectriaceae cause diseases of <span class="hlt">trees</span>, including those in the genera Eucalyptus and Syzygium. During disease surveys on these <span class="hlt">trees</span> in southern China, fruiting structures typical of fungi in the Cryphonectriaceae and associated with dying branches and stems were observed. Morphological comparisons suggested that these fungi were distinct from the well known Chrysoporthe deuterocubensis, also found on these <span class="hlt">trees</span> in China. The aim of this study was to identify these fungi and evaluate their pathogenicity to Eucalyptus clones/<span class="hlt">species</span> as well as Syzygium cumini. Three morphologically similar fungal isolates collected previously from Indonesia also were included in the study. Isolates were characterized based on comparisons of morphology and DNA sequence data for the partial LSU and ITS nuclear ribosomal DNA, ?-tubulin and TEF-1? gene regions. After glasshouse trials to select virulent isolates field inoculations were undertaken to screen different commercial Eucalyptus clones/<span class="hlt">species</span> and S. cumini <span class="hlt">trees</span> for susceptibility to infection. Phylogenetic analyses showed that the Chinese isolates and those from Indonesia reside in a clade close to previously identified South African Celoporthe isolates. Based on morphology and DNA sequence comparisons, four new Celoporthe spp. were identified and they are described as C. syzygii, C. eucalypti, C. guangdongensis and C. indonesiensis. Field inoculations indicated that the three Chinese Celoporthe spp., C. syzygii, C. eucalypti and C. guangdongensis, are pathogenic to all tested Eucalyptus and S. cumini <span class="hlt">trees</span>. Significant differences in the susceptibility of the inoculated Eucalyptus clones/<span class="hlt">species</span> suggest that it will be possible to select disease-tolerant planting stock for forestry operations in the future. PMID:21700641</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.B53F..04M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.B53F..04M"><span id="translatedtitle"><span class="hlt">Tree</span> <span class="hlt">Species</span> Linked to Large Differences in Ecosystem Carbon Distribution in the Boreal Forest of Alaska</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Melvin, A. M.; Mack, M. C.; Johnstone, J. F.; Schuur, E. A. G.; Genet, H.; McGuire, A. D.</p> <p>2014-12-01</p> <p>In the boreal forest of Alaska, increased fire severity associated with climate change is altering plant-soil-microbial feedbacks and ecosystem carbon (C) dynamics. The boreal landscape has historically been dominated by black spruce (Picea mariana), a <span class="hlt">tree</span> <span class="hlt">species</span> associated with slow C turnover and large soil organic matter (SOM) accumulation. Historically, low severity fires have led to black spruce regeneration post-fire, thereby maintaining slow C cycling rates and large SOM pools. In recent decades however, an increase in high severity fires has led to greater consumption of the soil organic layer (SOL) during fire and subsequent establishment of deciduous <span class="hlt">tree</span> <span class="hlt">species</span> in areas previously dominated by black spruce. This shift to a more deciduous dominated landscape has many implications for ecosystem structure and function, as well as feedbacks to global C cycling. To improve our understanding of how boreal <span class="hlt">tree</span> <span class="hlt">species</span> affect C cycling, we quantified above- and belowground C stocks and fluxes in adjacent, mid-successional stands of black spruce and Alaska paper birch (Betula neoalaskana) that established following a 1958 fire near Fairbanks, Alaska. Although total ecosystem C pools (aboveground live <span class="hlt">tree</span> biomass + dead wood + SOL + top 10 cm of mineral soil) were similar for the two stand types, the distribution of C among pools was markedly different. In black spruce, 78% of measured C was found in soil pools, primarily in the SOL, where spruce contained twice the C stored in paper birch (4.8 ± 0.3 vs. 2.4 ± 0.1 kg C m-2). In contrast, aboveground biomass dominated ecosystem C pools in birch forest (6.0 ± 0.3 vs. 2.5 ± 0.2 kg C m-2 in birch and spruce, respectively). Our findings suggest that <span class="hlt">tree</span> <span class="hlt">species</span> exert a strong influence over plant-soil-microbial feedbacks and may have long-term effects on ecosystem C sequestration and storage that feedback to the climate system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014BGeo...11.1649L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014BGeo...11.1649L"><span id="translatedtitle">Soil greenhouse gas fluxes from different <span class="hlt">tree</span> <span class="hlt">species</span> on Taihang Mountain, North China</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, X. P.; Zhang, W. J.; Hu, C. S.; Tang, X. G.</p> <p>2014-03-01</p> <p>The objectives of this study were to investigate seasonal variation of greenhouse gas fluxes from soils on sites dominated by plantation (Robinia pseudoacacia, Punica granatum, and Ziziphus jujube) and natural regenerated forests (Vitex negundo var. heterophylla, Leptodermis oblonga, and Bothriochloa ischcemum), and to identify how <span class="hlt">tree</span> <span class="hlt">species</span>, litter exclusion, and soil properties (soil temperature, soil moisture, soil organic carbon, total N, soil bulk density, and soil pH) explained the temporal and spatial variation in soil greenhouse gas fluxes. Fluxes of greenhouse gases were measured using static chamber and gas chromatography techniques. Six static chambers were randomly installed in each <span class="hlt">tree</span> <span class="hlt">species</span>. Three chambers were randomly designated to measure the impacts of surface litter exclusion, and the remaining three were used as a control. Field measurements were conducted biweekly from May 2010 to April 2012. Soil CO2 emissions from all <span class="hlt">tree</span> <span class="hlt">species</span> were significantly affected by soil temperature, soil moisture, and their interaction. Driven by the seasonality of temperature and precipitation, soil CO2 emissions demonstrated a clear seasonal pattern, with fluxes significantly higher during the rainy season than during the dry season. Soil CH4 and N2O fluxes were not significantly correlated with soil temperature, soil moisture, or their interaction, and no significant seasonal differences were detected. Soil organic carbon and total N were significantly positively correlated with CO2 and N2O fluxes. Soil bulk density was significantly negatively correlated with CO2 and N2O fluxes. Soil pH was not correlated with CO2 and N2O emissions. Soil CH4 fluxes did not display pronounced dependency on soil organic carbon, total N, soil bulk density, and soil pH. Removal of surface litter significantly decreased in CO2 emissions and CH4 uptakes. Soils in six <span class="hlt">tree</span> <span class="hlt">species</span> acted as sinks for atmospheric CH4. With the exception of Ziziphus jujube, soils in all <span class="hlt">tree</span> <span class="hlt">species</span> acted as sinks for atmospheric N2O. <span class="hlt">Tree</span> <span class="hlt">species</span> had a significant effect on CO2 and N2O releases but not on CH4 uptake. The lower net global warming potential in natural regenerated vegetation suggested that natural regenerated vegetation were more desirable plant <span class="hlt">species</span> in reducing global warming.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/20525604','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/20525604"><span id="translatedtitle">Maximum likelihood estimates of <span class="hlt">species</span> <span class="hlt">trees</span>: how accuracy of phylogenetic inference depends upon the divergence history and sampling design.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>McCormack, John E; Huang, Huateng; Knowles, L Lacey</p> <p>2009-10-01</p> <p>The understanding that gene <span class="hlt">trees</span> are often in discord with each other and with the <span class="hlt">species</span> <span class="hlt">trees</span> that contain them has led researchers to methods that incorporate the inherent stochasticity of genetic processes in the phylogenetic estimation procedure. Recently developed methods for <span class="hlt">species-tree</span> estimation that not only consider the retention and sorting of ancestral polymorphism but also quantify the actual probabilities of incomplete lineage sorting are expected to provide an improvement over earlier summary-statistic based approaches that discard much of the information content of gene <span class="hlt">trees</span>. However, these new methods have yet to be tested on truly challenging evolutionary histories such as those marked by recent rapid speciation where high levels of incomplete lineage sorting and discord among gene <span class="hlt">trees</span> predominate. Here, we test a new maximum-likelihood method that incorporates stochastic models of both nucleotide substitution and lineage sorting for <span class="hlt">species-tree</span> estimation. Using a simulation approach, we consider a broad range of <span class="hlt">species-tree</span> topologies under 2 scenarios representing moderate and severe incomplete lineage sorting. We show that the maximum-likelihood method results in more accurate <span class="hlt">species</span> <span class="hlt">trees</span> than a summary-statistic based approach, demonstrating that information contained in discordant gene <span class="hlt">trees</span> can be effectively extracted using a full probabilistic model. Moreover, we demonstrate that the shape of the original <span class="hlt">species</span> <span class="hlt">tree</span> (i.e., the relative lengths of internal branches) has a significant impact on whether the <span class="hlt">species</span> <span class="hlt">tree</span> is estimated accurately. In the speciation histories explored here, it is not just the recent origin of <span class="hlt">species</span> that affects the accuracy of the estimates but the variance in relative <span class="hlt">species</span> divergence times as well. Additionally, we show that sampling effort (number of individuals and/or loci) and sampling design (ratio of individuals to loci) are both important factors affecting the accuracy of <span class="hlt">species-tree</span> estimates, which is again affected by the relative timing of divergence among <span class="hlt">species</span>. The inherent difficulties of estimating relationships when <span class="hlt">species</span> have undergone a recent radiation are discussed, and in particular, the limitations with maximum-likelihood estimates of <span class="hlt">species</span> <span class="hlt">trees</span> that do not consider uncertainty in the estimated gene <span class="hlt">trees</span> of individual loci. Thus, despite substantial improvements over current summary-statistic based approaches, and the increased sophistication of procedures that incorporate the process of gene lineage coalescence, recent radiations still appear to pose daunting challenges for phylogenetics. PMID:20525604</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26117705','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26117705"><span id="translatedtitle">Exploring <span class="hlt">Tree</span>-Like and Non-<span class="hlt">Tree</span>-Like Patterns Using Genome Sequences: An Example Using the Inbreeding Plant <span class="hlt">Species</span> Arabidopsis thaliana (L.) Heynh.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Stenz, Noah W M; Larget, Bret; Baum, David A; Ané, Cécile</p> <p>2015-09-01</p> <p>Genome sequence data contain abundant information about genealogical history, but methods for extracting and interpreting this information are not yet fully developed. We analyzed genome sequences for multiple accessions of the selfing plant, Arabidopsis thaliana, with the goal of better understanding its genealogical history. As expected from accessions of the same <span class="hlt">species</span>, we found much discordance between nuclear gene <span class="hlt">trees</span>. Nonetheless, we inferred the optimal population <span class="hlt">tree</span> under the assumption that all discordance is due to incomplete lineage sorting. To cope with the size of the data (many genes and many taxa), our pipeline is based on parallel computing and divides the problem into four-taxon <span class="hlt">trees</span>. However, just because a population <span class="hlt">tree</span> can be estimated does not mean that the assumptions of the multispecies coalescent model hold. Therefore, we implemented a new, nonparametric test to evaluate whether a population <span class="hlt">tree</span> adequately explains the observed quartet frequencies (the frequencies of gene <span class="hlt">trees</span> with each resolution of each four-taxon set). This test also considers other models: panmixia and a partially resolved population <span class="hlt">tree</span>, that is, a <span class="hlt">tree</span> in which some nodes are collapsed into local panmixia. We found that a partially resolved population <span class="hlt">tree</span> provides the best fit to the data, providing evidence for <span class="hlt">tree</span>-like structure within A. thaliana, qualitatively similar to what might be expected between different, closely related <span class="hlt">species</span>. Further, we show that the pattern of deviation from expectations can be used to identify instances of introgression and detect one clear case of reticulation among ecotypes that have come into contact in the United Kingdom. Our study illustrates how we can use genome sequence data to evaluate whether phylogenetic relationships are strictly <span class="hlt">tree</span>-like or reticulating. PMID:26117705</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26865971','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26865971"><span id="translatedtitle"><span class="hlt">Tree</span> <span class="hlt">species</span> richness decreases while <span class="hlt">species</span> evenness increases with disturbance frequency in a natural boreal forest landscape.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yeboah, Daniel; Chen, Han Y H; Kingston, Steve</p> <p>2016-02-01</p> <p>Understanding <span class="hlt">species</span> diversity and disturbance relationships is important for biodiversity conservation in disturbance-driven boreal forests. <span class="hlt">Species</span> richness and evenness may respond differently with stand development following fire. Furthermore, few studies have simultaneously accounted for the influences of climate and local site conditions on <span class="hlt">species</span> diversity. Using forest inventory data, we examined the relationships between <span class="hlt">species</span> richness, Shannon's index, evenness, and time since last stand-replacing fire (TSF) in a large landscape of disturbance-driven boreal forest. TSF has negative effect on <span class="hlt">species</span> richness and Shannon's index, and a positive effect on <span class="hlt">species</span> evenness. Path analysis revealed that the environmental variables affect richness and Shannon's index only through their effects on TSF while affecting evenness directly as well as through their effects on TSF. Synthesis and applications. Our results demonstrate that <span class="hlt">species</span> richness and Shannon's index decrease while <span class="hlt">species</span> evenness increases with TSF in a boreal forest landscape. Furthermore, we show that disturbance frequency, local site conditions, and climate simultaneously influence <span class="hlt">tree</span> <span class="hlt">species</span> diversity through complex direct and indirect effects in the studied boreal forest. PMID:26865971</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24337711','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24337711"><span id="translatedtitle"><span class="hlt">Tree</span> <span class="hlt">species</span> from different functional groups respond differently to environmental changes during establishment.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Barbosa, Eduardo R M; van Langevelde, Frank; Tomlinson, Kyle W; Carvalheiro, Luísa G; Kirkman, Kevin; de Bie, Steven; Prins, Herbert H T</p> <p>2014-04-01</p> <p>Savanna plant communities change considerably across time and space. The processes driving savanna plant <span class="hlt">species</span> diversity, coexistence and turnover along environmental gradients are still unclear. Understanding how <span class="hlt">species</span> respond differently to varying environmental conditions during the seedling stage, a critical stage for plant population dynamics, is needed to explain the current composition of plant communities and to enable us to predict their responses to future environmental changes. Here we investigate whether seedling response to changes in resource availability, and to competition with grass, varied between two functional groups of African savanna <span class="hlt">trees</span>: <span class="hlt">species</span> with small leaves, spines and N-fixing associations (fine-leaved <span class="hlt">species</span>), and <span class="hlt">species</span> with broad leaves, no spines, and lacking N-fixing associations (broad-leaved <span class="hlt">species</span>). We show that while <span class="hlt">tree</span> <span class="hlt">species</span> were strongly suppressed by grass, the effect of resource availability on seedling performance varied considerably between the two functional groups. Nutrient inputs increased stem length only of broad-leaved <span class="hlt">species</span> and only under an even watering treatment. Low light conditions benefited mostly broad-leaved <span class="hlt">species</span>' growth. Savannas are susceptible to ongoing global environment changes. Our results suggest that an increase in woody cover is only likely to occur in savannas if grass cover is strongly suppressed (e.g. by fire or overgrazing). However, if woody cover does increase, broad-leaved <span class="hlt">species</span> will benefit most from the resulting shaded environments, potentially leading to an expansion of the distribution of these <span class="hlt">species</span>. Eutrophication and changes in rainfall patterns may also affect the balance between fine- and broad-leaved <span class="hlt">species</span>. PMID:24337711</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.B53K..02D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.B53K..02D"><span id="translatedtitle">Within-stand variability of leaf phenology in deciduous <span class="hlt">tree</span> <span class="hlt">species</span>: characterization and ecological implications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Delpierre, N.; Cecchini, S.; Dufrêne, E.; Guillemot, J.; Nicolas, M.</p> <p>2014-12-01</p> <p>The vast majority of phenological studies address questions relative to the spatial or temporal variability of phenological timings integrated at the forest stand (i.e. <span class="hlt">tree</span> population) scale. Within a forest stand, the inter-individual variability of phenological timings is expected to affect a range of <span class="hlt">tree</span> functions among which the access to light, the use of carbon and nitrogen reserves, the absorption of minerals and the sensitivity to pathogens. Hence the individual's phenological traits are likely to be strongly selected, resulting in an adaptation of the population to local conditions, as evidenced by latitudinal and altitudinal clines observed in common garden experiments. Studies dedicated to the within-stand variability of the timing of phenophases have to date been mostly designed for contrasting the behaviours of understory versus overstory <span class="hlt">species</span> or seedlings compared to their adult conspecifics. The few published papers studying the phenological timings among adult conspecifics revealed unclear patterns. We aimed at clarifying the understanding of the within-stand variability of <span class="hlt">tree</span> phenology of three of the main European deciduous <span class="hlt">species</span> (Quercus petraea, Quercus robur and Fagus sylvatica) through the analysis of a unique phenological database collected over 44 (28 Oak sites, 16 Beech stands) forest stands at the <span class="hlt">tree</span> level for 4 years over France. We show that within a forest stand, individual <span class="hlt">trees</span> have a distinct "phenological identity" resulting in a year to year conservation of (a) the individuals' spring and autumn phenological rankings and (b) the individuals' critical temperature sums required for budburst and senescence. The individual's spring "phenological identity" affects its functioning and, ultimately, its competitive ability: big <span class="hlt">trees</span> burst earlier. Acknowledging that Angiosperms show low genetic diversity between populations, we show that the between-site variability of critical temperature sums needed for budburst or senescence is low. We show that this between-site variability is linked to climate and geographical gradients, which suggest local adaptations of the populations' phenological traits.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3419707','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3419707"><span id="translatedtitle">Geological Substrates Shape <span class="hlt">Tree</span> <span class="hlt">Species</span> and Trait Distributions in African Moist Forests</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Fayolle, Adeline; Engelbrecht, Bettina; Freycon, Vincent; Mortier, Frédéric; Swaine, Michael; Réjou-Méchain, Maxime; Doucet, Jean-Louis; Fauvet, Nicolas; Cornu, Guillaume; Gourlet-Fleury, Sylvie</p> <p>2012-01-01</p> <p>Background Understanding the factors that shape the distribution of tropical <span class="hlt">tree</span> <span class="hlt">species</span> at large scales is a central issue in ecology, conservation and forest management. The aims of this study were to (i) assess the importance of environmental factors relative to historical factors for <span class="hlt">tree</span> <span class="hlt">species</span> distributions in the semi-evergreen forests of the northern Congo basin; and to (ii) identify potential mechanisms explaining distribution patterns through a trait-based approach. Methodology/Principal Findings We analyzed the distribution patterns of 31 common <span class="hlt">tree</span> <span class="hlt">species</span> in an area of more than 700,000 km2 spanning the borders of Cameroon, the Central African Republic, and the Republic of Congo using forest inventory data from 56,445 0.5-ha plots. Spatial variation of environmental (climate, topography and geology) and historical factors (human disturbance) were quantified from maps and satellite records. Four key functional traits (leaf phenology, shade tolerance, wood density, and maximum growth rate) were extracted from the literature. The geological substrate was of major importance for the distribution of the focal <span class="hlt">species</span>, while climate and past human disturbances had a significant but lesser impact. <span class="hlt">Species</span> distribution patterns were significantly related to functional traits. <span class="hlt">Species</span> associated with sandy soils typical of sandstone and alluvium were characterized by slow growth rates, shade tolerance, evergreen leaves, and high wood density, traits allowing persistence on resource-poor soils. In contrast, fast-growing pioneer <span class="hlt">species</span> rarely occurred on sandy soils, except for Lophira alata. Conclusions/Significance The results indicate strong environmental filtering due to differential soil resource availability across geological substrates. Additionally, long-term human disturbances in resource-rich areas may have accentuated the observed patterns of <span class="hlt">species</span> and trait distributions. Trait differences across geological substrates imply pronounced differences in population and ecosystem processes, and call for different conservation and management strategies. PMID:22905127</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24488084','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24488084"><span id="translatedtitle">The right <span class="hlt">tree</span> for the job? perceptions of <span class="hlt">species</span> suitability for the provision of ecosystem services.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Smaill, Simeon J; Bayne, Karen M; Coker, Graham W R; Paul, Thomas S H; Clinton, Peter W</p> <p>2014-04-01</p> <p>Stakeholders in plantation forestry are increasingly aware of the importance of the ecosystem services and non-market values associated with forests. In New Zealand, there is significant interest in establishing <span class="hlt">species</span> other than Pinus radiata D. Don (the dominant plantation <span class="hlt">species</span>) in the belief that alternative <span class="hlt">species</span> are better suited to deliver these services. Significant risk is associated with this position as there is little objective data to support these views. To identify which <span class="hlt">species</span> were likely to be planted to deliver ecosystem services, a survey was distributed to examine stakeholder perceptions. Stakeholders were asked which of 15 <span class="hlt">tree</span> attributes contributed to the provision of five ecosystem services (amenity value, bioenergy production, carbon capture, the diversity of native habitat, and erosion control/water quality) and to identify which of 22 candidate <span class="hlt">tree</span> <span class="hlt">species</span> possessed those attributes. These data were combined to identify the <span class="hlt">species</span> perceived most suitable for the delivery of each ecosystem service. Sequoia sempervirens (D.Don) Endl. closely matched the stakeholder derived ideotypes associated with all five ecosystem services. Comparisons to data from growth, physiological and ecological studies demonstrated that many of the opinions held by stakeholders were inaccurate, leading to erroneous assumptions regarding the suitability of most candidate <span class="hlt">species</span>. Stakeholder perceptions substantially influence <span class="hlt">tree</span> <span class="hlt">species</span> selection, and plantations established on the basis of inaccurate opinions are unlikely to deliver the desired outcomes. Attitudinal surveys associated with engagement campaigns are essential to improve stakeholder knowledge, advancing the development of fit-for-purpose forest management that provides the required ecosystem services. PMID:24488084</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26853539','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26853539"><span id="translatedtitle">Development of oligonucleotide microarrays for simultaneous multi-<span class="hlt">species</span> identification of Phellinus <span class="hlt">tree</span>-pathogenic fungi.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tzean, Yuh; Shu, Po-Yao; Liou, Ruey-Fen; Tzean, Shean-Shong</p> <p>2016-03-01</p> <p>Polyporoid Phellinus fungi are ubiquitously present in the environment and play an important role in shaping forest ecology. Several <span class="hlt">species</span> of Phellinus are notorious pathogens that can affect a broad variety of <span class="hlt">tree</span> <span class="hlt">species</span> in forest, plantation, orchard and urban habitats; however, current detection methods are overly complex and lack the sensitivity required to identify these pathogens at the <span class="hlt">species</span> level in a timely fashion for effective infestation control. Here, we describe eight oligonucleotide microarray platforms for the simultaneous and specific detection of 17 important Phellinus <span class="hlt">species</span>, using probes generated from the internal transcribed spacer regions unique to each <span class="hlt">species</span>. The sensitivity, robustness and efficiency of this Phellinus microarray system was subsequently confirmed against template DNA from two key Phellinus <span class="hlt">species</span>, as well as field samples collected from <span class="hlt">tree</span> roots, trunks and surrounding soil. This system can provide early, specific and convenient detection of Phellinus <span class="hlt">species</span> for forestry, arboriculture and quarantine inspection, and could potentially help to mitigate the environmental and economic impact of Phellinus-related diseases. PMID:26853539</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/318771','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/318771"><span id="translatedtitle">How environmental conditions affect canopy leaf-level photosynthesis in four deciduous <span class="hlt">tree</span> <span class="hlt">species</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bassow, S.L.; Bazzaz, F.A.</p> <p>1998-12-01</p> <p><span class="hlt">Species</span> composition of temperate forests vary with successional age and seems likely to change in response to significant global climate change. Because photosynthesis rates in co-occurring <span class="hlt">tree</span> <span class="hlt">species</span> can differ in their sensitivity to environmental conditions, these changes in <span class="hlt">species</span> composition are likely to alter the carbon dynamics of temperate forests. To help improve their understanding of such atmosphere-biosphere interactions, the authors explored changes in leaf-level photosynthesis in a 60--70 yr old temperate mixed-deciduous forest in Petersham, Massachusetts (USA). Diurnally and seasonally varying environmental conditions differentially influenced in situ leaf-level photosynthesis rates in the canopies of four mature temperate deciduous <span class="hlt">tree</span> <span class="hlt">species</span>: red oak (Quercus rubra), red maple (Acer rubrum), white birch (Betula papyrifera), and yellow birch (Betula alleghaniensis). The authors measured in situ photosynthesis at two heights within the canopies through a diurnal time course on 7 d over two growing seasons. They simultaneously measured a suite of environmental conditions surrounding the leaf at the time of each measurement. The authors used path analysis to examine the influence of environmental factors on in situ photosynthesis in the <span class="hlt">tree</span> canopies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015NatGe...8..228R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015NatGe...8..228R"><span id="translatedtitle">Influence of <span class="hlt">tree</span> <span class="hlt">species</span> on continental differences in boreal fires and climate feedbacks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rogers, Brendan M.; Soja, Amber J.; Goulden, Michael L.; Randerson, James T.</p> <p>2015-03-01</p> <p>Wildfires are common in boreal forests around the globe and strongly influence ecosystem processes. However, North American forests support more high-intensity crown fires than Eurasia, where lower-intensity surface fires are common. These two types of fire can result in different net effects on climate as a consequence of their contrasting impacts on terrestrial albedo and carbon stocks. Here we use remote-sensing imagery, climate reanalysis data and forest inventories to evaluate differences in boreal fire dynamics between North America and Eurasia and their key drivers. Eurasian fires were less intense, destroyed less live vegetation, killed fewer <span class="hlt">trees</span> and generated a smaller negative shortwave forcing. As fire weather conditions were similar across continents, we suggest that different fire dynamics between the two continents resulted from their dominant <span class="hlt">tree</span> <span class="hlt">species</span>. In particular, <span class="hlt">species</span> that have evolved to spread and be consumed by crown fires as part of their life cycle dominate North American boreal forests. In contrast, <span class="hlt">tree</span> <span class="hlt">species</span> that have evolved to resist and suppress crown fires dominate Eurasian boreal forests. We conclude that <span class="hlt">species</span>-level traits must be considered in global evaluations of the effects of fire on emissions and climate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008QSRv...27.2467K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008QSRv...27.2467K"><span id="translatedtitle">Early postglacial appearance of <span class="hlt">tree</span> <span class="hlt">species</span> in northern Scandinavia: review and perspective</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kullman, Leif</p> <p>2008-12-01</p> <p>This paper reviews megafossil evidence for the first postglacial records of different <span class="hlt">tree</span> <span class="hlt">species</span> in northern Scandinavia. Betula pubescens coll. appeared at the Arctic coast of northern Norway by 16, 900 yr BP. In addition, Betula pubescens (14, 000 yr BP), Pinus sylvestris (11, 700 yr BP) and Picea abies (11, 000 yr BP) existed on early ice- free mountain peaks (nunataks) at different locations in the Scandes during the Lateglacial. Larix sibirica, currently not native to Fennoscandia, and several thermophilous broadleaved <span class="hlt">tree</span> <span class="hlt">species</span> were recorded in the earliest part of the Holocene. The conventional interpretation of pollen and macrofossil records from peat and sediment stratigraphies do not consider the occurrence of the <span class="hlt">species</span> mentioned above that early at these northern and high altitude sites. This very rapid arrival after the local deglaciation implies that the traditional model of far distant glacial refugial areas for <span class="hlt">tree</span> <span class="hlt">species</span> has to be challenged. The current results are more compatible with a situation involving scattered "cryptic" refugia quite close to margin of the ice sheet at its full-glacial extension. This fits a more general pattern currently emerging on different continents. In general, "cryptic" refugia should be considered in connection with modelling extinction risks related to modern and possible future "climatic crises".</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.9950I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.9950I"><span id="translatedtitle">Leaf and whole-<span class="hlt">tree</span> water use relations of Australian rainforest <span class="hlt">species</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ishida, Yoko; Laurance, Susan; Liddell, Michael; Lloyd, Jonathan</p> <p>2015-04-01</p> <p>Climate change induces drought events and may therefore cause significant impact on tropical rainforests, where most plants are reliant on high water availability - potentially affecting the distribution, composition and abundance of plant <span class="hlt">species</span>. Using an experimental approach, we are studying the effects of a simulated drought on lowland rainforest plants at the Daintree Rainforest Observatory (DRO), in tropical northern Australia. Before to build up the rainout infrastructure, we installed sap flow meters (HRM) on 62 rainforest <span class="hlt">trees</span>. Eight <span class="hlt">tree</span> <span class="hlt">species</span> were selected with diverse ecological strategies including wood density values ranging from 0.34 to 0.88 g/cm3 and could be replicated within a 1ha plot: Alstonia scholaris (Apocynaceae), Argyrondendron peralatum (Malvaceae), Elaeocarpus angustifolius (Elaeocarpaceae), Endiandra microneura (Lauraceae), Myristica globosa (Myristicaceae), Syzygium graveolens (Myrtaceae), Normanbya normanbyi (Arecaceae), and Castanospermum australe (Fabaceae). Our preliminary results from sap flow data obtained from October 2013 to December of 2014 showed differences in the amount of water used by our <span class="hlt">trees</span> varied in response to <span class="hlt">species</span>, size and climate. For example Syzygium graveolens has used a maximum of 60 litres/day while Argyrondendrum peralatum used 13 litres/day. Other potential causes for differential water-use between <span class="hlt">species</span> and the implications of our research will be discussed. We will continue to monitor sap flow during the rainfall exclusion (2014 to 2016) to determine the effects of plant physiological traits on water use strategies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70032827','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70032827"><span id="translatedtitle">The relationship between <span class="hlt">tree</span> growth patterns and likelihood of mortality: A study of two <span class="hlt">tree</span> <span class="hlt">species</span> in the Sierra Nevada</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Das, A.J.; Battles, J.J.; Stephenson, N.L.; van Mantgem, P.J.</p> <p>2007-01-01</p> <p>We examined mortality of Abies concolor (Gord. & Glend.) Lindl. (white fir) and Pinus lambertiana Dougl. (sugar pine) by developing logistic models using three growth indices obtained from <span class="hlt">tree</span> rings: average growth, growth trend, and count of abrupt growth declines. For P. lambertiana, models with average growth, growth trend, and count of abrupt declines improved overall prediction (78.6% dead <span class="hlt">trees</span> correctly classified, 83.7% live <span class="hlt">trees</span> correctly classified) compared with a model with average recent growth alone (69.6% dead <span class="hlt">trees</span> correctly classified, 67.3% live <span class="hlt">trees</span> correctly classified). For A. concolor, counts of abrupt declines and longer time intervals improved overall classification (<span class="hlt">trees</span> with DBH ???20 cm: 78.9% dead <span class="hlt">trees</span> correctly classified and 76.7% live <span class="hlt">trees</span> correctly classified vs. 64.9% dead <span class="hlt">trees</span> correctly classified and 77.9% live <span class="hlt">trees</span> correctly classified; <span class="hlt">trees</span> with DBH <20 cm: 71.6% dead <span class="hlt">trees</span> correctly classified and 71.0% live <span class="hlt">trees</span> correctly classified vs. 67.2% dead <span class="hlt">trees</span> correctly classified and 66.7% live <span class="hlt">trees</span> correctly classified). In general, count of abrupt declines improved live-<span class="hlt">tree</span> classification. External validation of A. concolor models showed that they functioned well at stands not used in model development, and the development of size-specific models demonstrated important differences in mortality risk between understory and canopy <span class="hlt">trees</span>. Population-level mortality-risk models were developed for A. concolor and generated realistic mortality rates at two sites. Our results support the contention that a more comprehensive use of the growth record yields a more robust assessment of mortality risk. ?? 2007 NRC.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=244048','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=244048"><span id="translatedtitle">Microbiology of Wetwood: Importance of Pectin Degradation and Clostridium <span class="hlt">Species</span> in Living <span class="hlt">Trees</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Schink, Bernhard; Ward, James C.; Zeikus, J. Gregory</p> <p>1981-01-01</p> <p>Wetwood samples from standing <span class="hlt">trees</span> of eastern cottonwood (Populus deltoides), black poplar (Populus nigra), and American elm (Ulmus americana) contained high numbers of aerobic and anaerobic pectin-degrading bacteria (104 to 106 cells per g of wood). High activity of polygalacturonate lyase (?0.5 U/ml) was also detected in the fetid liquid that spurted from wetwood zones in the lower trunk when the <span class="hlt">trees</span> were bored. A prevalent pectin-degrading obligately anaerobic bacterium isolated from these wetwoods was identified as Clostridium butyricum. Pectin decomposition by C. butyricum strain 4P1 was associated with an inducible polygalacturonate lyase and pectin methylesterase, the same types of pectinolytic activity expressed in the wetwood of these <span class="hlt">trees</span>. The pH optimum of the extracellular polygalacturonate lyase was alkaline (near pH 8.5). In vitro tests with sapwood samples from a conifer (Douglas fir, Pseudotsuga menziesii) showed that tori in membranes of bordered pits are degraded by pure cultures of strain 4P1, polygalacturonate lyase enzyme preparations of strain 4P1, and mixed methanogenic cultures from the <span class="hlt">tree</span> samples of wetwood. These results provide evidence that pectin in xylem tissue is actively degraded by C. butyricum strain 4P1 via polygalacturonate lyase activity. The importance of pectin degradation by bacteria, including Clostridium <span class="hlt">species</span>, appears paramount in the formation and maintenance of the wetwood syndrome in certain living <span class="hlt">trees</span>. Images PMID:16345848</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25168006','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25168006"><span id="translatedtitle">Influence of shade tolerance and development stage on the allometry of ten temperate <span class="hlt">tree</span> <span class="hlt">species</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Franceschini, Tony; Schneider, Robert</p> <p>2014-11-01</p> <p>Allometry studies the change in scale between two dimensions of an organism. The metabolic theory of ecology predicts invariant allometric scaling exponents, while empirical studies evidenced inter- and intra-specific variations. This work aimed at identifying the sources of variations of the allometric exponents at both inter- and intra-specific levels using stem analysis from 9,363 <span class="hlt">trees</span> for ten Eastern Canada <span class="hlt">species</span> with a large shade-tolerance gradient. Specifically, the yearly allometric exponents, ?(v,DBH) [volume (v) and diameter at breast height (DBH)], ?(v,h) [v and height (h)], and ?(h,DBH) (h and DBH) were modelled as a function of <span class="hlt">tree</span> age for each <span class="hlt">species</span>. ?(v,DBH), and ?(h,DBH) increased with <span class="hlt">tree</span> age and then reached a plateau ranging from 2.45 to 3.12 for ?(v,DBH), and 0.874-1.48 for ?(h,DBH). Pine <span class="hlt">species</span> presented a local maximum. No effect of <span class="hlt">tree</span> age on ?(v,h) was found for conifers, while it increased until a plateau ranging from 3.71 to 5.16 for broadleaves. The influence of shade tolerance on the growth trajectories was then explored. In the juvenile stage, ?(v,DBH), and ?(h,DBH) increased with shade tolerance while ?(v,h) was shade-tolerance independent. In the mature stage, ?(v,h) increased with shade tolerance, whereas ?(h,DBH) decreased and ?(v,DBH) was shade-tolerance independent. The interaction between development stage and shade tolerance for allometric exponents demonstrates the importance of the changing functional requirements of <span class="hlt">trees</span> for resource allocation at both the inter- and intra-specific level. These results indicate the need to also integrate specific functional traits, growth strategies and allocation, in allometric theoretical frameworks. PMID:25168006</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4118849','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4118849"><span id="translatedtitle">Epigenetic Variability in the Genetically Uniform Forest <span class="hlt">Tree</span> <span class="hlt">Species</span> Pinus pinea L</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Sáez-Laguna, Enrique; Guevara, María-Ángeles; Díaz, Luis-Manuel; Sánchez-Gómez, David; Collada, Carmen; Aranda, Ismael; Cervera, María-Teresa</p> <p>2014-01-01</p> <p>There is an increasing interest in understanding the role of epigenetic variability in forest <span class="hlt">species</span> and how it may contribute to their rapid adaptation to changing environments. In this study we have conducted a genome-wide analysis of cytosine methylation pattern in Pinus pinea, a <span class="hlt">species</span> characterized by very low levels of genetic variation and a remarkable degree of phenotypic plasticity. DNA methylation profiles of different vegetatively propagated <span class="hlt">trees</span> from representative natural Spanish populations of P. pinea were analyzed with the Methylation Sensitive Amplified Polymorphism (MSAP) technique. A high degree of cytosine methylation was detected (64.36% of all scored DNA fragments). Furthermore, high levels of epigenetic variation were observed among the studied individuals. This high epigenetic variation found in P. pinea contrasted with the lack of genetic variation based on Amplified Fragment Length Polymorphism (AFLP) data. In this manner, variable epigenetic markers clearly discriminate individuals and differentiates two well represented populations while the lack of genetic variation revealed with the AFLP markers fail to differentiate at both, individual or population levels. In addition, the use of different replicated <span class="hlt">trees</span> allowed identifying common polymorphic methylation sensitive MSAP markers among replicates of a given propagated <span class="hlt">tree</span>. This set of MSAPs allowed discrimination of the 70% of the analyzed <span class="hlt">trees</span>. PMID:25084460</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25811074','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25811074"><span id="translatedtitle">Experimental evidence of large changes in terrestrial chlorine cycling following altered <span class="hlt">tree</span> <span class="hlt">species</span> composition.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Montelius, Malin; Thiry, Yves; Marang, Laura; Ranger, Jacques; Cornelis, Jean-Thomas; Svensson, Teresia; Bastviken, David</p> <p>2015-04-21</p> <p>Organochlorine molecules (Clorg) are surprisingly abundant in soils and frequently exceed chloride (Cl(-)) levels. Despite the widespread abundance of Clorg and the common ability of microorganisms to produce Clorg, we lack fundamental knowledge about how overall chlorine cycling is regulated in forested ecosystems. Here we present data from a long-term reforestation experiment where native forest was cleared and replaced with five different <span class="hlt">tree</span> <span class="hlt">species</span>. Our results show that the abundance and residence times of Cl(-) and Clorg after 30 years were highly dependent on which <span class="hlt">tree</span> <span class="hlt">species</span> were planted on the nearby plots. Average Cl(-) and Clorg content in soil humus were higher, at experimental plots with coniferous <span class="hlt">trees</span> than in those with deciduous <span class="hlt">trees</span>. Plots with Norway spruce had the highest net accumulation of Cl(-) and Clorg over the experiment period, and showed a 10 and 4 times higher Cl(-) and Clorg storage (kg ha(-1)) in the biomass, respectively, and 7 and 9 times higher storage of Cl(-) and Clorg in the soil humus layer, compared to plots with oak. The results can explain why local soil chlorine levels are frequently independent of atmospheric deposition, and provide opportunities for improved modeling of chlorine distribution and cycling in terrestrial ecosystems. PMID:25811074</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/22902686','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22902686"><span id="translatedtitle">Tuning of color contrast signals to visual sensitivity maxima of <span class="hlt">tree</span> shrews by three Bornean highland Nepenthes <span class="hlt">species</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Moran, Jonathan A; Clarke, Charles; Greenwood, Melinda; Chin, Lijin</p> <p>2012-10-01</p> <p>Three <span class="hlt">species</span> of Nepenthes pitcher plants (Nepenthes rajah, Nepenthes lowii and Nepenthes macrophylla) specialize in harvesting nutrients from <span class="hlt">tree</span> shrew excreta in their pitchers. In all three <span class="hlt">species</span>, nectaries on the underside of the pitcher lid are the focus of the <span class="hlt">tree</span> shrews' attention. <span class="hlt">Tree</span> shrews are dichromats, with visual sensitivity in the blue and green wavebands. All three Nepenthes <span class="hlt">species</span> were shown to produce visual signals, in which the underside of the pitcher lid (the area of highest nectar production) stood out in high contrast to the adjacent area on the pitcher (i.e., was brighter), in the blue and green wavebands visible to the <span class="hlt">tree</span> shrews. N. rajah showed the tightest degree of "tuning," notably in the green waveband. Conversely, pitchers of Nepenthes burbidgeae, a typical insectivorous <span class="hlt">species</span> sympatric with N. rajah, did not produce a color pattern tuned to <span class="hlt">tree</span> shrew sensitivity maxima. PMID:22902686</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/19197495','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/19197495"><span id="translatedtitle">Diurnal and seasonal carbon balance of four tropical <span class="hlt">tree</span> <span class="hlt">species</span> differing in successional status.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Souza, G M; Ribeiro, R V; Sato, A M; Oliveira, M S</p> <p>2008-11-01</p> <p>This study addressed some questions about how a suitable leaf carbon balance can be attained for different functional groups of tropical <span class="hlt">tree</span> <span class="hlt">species</span> under contrasting forest light environments. The study was carried out in a fragment of semi-deciduous seasonal forest in Narandiba county, São Paulo Estate, Brazil. 10-month-old seedlings of four tropical <span class="hlt">tree</span> <span class="hlt">species</span>, Bauhinia forficata Link (Caesalpinioideae) and Guazuma ulmifolia Lam. (Sterculiaceae) as light-demanding pioneer <span class="hlt">species</span>, and Hymenaea courbaril L. (Caesalpinioideae) and Esenbeckia leiocarpa Engl. (Rutaceae) as late successional <span class="hlt">species</span>, were grown under gap and understorey conditions. Diurnal courses of net photosynthesis (Pn) and transpiration were recorded with an open system portable infrared gas analyzer in two different seasons. Dark respiration and photorespiration were also evaluated in the same leaves used for Pn measurements after dark adaptation. Our results showed that diurnal-integrated dark respiration (Rdi) of late successional <span class="hlt">species</span> were similar to pioneer <span class="hlt">species</span>. On the other hand, photorespiration rates were often higher in pioneer than in late successional <span class="hlt">species</span> in the gap. However, the relative contribution of these parameters to leaf carbon balance was similar in all <span class="hlt">species</span> in both environmental conditions. Considering diurnal-integrated values, gross photosynthesis (Pgi) was dramatically higher in gap than in understorey, regardless of <span class="hlt">species</span>. In both evaluated months, there were no differences among <span class="hlt">species</span> of different functional groups under shade conditions. The same was observed in May (dry season) under gap conditions. In such light environment, pioneers were distinguished from late successional <span class="hlt">species</span> in November (wet season), showing that ecophysiological performance can have a straightforward relation to seasonality. PMID:19197495</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140016963','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140016963"><span id="translatedtitle"><span class="hlt">Multipurpose</span> Cargo Transfer Bag</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Broyan, James; Baccus, Shelley</p> <p>2014-01-01</p> <p>The Logistics Reduction (LR) project within the Advanced Exploration Systems (AES) program is tasked with reducing logistical mass and repurposing logistical items. <span class="hlt">Multipurpose</span> Cargo Transfer Bags (MCTB) have been designed such that they can serve the same purpose as a Cargo Transfer Bag, the suitcase-shaped common logistics carrying bag for Shuttle and the International Space Station. After use as a cargo carrier, a regular CTB becomes trash, whereas the MCTB can be unzipped, unsnapped, and unfolded to be reused. Reuse ideas that have been investigated include partitions, crew quarters, solar radiation storm shelters, acoustic blankets, and forward osmosis water processing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ISPAr.XL3..473F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ISPAr.XL3..473F"><span id="translatedtitle">On the Use of Shortwave Infrared for <span class="hlt">Tree</span> <span class="hlt">Species</span> Discrimination in Tropical Semideciduous Forest</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ferreira, M. P.; Zortea, M.; Zanotta, D. C.; Féret, J. B.; Shimabukuro, Y. E.; Souza Filho, C. R.</p> <p>2015-08-01</p> <p><span class="hlt">Tree</span> <span class="hlt">species</span> mapping in tropical forests provides valuable insights for forest managers. Keystone <span class="hlt">species</span> can be located for collection of seeds for forest restoration, reducing fieldwork costs. However, mapping of <span class="hlt">tree</span> <span class="hlt">species</span> in tropical forests using remote sensing data is a challenge due to high floristic and spectral diversity. Little is known about the use of different spectral regions as most of studies performed so far used visible/near-infrared (390-1000 nm) features. In this paper we show the contribution of shortwave infrared (SWIR, 1045-2395 nm) for <span class="hlt">tree</span> <span class="hlt">species</span> discrimination in a tropical semideciduous forest. Using high-resolution hyperspectral data we also simulated WorldView-3 (WV-3) multispectral bands for classification purposes. Three machine learning methods were tested to discriminate <span class="hlt">species</span> at the pixel-level: Linear Discriminant Analysis (LDA), Support Vector Machines with Linear (L-SVM) and Radial Basis Function (RBF-SVM) kernels, and Random Forest (RF). Experiments were performed using all and selected features from the VNIR individually and combined with SWIR. Feature selection was applied to evaluate the effects of dimensionality reduction and identify potential wavelengths that may optimize <span class="hlt">species</span> discrimination. Using VNIR hyperspectral bands, RBF-SVM achieved the highest average accuracy (77.4%). Inclusion of the SWIR increased accuracy to 85% with LDA. The same pattern was also observed when WV-3 simulated channels were used to classify the <span class="hlt">species</span>. The VNIR bands provided and accuracy of 64.2% for LDA, which was increased to 79.8 % using the new SWIR bands that are operationally available in this platform. Results show that incorporating SWIR bands increased significantly average accuracy for both the hyperspectral data and WorldView-3 simulated bands.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25225398','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25225398"><span id="translatedtitle">Predicting <span class="hlt">species</span>' range limits from functional traits for the <span class="hlt">tree</span> flora of North America.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Stahl, Ulrike; Reu, Björn; Wirth, Christian</p> <p>2014-09-23</p> <p>Using functional traits to explain <span class="hlt">species</span>' range limits is a promising approach in functional biogeography. It replaces the idiosyncrasy of <span class="hlt">species</span>-specific climate ranges with a generic trait-based predictive framework. In addition, it has the potential to shed light on specific filter mechanisms creating large-scale vegetation patterns. However, its application to a continental flora, spanning large climate gradients, has been hampered by a lack of trait data. Here, we explore whether five key plant functional traits (seed mass, wood density, specific leaf area (SLA), maximum height, and longevity of a <span class="hlt">tree</span>)--indicative of life history, mechanical, and physiological adaptations--explain the climate ranges of 250 North American <span class="hlt">tree</span> <span class="hlt">species</span> distributed from the boreal to the subtropics. Although the relationship between traits and the median climate across a <span class="hlt">species</span> range is weak, quantile regressions revealed strong effects on range limits. Wood density and seed mass were strongly related to the lower but not upper temperature range limits of <span class="hlt">species</span>. Maximum height affects the <span class="hlt">species</span> range limits in both dry and humid climates, whereas SLA and longevity do not show clear relationships. These results allow the definition and delineation of climatic "no-go areas" for North American <span class="hlt">tree</span> <span class="hlt">species</span> based on key traits. As some of these key traits serve as important parameters in recent vegetation models, the implementation of trait-based climatic constraints has the potential to predict both range shifts and ecosystem consequences on a more functional basis. Moreover, for future trait-based vegetation models our results provide a benchmark for model evaluation. PMID:25225398</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFM.B43C0452B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFM.B43C0452B"><span id="translatedtitle">Sap Flux Scaled Transpiration in Ring-porous <span class="hlt">Tree</span> <span class="hlt">Species</span>: Assumptions, Pitfalls and Calibration</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bush, S. E.; Hultine, K. R.; Ehleringer, J. R.</p> <p>2008-12-01</p> <p>Thermal dissipation probes for measuring sap flow (Granier-type) at the whole <span class="hlt">tree</span> and stand level are routinely used in forest ecology and site water balance studies. While the original empirical relationship used to calculate sap flow was reported as independent of wood anatomy (ring-porous, diffuse-porous, tracheid), it has been suggested that potentially large errors in sap flow calculations may occur when using the original calibration for ring-porous <span class="hlt">species</span>, due to large radial trends in sap velocity and/or shallow sapwood depth. Despite these concerns, sap flux measurements have rarely been calibrated in ring-porous taxa. We used a simple technique to calibrate thermal dissipation sap flux measurements on ring-porous <span class="hlt">trees</span> in the lab. Calibration measurements were conducted on five ring-porous <span class="hlt">species</span> in the Salt Lake City, USA metropolitan area including Quercus gambelii (Gambel oak), Gleditsia triacanthos (Honey locust), Elaeagnus angustifolia (Russian olive), Sophora japonica (Japanese pagoda), and Celtis occidentalis (Common hackberry). Six stems per <span class="hlt">species</span> of approximately 1 m in length were instrumented with heat dissipation probes to measure sap flux concurrently with gravimetric measurements of water flow through each stem. Safranin dye was pulled through the stems following flow rate measurements to determine sapwood area. As expected, nearly all the conducting sapwood area was limited to regions within the current year growth rings. Consequently, we found that the original Granier equation underestimated sap flux density for all <span class="hlt">species</span> considered. Our results indicate that the use of thermal dissipation probes for measuring sap flow in ring-porous <span class="hlt">species</span> should be independently calibrated, particularly when <span class="hlt">species</span>- specific calibration data are not available. Ring-porous taxa are widely distributed and represent an important component of the regional water budgets of many temperate regions. Our results are important for evaluating plant water use of ring-porous <span class="hlt">tree</span> <span class="hlt">species</span> with thermal dissipation probes at multiple spatial scales.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1964803','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1964803"><span id="translatedtitle">Crown Plasticity and Competition for Canopy Space: A New Spatially Implicit Model Parameterized for 250 North American <span class="hlt">Tree</span> <span class="hlt">Species</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Purves, Drew W.; Lichstein, Jeremy W.; Pacala, Stephen W.</p> <p>2007-01-01</p> <p>Background Canopy structure, which can be defined as the sum of the sizes, shapes and relative placements of the <span class="hlt">tree</span> crowns in a forest stand, is central to all aspects of forest ecology. But there is no accepted method for deriving canopy structure from the sizes, <span class="hlt">species</span> and biomechanical properties of the individual <span class="hlt">trees</span> in a stand. Any such method must capture the fact that <span class="hlt">trees</span> are highly plastic in their growth, forming tessellating crown shapes that fill all or most of the canopy space. Methodology/Principal Findings We introduce a new, simple and rapidly-implemented model–the Ideal <span class="hlt">Tree</span> Distribution, ITD–with <span class="hlt">tree</span> form (height allometry and crown shape), growth plasticity, and space-filling, at its core. The ITD predicts the canopy status (in or out of canopy), crown depth, and total and exposed crown area of the <span class="hlt">trees</span> in a stand, given their <span class="hlt">species</span>, sizes and potential crown shapes. We use maximum likelihood methods, in conjunction with data from over 100,000 <span class="hlt">trees</span> taken from forests across the coterminous US, to estimate ITD model parameters for 250 North American <span class="hlt">tree</span> <span class="hlt">species</span>. With only two free parameters per <span class="hlt">species</span>–one aggregate parameter to describe crown shape, and one parameter to set the so-called depth bias–the model captures between-<span class="hlt">species</span> patterns in average canopy status, crown radius, and crown depth, and within-<span class="hlt">species</span> means of these metrics vs stem diameter. The model also predicts much of the variation in these metrics for a <span class="hlt">tree</span> of a given <span class="hlt">species</span> and size, resulting solely from deterministic responses to variation in stand structure. Conclusions/Significance This new model, with parameters for US <span class="hlt">tree</span> <span class="hlt">species</span>, opens up new possibilities for understanding and modeling forest dynamics at local and regional scales, and may provide a new way to interpret remote sensing data of forest canopies, including LIDAR and aerial photography. PMID:17849000</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/15092455','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/15092455"><span id="translatedtitle">Effect of chlorine pollution on three fruit <span class="hlt">tree</span> <span class="hlt">species</span> at Ranoli near Baroda, India.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Vijayan, R; Bedi, S J</p> <p>1989-01-01</p> <p>This paper describes the effect of chlorine pollution from an alkalies and chemical plant at Ranoli, near Baroda, on three tropical fruit <span class="hlt">tree</span> <span class="hlt">species</span>-Mangifera indica L. (mango) Manilkara hexandra Dubard. (rayan) and Syzygium cumini Skeels (Jamun). As compared to controls growing in a less polluted area, <span class="hlt">trees</span> growing close to the plant showed reduced mean leaf area, a higher percentage of leaf area damaged, a reduction in fruit yield, chlorophyll pigments, protein and carbohydrate content, and higher accumulation of chloride in the foliar tissues. The accumulation of pollutaant, chloride, in the foliar tissues was very high in mango and jamun. Based on the degree of damage to the plants, the <span class="hlt">species</span> studied were arranged in decreasing order of their sensitivity to chlorine pollution-mango, jamun and rayan. PMID:15092455</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23416882','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23416882"><span id="translatedtitle">Analyzing lead absorption by the sycamore <span class="hlt">tree</span> <span class="hlt">species</span> in the industrial park of Rasht, Iran.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hashemi, Seyed Armin; FallahChay, Mir Mozaffar; Tarighi, Fattaneh</p> <p>2015-07-01</p> <p>In this study, the subject of heavy metal concentration in soil, rock, sediment, surface water and groundwater, which can be caused by natural or man-posed pollution, was analyzed in the industrial park of Rasht. These concentrations were compared with the standard range of environmental data. Heavy metals are important environmental pollutants that can cause health hazards to humans, plants and microorganisms by entering food chain. This study aimed to investigate the absorption of lead by the leaves of sycamore <span class="hlt">tree</span> <span class="hlt">species</span> in the industrial park of Rasht. For this purpose, a sample of 32 sycamore <span class="hlt">tree</span> <span class="hlt">species</span> were randomly selected at a specified time, and the concentration of lead were measured using an atomic absorption device. Results showed that the amount of lead absorption by sycamore leaves is remarkable. The highest amount of lead absorption by sycamore leaves was detected at station 1 (Khazar Steel) and the lowest amount at station 2 (control station). PMID:23416882</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/10562404','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/10562404"><span id="translatedtitle">Foliar temperature-respiration response functions for broad-leaved <span class="hlt">tree</span> <span class="hlt">species</span> in the southern Appalachians.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bolstad; Mitchell; Vose</p> <p>1999-11-01</p> <p>We measured leaf respiration in 18 eastern deciduous forest <span class="hlt">tree</span> <span class="hlt">species</span> to determine if there were differences in temperature-respiration response functions among <span class="hlt">species</span> or among canopy positions. Leaf respiration rates were measured in situ and on detached branches for Acer pensylvanicum L., A. rubrum L., Betula spp. (B. alleghaniensis Britt. and B. lenta L.), Carya glabra (Mill.) Sweet, Cornus florida L., Fraxinus spp. (primarily F. americana L.), Liriodendron tulipifera L., Magnolia fraseri Walt., Nyssa sylvatica Marsh., Oxydendrum arboreum L., Platanus occidentalis L., Quercus alba L., Q. coccinea Muenchh., Q. prinus L., Q. rubra L., Rhododendron maximum L., Robinia psuedoacacia L., and Tilia americana L. in the southern Appalachian Mountains, USA. Dark respiration was measured on fully expanded leaves at 10, 15, 20, 25, and 30 degrees C with an infrared gas analyzer equipped with a temperature-controlled cuvette. Temperature-respiration response functions were fit for each leaf. There were significant differences in response functions among <span class="hlt">species</span> and by canopy position within <span class="hlt">species</span>. These differences were observed when respiration was expressed on a mass, nitrogen, or area basis. Cumulative nighttime leaf respiration was calculated and averaged over ten randomly selected nights for each leaf. Differences in mean cumulative nighttime respiration were statistically significant among canopy positions and <span class="hlt">species</span>. We conclude that effects of canopy position and <span class="hlt">species</span> on temperature-respiration response functions may need to be considered when making estimates of whole-<span class="hlt">tree</span> or canopy respiration. PMID:10562404</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/21971584','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21971584"><span id="translatedtitle">Atmospheric change alters foliar quality of host <span class="hlt">trees</span> and performance of two outbreak insect <span class="hlt">species</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Couture, John J; Meehan, Timothy D; Lindroth, Richard L</p> <p>2012-03-01</p> <p>This study examined the independent and interactive effects of elevated carbon dioxide (CO(2)) and ozone (O(3)) on the foliar quality of two deciduous <span class="hlt">trees</span> <span class="hlt">species</span> and the performance of two outbreak herbivore <span class="hlt">species</span>. Trembling aspen (Populus tremuloides) and paper birch (Betula papyrifera) were grown at the Aspen FACE research site in northern Wisconsin, USA, under four combinations of ambient and elevated CO(2) and O(3). We measured the effects of elevated CO(2) and O(3) on aspen and birch phytochemistry and on gypsy moth (Lymantria dispar) and forest tent caterpillar (Malacosoma disstria) performance. Elevated CO(2) nominally affected foliar quality for both <span class="hlt">tree</span> <span class="hlt">species</span>. Elevated O(3) negatively affected aspen foliar quality, but only marginally influenced birch foliar quality. Elevated CO(2) slightly improved herbivore performance, while elevated O(3) decreased herbivore performance, and both responses were stronger on aspen than birch. Interestingly, elevated CO(2) largely offset decreased herbivore performance under elevated O(3). Nitrogen, lignin, and C:N were identified as having strong influences on herbivore performance when larvae were fed aspen, but no significant relationships were observed for insects fed birch. Our results support the notion that herbivore performance can be affected by atmospheric change through altered foliar quality, but how herbivores will respond will depend on interactions among CO(2), O(3), and <span class="hlt">tree</span> <span class="hlt">species</span>. An emergent finding from this study is that <span class="hlt">tree</span> age and longevity of exposure to pollutants may influence the effects of elevated CO(2) and O(3) on plant-herbivore interactions, highlighting the need to continue long-term atmospheric change research. PMID:21971584</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4324066','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4324066"><span id="translatedtitle">Do ectomycorrhizal and arbuscular mycorrhizal temperate <span class="hlt">tree</span> <span class="hlt">species</span> systematically differ in root order-related fine root morphology and biomass?</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kubisch, Petra; Hertel, Dietrich; Leuschner, Christoph</p> <p>2015-01-01</p> <p>While most temperate broad-leaved <span class="hlt">tree</span> <span class="hlt">species</span> form ectomycorrhizal (EM) symbioses, a few <span class="hlt">species</span> have arbuscular mycorrhizas (AM). It is not known whether EM and AM <span class="hlt">tree</span> <span class="hlt">species</span> differ systematically with respect to fine root morphology, fine root system size and root functioning. In a <span class="hlt">species</span>-rich temperate mixed forest, we studied the fine root morphology and biomass of three EM and three AM <span class="hlt">tree</span> <span class="hlt">species</span> from the genera Acer, Carpinus, Fagus, Fraxinus, and Tilia searching for principal differences between EM and AM <span class="hlt">trees</span>. We further assessed the evidence of convergence or divergence in root traits among the six co-occurring <span class="hlt">species</span>. Eight fine root morphological and chemical traits were investigated in root segments of the first to fourth root order in three different soil depths and the relative importance of the factors root order, <span class="hlt">tree</span> <span class="hlt">species</span> and soil depth for root morphology was determined. Root order was more influential than <span class="hlt">tree</span> <span class="hlt">species</span> while soil depth had only a small effect on root morphology All six <span class="hlt">species</span> showed similar decreases in specific root length and specific root area from the 1st to the 4th root order, while the <span class="hlt">species</span> patterns differed considerably in root tissue density, root N concentration, and particularly with respect to root tip abundance. Most root morphological traits were not significantly different between EM and AM <span class="hlt">species</span> (except for specific root area that was larger in AM <span class="hlt">species</span>), indicating that mycorrhiza type is not a key factor influencing fine root morphology in these <span class="hlt">species</span>. The order-based root analysis detected <span class="hlt">species</span> differences more clearly than the simple analysis of bulked fine root mass. Despite convergence in important root traits among AM and EM <span class="hlt">species</span>, even congeneric <span class="hlt">species</span> may differ in certain fine root morphological traits. This suggests that, in general, <span class="hlt">species</span> identity has a larger influence on fine root morphology than mycorrhiza type. PMID:25717334</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25204074','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25204074"><span id="translatedtitle">Effects of <span class="hlt">tree</span> <span class="hlt">species</span> and wood particle size on the properties of cement-bonded particleboard manufacturing from <span class="hlt">tree</span> prunings.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nasser, Ramadan A; Al-Mefarrej, H A; Abdel-Aal, M A; Alshahrani, T S</p> <p>2014-09-01</p> <p>This study investigated the possibility of using the prunings of six locally grown <span class="hlt">tree</span> <span class="hlt">species</span> in Saudi Arabia for cement-bonded particleboard (CBP) production. Panels were made using four different wood particle sizes and a constant wood/cement ratio (1/3 by weight) and target density (1200 kg/m3). The mechanical properties and dimensional stability of the produced panels were determined. The interfacial area and distribution of the wood particles in cement matrix were also investigated by scanning electron microscopy. The results revealed that the panels produced from these pruning materials at a target density of 1200 kg m(-3) meet the strength and dimensional stability requirements of the commercial CBP panels. The mean moduli of rupture and elasticity (MOR and MOE) ranged from 9.68 to 11.78 N mm2 and from 3952 to 5667 N mm2, respectively. The mean percent water absorption for twenty four hours (WA24) ranged from 12.93% to 23.39%. Thickness swelling values ranged from 0.62% to 1.53%. For CBP panels with high mechanical properties and good dimensional stability, mixed-size or coarse particles should be used. Using the <span class="hlt">tree</span> prunings for CBPs production may help to solve the problem of getting rid of these residues by reducing their negative effects on environment, which are caused by poor disposal of such materials through direct combustion process and appearance of black cloud and then the impact on human health or the random accumulation and its indirect effects on the environment. PMID:25204074</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3532498','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3532498"><span id="translatedtitle">Structural and Chemical Characterization of Hardwood from <span class="hlt">Tree</span> <span class="hlt">Species</span> with Applications as Bioenergy Feedstocks</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Çetinkol, Özgül Persil; Smith-Moritz, Andreia M.; Cheng, Gang; Lao, Jeemeng; George, Anthe; Hong, Kunlun; Henry, Robert; Simmons, Blake A.; Heazlewood, Joshua L.; Holmes, Bradley M.</p> <p>2012-01-01</p> <p>Eucalypt <span class="hlt">species</span> are a group of flowering <span class="hlt">trees</span> widely used in pulp production for paper manufacture. For several decades, the wood pulp industry has focused research and development efforts on improving yields, growth rates and pulp quality through breeding and the genetic improvement of key <span class="hlt">tree</span> <span class="hlt">species</span>. Recently, this focus has shifted from the production of high quality pulps to the investigation of the use of eucalypts as feedstocks for biofuel production. Here the structure and chemical composition of the heartwood and sapwood of Eucalyptus dunnii, E. globulus, E. pillularis, E. urophylla, an E. urophylla-E. grandis cross, Corymbia citriodora ssp. variegata, and Acacia mangium were compared using nuclear magnetic resonance spectroscopy (NMR), X-ray diffraction (XRD) and biochemical composition analysis. Some trends relating to these compositions were also identified by Fourier transform near infrared (FT-NIR) spectroscopy. These results will serve as a foundation for a more comprehensive database of wood properties that will help develop criteria for the selection of <span class="hlt">tree</span> <span class="hlt">species</span> for use as biorefinery feedstocks. PMID:23300786</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013BGD....1011037L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013BGD....1011037L"><span id="translatedtitle">Soil greenhouse gas fluxes from different <span class="hlt">tree</span> <span class="hlt">species</span> on Taihang Mountain, North China</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, X. P.; Zhang, W. J.; Hu, C. S.; Tang, X. G.</p> <p>2013-07-01</p> <p>The objectives of this study were to investigate seasonal variation of greenhouse gas fluxes from soils on sites dominated by plantation (Robinia pseudoacacia, Punica granatum, and Ziziphus jujube) and natural regenerated forests (Vitex negundo var. heterophylla, Leptodermis oblonga, and Bothriochloa ischcemum), and to identify how <span class="hlt">tree</span> <span class="hlt">species</span>, litter exclusion, and soil properties (soil temperature, soil moisture, soil organic carbon, total N, soil bulk density, and soil pH) explained the temporal and spatial variance in soil greenhouse gas fluxes. Fluxes of greenhouse gases were measured using static chamber and gas chromatography techniques. Six static chambers were randomly installed in each <span class="hlt">tree</span> <span class="hlt">species</span>. Three chambers were randomly designated to measure the impacts of surface litter exclusion, and the remaining three were used as a control. Field measurements were conducted biweekly from May 2010 through April 2012. Soil CO2 emissions from all <span class="hlt">tree</span> <span class="hlt">species</span> were significantly affected by soil temperature, soil moisture, and their interaction. Driven by the seasonality of temperature and precipitation, soil CO2 emissions demonstrated a clear seasonal pattern, with fluxes significantly higher during the rainy season than during the dry season. Soil CH4 and N2O fluxes were not significantly correlated with soil temperature, soil moisture, or their interaction, and no significant seasonal differences were detected. Soil CO2 and N2O fluxes were significantly correlated with soil organic carbon, total N, and soil bulk density, while soil pH was not correlated with CO2 and N2O emissions. Soil CH4 fluxes did not display pronounced dependency on soil organic carbon, total N, soil bulk density, and soil pH. Removal of surface litter resulted in significant decreases in CO2 emissions and CH4 uptakes, but had no significant influence on N2O fluxes. Soils in six <span class="hlt">tree</span> <span class="hlt">species</span> acted as sinks for atmospheric CH4. With the exception of Ziziphus jujube, Soils in all sites acted as sinks for atmospheric N2O. <span class="hlt">Tree</span> <span class="hlt">species</span> had a significant effect on CO2 and N2O fluxes but not on CH4 uptake. The lower net global warming potential in natural regenerated vegetation suggested that natural regenerated vegetation were more desirable plant <span class="hlt">species</span> in reducing global warming.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..1410046C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..1410046C"><span id="translatedtitle">Chemical composition and fuel wood characteristics of fast growing <span class="hlt">tree</span> <span class="hlt">species</span> in India</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chauhan, S. K.; Soni, R.</p> <p>2012-04-01</p> <p>India is one of the growing economy in the world and energy is a critical input to sustain the growth of development. Country aims at security and efficiency of energy. Though fossil fuel will continue to play a dominant role in energy scenario but country is committed to global environmental well being thus stressing on environment friendly technologies. Concerns of energy security in this changing climatic situation have led to increasing support for the development of new renewable source of energy. Government though is determined to facilitate bio-energy and many projects have been established but initial after-affects more specifically on the domestic fuelwood are evident. Even the biomass power generating units are facing biomass crisis and accordingly the prices are going up. The CDM projects are supporting the viability of these units resultantly the Indian basket has a large number of biomass projects (144 out of total 506 with 28 per cent CERs). The use for fuelwood as a primary source of energy for domestic purpose by the poor people (approx. 80 per cent) and establishment of bio-energy plants may lead to deforestation to a great extent and only solution to this dilemma is to shift the wood harvest from the natural forests to energy plantations. However, there is conspicuous lack of knowledge with regards to the fuelwood characteristics of fast growing <span class="hlt">tree</span> <span class="hlt">species</span> for their selection for energy plantations. The calorific value of the <span class="hlt">species</span> is important criteria for selection for fuel but it is affected by the proportions of biochemical constituents present in them. The aim of the present work was to study the biomass production, calorific value and chemical composition of different short rotation <span class="hlt">tree</span> <span class="hlt">species</span>. The study was done from the perspective of using the fast growing <span class="hlt">tree</span> <span class="hlt">species</span> for energy production at short rotation and the study concluded that short rotation <span class="hlt">tree</span> <span class="hlt">species</span> like Gmelina arborea, Eucalyptus tereticornis, Pongamia pinnata,Terminalia arjuna, Toona ciliate, etc. have better fuelwood properties and can be considered for inclusion in the energy plantation programme to minimize pressure on the traditional forests. Key words: Short rotation <span class="hlt">tree</span> <span class="hlt">species</span>, bio-energy, calorific value, bio-chemicals</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24027913','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24027913"><span id="translatedtitle">Identification of endangered or threatened Costa Rican <span class="hlt">tree</span> <span class="hlt">species</span> by wood anatomy and fluorescence activity.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Moya, Róger; Wiemann, Michael C; Olivares, Carlos</p> <p>2013-09-01</p> <p>A total of 45 native Costa Rican <span class="hlt">tree</span> <span class="hlt">species</span> are threatened or in danger of extinction, but the Convention on International Trade Endangered <span class="hlt">Species</span> (CITES) includes only eight of these in its Appendices. However, the identification of other <span class="hlt">species</span> based on their wood anatomy is limited. The present study objective was to describe and to compare wood anatomy and fluorescence activity in some endangered or threatened <span class="hlt">species</span> of Costa Rica. A total of 45 (22 endangered and 23 threatened with extinction) wood samples of these <span class="hlt">species</span>, from the xylaria of the Instituto Tecnológico de Costa Rica and the Forest Products Laboratory in Madison, Wisconsin, were examined. Surface fluorescence was positive in eight <span class="hlt">species</span>, water extract fluorescence was positive in six <span class="hlt">species</span> and ethanol extract fluorescence was positive in 24 <span class="hlt">species</span>. Almost all <span class="hlt">species</span> were diffuse porous except for occasional (Cedrela odorata, C. fissilis, Cordia gerascanthus) or regular (C. salvadorensis and C. tonduzii) semi-ring porosity. A dendritic vessel arrangement was found in Sideroxylon capari, and pores were solitary in Guaiacum sanctum and Vantanea barbourii. Vessel element length was shortest in Guaiacum sanctum and longest in Humiriastrum guianensis, Minquartia guianensis and Vantanea barbourii. Finally, anatomical information and fluorescence activity were utilized to construct an identification key of <span class="hlt">species</span>, in which fluorescence is a feature used in identification. PMID:24027913</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4383566','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4383566"><span id="translatedtitle">The Effects of Drought and Shade on the Performance, Morphology and Physiology of Ghanaian <span class="hlt">Tree</span> <span class="hlt">Species</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Amissah, Lucy; Mohren, Godefridus M. J.; Kyereh, Boateng; Poorter, Lourens</p> <p>2015-01-01</p> <p>In tropical forests light and water availability are the most important factors for seedling growth and survival but an increasing frequency of drought may affect <span class="hlt">tree</span> regeneration. One central question is whether drought and shade have interactive effects on seedling growth and survival. Here, we present results of a greenhouse experiment, in which seedlings of 10 Ghanaian <span class="hlt">tree</span> <span class="hlt">species</span> were exposed to combinations of strong seasonal drought (continuous watering versus withholding water for nine weeks) and shade (5% irradiance versus 20% irradiance). We evaluated the effects of drought and shade on seedling survival and growth and plasticity of 11 underlying traits related to biomass allocation, morphology and physiology. Seedling survival under dry conditions was higher in shade than in high light, thus providing support for the “facilitation hypothesis” that shade enhances plant performance through improved microclimatic conditions, and rejecting the trade-off hypothesis that drought should have stronger impact in shade because of reduced root investment. Shaded plants had low biomass fraction in roots, in line with the trade-off hypothesis, but they compensated for this with a higher specific root length (i.e., root length per unit root mass), resulting in a similar root length per plant mass and, hence, similar water uptake capacity as high-light plants. The majority (60%) of traits studied responded independently to drought and shade, indicating that within <span class="hlt">species</span> shade- and drought tolerances are not in trade-off, but largely uncoupled. When individual <span class="hlt">species</span> responses were analysed, then for most of the traits only one to three <span class="hlt">species</span> showed significant interactive effects between drought and shade. The uncoupled response of most <span class="hlt">species</span> to drought and shade should provide ample opportunity for niche differentiation and <span class="hlt">species</span> coexistence under a range of water and light conditions. Overall our greenhouse results suggest that, in the absence of root competition shaded tropical forest <span class="hlt">tree</span> seedlings may be able to survive prolonged drought. PMID:25836337</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3040169','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3040169"><span id="translatedtitle">The Influence of Recent Climate Change on <span class="hlt">Tree</span> Height Growth Differs with <span class="hlt">Species</span> and Spatial Environment</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Messaoud, Yassine; Chen, Han Y. H.</p> <p>2011-01-01</p> <p><span class="hlt">Tree</span> growth has been reported to increase in response to recent global climate change in controlled and semi-controlled experiments, but few studies have reported response of <span class="hlt">tree</span> growth to increased temperature and atmospheric carbon dioxide (CO2) concentration in natural environments. This study addresses how recent global climate change has affected height growth of trembling aspen (Populus tremuloides Michx) and black spruce (Picea mariana Mill B.S.) in their natural environments. We sampled 145 stands dominated by aspen and 82 dominated by spruce over the entire range of their distributions in British Columbia, Canada. These stands were established naturally after fire between the 19th and 20th centuries. Height growth was quantified as total heights of sampled dominant and co-dominant <span class="hlt">trees</span> at breast-height age of 50 years. We assessed the relationships between 50-year height growth and environmental factors at both spatial and temporal scales. We also tested whether the <span class="hlt">tree</span> growth associated with global climate change differed with spatial environment (latitude, longitude and elevation). As expected, height growth of both <span class="hlt">species</span> was positively related to temperature variables at the regional scale and with soil moisture and nutrient availability at the local scale. While height growth of trembling aspen was not significantly related to any of the temporal variables we examined, that of black spruce increased significantly with stand establishment date, the anomaly of the average maximum summer temperature between May-August, and atmospheric CO2 concentration, but not with the Palmer Drought Severity Index. Furthermore, the increase of spruce height growth associated with recent climate change was higher in the western than in eastern part of British Columbia. This study demonstrates that the response of height growth to recent climate change, i.e., increasing temperature and atmospheric CO2 concentration, did not only differ with <span class="hlt">tree</span> <span class="hlt">species</span>, but also their growing spatial environment. PMID:21358817</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUSMNB22F..03S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUSMNB22F..03S"><span id="translatedtitle">The Role of Native <span class="hlt">Tree</span> <span class="hlt">Species</span> on Leaf Breakdown Dynamics of the Invasive <span class="hlt">Tree</span> of Heaven ( Ailanthus altissima) in an Urban Stream</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Swan, C.; Healey, B.</p> <p>2005-05-01</p> <p>Anthropogenic disturbance of ecosystem processes is increasingly being explored in urban settings. One profound impact is the striking increase in the distribution of invasive plant <span class="hlt">species</span>. For example, <span class="hlt">Tree</span> of Heaven (Ailanthus altissima, TOH), introduced into the U.S. from Asia in 1784, is a successful colonist of recently deforested habitats. As a result, remnant patches in urban ecosystems have become overrun with this <span class="hlt">tree</span> <span class="hlt">species</span>, excluding native <span class="hlt">species</span> via fast growth and allelopathy. While suffering from human-induced degradation, urban streams still support food webs that function to process riparian-derived organic matter (e.g., leaves, wood). The purpose of this study was to (1) estimate leaf litter breakdown of native <span class="hlt">tree</span> leaves and those of TOH in an urban stream, (2) study the detritivore feeding rate of the same leaf <span class="hlt">species</span>, and (3) determine if increasing native <span class="hlt">species</span> richness of leaf litter can alter breakdown of TOH leaves. Field manipulations of leaf pack composition were done in a highly urbanized stream (>30% upstream urban land use) in Baltimore County, Maryland, USA. This was complimented by a series of laboratory feeding experiments employing similar leaf treatments and local shredding invertebrate taxa. Breakdown of TOH alone was extremely rapid, significantly exceeding that of all native <span class="hlt">tree</span> <span class="hlt">species</span> employed. Furthermore, mixing TOH with native <span class="hlt">tree</span> <span class="hlt">species</span>, red maple and white oak, substantially reduced TOH decay compared to decay of TOH alone. However, supporting laboratory studies showed that TOH was a preferred resource by shredding invertebrates over all native <span class="hlt">species</span>. Subsequent analysis of the structural integrity of all leaf <span class="hlt">species</span> revealed that TOH was the least resistant to force, possibly explaining the counterintuitive decrease of TOH decay in mixtures. We interpret this as meaning the stream invertebrates, while preferring to consume TOH, appeared not to influence TOH decay in mixtures with native <span class="hlt">species</span>. Instead, the relatively tougher nature of native <span class="hlt">species</span> appeared to slow TOH breakdown by armoring the invasive from the highly-variable flow regime characteristic of urban streams. Therefore, the presence of native <span class="hlt">tree</span> <span class="hlt">species</span> in urban riparian zones may be critical to how invasive <span class="hlt">trees</span>, like TOH, could alter carbon flux in urban streams.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23440213','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23440213"><span id="translatedtitle"><span class="hlt">Species</span> distributions in response to individual soil nutrients and seasonal drought across a community of tropical <span class="hlt">trees</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Condit, Richard; Engelbrecht, Bettina M J; Pino, Delicia; Pérez, Rolando; Turner, Benjamin L</p> <p>2013-03-26</p> <p>Tropical forest vegetation is shaped by climate and by soil, but understanding how the distributions of individual <span class="hlt">tree</span> <span class="hlt">species</span> respond to specific resources has been hindered by high diversity and consequent rarity. To study <span class="hlt">species</span> over an entire community, we surveyed <span class="hlt">trees</span> and measured soil chemistry across climatic and geological gradients in central Panama and then used a unique hierarchical model of <span class="hlt">species</span> occurrence as a function of rainfall and soil chemistry to circumvent analytical difficulties posed by rare <span class="hlt">species</span>. The results are a quantitative assessment of the responses of 550 <span class="hlt">tree</span> <span class="hlt">species</span> to eight environmental factors, providing a measure of the importance of each factor across the entire <span class="hlt">tree</span> community. Dry-season intensity and soil phosphorus were the strongest predictors, each affecting the distribution of more than half of the <span class="hlt">species</span>. Although we anticipated clear-cut responses to dry-season intensity, the finding that many <span class="hlt">species</span> have pronounced associations with either high or low phosphorus reveals a previously unquantified role for this nutrient in limiting tropical <span class="hlt">tree</span> distributions. The results provide the data necessary for understanding distributional limits of <span class="hlt">tree</span> <span class="hlt">species</span> and predicting future changes in forest composition. PMID:23440213</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3612601','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3612601"><span id="translatedtitle"><span class="hlt">Species</span> distributions in response to individual soil nutrients and seasonal drought across a community of tropical <span class="hlt">trees</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Condit, Richard; Engelbrecht, Bettina M. J.; Pino, Delicia; Pérez, Rolando; Turner, Benjamin L.</p> <p>2013-01-01</p> <p>Tropical forest vegetation is shaped by climate and by soil, but understanding how the distributions of individual <span class="hlt">tree</span> <span class="hlt">species</span> respond to specific resources has been hindered by high diversity and consequent rarity. To study <span class="hlt">species</span> over an entire community, we surveyed <span class="hlt">trees</span> and measured soil chemistry across climatic and geological gradients in central Panama and then used a unique hierarchical model of <span class="hlt">species</span> occurrence as a function of rainfall and soil chemistry to circumvent analytical difficulties posed by rare <span class="hlt">species</span>. The results are a quantitative assessment of the responses of 550 <span class="hlt">tree</span> <span class="hlt">species</span> to eight environmental factors, providing a measure of the importance of each factor across the entire <span class="hlt">tree</span> community. Dry-season intensity and soil phosphorus were the strongest predictors, each affecting the distribution of more than half of the <span class="hlt">species</span>. Although we anticipated clear-cut responses to dry-season intensity, the finding that many <span class="hlt">species</span> have pronounced associations with either high or low phosphorus reveals a previously unquantified role for this nutrient in limiting tropical <span class="hlt">tree</span> distributions. The results provide the data necessary for understanding distributional limits of <span class="hlt">tree</span> <span class="hlt">species</span> and predicting future changes in forest composition. PMID:23440213</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26632594','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26632594"><span id="translatedtitle">The effect of soil-borne pathogens depends on the abundance of host <span class="hlt">tree</span> <span class="hlt">species</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Liu, Yu; Fang, Suqin; Chesson, Peter; He, Fangliang</p> <p>2015-01-01</p> <p>The overarching issue for understanding biodiversity maintenance is how fitness advantages accrue to a <span class="hlt">species</span> as it becomes rare, as this is the defining feature of stable coexistence mechanisms. Without these fitness advantages, average fitness differences between <span class="hlt">species</span> will lead to exclusion. However, empirical evidence is lacking, especially for forests, due to the difficulty of manipulating density on a large-enough scale. Here we took advantage of naturally occurring contrasts in abundance between sites of a subtropical <span class="hlt">tree</span> <span class="hlt">species</span>, Ormosia glaberrima, to demonstrate how low-density fitness advantages accrue by the Janzen-Connell mechanism. The results showed that soil pathogens suppressed seedling recruitment of O. glaberrima when it is abundant but had little effect on the seedlings when it is at low density due to the lack of pathogens. The difference in seedling survival between abundant and low-density sites demonstrates strong dependence of pathogenic effect on the abundance of host <span class="hlt">species</span>. PMID:26632594</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4686666','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4686666"><span id="translatedtitle">The effect of soil-borne pathogens depends on the abundance of host <span class="hlt">tree</span> <span class="hlt">species</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Liu, Yu; Fang, Suqin; Chesson, Peter; He, Fangliang</p> <p>2015-01-01</p> <p>The overarching issue for understanding biodiversity maintenance is how fitness advantages accrue to a <span class="hlt">species</span> as it becomes rare, as this is the defining feature of stable coexistence mechanisms. Without these fitness advantages, average fitness differences between <span class="hlt">species</span> will lead to exclusion. However, empirical evidence is lacking, especially for forests, due to the difficulty of manipulating density on a large-enough scale. Here we took advantage of naturally occurring contrasts in abundance between sites of a subtropical <span class="hlt">tree</span> <span class="hlt">species</span>, Ormosia glaberrima, to demonstrate how low-density fitness advantages accrue by the Janzen–Connell mechanism. The results showed that soil pathogens suppressed seedling recruitment of O. glaberrima when it is abundant but had little effect on the seedlings when it is at low density due to the lack of pathogens. The difference in seedling survival between abundant and low-density sites demonstrates strong dependence of pathogenic effect on the abundance of host <span class="hlt">species</span>. PMID:26632594</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5320909','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5320909"><span id="translatedtitle">Ecological response surfaces for north American boreal <span class="hlt">tree</span> <span class="hlt">species</span> and their use in forest classification</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lenihan, J.M.</p> <p>1993-01-01</p> <p>Empirical ecological response surfaces were derived for eight dominant <span class="hlt">tree</span> <span class="hlt">species</span> in the boreal forest region of Canada. Stepwise logistic regression was used to model <span class="hlt">species</span> dominance as a response to five climatic predictor variables. The predictor variables (annual snowfall, degree-days, absolute minimum temperature, annual soil moisture deficit, and actual evapotranspiration summed over the summer months) influence the response of plants more directly than the annual or monthly measures of temperature and precipitation commonly used in response surface modeling. The response surfaces provided estimates of the probability of <span class="hlt">species</span> dominance across the spatial extent of North America with a high degree of success. Much of the variation in the probability of dominance could be related to the <span class="hlt">species</span>' individualistic response to climatic constraints within different airmass region. A forest type classification for the Canadian boreal forest region was derived by a cluster analysis based on the probability estimates. (Copyright (c) IAVS: Opulus Press Uppsala. Printed in Sweden, 1993.)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010PhDT.......140B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010PhDT.......140B"><span id="translatedtitle">Seasonal trends in separability of leaf reflectance spectra for Ailanthus altissima and four other <span class="hlt">tree</span> <span class="hlt">species</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Burkholder, Aaron</p> <p></p> <p>This project investigated the spectral separability of the invasive <span class="hlt">species</span> Ailanthus altissima, commonly called <span class="hlt">tree</span> of heaven, and four other native <span class="hlt">species</span>. Leaves were collected from Ailanthus and four native <span class="hlt">tree</span> <span class="hlt">species</span> from May 13 through August 24, 2008, and spectral reflectance factor measurements were gathered for each <span class="hlt">tree</span> using an ASD (Boulder, Colorado) FieldSpec Pro full-range spectroradiometer. The original data covered the range from 350-2500 nm, with one reflectance measurement collected per one nm wavelength. To reduce dimensionality, the measurements were resampled to the actual resolution of the spectrometer's sensors, and regions of atmospheric absorption were removed. Continuum removal was performed on the reflectance data, resulting in a second dataset. For both the reflectance and continuum removed datasets, least angle regression (LARS) and random forest classification were used to identify a single set of optimal wavelengths across all sampled dates, a set of optimal wavelengths for each date, and the dates for which Ailanthus is most separable from other <span class="hlt">species</span>. It was found that classification accuracy varies both with dates and bands used. Contrary to expectations that early spring would provide the best separability, the lowest classification error was observed on July 22 for the reflectance data, and on May 13, July 11 and August 1 for the continuum removed data. This suggests that July and August are also potentially good months for <span class="hlt">species</span> differentiation. Applying continuum removal in many cases reduced classification error, although not consistently. Band selection seems to be more important for reflectance data in that it results in greater improvement in classification accuracy, and LARS appears to be an effective band selection tool. The optimal spectral bands were selected from across the spectrum, often with bands from the blue (401-431 nm), NIR (1115 nm) and SWIR (1985-1995 nm), suggesting that hyperspectral sensors with broad wavelength sensitivity are important for mapping and identification of Ailanthus.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70033546','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70033546"><span id="translatedtitle">The effects of flooding and sedimentation on seed germination of two bottomland hardwood <span class="hlt">tree</span> <span class="hlt">species</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Pierce, A.R.; King, S.L.</p> <p>2007-01-01</p> <p>Flooding and sedimentation are two of the dominant disturbances that influence <span class="hlt">tree</span> <span class="hlt">species</span> composition and succession in floodplain forests. The importance of these disturbances may be most notable during the germination and establishment phases of plant succession. Channelization of most alluvial systems in the southeastern United States has caused dramatic and systematic alterations to both hydrologic and sedimentation processes of floodplain systems. We determined the influence of these altered abiotic processes on the germination and growth of two common floodplain <span class="hlt">tree</span> <span class="hlt">species</span>: swamp chestnut oak (Quercus michauxii Nutt.) and overcup oak (Q. lyrata Walt.). Flood durations of 0 days, 15 days, and 30 days prior to germination was a factor in germination, but the effect varied by <span class="hlt">species</span>. For instance, ovcrcup oak, which has a higher tolerance to flooding than swamp chestnut oak, had higher germination rates in the flooded treatments (15-day x?? = 78% and 30-day x?? = 85%) compared to the non-flooded treatment (x?? = 54%). In contrast, germination rates of swamp chestnut oak were negatively affected by the 30-day flood treatment. Sediment deposition rates of 2 cm of top soil, 2 cm of sand, and 8 cm of sand also affected germination, but were secondary to flood duration. The main effect of the sediment treatment in this experiment was a reduction in above-ground height of seedlings. Our study provides evidence for the importance of both flooding and sedimentation in determining <span class="hlt">tree</span> <span class="hlt">species</span> composition in floodplain systems, and that tolerance levels to such stressors vary by <span class="hlt">species</span>. ?? 2007, The Society of Wetland Scientists.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26153428','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26153428"><span id="translatedtitle">Clonality as a driver of spatial genetic structure in populations of clonal <span class="hlt">tree</span> <span class="hlt">species</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dering, Monika; Chybicki, Igor Jerzy; R?czka, Grzegorz</p> <p>2015-09-01</p> <p>Random genetic drift, natural selection and restricted gene dispersal are basic factors of the spatial genetic structure (SGS) in plant populations. Clonal reproduction has a profound effect on population dynamics and genetic structure and thus emerges as a potential factor in contributing to and modelling SGS. In order to assess the impact of clonality on SGS we studied clonal structure and SGS in the population of Populus alba. Six hundred and seventy-two individuals were mapped and genotyped with 16 nuclear microsatellite markers. To answer the more general question regarding the relationship between SGS and clonality we used Sp statistics, which allows for comparisons of the extent of SGS among different studies, and the comparison of published data on SGS in clonal and non-clonal <span class="hlt">tree</span> <span class="hlt">species</span>. Sp statistic was extracted for 14 clonal and 27 non-clonal <span class="hlt">species</span> belonging to 7 and 18 botanical families, respectively. Results of genetic investigations conducted in the population of P. alba showed over-domination of clonal reproduction, which resulted in very low clonal diversity (R = 0.12). Significant SGS was found at both ramet (Sp = 0.095) and genet level (Sp = 0.05) and clonal reproduction was indicated as an important but not sole driving factor of SGS. Within-population structure, probably due to family structure also contributed to high SGS. High mean dominance index (D = 0.82) indicated low intermingling among genets. Literature survey revealed that clonal <span class="hlt">tree</span> <span class="hlt">species</span> significantly differ from non-clonal <span class="hlt">species</span> with respect to SGS, having 2.8-fold higher SGS. This led us to conclude that clonality is a life-history trait that can have deep impact on processes acting in populations of clonal <span class="hlt">tree</span> <span class="hlt">species</span> leading to significant SGS. PMID:26153428</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4561634','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4561634"><span id="translatedtitle">Environmental correlates for <span class="hlt">tree</span> occurrences, <span class="hlt">species</span> distribution and richness on a high-elevation tropical island</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Birnbaum, Philippe; Ibanez, Thomas; Pouteau, Robin; Vandrot, Hervé; Hequet, Vanessa; Blanchard, Elodie; Jaffré, Tanguy</p> <p>2015-01-01</p> <p>High-elevation tropical islands are ideally suited for examining the factors that determine <span class="hlt">species</span> distribution, given the complex topographies and climatic gradients that create a wide variety of habitats within relatively small areas. New Caledonia, a megadiverse Pacific archipelago, has long focussed the attention of botanists working on the spatial and environmental ranges of specific groups, but few studies have embraced the entire <span class="hlt">tree</span> flora of the archipelago. In this study we analyse the distribution of 702 native <span class="hlt">species</span> of rainforest <span class="hlt">trees</span> of New Caledonia, belonging to 195 genera and 80 families, along elevation and rainfall gradients on ultramafic (UM) and non-ultramafic (non-UM) substrates. We compiled four complementary data sources: (i) herbarium specimens, (ii) plots, (iii) photographs and (iv) observations, totalling 38 936 unique occurrences distributed across the main island. Compiled into a regular 1-min grid (1.852 × 1.852 km), this dataset covered ∼22 % of the island. The studied rainforest <span class="hlt">species</span> exhibited high environmental tolerance; 56 % of them were not affiliated to a substrate type and they exhibited wide elevation (average 891 ± 332 m) and rainfall (average 2.2 ± 0.8 m year−1) ranges. Conversely their spatial distribution was highly aggregated, which suggests dispersal limitation. The observed <span class="hlt">species</span> richness was driven mainly by the density of occurrences. However, at the highest elevations or rainfalls, and particularly on UM, the observed richness tends to be lower, independently of the sampling effort. The study highlights the imbalance of the dataset in favour of higher values of rainfall and of elevation. Projected onto a map, under-represented areas are a guide as to where future sampling efforts are most required to complete our understanding of rainforest <span class="hlt">tree</span> <span class="hlt">species</span> distribution. PMID:26162898</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26162898','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26162898"><span id="translatedtitle">Environmental correlates for <span class="hlt">tree</span> occurrences, <span class="hlt">species</span> distribution and richness on a high-elevation tropical island.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Birnbaum, Philippe; Ibanez, Thomas; Pouteau, Robin; Vandrot, Hervé; Hequet, Vanessa; Blanchard, Elodie; Jaffré, Tanguy</p> <p>2015-01-01</p> <p>High-elevation tropical islands are ideally suited for examining the factors that determine <span class="hlt">species</span> distribution, given the complex topographies and climatic gradients that create a wide variety of habitats within relatively small areas. New Caledonia, a megadiverse Pacific archipelago, has long focussed the attention of botanists working on the spatial and environmental ranges of specific groups, but few studies have embraced the entire <span class="hlt">tree</span> flora of the archipelago. In this study we analyse the distribution of 702 native <span class="hlt">species</span> of rainforest <span class="hlt">trees</span> of New Caledonia, belonging to 195 genera and 80 families, along elevation and rainfall gradients on ultramafic (UM) and non-ultramafic (non-UM) substrates. We compiled four complementary data sources: (i) herbarium specimens, (ii) plots, (iii) photographs and (iv) observations, totalling 38 936 unique occurrences distributed across the main island. Compiled into a regular 1-min grid (1.852 × 1.852 km), this dataset covered ∼22 % of the island. The studied rainforest <span class="hlt">species</span> exhibited high environmental tolerance; 56 % of them were not affiliated to a substrate type and they exhibited wide elevation (average 891 ± 332 m) and rainfall (average 2.2 ± 0.8 m year(-1)) ranges. Conversely their spatial distribution was highly aggregated, which suggests dispersal limitation. The observed <span class="hlt">species</span> richness was driven mainly by the density of occurrences. However, at the highest elevations or rainfalls, and particularly on UM, the observed richness tends to be lower, independently of the sampling effort. The study highlights the imbalance of the dataset in favour of higher values of rainfall and of elevation. Projected onto a map, under-represented areas are a guide as to where future sampling efforts are most required to complete our understanding of rainforest <span class="hlt">tree</span> <span class="hlt">species</span> distribution. PMID:26162898</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001AGUFM.H31F..05E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001AGUFM.H31F..05E"><span id="translatedtitle">Impact of Canopy Coupling on Canopy Average Stomatal Conductance Across Seven <span class="hlt">Tree</span> <span class="hlt">Species</span> in Northern Wisconsin</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ewers, B. E.; Mackay, D. S.; Samanta, S.; Ahl, D. E.; Burrows, S. S.; Gower, S. T.</p> <p>2001-12-01</p> <p>Land use changes over the last century in northern Wisconsin have resulted in a heterogeneous landscape composed of the following four main forest types: northern hardwoods, northern conifer, aspen/fir, and forested wetland. Based on sap flux measurements, aspen/fir has twice the canopy transpiration of northern hardwoods. In addition, daily transpiration was only explained by daily average vapor pressure deficit across the cover types. The objective of this study was to determine if canopy average stomatal conductance could be used to explain the <span class="hlt">species</span> effects on <span class="hlt">tree</span> transpiration. Our first hypothesis is that across all of the <span class="hlt">species</span>, stomatal conductance will respond to vapor pressure deficit so as to maintain a minimum leaf water potential to prevent catostrophic cavitiation. The consequence of this hypothesis is that among <span class="hlt">species</span> and individuals there is a proportionality between high stomatal conductance and the sensitivity of stomatal conductance to vapor pressure deficit. Our second hypothesis is that <span class="hlt">species</span> that do not follow the proportionality deviate because the canopies are decoupled from the atmosphere. To test our two hypotheses we calculated canopy average stomatal conductance from sap flux measurements using an inversion of the Penman-Monteith equation. We estimated the canopy coupling using a leaf energy budget model that requires leaf transpiration and canopy aerodynamic conductance. We optimized the parameters of the aerodynamic conductance model using a Monte Carlo technique across six parameters. We determined the optimal model for each <span class="hlt">species</span> by selecting parameter sets that resulted in the proportionality of our first hypothesis. We then tested the optimal energy budget models of each <span class="hlt">species</span> by comparing leaf temperature and leaf width predicted by the models to measurements of each <span class="hlt">tree</span> <span class="hlt">species</span>. In red pine, sugar maple, and trembling aspen <span class="hlt">trees</span> under high canopy coupling conditions, we found the hypothesized proportionality between high stomatal conductance and the sensitivity of stomatal conductance to vapor pressure deficit. In addition, the canopy conductance of trembling aspen was twice as high as sugar maple and the aspen <span class="hlt">trees</span> showed much more variability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25220499','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25220499"><span id="translatedtitle">Chemical taxonomy of <span class="hlt">tree</span> peony <span class="hlt">species</span> from China based on root cortex metabolic fingerprinting.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>He, Chunnian; Peng, Bing; Dan, Yang; Peng, Yong; Xiao, Peigen</p> <p>2014-11-01</p> <p>The section Moutan of the genus Paeonia consists of eight <span class="hlt">species</span> that are confined to a small area in China. A wide range of metabolites, including monoterpenoid glucosides, flavonoids, tannins, stilbenes, triterpenoids, steroids, paeonols, and phenols, have been found in the <span class="hlt">species</span> belonging to section Moutan. However, although previous studies have analyzed the metabolites found in these <span class="hlt">species</span>, the metabolic similarities that can be used for the chemotaxonomic distinction of section Moutan <span class="hlt">species</span> are not yet clear. In this study, HPLC-DAD-based metabolic fingerprinting was applied to the classification of eight <span class="hlt">species</span>: Paeoniasuffruticosa, Paeoniaqiui, Paeoniaostii, Paeoniarockii, Paeoniajishanensis, Paeoniadecomposita, Paeoniadelavayi, and Paeonialudlowii. In total, of the 47 peaks that exhibited an occurrence frequency of 75% in all 23 <span class="hlt">tree</span> peony samples, 43 of these metabolites were identified according to their retention times and UV absorption spectra, together with combined HPLC-QTOF-MS. These data were compared with reference standard compounds. The 43 isolated compounds included 17 monoterpenoid glucosides, 11 galloyl glucoses, 5 flavonoids, 6 paeonols and 4 phenols. Principal component analysis (PCA), and hierarchical cluster analysis (HCA), showed a clear separation between the <span class="hlt">species</span> based on metabolomics similarities and four groups were identified. The results exhibited good agreement with the classical classification based on the morphological characteristics and geographical distributions of the subsections Vaginatae F.C. Stern and Delavayanae F.C. Stern with the exception of P. decomposita, which was found to be a transition <span class="hlt">species</span> between these two subsections. According to their metabolic fingerprinting characteristics, P. ostii and P. suffruticosa can be considered one <span class="hlt">species</span>, and this result is consistent with the viewpoint of medicinal plant scientists but different from that of classical morphological processing. Significantly large variations were obtained in the metabolic profiles of P. delavayi, whereas no significant difference was found between P. delavayi and P. ludlowii. This indicates that these two <span class="hlt">species</span> have a close genetic relationship. In conclusion, the combination of HPLC-DAD and multivariate analyses has great potential for guiding future chemotaxonomic studies to examine the potential pharmaceutical value of the effective constituents of <span class="hlt">tree</span> peony <span class="hlt">species</span> and appears to be able to clarify the confusion and skepticism associated with the reported morphology- and molecular phylogenetics-based taxonomy of <span class="hlt">tree</span> peonies. PMID:25220499</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/18692976','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/18692976"><span id="translatedtitle">The All-<span class="hlt">Species</span> Living <span class="hlt">Tree</span> project: a 16S rRNA-based phylogenetic <span class="hlt">tree</span> of all sequenced type strains.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yarza, Pablo; Richter, Michael; Peplies, Jörg; Euzeby, Jean; Amann, Rudolf; Schleifer, Karl-Heinz; Ludwig, Wolfgang; Glöckner, Frank Oliver; Rosselló-Móra, Ramon</p> <p>2008-09-01</p> <p>The signing authors together with the journal Systematic and Applied Microbiology (SAM) have started an ambitious project that has been conceived to provide a useful tool especially for the scientific microbial taxonomist community. The aim of what we have called "The All-<span class="hlt">Species</span> Living <span class="hlt">Tree</span>" is to reconstruct a single 16S rRNA <span class="hlt">tree</span> harboring all sequenced type strains of the hitherto classified <span class="hlt">species</span> of Archaea and Bacteria. This <span class="hlt">tree</span> is to be regularly updated by adding the <span class="hlt">species</span> with validly published names that appear monthly in the Validation and Notification lists of the International Journal of Systematic and Evolutionary Microbiology. For this purpose, the SAM executive editors, together with the responsible teams of the ARB, SILVA, and LPSN projects (www.arb-home.de, www.arb-silva.de, and www.bacterio.cict.fr, respectively), have prepared a 16S rRNA database containing over 6700 sequences, each of which represents a single type strain of a classified <span class="hlt">species</span> up to 31 December 2007. The selection of sequences had to be undertaken manually due to a high error rate in the names and information fields provided for the publicly deposited entries. In addition, from among the often occurring multiple entries for a single type strain, the best-quality sequence was selected for the project. The living <span class="hlt">tree</span> database that SAM now provides contains corrected entries and the best-quality sequences with a manually checked alignment. The <span class="hlt">tree</span> reconstruction has been performed by using the maximum likelihood algorithm RAxML. The <span class="hlt">tree</span> provided in the first release is a result of the calculation of a single dataset containing 9975 single entries, 6728 corresponding to type strain gene sequences, as well as 3247 additional high-fquality sequences to give robustness to the reconstruction. <span class="hlt">Trees</span> are dynamic structures that change on the basis of the quality and availability of the data used for their calculation. Therefore, the addition of new type strain sequences in further subsequent releases may help to resolve certain branching orders that appear ambiguous in this first release. On the web sites: www.elsevier.de/syapm and www.arb-silva.de/living-<span class="hlt">tree</span>, the All-<span class="hlt">Species</span> Living <span class="hlt">Tree</span> team will release a regularly updated database compatible with the ARB software environment containing the whole 16S rRNA dataset used to reconstruct "The All-<span class="hlt">Species</span> Living <span class="hlt">Tree</span>". As a result, the latest reconstructed phylogeny will be provided. In addition to the ARB file, a readable multi-FASTA universal sequence editor file with the complete alignment will be provided for those not using ARB. There is also a complete set of supplementary tables and figures illustrating the selection procedure and its outcome. It is expected that the All-<span class="hlt">Species</span> Living <span class="hlt">Tree</span> will help to improve future classification efforts by simplifying the selection of the correct type strain sequences. For queries, information updates, remarks on the dataset or <span class="hlt">tree</span> reconstructions shown, a contact email address has been created (living-<span class="hlt">tree</span>@arb-silva.de). This provides an entry point for anyone from the scientific community to provide additional input for the construction and improvement of the first <span class="hlt">tree</span> compiling all sequenced type strains of all prokaryotic <span class="hlt">species</span> for which names had been validly published. PMID:18692976</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/21774305','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21774305"><span id="translatedtitle">[Dynamic changes of dominant <span class="hlt">tree</span> <span class="hlt">species</span> in broad-leaved Korean pine forest at different succession stages in Changbai Mountains].</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Guo, Li-ping; Ji, Lan-zhu; Wang, Zhen; Wang, Zhi-xuan</p> <p>2011-04-01</p> <p>Taking the broad-leaved Korean pine forest stands at four different succession stages after clear-cutting in Changbai Mountains as test objects, this paper studied the change characteristics of community composition and dominant <span class="hlt">species</span>. The <span class="hlt">tree</span> <span class="hlt">species</span> richness, Shannon diversity index, and Simpson dominance index at different succession stages had less change, but the evenness and abundance changed greatly. As succession progressed, the community composition changed constantly, i.e., <span class="hlt">species</span> number decreased, while the basal area sum and the maximum importance value of dominant <span class="hlt">tree</span> <span class="hlt">species</span> increased, suggesting that the dominance of dominant <span class="hlt">species</span> was continuously improved with succession. In the succession process of broad-leaved Korean pine forest in Changbai Mountains, Betula platyphylla, Populus davidiana, Phellodendron amurense, Ulmus japonica, and other intolerant or semi-intolerant <span class="hlt">tree</span> <span class="hlt">species</span> decreased, while Tilia amurensis, Fraxinus mandshurica, Pinus koraiensis, Acer mono, and other shade-tolerant <span class="hlt">species</span> increased. PMID:21774305</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4070915','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4070915"><span id="translatedtitle">Leaf Phenological Characters of Main <span class="hlt">Tree</span> <span class="hlt">Species</span> in Urban Forest of Shenyang</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Xu, Sheng; Xu, Wenduo; Chen, Wei; He, Xingyuan; Huang, Yanqing; Wen, Hua</p> <p>2014-01-01</p> <p>Background Plant leaves, as the main photosynthetic organs and the high energy converters among primary producers in terrestrial ecosystems, have attracted significant research attention. Leaf lifespan is an adaptive characteristic formed by plants to obtain the maximum carbon in the long-term adaption process. It determines important functional and structural characteristics exhibited in the environmental adaptation of plants. However, the leaf lifespan and leaf characteristics of urban forests were not studied up to now. Methods By using statistic, linear regression methods and correlation analysis, leaf phenological characters of main <span class="hlt">tree</span> <span class="hlt">species</span> in urban forest of Shenyang were observed for five years to obtain the leafing phenology (including leafing start time, end time, and duration), defoliating phenology (including defoliation start time, end time, and duration), and the leaf lifespan of the main <span class="hlt">tree</span> <span class="hlt">species</span>. Moreover, the relationships between temperature and leafing phenology, defoliating phenology, and leaf lifespan were analyzed. Findings The timing of leafing differed greatly among <span class="hlt">species</span>. The early leafing <span class="hlt">species</span> would have relatively early end of leafing; the longer it took to the end of leafing would have a later time of completed leafing. The timing of defoliation among different <span class="hlt">species</span> varied significantly, the early defoliation <span class="hlt">species</span> would have relatively longer duration of defoliation. If the mean temperature rise for 1°C in spring, the time of leafing would experience 5 days earlier in spring. If the mean temperature decline for 1°C, the time of defoliation would experience 3 days delay in autumn. Interpretation There is significant correlation between leaf longevity and the time of leafing and defoliation. According to correlation analysis and regression analysis, there is significant correlation between temperature and leafing and defoliation phenology. Early leafing <span class="hlt">species</span> would have a longer life span and consequently have advantage on carbon accumulation compared with later defoliation <span class="hlt">species</span>. PMID:24963625</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26854019','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26854019"><span id="translatedtitle">Convergent production and tolerance among 107 woody <span class="hlt">species</span> and divergent production between shrubs and <span class="hlt">trees</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>He, Wei-Ming; Sun, Zhen-Kai</p> <p>2016-01-01</p> <p>Green leaves face two fundamental challenges (i.e., carbon fixation and stress tolerance) during their lifespan. However, the relationships between leaf production potential and leaf tolerance potential have not been explicitly tested with a broad range of plant <span class="hlt">species</span> in the same environment. To do so, we conducted a field investigation based on 107 woody plants grown in a common garden and complementary laboratory measurements. The values, as measured by a chlorophyll meter, were significantly related to the direct measurements of chlorophyll content on a leaf area basis. Area-based chlorophyll content was positively correlated with root surface area, whole-plant biomass, leaf mass per area (LMA), and force to punch. Additionally, LMA had a positive correlation with force to punch. Shrubs had a higher leaf chlorophyll content than <span class="hlt">trees</span>; however, shrubs and <span class="hlt">trees</span> exhibited a similar leaf lifespan, force to punch, and LMA. These findings suggest that the production potential of leaves and their tolerance to stresses may be convergent in woody <span class="hlt">species</span> and that the leaf production potential may differ between shrubs and <span class="hlt">trees</span>. This study highlights the possibility that functional convergence and divergence might be linked to long-term selection pressures and genetic constraints. PMID:26854019</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4356318','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4356318"><span id="translatedtitle">A genotyping protocol for multiple tissue types from the polyploid <span class="hlt">tree</span> <span class="hlt">species</span> Sequoia sempervirens (Cupressaceae)1</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Narayan, Lakshmi; Dodd, Richard S.; O’Hara, Kevin L.</p> <p>2015-01-01</p> <p>Premise of the study: Identifying clonal lineages in asexually reproducing plants using microsatellite markers is complicated by the possibility of nonidentical genotypes from the same clonal lineage due to somatic mutations, null alleles, and scoring errors. We developed and tested a clonal identification protocol that is robust to these issues for the asexually reproducing hexaploid <span class="hlt">tree</span> <span class="hlt">species</span> coast redwood (Sequoia sempervirens). Methods: Microsatellite data from four previously published and two newly developed primers were scored using a modified protocol, and clones were identified using Bruvo genetic distances. The effectiveness of this clonal identification protocol was assessed using simulations and by genotyping a test set of paired samples of different tissue types from the same <span class="hlt">trees</span>. Results: Data from simulations showed that our protocol allowed us to accurately identify clonal lineages. Multiple test samples from the same <span class="hlt">trees</span> were identified correctly, although certain tissue type pairs had larger genetic distances on average. Discussion: The methods described in this paper will allow for the accurate identification of coast redwood clones, facilitating future studies of the reproductive ecology of this <span class="hlt">species</span>. The techniques used in this paper can be applied to studies of other clonal organisms as well. PMID:25798341</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4745073','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4745073"><span id="translatedtitle">Convergent production and tolerance among 107 woody <span class="hlt">species</span> and divergent production between shrubs and <span class="hlt">trees</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>He, Wei-Ming; Sun, Zhen-Kai</p> <p>2016-01-01</p> <p>Green leaves face two fundamental challenges (i.e., carbon fixation and stress tolerance) during their lifespan. However, the relationships between leaf production potential and leaf tolerance potential have not been explicitly tested with a broad range of plant <span class="hlt">species</span> in the same environment. To do so, we conducted a field investigation based on 107 woody plants grown in a common garden and complementary laboratory measurements. The values, as measured by a chlorophyll meter, were significantly related to the direct measurements of chlorophyll content on a leaf area basis. Area-based chlorophyll content was positively correlated with root surface area, whole-plant biomass, leaf mass per area (LMA), and force to punch. Additionally, LMA had a positive correlation with force to punch. Shrubs had a higher leaf chlorophyll content than <span class="hlt">trees</span>; however, shrubs and <span class="hlt">trees</span> exhibited a similar leaf lifespan, force to punch, and LMA. These findings suggest that the production potential of leaves and their tolerance to stresses may be convergent in woody <span class="hlt">species</span> and that the leaf production potential may differ between shrubs and <span class="hlt">trees</span>. This study highlights the possibility that functional convergence and divergence might be linked to long-term selection pressures and genetic constraints. PMID:26854019</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2710901','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2710901"><span id="translatedtitle">Wood density and its radial variation in six canopy <span class="hlt">tree</span> <span class="hlt">species</span> differing in shade-tolerance in western Thailand</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Nock, Charles A.; Geihofer, Daniela; Grabner, Michael; Baker, Patrick J.; Bunyavejchewin, Sarayudh; Hietz, Peter</p> <p>2009-01-01</p> <p>Background and Aims Wood density is a key variable for understanding life history strategies in tropical <span class="hlt">trees</span>. Differences in wood density and its radial variation were related to the shade-tolerance of six canopy <span class="hlt">tree</span> <span class="hlt">species</span> in seasonally dry tropical forest in Thailand. In addition, using <span class="hlt">tree</span> ring measurements, the influence of <span class="hlt">tree</span> size, age and annual increment on radial density gradients was analysed. Methods Wood density was determined from <span class="hlt">tree</span> cores using X-ray densitometry. X-ray films were digitized and images were measured, resulting in a continuous density profile for each sample. Mixed models were then developed to analyse differences in average wood density and in radial gradients in density among the six <span class="hlt">tree</span> <span class="hlt">species</span>, as well as the effects of <span class="hlt">tree</span> age, size and annual increment on radial increases in Melia azedarach. Key Results Average wood density generally reflected differences in shade-tolerance, varying by nearly a factor of two. Radial gradients occurred in all <span class="hlt">species</span>, ranging from an increase of (approx. 70%) in the shade-intolerant Melia azedarach to a decrease of approx. 13% in the shade-tolerant Neolitsea obtusifolia, but the slopes of radial gradients were generally unrelated to shade-tolerance. For Melia azedarach, radial increases were most-parsimoniously explained by log-transformed <span class="hlt">tree</span> age and annual increment rather than by <span class="hlt">tree</span> size. Conclusions The results indicate that average wood density generally reflects differences in shade-tolerance in seasonally dry tropical forests; however, inferences based on wood density alone are potentially misleading for <span class="hlt">species</span> with complex life histories. In addition, the findings suggest that a ‘whole-<span class="hlt">tree</span>’ view of life history and biomechanics is important for understanding patterns of radial variation in wood density. Finally, accounting for wood density gradients is likely to improve the accuracy of estimates of stem biomass and carbon in tropical <span class="hlt">trees</span>. PMID:19454592</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000AcO....21...37K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000AcO....21...37K"><span id="translatedtitle">Some autecological characteristics of early to late successional <span class="hlt">tree</span> <span class="hlt">species</span> in Venezuela</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kammesheidt, Ludwig</p> <p>2000-01-01</p> <p>The breadth of the continuum concept of strategy with respect to succession was tested on 21 <span class="hlt">tree</span> and shrub <span class="hlt">species</span> common in either unlogged or logged stands, respectively, in the Forest Reserve of Caparo, Venezuela, by examining morphological, physiological and population characteristics. Based on a preliminary abundance analysis, `early', `mid' and `late' successional <span class="hlt">species</span> as well as `generalists' were distinguished. Early successional <span class="hlt">species</span>, i.e. Ochroma lagopus, Heliocarpus popayanensis and Cecropia peltata were similar in many autecological aspects, e.g. monolayered leaf arrangement, orthotropic architectural models, no adaptive reiteration, clumped distribution, but differed in gap association and distribution along a drainage gradient. Mid-successional <span class="hlt">species</span> established themselves both in large and small gaps (> 300 m[sup2 ]; 80-300 m[sup2 ]) and showed a clumped to regular distribution pattern in logged areas; they exhibited more diverse crown and leaf characteristics than early successional <span class="hlt">species</span>. Late successional <span class="hlt">species</span> established themselves only in small gaps and understorey, and showed a regular spatial pattern in undisturbed areas. All late successional <span class="hlt">species</span> displayed architectural models with plagiotropic lateral axes and showed a multilayered leaf arrangement. Adaptive reiteration was a common feature of late successional <span class="hlt">species</span> which could be further subdivided into large, medium-sized and small <span class="hlt">trees</span>, indicating different light requirements at maturity. Generalists were common treelet and shrub <span class="hlt">species</span> in both disturbed and undisturbed sites where they are also capable of completing their life cycle. The light compensation point (LCP) of an individual plant was strongly influenced by its crown illuminance. Large late successional <span class="hlt">species</span> showed the widest range of LCP values, reflecting the increasing light availability with increasing height in mature forest. On the basis of many autecological characteristics, it was found (i) that there is in fact a continuum of <span class="hlt">species</span> strategies with respect to succession even among early and mid-successional <span class="hlt">species</span> and (ii) that the latter group of <span class="hlt">species</span> showed the widest breadth of autecological traits, reflecting the heterogeneous environment in which they establish and mature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AIPC.1180..117B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AIPC.1180..117B"><span id="translatedtitle"><span class="hlt">Multipurpose</span> Compact Spectrometric Unit</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bo?arov, Viktor; ?ermák, Pavel; Mamedov, Fadahat; Štekl, Ivan</p> <p>2009-11-01</p> <p>A new standalone compact spectrometer was developed. The device consists of analog (peamplifier, amplifier) and digital parts. The digital part is based on the 160 MIPS Digital Signal Processor. It contains 20 Msps Flash-ADC, 1 MB RAM for spectra storage, 128 KB Flash/ROM for firmware storage, Real Time Clock and several voltage regulators providing the power for user peripherals (e.g. amplifier, temperature sensors, etc.). Spectrometer is connected with a notebook via high-speed USB 2.0 bus. The spectrometer is <span class="hlt">multipurpose</span> device, which is planned to be used for measurements of Rn activities, energy of detected particles by CdTe pixel detector or for coincidence measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21322961','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21322961"><span id="translatedtitle"><span class="hlt">Multipurpose</span> Compact Spectrometric Unit</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bocarov, Viktor; Cermak, Pavel; Mamedov, Fadahat; Stekl, Ivan</p> <p>2009-11-09</p> <p>A new standalone compact spectrometer was developed. The device consists of analog (peamplifier, amplifier) and digital parts. The digital part is based on the 160 MIPS Digital Signal Processor. It contains 20 Msps Flash-ADC, 1 MB RAM for spectra storage, 128 KB Flash/ROM for firmware storage, Real Time Clock and several voltage regulators providing the power for user peripherals (e.g. amplifier, temperature sensors, etc.). Spectrometer is connected with a notebook via high-speed USB 2.0 bus. The spectrometer is <span class="hlt">multipurpose</span> device, which is planned to be used for measurements of Rn activities, energy of detected particles by CdTe pixel detector or for coincidence measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930020554','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930020554"><span id="translatedtitle"><span class="hlt">Multipurpose</span> satellite bus (MPS)</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1991-01-01</p> <p>The Naval Postgraduate School Advanced Design Project sponsored by the Universities Space Research Association Advanced Design Program is a <span class="hlt">multipurpose</span> satellite bus (MPS). The design was initiated from a Statement of Work (SOW) developed by the Defense Advanced Research Projects Agency (DARPA). The SOW called for a 'proposal to design a small, low-cost, lightweight, general purpose spacecraft bus capable of accommodating any of a variety of mission payloads. Typical payloads envisioned include those associated with meteorological, communication, surveillance and tracking, target location, and navigation mission areas.' The design project investigates two dissimilar missions, a meteorological payload and a communications payload, mated with a single spacecraft bus with minimal modifications. The MPS is designed for launch aboard the Pegasus Air Launched Vehicle (ALV) or the Taurus Standard Small Launch Vehicle (SSLV).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19910009823','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19910009823"><span id="translatedtitle"><span class="hlt">Multipurpose</span> hardened spacecraft insulation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Steimer, Carlos H.</p> <p>1990-01-01</p> <p>A <span class="hlt">Multipurpose</span> Hardened Spacecraft Multilayer Insulation (MLI) system was developed and implemented to meet diverse survivability and performance requirements. Within the definition and confines of a MLI assembly (blanket), the design: (1) provides environmental protection from natural and induced nuclear, thermal, and electromagnetic radiation; (2) provides adequate electrostatic discharge protection for a geosynchronous satellite; (3) provides adequate shielding to meet radiated emission needs; and (4) will survive ascent differential pressure loads between enclosed volume and space. The MLI design is described which meets these requirements and design evolution and verification is discussed. The application is for MLI blankets which closeout the area between the laser crosslink subsystem (LCS) equipment and the DSP spacecraft cabin. Ancillary needs were implemented to ease installation at launch facility and to survive ascent acoustic and vibration loads. Directional venting accommodations were also incorporated to avoid contamination of LCS telescope, spacecraft sensors, and second surface mirrors (SSMs).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/Publications.htm?seq_no_115=246108','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/Publications.htm?seq_no_115=246108"><span id="translatedtitle">Exotic <span class="hlt">tree</span> leaf litter accumulation and mass loss dynamics compared with two sympatric native <span class="hlt">species</span> in South Florida, USA</span></a></p> <p><a target="_blank" href="http://www.ars.usda.gov/services/TekTran.htm">Technology Transfer Automated Retrieval System (TEKTRAN)</a></p> <p></p> <p></p> <p>The invasive <span class="hlt">tree</span> Melaleuca quinquenervia (melaleuca) forms dense forests in ecologically sensitive habitats, including portions of the Florida Everglades. Within these stands, forest understories are characterized by low <span class="hlt">species</span> diversity and a dense layer of accumulated melaleuca litter. However...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23409151','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23409151"><span id="translatedtitle">Separating the effects of environment and space on <span class="hlt">tree</span> <span class="hlt">species</span> distribution: from population to community.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lin, Guojun; Stralberg, Diana; Gong, Guiquan; Huang, Zhongliang; Ye, Wanhui; Wu, Linfang</p> <p>2013-01-01</p> <p>Quantifying the relative contributions of environmental conditions and spatial factors to <span class="hlt">species</span> distribution can help improve our understanding of the processes that drive diversity patterns. In this study, based on <span class="hlt">tree</span> inventory, topography and soil data from a 20-ha stem-mapped permanent forest plot in Guangdong Province, China, we evaluated the influence of different ecological processes at different spatial scales using canonical redundancy analysis (RDA) at the community level and multiple linear regression at the <span class="hlt">species</span> level. At the community level, the proportion of explained variation in <span class="hlt">species</span> distribution increased with grid-cell sizes, primarily due to a monotonic increase in the explanatory power of environmental variables. At the <span class="hlt">species</span> level, neither environmental nor spatial factors were important determinants of overstory <span class="hlt">species</span>' distributions at small cell sizes. However, purely spatial variables explained most of the variation in the distributions of understory <span class="hlt">species</span> at fine and intermediate cell sizes. Midstory <span class="hlt">species</span> showed patterns that were intermediate between those of overstory and understory <span class="hlt">species</span>. At the 20-m cell size, the influence of spatial factors was stronger for more dispersal-limited <span class="hlt">species</span>, suggesting that much of the spatial structuring in this community can be explained by dispersal limitation. Comparing environmental factors, soil variables had higher explanatory power than did topography for <span class="hlt">species</span> distribution. However, both topographic and edaphic variables were highly spatial structured. Our results suggested that dispersal limitation has an important influence on fine-intermediate scale (from several to tens of meters) <span class="hlt">species</span> distribution, while environmental variability facilitates <span class="hlt">species</span> distribution at intermediate (from ten to tens of meters) and broad (from tens to hundreds of meters) scales. PMID:23409151</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24299988','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24299988"><span id="translatedtitle"><span class="hlt">Species</span> assemblage patterns around a dominant emergent <span class="hlt">tree</span> are associated with drought resistance.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wyse, Sarah V; Macinnis-Ng, Catriona M O; Burns, Bruce R; Clearwater, Michael J; Schwendenmann, Luitgard</p> <p>2013-12-01</p> <p>Water availability has long been recognized as an important driver of <span class="hlt">species</span> distribution patterns in forests. The conifer Agathis australis (D. Don) Lindl. (kauri; Araucariaceae) grows in the <span class="hlt">species</span>-rich forests of northern New Zealand. It is accompanied by distinctive <span class="hlt">species</span> assemblages, and during summer the soil beneath A. australis is often significantly drier than soils beneath surrounding broadleaved angiosperm canopy <span class="hlt">species</span>. We used a shade house dry-down experiment to determine whether <span class="hlt">species</span> that grow close to A. australis differed in drought tolerance physiology compared with <span class="hlt">species</span> that rarely grow close to A. australis. Stomatal conductance (g(s)) was plotted against leaf water potential (?) to identify drought tolerance strategies. Seedlings of <span class="hlt">species</span> that occur in close spatial association with A. australis (including A. australis seedlings) were most resistant to drought stress, and all displayed a drought avoidance strategy of either declining gs to maintain ? or simultaneous declines in g(s) and ?. The <span class="hlt">species</span> not commonly occurring beneath A. australis, but abundant in the surrounding forest, were the most drought-sensitive <span class="hlt">species</span> and succumbed relatively quickly to drought-induced mortality with rapidly declining gs and ? values. These results were confirmed with diurnal measurements of g(s) and assimilation rates throughout the day, and leaf wilting analysis. We conclude that the varied abilities of the <span class="hlt">species</span> to survive periods of drought stress as seedlings shapes the composition of the plant communities beneath A. australis <span class="hlt">trees</span>. Furthermore, forest diversity may be impacted by climate change as the predicted intensification of droughts in northern New Zealand is likely to select for drought-tolerant <span class="hlt">species</span> over drought-intolerant <span class="hlt">species</span>. PMID:24299988</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3568135','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3568135"><span id="translatedtitle">Separating the Effects of Environment and Space on <span class="hlt">Tree</span> <span class="hlt">Species</span> Distribution: From Population to Community</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Lin, Guojun; Stralberg, Diana; Gong, Guiquan; Huang, Zhongliang; Ye, Wanhui; Wu, Linfang</p> <p>2013-01-01</p> <p>Quantifying the relative contributions of environmental conditions and spatial factors to <span class="hlt">species</span> distribution can help improve our understanding of the processes that drive diversity patterns. In this study, based on <span class="hlt">tree</span> inventory, topography and soil data from a 20-ha stem-mapped permanent forest plot in Guangdong Province, China, we evaluated the influence of different ecological processes at different spatial scales using canonical redundancy analysis (RDA) at the community level and multiple linear regression at the <span class="hlt">species</span> level. At the community level, the proportion of explained variation in <span class="hlt">species</span> distribution increased with grid-cell sizes, primarily due to a monotonic increase in the explanatory power of environmental variables. At the <span class="hlt">species</span> level, neither environmental nor spatial factors were important determinants of overstory <span class="hlt">species</span>' distributions at small cell sizes. However, purely spatial variables explained most of the variation in the distributions of understory <span class="hlt">species</span> at fine and intermediate cell sizes. Midstory <span class="hlt">species</span> showed patterns that were intermediate between those of overstory and understory <span class="hlt">species</span>. At the 20-m cell size, the influence of spatial factors was stronger for more dispersal-limited <span class="hlt">species</span>, suggesting that much of the spatial structuring in this community can be explained by dispersal limitation. Comparing environmental factors, soil variables had higher explanatory power than did topography for <span class="hlt">species</span> distribution. However, both topographic and edaphic variables were highly spatial structured. Our results suggested that dispersal limitation has an important influence on fine-intermediate scale (from several to tens of meters) <span class="hlt">species</span> distribution, while environmental variability facilitates <span class="hlt">species</span> distribution at intermediate (from ten to tens of meters) and broad (from tens to hundreds of meters) scales. PMID:23409151</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4418704','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4418704"><span id="translatedtitle"><span class="hlt">Tree</span> <span class="hlt">Species</span> Composition and Harvest Intensity Affect Herbivore Density and Leaf Damage on Beech, Fagus sylvatica, in Different Landscape Contexts</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Mangels, Jule; Blüthgen, Nico; Frank, Kevin; Grassein, Fabrice; Hilpert, Andrea; Mody, Karsten</p> <p>2015-01-01</p> <p>Most forests are exposed to anthropogenic management activities that affect <span class="hlt">tree</span> <span class="hlt">species</span> composition and natural ecosystem processes. Changes in ecosystem processes such as herbivory depend on management intensity, and on regional environmental conditions and <span class="hlt">species</span> pools. Whereas influences of specific forest management measures have already been addressed for different herbivore taxa on a local scale, studies considering effects of different aspects of forest management across different regions are rare. We assessed the influence of <span class="hlt">tree</span> <span class="hlt">species</span> composition and intensity of harvesting activities on arthropod herbivores and herbivore-related damage to beech <span class="hlt">trees</span>, Fagus sylvatica, in 48 forest plots in three regions of Germany. We found that herbivore abundance and damage to beech <span class="hlt">trees</span> differed between regions and that – despite the regional differences - density of <span class="hlt">tree</span>-associated arthropod taxa and herbivore damage were consistently affected by <span class="hlt">tree</span> <span class="hlt">species</span> composition and harvest intensity. Specifically, overall herbivore damage to beech <span class="hlt">trees</span> increased with increasing dominance of beech <span class="hlt">trees</span> – suggesting the action of associational resistance processes – and decreased with harvest intensity. The density of leaf chewers and mines was positively related to leaf damage, and several arthropod groups responded to beech dominance and harvest intensity. The distribution of damage patterns was consistent with a vertical shift of herbivores to higher crown layers during the season and with higher beech dominance. By linking quantitative data on arthropod herbivore abundance and herbivory with <span class="hlt">tree</span> <span class="hlt">species</span> composition and harvesting activity in a wide variety of beech forests, our study helps to better understand the influence of forest management on interactions between a naturally dominant deciduous forest <span class="hlt">tree</span> and arthropod herbivores. PMID:25938417</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/18695228','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/18695228"><span id="translatedtitle">Colloquium paper: how many <span class="hlt">tree</span> <span class="hlt">species</span> are there in the Amazon and how many of them will go extinct?</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hubbell, Stephen P; He, Fangliang; Condit, Richard; Borda-de-Agua, Luís; Kellner, James; Ter Steege, Hans</p> <p>2008-08-12</p> <p>New roads, agricultural projects, logging, and mining are claiming an ever greater area of once-pristine Amazonian forest. The Millennium Ecosystems Assessment (MA) forecasts the extinction of a large fraction of Amazonian <span class="hlt">tree</span> <span class="hlt">species</span> based on projected loss of forest cover over the next several decades. How accurate are these estimates of extinction rates? We use neutral theory to estimate the number, relative abundance, and range size of <span class="hlt">tree</span> <span class="hlt">species</span> in the Amazon metacommunity and estimate likely <span class="hlt">tree-species</span> extinctions under published optimistic and nonoptimistic Amazon scenarios. We estimate that the Brazilian portion of the Amazon Basin has (or had) 11,210 <span class="hlt">tree</span> <span class="hlt">species</span> that reach sizes >10 cm DBH (stem diameter at breast height). Of these, 3,248 <span class="hlt">species</span> have population sizes >1 million individuals, and, ignoring possible climate-change effects, almost all of these common <span class="hlt">species</span> persist under both optimistic and nonoptimistic scenarios. At the rare end of the abundance spectrum, however, neutral theory predicts the existence of approximately 5,308 <span class="hlt">species</span> with <10,000 individuals each that are expected to suffer nearly a 50% extinction rate under the nonoptimistic deforestation scenario and an approximately 37% loss rate even under the optimistic scenario. Most of these <span class="hlt">species</span> have small range sizes and are highly vulnerable to local habitat loss. In ensembles of 100 stochastic simulations, we found mean total extinction rates of 20% and 33% of <span class="hlt">tree</span> <span class="hlt">species</span> in the Brazilian Amazon under the optimistic and nonoptimistic scenarios, respectively. PMID:18695228</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/18941286','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/18941286"><span id="translatedtitle">Physiological characteristics of tropical rain forest <span class="hlt">tree</span> <span class="hlt">species</span>: a basis for the development of silvicultural technology.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sasaki, Satohiko</p> <p>2008-01-01</p> <p>The physiological characteristics of the dominant <span class="hlt">tree</span> <span class="hlt">species</span> in the tropical rain forest mainly belonging to dipterocarps as well as the environmental conditions especially for the light in the forest were studied to establish the silvicultural system for the forest regeneration in the tropical South Asia. The flowering patterns of the dipterocarp <span class="hlt">trees</span> are usually irregular and unpredictable, which make difficult to collect sufficient seeds for raising the seedlings. The field survey revealed the diverged features of the so-called gregarious or simultaneous flowering of various <span class="hlt">species</span> of this group. Appropriate conditions and methods for the storage of the seeds were established according to the detailed analyses of the morphological and physiological characteristics of the seeds such as the low temperature tolerance and the moisture contents. The intensity and spectra of the light in the forest primarily determine the growth and the morphological development of the seedlings under the canopy. Based on the measurements of the diffused light at the sites in the tropical forest in the varying sunlight, the parameters such as "the steady state of the diffuse light" and "the turning point" were defined, which were useful to evaluate the light conditions in the forest. To improve the survival of the transplanted seedlings, a planting method of "the bare-root seedlings", the seedlings easy to be handled by removal of all leaves, soil and pots, was developed. Its marked efficiency was proved with various dipterocarps and other tropical <span class="hlt">trees</span> by the field trial in the practical scale. Tolerance of the various <span class="hlt">species</span> to the extreme environmental conditions such as fires, acid soils and drought were examined by the experiments and the field survey, which revealed marked adaptability of Shorea roxburghii as a potential <span class="hlt">species</span> for regeneration of the tropical forests. PMID:18941286</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23689840','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23689840"><span id="translatedtitle">Experimental warming studies on <span class="hlt">tree</span> <span class="hlt">species</span> and forest ecosystems: a literature review.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chung, Haegeun; Muraoka, Hiroyuki; Nakamura, Masahiro; Han, Saerom; Muller, Onno; Son, Yowhan</p> <p>2013-07-01</p> <p>Temperature affects a cascade of ecological processes and functions of forests. With future higher global temperatures being inevitable it is critical to understand and predict how forest ecosystems and <span class="hlt">tree</span> <span class="hlt">species</span> will respond. This paper reviews experimental warming studies in boreal and temperate forests or <span class="hlt">tree</span> <span class="hlt">species</span> beyond the direct effects of higher temperature on plant ecophysiology by scaling up to forest level responses and considering the indirect effects of higher temperature. In direct response to higher temperature (1) leaves emerged earlier and senesced later, resulting in a longer growing season (2) the abundance of herbivorous insects increased and their performance was enhanced and (3) soil nitrogen mineralization and leaf litter decomposition were accelerated. Besides these generalizations across <span class="hlt">species</span>, plant ecophysiological traits were highly <span class="hlt">species</span>-specific. Moreover, we showed that the effect of temperature on photosynthesis is strongly dependent on the position of the leaf or plant within the forest (canopy or understory) and the time of the year. Indirect effects of higher temperature included among others higher carbon storage in <span class="hlt">trees</span> due to increased soil nitrogen availability and changes in insect performance due to alterations in plant ecophysiological traits. Unfortunately only a few studies extrapolated results to forest ecosystem level and considered the indirect effects of higher temperature. Thus more intensive, long-term studies are needed to further confirm the emerging trends shown in this review. Experimental warming studies provide us with a useful tool to examine the cascade of ecological processes in forest ecosystems that will change with future higher temperature. PMID:23689840</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2805504','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2805504"><span id="translatedtitle">Physiological characteristics of tropical rain forest <span class="hlt">tree</span> <span class="hlt">species</span>: A basis for the development of silvicultural technology</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>SASAKI, Satohiko</p> <p>2008-01-01</p> <p>The physiological characteristics of the dominant <span class="hlt">tree</span> <span class="hlt">species</span> in the tropical rain forest mainly belonging to dipterocarps as well as the environmental conditions especially for the light in the forest were studied to establish the silvicultural system for the forest regeneration in the tropical South Asia. The flowering patterns of the dipterocarp <span class="hlt">trees</span> are usually irregular and unpredictable, which make difficult to collect sufficient seeds for raising the seedlings. The field survey revealed the diverged features of the so-called gregarious or simultaneous flowering of various <span class="hlt">species</span> of this group. Appropriate conditions and methods for the storage of the seeds were established according to the detailed analyses of the morphological and physiological characteristics of the seeds such as the low temperature tolerance and the moisture contents. The intensity and spectra of the light in the forest primarily determine the growth and the morphological development of the seedlings under the canopy. Based on the measurements of the diffused light at the sites in the tropical forest in the varying sunlight, the parameters such as “the steady state of the diffuse light” and “the turning point” were defined, which were useful to evaluate the light conditions in the forest. To improve the survival of the transplanted seedlings, a planting method of “the bare-root seedlings”, the seedlings easy to be handled by removal of all leaves, soil and pots, was developed. Its marked efficiency was proved with various dipterocarps and other tropical <span class="hlt">trees</span> by the field trial in the practical scale. Tolerance of the various <span class="hlt">species</span> to the extreme environmental conditions such as fires, acid soils and drought were examined by the experiments and the field survey, which revealed marked adaptability of Shorea roxburghii as a potential <span class="hlt">species</span> for regeneration of the tropical forests. PMID:18941286</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25345038','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25345038"><span id="translatedtitle">[Distribution of fine root biomass of main planting <span class="hlt">tree</span> <span class="hlt">species</span> in Loess Plateau, China].</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jian, Sheng-Qi; Zhao, Chuan-Yan; Fang, Shu-Min; Yu, Kai</p> <p>2014-07-01</p> <p>The distribution of fine roots of Pinus tabuliformis, Populus tomentosa, Prunus armeniaca, Robinia pseudoacacia, Hippophae rhamnoides, and Caragana korshinskii was investigated by using soil core method and the fine root was defined as root with diameter less than 2 mm. The soil moisture and soil properties were measured. The results showed that in the horizontal direction, the distribution of fine root biomass of P. tabuliformis presented a conic curve, and the fine root biomass of the other <span class="hlt">species</span> expressed logarithm correlation. Radial roots developed, the fine root biomass were concentrated within the scope of the 2-3 times crown, indicating that <span class="hlt">trees</span> extended their roots laterally to seek water farther from the <span class="hlt">tree</span>. In the vertical direction, the fine root biomass decreased with the increasing soil depth. Fine root biomass had significant negative correlation with soil water content and bulk density, while significant positive correlation with organic matter and total N contents. PMID:25345038</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26426801','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26426801"><span id="translatedtitle">Site-adapted admixed <span class="hlt">tree</span> <span class="hlt">species</span> reduce drought susceptibility of mature European beech.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Metz, Jérôme; Annighöfer, Peter; Schall, Peter; Zimmermann, Jorma; Kahl, Tiemo; Schulze, Ernst-Detlef; Ammer, Christian</p> <p>2016-02-01</p> <p>Some forest-related studies on possible effects of climate change conclude that growth potential of European beech (Fagus sylvatica L.) might be impaired by the predicted increase in future serious drought events during the growing season. Other recent research suggests that not only multiyear increment rates but also growth resistance and recovery of beech during, respectively, after dry years may differ between pure and mixed stands. Thus, we combined dendrochronological investigations and wood stable isotope measurements to further investigate the impact of neighborhood diversity on long-term performance, short-term drought response and soil water availability of European beech in three major geographic regions of Germany. During the last four decades, target <span class="hlt">trees</span> whose competitive neighborhood consisted of co-occurring <span class="hlt">species</span> exhibited a superior growth performance compared to beeches in pure stands of the same investigation area. This general pattern was also found in exceptional dry years. Although the summer droughts of 1976 and 2003 predominantly caused stronger relative growth declines if target <span class="hlt">trees</span> were exposed to interspecific competition, with few exceptions they still formed wider annual rings than beeches growing in close-by monocultures. Within the same study region, recovery of standardized beech target <span class="hlt">tree</span> radial growth was consistently slower in monospecific stands than in the neighborhood of other competitor <span class="hlt">species</span>. These findings suggest an improved water availability of beech in mixtures what is in line with the results of the stable isotope analysis. Apparently, the magnitude of competitive complementarity determines the growth response of target beech <span class="hlt">trees</span> in mixtures. Our investigation strongly suggest that the sensitivity of European beech to environmental constrains depends on neighborhood identity. Therefore, the systematic formation of mixed stands tends to be an appropriate silvicultural measure to mitigate the effects of global warming and droughts on growth patterns of Fagus sylvatica. PMID:26426801</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26378305','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26378305"><span id="translatedtitle">Neighborhood diversity of large <span class="hlt">trees</span> shows independent <span class="hlt">species</span> patterns in a mixed dipterocarp forest in Sri Lanka.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Punchi-Manage, Ruwan; Wiegand, Thorsten; Wiegand, Kerstin; Getzin, Stephan; Huth, Andreas; Gunatilleke, C V Savitri; Gunatilleke, I A U Nimal</p> <p>2015-07-01</p> <p>Interactions among neighboring individuals influence plant performance and should create spatial patterns in local community structure. In order to assess the role of large <span class="hlt">trees</span> in generating spatial patterns in local <span class="hlt">species</span> richness, we used the individual <span class="hlt">species</span>-area relationship (ISAR) to evaluate the <span class="hlt">species</span> richness of <span class="hlt">trees</span> of different size classes (and dead <span class="hlt">trees</span>) in circular neighborhoods with varying radius around large <span class="hlt">trees</span> of different focal <span class="hlt">species</span>. To reveal signals of <span class="hlt">species</span> interactions, we compared the ISAR function of the individuals of focal <span class="hlt">species</span> with that of randomly selected nearby locations. We expected that large <span class="hlt">trees</span> should strongly affect the community structure of smaller <span class="hlt">trees</span> in their neighborhood, but that these effects should fade away with increasing size class. Unexpectedly, we found that only few focal <span class="hlt">species</span> showed signals of <span class="hlt">species</span> interactions with <span class="hlt">trees</span> of the different size classes and that this was less likely for less abundant focal <span class="hlt">species</span>. However, the few and relatively weak departures from independence were consistent with expectations of the effect of competition for space and the dispersal syndrome on spatial patterns. A noisy signal of competition for space found for large <span class="hlt">trees</span> built up gradually with increasing life stage; it was not yet present for large saplings but detectable for intermediates. Additionally, focal <span class="hlt">species</span> with animal-dispersed seeds showed higher <span class="hlt">species</span> richness in their neighborhood than those with gravity- and gyration-dispersed seeds. Our analysis across the entire ontogeny from recruits to large <span class="hlt">trees</span> supports the hypothesis that stochastic effects dilute deterministic <span class="hlt">species</span> interactions in highly diverse communities. Stochastic dilution is a consequence of the stochastic geometry of biodiversity in <span class="hlt">species</span>-rich communities where the identities of the nearest neighbors of a given plant are largely unpredictable. While the outcome of local <span class="hlt">species</span> interactions is governed for each plant by deterministic fitness and niche differences, the large variability of competitors causes also a large variability in the outcomes of interactions and does not allow for strong directed responses at the <span class="hlt">species</span> level. Collectively, our results highlight the critical effect of the stochastic geometry of biodiversity in structuring local spatial patterns of tropical forest diversity. PMID:26378305</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26508430','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26508430"><span id="translatedtitle">Pollution Response Score of <span class="hlt">Tree</span> <span class="hlt">Species</span> in Relation to Ambient Air Quality in an Urban Area.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mukherjee, Arideep; Agrawal, Madhoolika</p> <p>2016-02-01</p> <p>Multivariate statistical techniques were employed on twelve leaf traits in four selected common <span class="hlt">tree</span> <span class="hlt">species</span> (Mangifera indica L., Polyalthia longifolia Sonn., Ficus benghalensis L. and Psidium guajava L.) to evaluate their responses with respect to major air pollutants in an urban area. Discriminant analysis (DA) identified chlorophyll/carotenoid ratio, leaf dry matter content, carotenoids, net water content and ascorbic acid as the major discriminating leaf traits, which varied maximally with respect to the pollution status. Pollution response score (PRS), calculated on the basis of discriminate functional coefficient values, increased with an increase in air pollution variables for all the tested <span class="hlt">species</span>, with the highest increase in P. longifolia and the lowest in F. benghalensis. The study highlights the usefulness of DA for evaluation of plant specific traits and PRS for selection of tolerant <span class="hlt">species</span>. PMID:26508430</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4103444','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4103444"><span id="translatedtitle">Microsatellite primers in the foundation <span class="hlt">tree</span> <span class="hlt">species</span> Pinus edulis and P. monophylla (Pinaceae)1</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Krohn, Andrew L.; Flores-Rentería, Lluvia; Gehring, Catherine A.</p> <p>2013-01-01</p> <p>• Premise of the study: Microsatellite primers were developed in the foundational <span class="hlt">tree</span> <span class="hlt">species</span> Pinus edulis to investigate population differentiation of P. edulis and hybridization among closely related <span class="hlt">species</span>. • Methods and Results: Using a hybridization protocol, primer sets for 11 microsatellite loci were developed using megagametophyte tissue from P. edulis and scored for polymorphism in three populations of P. edulis and a single P. monophylla population. The primers amplified simple and compound di-, tri-, and pentanucleotide repeats with two to 18 alleles per locus. • Conclusions: These results demonstrate the utility of the described primers for studies of population differentiation within and among P. edulis populations as well as across putative hybrid zones where P. edulis may coexist with sister <span class="hlt">species</span>. PMID:25202571</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25450097','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25450097"><span id="translatedtitle">Applying <span class="hlt">species-tree</span> analyses to deep phylogenetic histories: challenges and potential suggested from a survey of empirical phylogenetic studies.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lanier, Hayley C; Knowles, L Lacey</p> <p>2015-02-01</p> <p>Coalescent-based methods for <span class="hlt">species-tree</span> estimation are becoming a dominant approach for reconstructing <span class="hlt">species</span> histories from multi-locus data, with most of the studies examining these methodologies focused on recently diverged <span class="hlt">species</span>. However, deeper phylogenies, such as the datasets that comprise many <span class="hlt">Tree</span> of Life (ToL) studies, also exhibit gene-<span class="hlt">tree</span> discordance. This discord may also arise from the stochastic sorting of gene lineages during the speciation process (i.e., reflecting the random coalescence of gene lineages in ancestral populations). It remains unknown whether guidelines regarding methodologies and numbers of loci established by simulation studies at shallow <span class="hlt">tree</span> depths translate into accurate <span class="hlt">species</span> relationships for deeper phylogenetic histories. We address this knowledge gap and specifically identify the challenges and limitations of <span class="hlt">species-tree</span> methods that account for coalescent variance for deeper phylogenies. Using simulated data with characteristics informed by empirical studies, we evaluate both the accuracy of estimated <span class="hlt">species</span> <span class="hlt">trees</span> and the characteristics associated with recalcitrant nodes, with a specific focus on whether coalescent variance is generally responsible for the lack of resolution. By determining the proportion of coalescent genealogies that support a particular node, we demonstrate that (1) <span class="hlt">species-tree</span> methods account for coalescent variance at deep nodes and (2) mutational variance - not gene-<span class="hlt">tree</span> discord arising from the coalescent - posed the primary challenge for accurate reconstruction across the <span class="hlt">tree</span>. For example, many nodes were accurately resolved despite predicted discord from the random coalescence of gene lineages and nodes with poor support were distributed across a range of depths (i.e., they were not restricted to a particular recent divergences). Given their broad taxonomic scope and large sampling of taxa, deep level phylogenies pose several potential methodological complications including difficulties with MCMC convergence and estimation of requisite population genetic parameters for coalescent-based approaches. Despite these difficulties, the findings generally support the utility of <span class="hlt">species-tree</span> analyses for the estimation of <span class="hlt">species</span> relationships throughout the ToL. We discuss strategies for successful application of <span class="hlt">species-tree</span> approaches to deep phylogenies. PMID:25450097</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..12.9690K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..12.9690K"><span id="translatedtitle">Local adaptation to drought and warming in grass and <span class="hlt">tree</span> <span class="hlt">species</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kreyling, Juergen; Thiel, Daniel; Beierkuhnlein, Carl</p> <p>2010-05-01</p> <p>Climate change is characterized by a general warming trend, combined with an increase in the occurrence of extreme events such as drought. Plant <span class="hlt">species</span> are known to differ in their responsiveness to these factors. Below the <span class="hlt">species</span> level, however, intraspecific variability or ecotypes may differ considerably in their performance, especially in widely distributed <span class="hlt">species</span>, with implications for modelling future <span class="hlt">species</span> distributions and adaptation to climate change. Here, we selected five provenances for each of four grass (Holcus lanatus, Arrhenatherum elatius, Alopecurus pratensis and Festuca pratensis) and one <span class="hlt">tree</span> <span class="hlt">species</span> (Pinus nigra) on the basis that climate of the origin was similar to future local projections for our site. Target areas were located from Spain in the southwest to Hungary in the southeast. The selected provenances were compared to local provenances in a pot experiment under warming (+1.5°C) and a single, severe drought (1000-year recurrence) in a fully factorial design. Survival, biomass production and phenology were measured as response variables. This study is part of the EVENT-experiments in Bayreuth. The results imply that local adaptation occurs mainly with respect to drought. The mean performance of at least some of the selected provenances generally surpassed the mean performance of the local provenance in each <span class="hlt">species</span>. It seems therefore possible to select pre-adapted ecotypes as an adaptation strategy in the face of climate change. Furthermore, climate envelope models may considerably over-estimate the plasticity of <span class="hlt">species</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23233512','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23233512"><span id="translatedtitle"><span class="hlt">Species</span> delineation in the <span class="hlt">tree</span> pathogen genus Celoporthe (Cryphonectriaceae) in southern Africa.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Vermeulen, Marcele; Gryzenhout, Marieka; Wingfield, Michael J; Roux, Jolanda</p> <p>2013-01-01</p> <p>The genus Celoporthe was first described when C. dispersa was discovered in South Africa associated with dieback and cankers on <span class="hlt">trees</span> in the Myrtales. Four additional <span class="hlt">species</span> were recently described from Eucalyptus and Syzygium cumini in China as well as S. aromaticum and Eucalyptus in Indonesia. Inoculation trials have shown that all Celoporthe <span class="hlt">species</span>, including those that have not been found on Eucalyptus <span class="hlt">species</span> in nature, are pathogenic to Eucalyptus and they are thus potentially threatening to commercial Eucalyptus forestry. New isolates, morphologically similar to Celoporthe, have been collected from S. legatti in South Africa and S. guineense in Zambia. Multigene phylogenetic analyses based on DNA sequences of the ITS region, TEF1? gene and two areas of the ?-tubulin gene revealed additional cryptic <span class="hlt">species</span> in Celoporthe. Phylogenetic data were supported by morphological differences. These resulted in the description of two previously unknown <span class="hlt">species</span> of Celoporthe, namely C. fontana and C. woodiana, for two of these cryptic groups, while the third group represented C. dispersa. These <span class="hlt">species</span> all can readily infect Eucalyptus as well as several <span class="hlt">species</span> of Syzygium, the latter of which are native to Africa. PMID:23233512</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015NatCC...5..148R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015NatCC...5..148R"><span id="translatedtitle">Geographic range predicts photosynthetic and growth response to warming in co-occurring <span class="hlt">tree</span> <span class="hlt">species</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Reich, Peter B.; Sendall, Kerrie M.; Rice, Karen; Rich, Roy L.; Stefanski, Artur; Hobbie, Sarah E.; Montgomery, Rebecca A.</p> <p>2015-02-01</p> <p>Populations near the warm edge of <span class="hlt">species</span> ranges may be particularly sensitive to climate change, but lack of empirical data on responses to warming represents a key gap in understanding future range dynamics. Herein we document the impacts of experimental warming on the performance of 11 boreal and temperate forest <span class="hlt">species</span> that co-occur at the ecotone between these biomes in North America. We measured in situ net photosynthetic carbon gain and growth of >4,100 juvenile <span class="hlt">trees</span> from local seed sources exposed to a chamberless warming experiment that used infrared heat lamps and soil heating cables to elevate temperatures by +3.4 °C above- and belowground for three growing seasons across 48 plots at two sites. In these ecologically realistic field settings, <span class="hlt">species</span> growing nearest their warm range limit exhibited reductions in net photosynthesis and growth, whereas <span class="hlt">species</span> near their cold range limit responded positively to warming. Differences among <span class="hlt">species</span> in their three-year growth responses to warming parallel their photosynthetic responses to warming, suggesting that leaf-level responses may scale to whole-plant performance. These responses are consistent with the hypothesis, from observational data and models, that warming will reduce the competitive ability of currently dominant southern boreal <span class="hlt">species</span> compared with locally rarer co-occurring <span class="hlt">species</span> that dominate warmer neighbouring regions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EnMan..55..687K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EnMan..55..687K"><span id="translatedtitle">Seasonal and Local Differences in Leaf Litter Flammability of Six Mediterranean <span class="hlt">Tree</span> <span class="hlt">Species</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kauf, Zorica; Fangmeier, Andreas; Rosavec, Roman; Å panjol, Željko</p> <p>2015-03-01</p> <p>One of the suggested management options for reducing fire danger is the selection of less flammable plant <span class="hlt">species</span>. Nevertheless, vegetation flammability is both complex and dynamic, making identification of such <span class="hlt">species</span> challenging. While large efforts have been made to connect plant traits to fire behavior, seasonal changes and within <span class="hlt">species</span> variability of traits are often neglected. Currently, even the most sophisticated fire danger systems presume that intrinsic characteristics of leaf litter stay unchanged, and plant <span class="hlt">species</span> flammability lists are often transferred from one area to another. In order to assess if these practices can be improved, we performed a study examining the relationship between morphological characteristics and flammability parameters of leaf litter, thereby taking into account seasonal and local variability. Litter from six Mediterranean <span class="hlt">tree</span> <span class="hlt">species</span> was sampled throughout the fire season from three different locations along a climate gradient. Samples were subjected to flammability testing involving an epiradiator operated at 400 °C surface temperature with 3 g sample weight. Specific leaf area, fuel moisture content, average area, and average mass of a single particle had significant influences on flammability parameters. Effects of sampling time and location were significant as well. Due to the standardized testing conditions, these effects could be attributed to changes in intrinsic characteristics of the material. As the aforementioned effects were inconsistent and <span class="hlt">species</span> specific, these results may potentially limit the generalization of <span class="hlt">species</span> flammability rankings. Further research is necessary in order to evaluate the importance of our findings for fire danger modeling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4433356','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4433356"><span id="translatedtitle">Classification of <span class="hlt">Tree</span> <span class="hlt">Species</span> in Overstorey Canopy of Subtropical Forest Using QuickBird Images</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Lin, Chinsu; Popescu, Sorin C.; Thomson, Gavin; Tsogt, Khongor; Chang, Chein-I</p> <p>2015-01-01</p> <p>This paper proposes a supervised classification scheme to identify 40 <span class="hlt">tree</span> <span class="hlt">species</span> (2 coniferous, 38 broadleaf) belonging to 22 families and 36 genera in high spatial resolution QuickBird multispectral images (HMS). Overall kappa coefficient (OKC) and <span class="hlt">species</span> conditional kappa coefficients (SCKC) were used to evaluate classification performance in training samples and estimate accuracy and uncertainty in test samples. Baseline classification performance using HMS images and vegetation index (VI) images were evaluated with an OKC value of 0.58 and 0.48 respectively, but performance improved significantly (up to 0.99) when used in combination with an HMS spectral-spatial texture image (SpecTex). One of the 40 <span class="hlt">species</span> had very high conditional kappa coefficient performance (SCKC ≥ 0.95) using 4-band HMS and 5-band VIs images, but, only five <span class="hlt">species</span> had lower performance (0.68 ≤ SCKC ≤ 0.94) using the SpecTex images. When SpecTex images were combined with a Visible Atmospherically Resistant Index (VARI), there was a significant improvement in performance in the training samples. The same level of improvement could not be replicated in the test samples indicating that a high degree of uncertainty exists in <span class="hlt">species</span> classification accuracy which may be due to individual <span class="hlt">tree</span> crown density, leaf greenness (inter-canopy gaps), and noise in the background environment (intra-canopy gaps). These factors increase uncertainty in the spectral texture features and therefore represent potential problems when using pixel-based classification techniques for multi-<span class="hlt">species</span> classification. PMID:25978466</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4524695','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4524695"><span id="translatedtitle">Are <span class="hlt">Tree</span> <span class="hlt">Species</span> Diversity and Genotypic Diversity Effects on Insect Herbivores Mediated by Ants?</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Campos-Navarrete, María José; Abdala-Roberts, Luis; Munguía-Rosas, Miguel A.; Parra-Tabla, Víctor</p> <p>2015-01-01</p> <p>Plant diversity can influence predators and omnivores and such effects may in turn influence herbivores and plants. However, evidence for these ecological feedbacks is rare. We evaluated if the effects of <span class="hlt">tree</span> <span class="hlt">species</span> (SD) and genotypic diversity (GD) on the abundance of different guilds of insect herbivores associated with big-leaf mahogany (Swietenia macrophylla) were contingent upon the protective effects of ants tending extra-floral nectaries of this <span class="hlt">species</span>. This study was conducted within a larger experiment consisting of mahogany monocultures and <span class="hlt">species</span> polycultures of four <span class="hlt">species</span> and –within each of these two plot types– mahogany was represented by either one or four maternal families. We selected 24 plots spanning these treatment combinations, 10 mahogany plants/plot, and within each plot experimentally reduced ant abundance on half of the selected plants, and surveyed ant and herbivore abundance. There were positive effects of SD on generalist leaf-chewers and sap-feeders, but for the latter group this effect depended on the ant reduction treatment: SD positively influenced sap-feeders under ambient ant abundance but had no effect when ant abundance was reduced; at the same time, ants had negative effects on sap feeders in monoculture but no effect in polyculture. In contrast, SD did not influence specialist stem-borers or leaf-miners and this effect was not contingent upon ant reduction. Finally, GD did not influence any of the herbivore guilds studied, and such effects did not depend on the ant treatment. Overall, we show that <span class="hlt">tree</span> <span class="hlt">species</span> diversity influenced interactions between a focal plant <span class="hlt">species</span> (mahogany) and ants, and that such effects in turn mediated plant diversity effects on some (sap-feeders) but not all the herbivores guilds studied. Our results suggest that the observed patterns are dependent on the combined effects of herbivore identity, diet breadth, and the source of plant diversity. PMID:26241962</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4177404','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4177404"><span id="translatedtitle">Size-Class Effect Contributes to <span class="hlt">Tree</span> <span class="hlt">Species</span> Assembly through Influencing Dispersal in Tropical Forests</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hu, Yue-Hua; Kitching, Roger L.; Lan, Guo-Yu; Zhang, Jiao-Lin; Sha, Li-Qing; Cao, Min</p> <p>2014-01-01</p> <p>We have investigated the processes of community assembly using size classes of <span class="hlt">trees</span>. Specifically our work examined (1) whether point process models incorporating an effect of size-class produce more realistic summary outcomes than do models without this effect; (2) which of three selected models incorporating, respectively environmental effects, dispersal and the joint-effect of both of these, is most useful in explaining <span class="hlt">species</span>-area relationships (SARs) and point dispersion patterns. For this evaluation we used <span class="hlt">tree</span> <span class="hlt">species</span> data from the 50-ha forest dynamics plot in Barro Colorado Island, Panama and the comparable 20 ha plot at Bubeng, Southwest China. Our results demonstrated that incorporating an size-class effect dramatically improved the SAR estimation at both the plots when the dispersal only model was used. The joint effect model produced similar improvement but only for the 50-ha plot in Panama. The point patterns results were not improved by incorporation of size-class effects using any of the three models. Our results indicate that dispersal is likely to be a key process determining both SARs and point patterns. The environment-only model and joint-effects model were effective at the <span class="hlt">species</span> level and the community level, respectively. We conclude that it is critical to use multiple summary characteristics when modelling spatial patterns at the <span class="hlt">species</span> and community levels if a comprehensive understanding of the ecological processes that shape species’ distributions is sought; without this results may have inherent biases. By influencing dispersal, the effect of size-class contributes to <span class="hlt">species</span> assembly and enhances our understanding of <span class="hlt">species</span> coexistence. PMID:25251538</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26241962','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26241962"><span id="translatedtitle">Are <span class="hlt">Tree</span> <span class="hlt">Species</span> Diversity and Genotypic Diversity Effects on Insect Herbivores Mediated by Ants?</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Campos-Navarrete, María José; Abdala-Roberts, Luis; Munguía-Rosas, Miguel A; Parra-Tabla, Víctor</p> <p>2015-01-01</p> <p>Plant diversity can influence predators and omnivores and such effects may in turn influence herbivores and plants. However, evidence for these ecological feedbacks is rare. We evaluated if the effects of <span class="hlt">tree</span> <span class="hlt">species</span> (SD) and genotypic diversity (GD) on the abundance of different guilds of insect herbivores associated with big-leaf mahogany (Swietenia macrophylla) were contingent upon the protective effects of ants tending extra-floral nectaries of this <span class="hlt">species</span>. This study was conducted within a larger experiment consisting of mahogany monocultures and <span class="hlt">species</span> polycultures of four <span class="hlt">species</span> and -within each of these two plot types- mahogany was represented by either one or four maternal families. We selected 24 plots spanning these treatment combinations, 10 mahogany plants/plot, and within each plot experimentally reduced ant abundance on half of the selected plants, and surveyed ant and herbivore abundance. There were positive effects of SD on generalist leaf-chewers and sap-feeders, but for the latter group this effect depended on the ant reduction treatment: SD positively influenced sap-feeders under ambient ant abundance but had no effect when ant abundance was reduced; at the same time, ants had negative effects on sap feeders in monoculture but no effect in polyculture. In contrast, SD did not influence specialist stem-borers or leaf-miners and this effect was not contingent upon ant reduction. Finally, GD did not influence any of the herbivore guilds studied, and such effects did not depend on the ant treatment. Overall, we show that <span class="hlt">tree</span> <span class="hlt">species</span> diversity influenced interactions between a focal plant <span class="hlt">species</span> (mahogany) and ants, and that such effects in turn mediated plant diversity effects on some (sap-feeders) but not all the herbivores guilds studied. Our results suggest that the observed patterns are dependent on the combined effects of herbivore identity, diet breadth, and the source of plant diversity. PMID:26241962</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25978466','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25978466"><span id="translatedtitle">Classification of <span class="hlt">Tree</span> <span class="hlt">Species</span> in Overstorey Canopy of Subtropical Forest Using QuickBird Images.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lin, Chinsu; Popescu, Sorin C; Thomson, Gavin; Tsogt, Khongor; Chang, Chein-I</p> <p>2015-01-01</p> <p>This paper proposes a supervised classification scheme to identify 40 <span class="hlt">tree</span> <span class="hlt">species</span> (2 coniferous, 38 broadleaf) belonging to 22 families and 36 genera in high spatial resolution QuickBird multispectral images (HMS). Overall kappa coefficient (OKC) and <span class="hlt">species</span> conditional kappa coefficients (SCKC) were used to evaluate classification performance in training samples and estimate accuracy and uncertainty in test samples. Baseline classification performance using HMS images and vegetation index (VI) images were evaluated with an OKC value of 0.58 and 0.48 respectively, but performance improved significantly (up to 0.99) when used in combination with an HMS spectral-spatial texture image (SpecTex). One of the 40 <span class="hlt">species</span> had very high conditional kappa coefficient performance (SCKC ? 0.95) using 4-band HMS and 5-band VIs images, but, only five <span class="hlt">species</span> had lower performance (0.68 ? SCKC ? 0.94) using the SpecTex images. When SpecTex images were combined with a Visible Atmospherically Resistant Index (VARI), there was a significant improvement in performance in the training samples. The same level of improvement could not be replicated in the test samples indicating that a high degree of uncertainty exists in <span class="hlt">species</span> classification accuracy which may be due to individual <span class="hlt">tree</span> crown density, leaf greenness (inter-canopy gaps), and noise in the background environment (intra-canopy gaps). These factors increase uncertainty in the spectral texture features and therefore represent potential problems when using pixel-based classification techniques for multi-<span class="hlt">species</span> classification. PMID:25978466</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26999820','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26999820"><span id="translatedtitle"><span class="hlt">Tree</span> Size Inequality Reduces Forest Productivity: An Analysis Combining Inventory Data for Ten European <span class="hlt">Species</span> and a Light Competition Model.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bourdier, Thomas; Cordonnier, Thomas; Kunstler, Georges; Piedallu, Christian; Lagarrigues, Guillaume; Courbaud, Benoit</p> <p>2016-01-01</p> <p>Plant structural diversity is usually considered as beneficial for ecosystem functioning. For instance, numerous studies have reported positive <span class="hlt">species</span> diversity-productivity relationships in plant communities. However, other aspects of structural diversity such as individual size inequality have been far less investigated. In forests, <span class="hlt">tree</span> size inequality impacts directly <span class="hlt">tree</span> growth and asymmetric competition, but consequences on forest productivity are still indeterminate. In addition, the effect of <span class="hlt">tree</span> size inequality on productivity is likely to vary with <span class="hlt">species</span> shade-tolerance, a key ecological characteristic controlling asymmetric competition and light resource acquisition. Using plot data from the French National Geographic Agency, we studied the response of stand productivity to size inequality for ten forest <span class="hlt">species</span> differing in shade tolerance. We fitted a basal area stand production model that included abiotic factors, stand density, stand development stage and a <span class="hlt">tree</span> size inequality index. Then, using a forest dynamics model we explored whether mechanisms of light interception and light use efficiency could explain the <span class="hlt">tree</span> size inequality effect observed for three of the ten <span class="hlt">species</span> studied. Size inequality negatively affected basal area increment for seven out of the ten <span class="hlt">species</span> investigated. However, this effect was not related to the shade tolerance of these <span class="hlt">species</span>. According to the model simulations, the negative <span class="hlt">tree</span> size inequality effect could result both from reduced total stand light interception and reduced light use efficiency. Our results demonstrate that negative relationships between size inequality and productivity may be the rule in <span class="hlt">tree</span> populations. The lack of effect of shade tolerance indicates compensatory mechanisms between effect on light availability and response to light availability. Such a pattern deserves further investigations for mixed forests where complementarity effects between <span class="hlt">species</span> are involved. When studying the effect of structural diversity on ecosystem productivity, <span class="hlt">tree</span> size inequality is a major facet that should be taken into account. PMID:26999820</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4801349','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4801349"><span id="translatedtitle"><span class="hlt">Tree</span> Size Inequality Reduces Forest Productivity: An Analysis Combining Inventory Data for Ten European <span class="hlt">Species</span> and a Light Competition Model</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Bourdier, Thomas; Cordonnier, Thomas; Kunstler, Georges; Piedallu, Christian; Lagarrigues, Guillaume; Courbaud, Benoit</p> <p>2016-01-01</p> <p>Plant structural diversity is usually considered as beneficial for ecosystem functioning. For instance, numerous studies have reported positive <span class="hlt">species</span> diversity-productivity relationships in plant communities. However, other aspects of structural diversity such as individual size inequality have been far less investigated. In forests, <span class="hlt">tree</span> size inequality impacts directly <span class="hlt">tree</span> growth and asymmetric competition, but consequences on forest productivity are still indeterminate. In addition, the effect of <span class="hlt">tree</span> size inequality on productivity is likely to vary with <span class="hlt">species</span> shade-tolerance, a key ecological characteristic controlling asymmetric competition and light resource acquisition. Using plot data from the French National Geographic Agency, we studied the response of stand productivity to size inequality for ten forest <span class="hlt">species</span> differing in shade tolerance. We fitted a basal area stand production model that included abiotic factors, stand density, stand development stage and a <span class="hlt">tree</span> size inequality index. Then, using a forest dynamics model we explored whether mechanisms of light interception and light use efficiency could explain the <span class="hlt">tree</span> size inequality effect observed for three of the ten <span class="hlt">species</span> studied. Size inequality negatively affected basal area increment for seven out of the ten <span class="hlt">species</span> investigated. However, this effect was not related to the shade tolerance of these <span class="hlt">species</span>. According to the model simulations, the negative <span class="hlt">tree</span> size inequality effect could result both from reduced total stand light interception and reduced light use efficiency. Our results demonstrate that negative relationships between size inequality and productivity may be the rule in <span class="hlt">tree</span> populations. The lack of effect of shade tolerance indicates compensatory mechanisms between effect on light availability and response to light availability. Such a pattern deserves further investigations for mixed forests where complementarity effects between <span class="hlt">species</span> are involved. When studying the effect of structural diversity on ecosystem productivity, <span class="hlt">tree</span> size inequality is a major facet that should be taken into account. PMID:26999820</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4469422','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4469422"><span id="translatedtitle"><span class="hlt">Species</span>-Specific Effects on Throughfall Kinetic Energy in Subtropical Forest Plantations Are Related to Leaf Traits and <span class="hlt">Tree</span> Architecture</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Bruelheide, Helge; Härdtle, Werner; Kröber, Wenzel; Li, Ying; von Oheimb, Goddert</p> <p>2015-01-01</p> <p>Soil erosion is a key threat to many ecosystems, especially in subtropical China where high erosion rates occur. While the mechanisms that induce soil erosion on agricultural land are well understood, soil erosion processes in forests have rarely been studied. Throughfall kinetic energy (TKE) is influenced in manifold ways and often determined by the <span class="hlt">tree’s</span> leaf and architectural traits. We investigated the role of <span class="hlt">species</span> identity in mono-specific stands on TKE by asking to what extent TKE is <span class="hlt">species</span>-specific and which leaf and architectural traits account for variation in TKE. We measured TKE of 11 different <span class="hlt">tree</span> <span class="hlt">species</span> planted in monocultures in a biodiversity-ecosystem-functioning experiment in subtropical China, using sand-filled splash cups during five natural rainfall events in summer 2013. In addition, 14 leaf and <span class="hlt">tree</span> architectural traits were measured and linked to TKE. Our results showed that TKE was highly <span class="hlt">species</span>-specific. Highest TKE was found below Choerospondias axillaris and Sapindus saponaria, while Schima superba showed lowest TKE. These <span class="hlt">species</span>-specific effects were mediated by leaf habit, leaf area (LA), leaf pinnation, leaf margin, stem diameter at ground level (GD), crown base height (CBH), <span class="hlt">tree</span> height, number of branches and leaf area index (LAI) as biotic factors and throughfall as abiotic factor. Among these, leaf habit, <span class="hlt">tree</span> height and LA showed the highest effect sizes on TKE and can be considered as major drivers of TKE. TKE was positively influenced by LA, GD, CBH, <span class="hlt">tree</span> height, LAI, and throughfall amount while it was negatively influenced by the number of branches. TKE was lower in evergreen, simple leaved and dentate leaved than in deciduous, pinnated or entire leaved <span class="hlt">species</span>. Our results clearly showed that soil erosion in forest plantations can be mitigated by the appropriate choice of <span class="hlt">tree</span> <span class="hlt">species</span>. PMID:26079260</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2710175','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2710175"><span id="translatedtitle">A Test of the Scale-dependence of the <span class="hlt">Species</span> Abundance–People Correlation for Veteran <span class="hlt">Trees</span> in Italy</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Pautasso, Marco; Chiarucci, Alessandro</p> <p>2008-01-01</p> <p>Background and Aims The spatial correlation of the presence of people and <span class="hlt">species</span> has been suggested to be scale-dependent. At local scales, large numbers of people often result in <span class="hlt">species</span> impoverishment. At coarse scales, <span class="hlt">species</span>-rich regions tend to be densely inhabited. Recently, broad-scale human presence has been shown to be correlated not only with numbers of <span class="hlt">species</span> but also with their abundance, as predicted by the more-individuals hypothesis. However, it is not known whether the <span class="hlt">species</span> abundance–human presence correlation could also be scale-dependent. Methods This hypothesis was tested by use of a database of veteran <span class="hlt">trees</span> in Italy. Veteran <span class="hlt">tree</span> <span class="hlt">species</span> richness and number of individuals were modelled as a function of human population size at two grains of analysis (provinces and regions), controlling for variations in area, latitude and spatial autocorrelation. Key Results A positive correlation was found between human presence and veteran <span class="hlt">tree</span> <span class="hlt">species</span>. As predicted, this correlation was stronger at a coarser resolution. However, only at the provincial but not regional level was there a positive correlation between human presence and veteran <span class="hlt">tree</span> abundance when controlling for area and latitude. These results were confirmed for native and exotic <span class="hlt">trees</span>. Conclusions The present findings rule out the more-individuals hypothesis as an explanation of the scale-dependence of the <span class="hlt">species</span>–people correlation for veteran <span class="hlt">trees</span> in Italy. Potential mechanisms behind the observed spatial coincidence of high numbers of people and veteran <span class="hlt">tree</span> <span class="hlt">species</span> are discussed and implications for conservation are highlighted. PMID:18250107</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23363076','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23363076"><span id="translatedtitle">Effects of <span class="hlt">tree</span> <span class="hlt">species</span> richness and composition on moose winter browsing damage and foraging selectivity: an experimental study.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Milligan, Harriet T; Koricheva, Julia</p> <p>2013-07-01</p> <p>The optimal foraging theory, the nutrient balance hypothesis, and the plant association theories predict that foraging decisions and resulting <span class="hlt">tree</span> damage by large mammalian browsers may be influenced by the <span class="hlt">species</span> richness and <span class="hlt">species</span> composition of forest stands. This may lead to either associational susceptibility (increased damage on a focal plant in a mixed stand) or associational resistance (reduced damage in a mixed stand). Better understanding of the mechanisms and the relative importance of <span class="hlt">tree</span> <span class="hlt">species</span> richness and composition effects on foraging by mammalian browsers is needed to support sustainable management of forests and mammal populations. However, existing knowledge of forest diversity effects on foraging by large mammalian browsers comes largely from observational studies while experimental evidence is limited. We analysed winter browsing by moose (Alces alces L.) in a long-term, large-scale experiment in Finland, which represents a <span class="hlt">tree</span> <span class="hlt">species</span> richness gradient from monocultures to 2-, 3- and 5-<span class="hlt">species</span> mixtures composed of Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies L.), Siberian larch (Larix sibirica Ledeb.), silver birch (Betula pendula Roth.) and black alder (Alnus glutinosa L.). The intensity of browsing per plot increased with <span class="hlt">tree</span> <span class="hlt">species</span> richness while browsing selectivity decreased with <span class="hlt">tree</span> <span class="hlt">species</span> being targeted more equally in <span class="hlt">species</span>-rich mixtures. <span class="hlt">Tree</span> <span class="hlt">species</span> composition of a plot was also an important determinant of intensity of browsing. The greatest browsing occurred in plots containing preferred <span class="hlt">species</span> (pine and birch) while intermediate preference <span class="hlt">species</span> (larch and alder) experienced associational susceptibility when growing with pine and birch compared with their monocultures or mixtures without pine and birch. In contrast, we found no evidence of associational resistance; the presence of a least preferred <span class="hlt">species</span> (spruce) in a mixture had no significant effect on moose browsing on other <span class="hlt">tree</span> <span class="hlt">species</span>. We demonstrate that the presence of alternative forage <span class="hlt">species</span> allows moose to spend longer opportunistically foraging in a plot, resulting in increased level of damage in <span class="hlt">species</span>-rich stands and stands containing preferred <span class="hlt">tree</span> <span class="hlt">species</span>. Our results highlight the limitations of the optimal foraging theory in predicting browsing patterns and demonstrate the importance of associational effects within mixed stands. PMID:23363076</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003EAEJA....14021K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003EAEJA....14021K"><span id="translatedtitle">Emission of short-chained oxygenated voc from the leaves of mature central european <span class="hlt">tree</span> <span class="hlt">species</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kreuzwieser, J.; Cojocariu, C.; Rennenberg, H.</p> <p>2003-04-01</p> <p>The photolytic and oxidative destruction of volatile organic compounds (VOC) in the atmosphere results in a net production of tropospheric ozone. Oxygenated VOC (OVOC) are either directly emitted into the atmosphere or are produced there by oxidation of other hydrocarbons. Besides anthropogenic sources, the emission of OVOC by vegetation, particularly by forest ecosystems, is considered a major source of atmospheric OVOC. Exact numbers on emission rates from important <span class="hlt">tree</span> <span class="hlt">species</span> as well as production mechanisms that lead to the release of OVOC from leaves are, however, not known. In the present study, field campaigns were conducted in typical forest ecosystems in Germany in order to elucidate the spectrum and the amount of OVOC emitted by Central European <span class="hlt">tree</span> <span class="hlt">species</span>. Exchange data obtained were compared with physiological and meteorological parameters to obtain information on the factors controlling trace gas exchange. The field campaigns were accompanied by studies under controlled conditions in the laboratory. The poster presents data on carbonyl exchange between Picea abies, Fagus sylvatica, Carpinus betulus and other <span class="hlt">species</span> and the atmosphere and indicates plant internal and meteorological factors (temperature, ambient OVOC concentrations, light intensities, water supply, etc.) that may determine exchange rates.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/16918546','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/16918546"><span id="translatedtitle">Manganese accumulation in the leaf mesophyll of four <span class="hlt">tree</span> <span class="hlt">species</span>: a PIXE/EDAX localization study.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fernando, D R; Bakkaus, E J; Perrier, N; Baker, A J M; Woodrow, I E; Batianoff, G N; Collins, R N</p> <p>2006-01-01</p> <p>Little is known about the spatial distribution of excess manganese (Mn) in the leaves of tolerant plants. Recently, the first such study of a Mn hyperaccumulator showed that the highest localized Mn concentrations occur in the photosynthetic tissue. This is in contrast to reports based on localization of foliar accumulation of other heavy metals. Here, four <span class="hlt">tree</span> <span class="hlt">species</span>, Gossia bidwillii, Virotia neurophylla, Macadamia integrifolia and Macadamia tetraphylla, which hyperaccumulate or strongly accumulate Mn, were studied. Cross-sectional foliar Mn localization was carried out in situ using proton-induced X-ray emission/energy dispersive X-ray analysis (PIXE/EDAX). All four <span class="hlt">species</span> contained photosynthetic tissues with multiple palisade layers. These were shown to be the primary sequestration sites for Mn. Mn was not detected in the epidermal tissues. The findings of this study demonstrate a concurrence of three traits in four <span class="hlt">tree</span> <span class="hlt">species</span>, that is, accumulation of excess Mn in the leaves, its primary sequestration in the photosynthetic tissues, and multiple-layer palisade mesophyll. PMID:16918546</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19690000403','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19690000403"><span id="translatedtitle">Novel <span class="hlt">multipurpose</span> timer for laboratories</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Eisler, W. J.; Klein, P. D.</p> <p>1969-01-01</p> <p><span class="hlt">Multipurpose</span> digital delay timer simultaneously controls both a buffer pump and a fraction-collector. Timing and control may be in 30-second increments for up to 15 hours. Use of glassware and scintillation vials make it economical.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.B52D..03B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.B52D..03B"><span id="translatedtitle">Remote <span class="hlt">tree</span> <span class="hlt">species</span> identification in a diverse tropical forest using airborne imaging spectroscopy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Baldeck, C.; Asner, G. P.; Kellner, J. R.; Martin, R.; Anderson, C.; Knapp, D. E.</p> <p>2013-12-01</p> <p>Plant <span class="hlt">species</span> identification and mapping based on remotely-sensed spectral signatures is a challenging task with the potential to contribute enormously to ecological studies. This task is especially difficult in highly diverse ecosystems such as tropical forests, and for these ecosystems it may be more strategic to direct efforts to identifying crowns of a focal <span class="hlt">species</span>. We used imaging spectrometer data collected by the Carnegie Airborne Observatory over Barro Colorado Island, Panama, to develop classification models for the identification of <span class="hlt">tree</span> crowns belonging to selected focal <span class="hlt">species</span>. We explored alternative methods for detecting crowns of focal <span class="hlt">species</span>, which included binary, one-class, and biased support vector machines (SVM). Best performance was given by binary and biased SVM, with poor performance observed for one-class SVM. Binary and biased SVM were able to identify crowns of focal <span class="hlt">species</span> with classification sensitivity and specificity of 87-91% and 89-94%, respectively. The main tradeoff between binary and biased SVM is that construction of binary SVM requires a far greater amount of training data while biased SVM is more difficult to parameterize. Our results show that with sufficient training data, focal <span class="hlt">species</span> can be mapped with a high degree of accuracy, in terms of both sensitivity and specificity, in this diverse tropical forest.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4766085','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4766085"><span id="translatedtitle">Naming Potentially Endangered Parasites: Foliicolous Mycobiota of Dimorphandra wilsonii, a Highly Threatened Brazilian <span class="hlt">Tree</span> <span class="hlt">Species</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>da Silva, Meiriele; Pinho, Danilo B.; Pereira, Olinto L.; Fernandes, Fernando M.; Barreto, Robert W.</p> <p>2016-01-01</p> <p>A survey of foliicolous fungi associated with Dimorphandra wilsonii and Dimorphandra mollis (Fabaceae) was conducted in the state of Minas Gerais, Brazil. Dimorphandra wilsonii is a <span class="hlt">tree</span> <span class="hlt">species</span> native to the Brazilian Cerrado that is listed as critically endangered. Fungi strictly depending on this plant <span class="hlt">species</span> may be on the verge of co-extinction. Here, results of the pioneering description of this mycobiota are provided to contribute to the neglected field of microfungi conservation. The mycobiota of D. mollis, which is a common <span class="hlt">species</span> with a broad geographical distribution that co-occurs with D. wilsonii, was examined simultaneously to exclude fungal <span class="hlt">species</span> occurring on both <span class="hlt">species</span> from further consideration for conservation because microfungi associated with D. wilsonii should not be regarded as under threat of co-extinction. Fourteen ascomycete fungal <span class="hlt">species</span> were collected, identified, described and illustrated namely: Byssogene wilsoniae sp. nov., Geastrumia polystigmatis, Janetia dimorphandra-mollis sp. nov., Janetia wilsoniae sp. nov., Johansonia chapadiensis, Microcalliopsis dipterygis, Phillipsiella atra, Piricauda paraguayensis, Pseudocercospora dimorphandrae sp. nov., Pseudocercosporella dimorphandrae sp. nov., Ramichloridiopsis wilsoniae sp. and gen. nov., Stomiopeltis suttoniae, Trichomatomyces byrsonimae and Vesiculohyphomyces cerradensis. Three fungi were exclusively found on D. wilsonii and were regarded as potentially threatened of extinction: B. wilsoniae, J. wilsoniae and R. wilsoniae. PMID:26910334</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26910334','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26910334"><span id="translatedtitle">Naming Potentially Endangered Parasites: Foliicolous Mycobiota of Dimorphandra wilsonii, a Highly Threatened Brazilian <span class="hlt">Tree</span> <span class="hlt">Species</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>da Silva, Meiriele; Pinho, Danilo B; Pereira, Olinto L; Fernandes, Fernando M; Barreto, Robert W</p> <p>2016-01-01</p> <p>A survey of foliicolous fungi associated with Dimorphandra wilsonii and Dimorphandra mollis (Fabaceae) was conducted in the state of Minas Gerais, Brazil. Dimorphandra wilsonii is a <span class="hlt">tree</span> <span class="hlt">species</span> native to the Brazilian Cerrado that is listed as critically endangered. Fungi strictly depending on this plant <span class="hlt">species</span> may be on the verge of co-extinction. Here, results of the pioneering description of this mycobiota are provided to contribute to the neglected field of microfungi conservation. The mycobiota of D. mollis, which is a common <span class="hlt">species</span> with a broad geographical distribution that co-occurs with D. wilsonii, was examined simultaneously to exclude fungal <span class="hlt">species</span> occurring on both <span class="hlt">species</span> from further consideration for conservation because microfungi associated with D. wilsonii should not be regarded as under threat of co-extinction. Fourteen ascomycete fungal <span class="hlt">species</span> were collected, identified, described and illustrated namely: Byssogene wilsoniae sp. nov., Geastrumia polystigmatis, Janetia dimorphandra-mollis sp. nov., Janetia wilsoniae sp. nov., Johansonia chapadiensis, Microcalliopsis dipterygis, Phillipsiella atra, Piricauda paraguayensis, Pseudocercospora dimorphandrae sp. nov., Pseudocercosporella dimorphandrae sp. nov., Ramichloridiopsis wilsoniae sp. and gen. nov., Stomiopeltis suttoniae, Trichomatomyces byrsonimae and Vesiculohyphomyces cerradensis. Three fungi were exclusively found on D. wilsonii and were regarded as potentially threatened of extinction: B. wilsoniae, J. wilsoniae and R. wilsoniae. PMID:26910334</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24335493','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24335493"><span id="translatedtitle">On the biogeography of Centipeda: a <span class="hlt">species-tree</span> diffusion approach.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nylinder, Stephan; Lemey, Philippe; De Bruyn, Mark; Suchard, Marc A; Pfeil, Bernard E; Walsh, Neville; Anderberg, Arne A</p> <p>2014-03-01</p> <p>Reconstructing the biogeographic history of groups present in continuous arid landscapes is challenging due to the difficulties in defining discrete areas for analyses, and even more so when <span class="hlt">species</span> largely overlap both in terms of geography and habitat preference. In this study, we use a novel approach to estimate ancestral areas for the small plant genus Centipeda. We apply continuous diffusion of geography by a relaxed random walk where each <span class="hlt">species</span> is sampled from its extant distribution on an empirical distribution of time-calibrated <span class="hlt">species-trees</span>. Using a distribution of previously published substitution rates of the internal transcribed spacer (ITS) for Asteraceae, we show how the evolution of Centipeda correlates with the temporal increase of aridity in the arid zone since the Pliocene. Geographic estimates of ancestral <span class="hlt">species</span> show a consistent pattern of speciation of early lineages in the Lake Eyre region, with a division in more northerly and southerly groups since ?840 ka. Summarizing the geographic slices of <span class="hlt">species-trees</span> at the time of the latest speciation event (?20 ka), indicates no presence of the genus in Australia west of the combined desert belt of the Nullabor Plain, the Great Victoria Desert, the Gibson Desert, and the Great Sandy Desert, or beyond the main continental shelf of Australia. The result indicates all western occurrences of the genus to be a result of recent dispersal rather than ancient vicariance. This study contributes to our understanding of the spatiotemporal processes shaping the flora of the arid zone, and offers a significant improvement in inference of ancestral areas for any organismal group distributed where it remains difficult to describe geography in terms of discrete areas. PMID:24335493</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3926304','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3926304"><span id="translatedtitle">On the Biogeography of Centipeda: A <span class="hlt">Species-Tree</span> Diffusion Approach</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Nylinder, Stephan; Lemey, Philippe; De Bruyn, Mark; Suchard, Marc A.; Pfeil, Bernard E.; Walsh, Neville; Anderberg, Arne A.</p> <p>2014-01-01</p> <p>Reconstructing the biogeographic history of groups present in continuous arid landscapes is challenging due to the difficulties in defining discrete areas for analyses, and even more so when <span class="hlt">species</span> largely overlap both in terms of geography and habitat preference. In this study, we use a novel approach to estimate ancestral areas for the small plant genus Centipeda. We apply continuous diffusion of geography by a relaxed random walk where each <span class="hlt">species</span> is sampled from its extant distribution on an empirical distribution of time-calibrated <span class="hlt">species-trees</span>. Using a distribution of previously published substitution rates of the internal transcribed spacer (ITS) for Asteraceae, we show how the evolution of Centipeda correlates with the temporal increase of aridity in the arid zone since the Pliocene. Geographic estimates of ancestral <span class="hlt">species</span> show a consistent pattern of speciation of early lineages in the Lake Eyre region, with a division in more northerly and southerly groups since ∼840 ka. Summarizing the geographic slices of <span class="hlt">species-trees</span> at the time of the latest speciation event (∼20 ka), indicates no presence of the genus in Australia west of the combined desert belt of the Nullabor Plain, the Great Victoria Desert, the Gibson Desert, and the Great Sandy Desert, or beyond the main continental shelf of Australia. The result indicates all western occurrences of the genus to be a result of recent dispersal rather than ancient vicariance. This study contributes to our understanding of the spatiotemporal processes shaping the flora of the arid zone, and offers a significant improvement in inference of ancestral areas for any organismal group distributed where it remains difficult to describe geography in terms of discrete areas. PMID:24335493</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25784922','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25784922"><span id="translatedtitle">Tradeoffs between chilling and forcing in satisfying dormancy requirements for Pacific Northwest <span class="hlt">tree</span> <span class="hlt">species</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Harrington, Constance A; Gould, Peter J</p> <p>2015-01-01</p> <p>Many temperate and boreal <span class="hlt">tree</span> <span class="hlt">species</span> have a chilling requirement, that is, they need to experience cold temperatures during fall and winter to burst bud normally in the spring. Results from trials with 11 Pacific Northwest <span class="hlt">tree</span> <span class="hlt">species</span> are consistent with the concept that plants can accumulate both chilling and forcing units simultaneously during the dormant season and they exhibit a tradeoff between amount of forcing and chilling. That is, the parallel model of chilling and forcing was effective in predicting budburst and well chilled plants require less forcing for bud burst than plants which have received less chilling. Genotypes differed in the shape of the possibility line which describes the quantitative tradeoff between chilling and forcing units. Plants which have an obligate chilling requirement (Douglas-fir, western hemlock, western larch, pines, and true firs) and received no or very low levels of chilling did not burst bud normally even with long photoperiods. Pacific madrone and western redcedar benefited from chilling in terms of requiring less forcing to promote bud burst but many plants burst bud normally without chilling. Equations predicting budburst were developed for each <span class="hlt">species</span> in our trials for a portion of western North America under current climatic conditions and for 2080. Mean winter temperature was predicted to increase 3.2-5.5°C and this change resulted in earlier predicted budburst for Douglas-fir throughout much of our study area (up to 74 days earlier) but later budburst in some southern portions of its current range (up to 48 days later) as insufficient chilling is predicted to occur. Other <span class="hlt">species</span> all had earlier predicted dates of budburst by 2080 than currently. Recent warming trends have resulted in earlier budburst for some woody plant <span class="hlt">species</span>; however, the substantial winter warming predicted by some climate models will reduce future chilling in some locations such that budburst will not consistently occur earlier. PMID:25784922</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/22367367','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22367367"><span id="translatedtitle">Effect of dust load on the leaf attributes of the <span class="hlt">tree</span> <span class="hlt">species</span> growing along the roadside.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chaturvedi, R K; Prasad, Shikha; Rana, Savita; Obaidullah, S M; Pandey, Vijay; Singh, Hema</p> <p>2013-01-01</p> <p>Dust is considered as one of the most widespread air pollutants. The objective of the study was to analyse the effect of dust load (DL) on the leaf attributes of the four <span class="hlt">tree</span> <span class="hlt">species</span> planted along the roadside at a low pollution Banaras Hindu University (BHU) campus and a highly polluted industrial area (Chunar, Mirzapur) of India. The studied leaf attributes were: leaf area, specific leaf area (SLA), relative water content (RWC), leaf nitrogen content (LNC), leaf phosphorus content (LPC), chlorophyll content (Chl), maximum stomatal conductance (Gs(max)), maximum photosynthetic rate (A (max)) and intrinsic water-use efficiency (WUEi). Results showed significant effect of sites and <span class="hlt">species</span> for DL and the leaf attributes. Average DL across the four <span class="hlt">tree</span> <span class="hlt">species</span> was greater at Chunar, whereas, the average values of leaf attributes were greater at the BHU campus. Maximum DL was observed for Tectona grandis at Chunar site and minimum for Syzygium cumini at BHU campus. Across the two sites, maximum value of SLA, Chl and Gs(max) were exhibited by S. cumini, whereas, the greatest value of RWC, LNC, LPC, A (max) and WUEi were observed in Anthocephalus cadamba. A. cadamba and S. cumini exhibited 28 and 27 times more dust accumulation, respectively, at the most polluted Chunar site as compared to the BHU campus. They also exhibited less reduction in A (max) due to dust deposition as compared to the other two <span class="hlt">species</span>. Therefore, both these <span class="hlt">species</span> may be promoted for plantation along the roadside of the sites having greater dust deposition. PMID:22367367</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4347443','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4347443"><span id="translatedtitle">Tradeoffs between chilling and forcing in satisfying dormancy requirements for Pacific Northwest <span class="hlt">tree</span> <span class="hlt">species</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Harrington, Constance A.; Gould, Peter J.</p> <p>2015-01-01</p> <p>Many temperate and boreal <span class="hlt">tree</span> <span class="hlt">species</span> have a chilling requirement, that is, they need to experience cold temperatures during fall and winter to burst bud normally in the spring. Results from trials with 11 Pacific Northwest <span class="hlt">tree</span> <span class="hlt">species</span> are consistent with the concept that plants can accumulate both chilling and forcing units simultaneously during the dormant season and they exhibit a tradeoff between amount of forcing and chilling. That is, the parallel model of chilling and forcing was effective in predicting budburst and well chilled plants require less forcing for bud burst than plants which have received less chilling. Genotypes differed in the shape of the possibility line which describes the quantitative tradeoff between chilling and forcing units. Plants which have an obligate chilling requirement (Douglas-fir, western hemlock, western larch, pines, and true firs) and received no or very low levels of chilling did not burst bud normally even with long photoperiods. Pacific madrone and western redcedar benefited from chilling in terms of requiring less forcing to promote bud burst but many plants burst bud normally without chilling. Equations predicting budburst were developed for each <span class="hlt">species</span> in our trials for a portion of western North America under current climatic conditions and for 2080. Mean winter temperature was predicted to increase 3.2–5.5°C and this change resulted in earlier predicted budburst for Douglas-fir throughout much of our study area (up to 74 days earlier) but later budburst in some southern portions of its current range (up to 48 days later) as insufficient chilling is predicted to occur. Other <span class="hlt">species</span> all had earlier predicted dates of budburst by 2080 than currently. Recent warming trends have resulted in earlier budburst for some woody plant <span class="hlt">species</span>; however, the substantial winter warming predicted by some climate models will reduce future chilling in some locations such that budburst will not consistently occur earlier. PMID:25784922</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26491055','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26491055"><span id="translatedtitle">Water availability as dominant control of heat stress responses in two contrasting <span class="hlt">tree</span> <span class="hlt">species</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ruehr, Nadine K; Gast, Andreas; Weber, Christina; Daub, Baerbel; Arneth, Almut</p> <p>2016-02-01</p> <p>Heat waves that trigger severe droughts are predicted to increase globally; however, we lack an understanding of how <span class="hlt">trees</span> respond to the combined change of extreme temperatures and water availability. Here, we studied the impacts of two consecutive heat waves as well as post-stress recovery in young Pseudotsuga menziesii (Mirb.) Franco (Douglas-fir) and Robinia pseudoacacia L. (black locust) growing under controlled conditions. Responses were compared under water supply close to the long-term average and under reduced irrigation to represent drought. Exposure to high temperatures (+10 °C above ambient) and vapour pressure deficit strongly affected the <span class="hlt">trees</span> in terms of water relations, photosynthesis and growth. Douglas-fir used water resources conservatively, and transpiration decreased in response to mild soil water limitation. In black locust, heat stress led to pronounced <span class="hlt">tree</span> water deficits (stem diameter shrinkage), accompanied by leaf shedding to alleviate stress on the hydraulic system. The importance of water availability during the heat waves became further apparent by a concurrent decline in photosynthesis and stomatal conductance with increasing leaf temperatures in both <span class="hlt">species</span>, reaching the lowest rates in the heat-drought treatments. Stress severity determined both the speed and the amount of recovery. Upon release of stress, photosynthesis recovered rapidly in drought-treated black locust, while it remained below control rates in heat (t = -2.4, P < 0.05) and heat-drought stressed <span class="hlt">trees</span> (t = 2.96, P < 0.05). In Douglas-fir, photosynthesis recovered quickly, while water-use efficiency increased in heat-drought <span class="hlt">trees</span> because stomatal conductance remained reduced (t = -2.92, P < 0.05). Moreover, Douglas-fir was able to compensate for stem-growth reductions following heat (-40%) and heat-drought stress (-68%), but most likely at the expense of storage and other growth processes. Our results highlight the importance of studying heat waves alongside changes in water availability. They further suggest that we should look beyond the actual stress event to identify lagged effects and acclimation processes that may determine <span class="hlt">tree</span> resilience in the long term. PMID:26491055</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMGC53C0547M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMGC53C0547M"><span id="translatedtitle">Selection bias in <span class="hlt">species</span> distribution models: An econometric approach on forest <span class="hlt">trees</span> based on structural modeling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Martin-StPaul, N. K.; Ay, J. S.; Guillemot, J.; Doyen, L.; Leadley, P.</p> <p>2014-12-01</p> <p><span class="hlt">Species</span> distribution models (SDMs) are widely used to study and predict the outcome of global changes on <span class="hlt">species</span>. In human dominated ecosystems the presence of a given <span class="hlt">species</span> is the result of both its ecological suitability and human footprint on nature such as land use choices. Land use choices may thus be responsible for a selection bias in the presence/absence data used in SDM calibration. We present a structural modelling approach (i.e. based on structural equation modelling) that accounts for this selection bias. The new structural <span class="hlt">species</span> distribution model (SSDM) estimates simultaneously land use choices and <span class="hlt">species</span> responses to bioclimatic variables. A land use equation based on an econometric model of landowner choices was joined to an equation of <span class="hlt">species</span> response to bioclimatic variables. SSDM allows the residuals of both equations to be dependent, taking into account the possibility of shared omitted variables and measurement errors. We provide a general description of the statistical theory and a set of applications on forest <span class="hlt">trees</span> over France using databases of climate and forest inventory at different spatial resolution (from 2km to 8km). We also compared the outputs of the SSDM with outputs of a classical SDM (i.e. Biomod ensemble modelling) in terms of bioclimatic response curves and potential distributions under current climate and climate change scenarios. The shapes of the bioclimatic response curves and the modelled <span class="hlt">species</span> distribution maps differed markedly between SSDM and classical SDMs, with contrasted patterns according to <span class="hlt">species</span> and spatial resolutions. The magnitude and directions of these differences were dependent on the correlations between the errors from both equations and were highest for higher spatial resolutions. A first conclusion is that the use of classical SDMs can potentially lead to strong miss-estimation of the actual and future probability of presence modelled. Beyond this selection bias, the SSDM we propose represents a crucial step to account for economic constraints on <span class="hlt">tree</span> <span class="hlt">species</span> distributions that will help to assess the trade-offs and opportunities arising from global changes and refine adaptive management strategies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3502455','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3502455"><span id="translatedtitle">Historical Human Footprint on Modern <span class="hlt">Tree</span> <span class="hlt">Species</span> Composition in the Purus-Madeira Interfluve, Central Amazonia</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Levis, Carolina; de Souza, Priscila Figueira; Schietti, Juliana; Emilio, Thaise; Pinto, José Luiz Purri da Veiga; Clement, Charles R.; Costa, Flavia R. C.</p> <p>2012-01-01</p> <p>Background Native Amazonian populations managed forest resources in numerous ways, often creating oligarchic forests dominated by useful <span class="hlt">trees</span>. The scale and spatial distribution of forest modification beyond pre-Columbian settlements is still unknown, although recent studies propose that human impact away from rivers was minimal. We tested the hypothesis that past human management of the useful <span class="hlt">tree</span> community decreases with distance from rivers. Methodology/Principal Findings In six sites, we inventoried <span class="hlt">trees</span> and palms with DBH≥10 cm and collected soil for charcoal analysis; we also mapped archaeological evidence around the sites. To quantify forest manipulation, we measured the relative abundance, richness and basal area of useful <span class="hlt">trees</span> and palms. We found a strong negative exponential relationship between forest manipulation and distance to large rivers. Plots located from 10 to 20 km from a main river had 20–40% useful arboreal <span class="hlt">species</span>, plots between 20 and 40 km had 12–23%, plots more than 40 km had less than 15%. Soil charcoal abundance was high in the two sites closest to secondary rivers, suggesting past agricultural practices. The shortest distance between archaeological evidence and plots was found in sites near rivers. Conclusions/Significance These results strongly suggest that past forest manipulation was not limited to the pre-Columbian settlements along major rivers, but extended over interfluvial areas considered to be primary forest today. The sustainable use of Amazonian forests will be most effective if it considers the degree of past landscape domestication, as human-modified landscapes concentrate useful plants for human sustainable use and management today. PMID:23185264</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/15059769','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/15059769"><span id="translatedtitle">Patterns of leaf conductance and water potential of five Himalayan <span class="hlt">tree</span> <span class="hlt">species</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Poudyal, K; Jha, P K; Zobel, D B; Thapa, C B</p> <p>2004-06-01</p> <p>We studied variations in water relations and drought response in five Himalayan <span class="hlt">tree</span> <span class="hlt">species</span> (Schima wallichii (DC.) Korth. (chilaune) and Castanopsis indica (Roxb.) Miq. (dhale katus) at an elevation of 1400 m, Quercus lanata Smith (banjh) and Rhododendron arboreum Smith (lali gurans) at 2020 m, and Quercus semecarpifolia Smith (khasru) at 2130 m) at Phulchowki Hill, Kathmandu, Nepal. Soil water potential at 15 (Psi(s15)) and 30 cm (Psi(s30)) depths, <span class="hlt">tree</span> water potential at predawn (Psi(pd)) and midday (Psi(md)), and leaf conductance during the morning (g(wAM)) and afternoon (g(wPM)) were observed from December 1998 to April 2001, except during the monsoon months. There was significant variation among sites, <span class="hlt">species</span> and months in Psi(pd), Psi(md), g(wAM) and g(wPM), and among months for all <span class="hlt">species</span> for Psi(s15). Mean Psi(pd) and Psi(md) were lowest in Q. semecarpifolia (-0.40 and -1.18 MPa, respectively) and highest in S. wallichii (-0.20 and -0.63 MPa, respectively). The minimum Psi value for all <span class="hlt">species</span> (-0.70 to -1.79 MPa) was observed in March 1999, after 4 months of unusually low rainfall. Some patterns of Psi(pd) were related to phenology and leaf damage. During leafing, Psi(pd) often increased. Mean g(wAM) and g(wPM) were highest in Q. semecarpifolia (172 and 190 mmol m(-2) s(-1), respectively) and lowest in C. indica (78 and 74 mmol m(-2) s(-1), respectively). Soil water potential (Psi) at 15 cm depth correlated with plant Psi in all <span class="hlt">species</span>, but rarely with g(wAM) and not with g(wPM). Plant Psi declined with increasing elevation, whereas g(w) increased. As Psi(pd) declined, so did maximal g(w), but overall, g(w) was correlated with Psi(pd) only for R. arboreum. Schima wallichii maintained high Psi, with low stomatal conductance, as did Castanopsis indica, except that C. indica had low Psi during dry months. Rhododendron arboreum maintained high Psi(pd) and g(w), despite low soil Psi. Quercus lanata had low g(w) and low Psi(pd) in some months, but showed no correlation between <span class="hlt">tree</span> Psi and g(w). Quercus semecarpifolia, which grows at the highest elevation, had low soil and plant Psi and high g(w). PMID:15059769</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/17169902','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/17169902"><span id="translatedtitle">Interannual consistency in canopy stomatal conductance control of leaf water potential across seven <span class="hlt">tree</span> <span class="hlt">species</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ewers, B E; Mackay, D S; Samanta, S</p> <p>2007-01-01</p> <p>We investigated interannual variability of canopy transpiration per unit ground area (E (C)) and per unit leaf area (E (L)) across seven <span class="hlt">tree</span> <span class="hlt">species</span> in northern Wisconsin over two years. These <span class="hlt">species</span> have previously been shown to be sufficient to upscale stand-level transpiration to the landscape level during one growing season. Our objective was to test whether a simple plant hydraulic model could capture interannual variation in transpiration. Three <span class="hlt">species</span>, wetland balsam fir (Abies balsamea (L.) Mill), basswood (Tilia Americana L.) and speckled alder (Alnus rugosa (DuRoi) Spreng), had no change in E (C) or E (L) between 2000 and 2001. Red pine (Pinus resinosa Ait) had a 57 and 19% increase in E (C) and E (L), respectively, and sugar maple (Acer saccharum Marsh) had an 83 and 41% increase in E (C) and E (L), respectively, from 2000 to 2001. Quaking aspen (Populus tremuloides Michx) had a 50 and 21% decrease in E (C) and E (L), respectively, from 2000 to 2001 in response to complete defoliation by forest tent caterpillar (Malascoma distria Hüber) and subsequent lower total leaf area index of the reflushed foliage. White cedar (Thuja occidentalis L.) had a 20% decrease in both E (C) and E (L) caused by lowered surface water in wetlands in 2001 because of lower precipitation and wetland flow management. Upland A. balsamea increased E (L) and E (C) by 55 and 53%, respectively, as a result of release from light competition of the defoliated, overstory P. tremuloides. We hypothesized that regardless of different drivers of interannual variability in E (C) and E (L), minimum leaf water potential would be regulated at the same value. Minimum midday water potentials were consistent over the two years within each of the seven <span class="hlt">species</span> despite large changes in transpiration between years. This regulation was independently verified by the exponential saturation between daily E (C) and vapor pressure deficit (D) and the tradeoff between a reference canopy stomatal conductance (G (S)) and the sensitivity of G (S) to D, indicating that <span class="hlt">trees</span> with high G (S) must decrease G (S) in response to atmospheric drought faster than <span class="hlt">trees</span> with low G (S). Our results show that models of forest canopy transpiration can be simplified by incorporating G (S) regulation of minimum leaf water potential for isohydric <span class="hlt">species</span>. PMID:17169902</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/21937729','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21937729"><span id="translatedtitle">Liberomyces gen. nov. with two new <span class="hlt">species</span> of endophytic coelomycetes from broadleaf <span class="hlt">trees</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pazoutová, Sylvie; Srutka, Petr; Holusa, Jaroslav; Chudícková, Milada; Kubátová, Alena; Kolarík, Miroslav</p> <p>2012-01-01</p> <p>During a study of endophytic and saprotrophic fungi in the sapwood and phloem of broadleaf <span class="hlt">trees</span> (Salix alba, Quercus robur, Ulmus laevis, Alnus glutinosa, Betula pendula) fungi belonging to an anamorphic coelomycetous genus not attributable to a described taxon were detected and isolated in pure culture. The new genus, Liberomyces, with two <span class="hlt">species</span>, L. saliciphilus and L. macrosporus, is described. Both <span class="hlt">species</span> have subglobose conidiomata containing holoblastic sympodial conidiogenous cells. The conidiomata dehisce irregularly or by ostiole and secrete a slimy suspension of conidia. The conidia are hyaline, narrowly allantoid with a typically curved distal end. In L. macrosporus simultaneous production of synanamorph with thin filamentous conidia was observed occasionally. The genus has no known teleomorph. Related sequences in the public databases belong to endophytes of angiosperms. Phylogenetic analysis revealed a position close to the Xylariales (Sordariomycetes), but family and order affiliation remained unclear. PMID:21937729</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70000298','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70000298"><span id="translatedtitle">Mapping regional distribution of a single <span class="hlt">tree</span> <span class="hlt">species</span>: Whitebark pine in the Greater Yellowstone Ecosystem</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Landenburger, L.; Lawrence, R.L.; Podruzny, S.; Schwartz, C.C.</p> <p>2008-01-01</p> <p>Moderate resolution satellite imagery traditionally has been thought to be inadequate for mapping vegetation at the <span class="hlt">species</span> level. This has made comprehensive mapping of regional distributions of sensitive <span class="hlt">species</span>, such as whitebark pine, either impractical or extremely time consuming. We sought to determine whether using a combination of moderate resolution satellite imagery (Landsat Enhanced Thematic Mapper Plus), extensive stand data collected by land management agencies for other purposes, and modern statistical classification techniques (boosted classification <span class="hlt">trees</span>) could result in successful mapping of whitebark pine. Overall classification accuracies exceeded 90%, with similar individual class accuracies. Accuracies on a localized basis varied based on elevation. Accuracies also varied among administrative units, although we were not able to determine whether these differences related to inherent spatial variations or differences in the quality of available reference data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3705482','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3705482"><span id="translatedtitle">Mapping Regional Distribution of a Single <span class="hlt">Tree</span> <span class="hlt">Species</span>: Whitebark Pine in the Greater Yellowstone Ecosystem</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Landenburger, Lisa; Lawrence, Rick L.; Podruzny, Shannon; Schwartz, Charles C.</p> <p>2008-01-01</p> <p>Moderate resolution satellite imagery traditionally has been thought to be inadequate for mapping vegetation at the <span class="hlt">species</span> level. This has made comprehensive mapping of regional distributions of sensitive <span class="hlt">species</span>, such as whitebark pine, either impractical or extremely time consuming. We sought to determine whether using a combination of moderate resolution satellite imagery (Landsat Enhanced Thematic Mapper Plus), extensive stand data collected by land management agencies for other purposes, and modern statistical classification techniques (boosted classification <span class="hlt">trees</span>) could result in successful mapping of whitebark pine. Overall classification accuracies exceeded 90%, with similar individual class accuracies. Accuracies on a localized basis varied based on elevation. Accuracies also varied among administrative units, although we were not able to determine whether these differences related to inherent spatial variations or differences in the quality of available reference data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3708130','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3708130"><span id="translatedtitle">Interspecific coordination and intraspecific plasticity of fine root traits in North American temperate <span class="hlt">tree</span> <span class="hlt">species</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Tobner, Cornelia M.; Paquette, Alain; Messier, Christian</p> <p>2013-01-01</p> <p>Fine roots play an important role in nutrient and water absorption and hence overall <span class="hlt">tree</span> performance. However, current understanding of the ecological role of belowground traits lags considerably behind those of aboveground traits. In this study, we used data on specific root length (SRL), fine root diameter (D) and branching intensity (BI) of two datasets to examine interspecific trait coordination as well as intraspecific trait variation across ontogenetic stage and soil conditions (i.e., plasticity). The first dataset included saplings of 12 North American temperate <span class="hlt">tree</span> <span class="hlt">species</span> grown in monocultures in a common garden experiment to examine interspecific trait coordination. The second dataset included adult and juvenile individuals of four <span class="hlt">species</span> (present in both datasets) co-occurring in natural forests on contrasting soils (i.e., humid organic, mesic, and xeric podzolic).The three fine root traits investigated were strongly coordinated, with high SRL being related to low D and high BI. Fine root traits and aboveground life-strategies (i.e., relative growth rate) were weakly coordinated and never significant. Intraspecific responses to changes in ontogenetic stage or soil conditions were trait dependent. SRL was significantly higher in juveniles compared to adults for Abies balsamea and Acer rubrum, but did not vary with soil condition. BI did not vary significantly with either ontogeny or soil conditions, while D was generally significantly lower in juveniles and higher in humid organic soils. D also had the least total variability most of which was due to changes in the environment (plasticity). This study brings support for the emerging evidence for interspecific root trait coordination in <span class="hlt">trees</span>. It also indicates that intraspecific responses to both ontogeny and soil conditions are trait dependent and less concerted. D appears to be a better indicator of environmental change than SRL and BI. PMID:23874347</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26079260','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26079260"><span id="translatedtitle"><span class="hlt">Species</span>-Specific Effects on Throughfall Kinetic Energy in Subtropical Forest Plantations Are Related to Leaf Traits and <span class="hlt">Tree</span> Architecture.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Goebes, Philipp; Bruelheide, Helge; Härdtle, Werner; Kröber, Wenzel; Kühn, Peter; Li, Ying; Seitz, Steffen; von Oheimb, Goddert; Scholten, Thomas</p> <p>2015-01-01</p> <p>Soil erosion is a key threat to many ecosystems, especially in subtropical China where high erosion rates occur. While the mechanisms that induce soil erosion on agricultural land are well understood, soil erosion processes in forests have rarely been studied. Throughfall kinetic energy (TKE) is influenced in manifold ways and often determined by the <span class="hlt">tree</span>'s leaf and architectural traits. We investigated the role of <span class="hlt">species</span> identity in mono-specific stands on TKE by asking to what extent TKE is <span class="hlt">species</span>-specific and which leaf and architectural traits account for variation in TKE. We measured TKE of 11 different <span class="hlt">tree</span> <span class="hlt">species</span> planted in monocultures in a biodiversity-ecosystem-functioning experiment in subtropical China, using sand-filled splash cups during five natural rainfall events in summer 2013. In addition, 14 leaf and <span class="hlt">tree</span> architectural traits were measured and linked to TKE. Our results showed that TKE was highly <span class="hlt">species</span>-specific. Highest TKE was found below Choerospondias axillaris and Sapindus saponaria, while Schima superba showed lowest TKE. These <span class="hlt">species</span>-specific effects were mediated by leaf habit, leaf area (LA), leaf pinnation, leaf margin, stem diameter at ground level (GD), crown base height (CBH), <span class="hlt">tree</span> height, number of branches and leaf area index (LAI) as biotic factors and throughfall as abiotic factor. Among these, leaf habit, <span class="hlt">tree</span> height and LA showed the highest effect sizes on TKE and can be considered as major drivers of TKE. TKE was positively influenced by LA, GD, CBH, <span class="hlt">tree</span> height, LAI, and throughfall amount while it was negatively influenced by the number of branches. TKE was lower in evergreen, simple leaved and dentate leaved than in deciduous, pinnated or entire leaved <span class="hlt">species</span>. Our results clearly showed that soil erosion in forest plantations can be mitigated by the appropriate choice of <span class="hlt">tree</span> <span class="hlt">species</span>. PMID:26079260</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3989313','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3989313"><span id="translatedtitle">Chimpanzees Preferentially Select Sleeping Platform Construction <span class="hlt">Tree</span> <span class="hlt">Species</span> with Biomechanical Properties that Yield Stable, Firm, but Compliant Nests</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Samson, David R.; Hunt, Kevin D.</p> <p>2014-01-01</p> <p>The daily construction of a sleeping platform or “nest” is a universal behavior among large-bodied hominoids. Among chimpanzees, most populations consistently select particular <span class="hlt">tree</span> <span class="hlt">species</span> for nesting, yet the principles that guide <span class="hlt">species</span> preferences are poorly understood. At Semliki, Cynometra alexandri constitutes only 9.6% of all <span class="hlt">trees</span> in the gallery forest in which the study populations ranges, but it was selected for 73.6% of the 1,844 chimpanzee night beds we sampled. To determine whether physical properties influence nesting site selection, we measured the physical characteristics of seven common <span class="hlt">tree</span> <span class="hlt">species</span> at the Toro-Semliki Wildlife Reserve, Uganda. We determined stiffness and bending strength for a sample of 326 branches from the seven most commonly used <span class="hlt">tree</span> <span class="hlt">species</span>. We selected test-branches with diameters typically used for nest construction. We measured internode distance, calculated mean leaf surface area (cm2) and assigned a <span class="hlt">tree</span> architecture category to each of the seven <span class="hlt">species</span>. C. alexandri fell at the extreme of the sample for all four variables and shared a <span class="hlt">tree</span> architecture with only one other of the most commonly selected <span class="hlt">species</span>. C. alexandri was the stiffest and had the greatest bending strength; it had the smallest internode distance and the smallest leaf surface area. C. alexandri and the second most commonly selected <span class="hlt">species</span>, Cola gigantea, share a ‘Model of Koriba’ <span class="hlt">tree</span> architecture. We conclude that chimpanzees are aware of the structural properties of C. alexandri branches and choose it because its properties afford chimpanzees sleeping platforms that are firm, stable and resilient. PMID:24740283</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/17269315','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/17269315"><span id="translatedtitle">[Morphological-ecological characters and growth patterns of main <span class="hlt">tree</span> <span class="hlt">species</span> leaves in urban forest of Shenyang].</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Xu, Wenduo; He, Xingyuan; Chen, Wei; Wen, Hua</p> <p>2006-11-01</p> <p>The study with statistic and multivariate analyses showed that the main meteorological factors affecting the growth and development rhythms of main <span class="hlt">tree</span> <span class="hlt">species</span> leaves in urban forest of Shenyang were > or = 5 degrees C accumulated temperature, accumulated sunshine hours, and mean temperature in the middle ten days of each phenological period. The meteorological factors needed by the <span class="hlt">tree</span> <span class="hlt">species</span> varied with their phenological period. Necessary low temperature and CI were required in germination period, and suitable WI and HI were needed in the growth period. The major quantitative morphological characters of 10 <span class="hlt">tree</span> <span class="hlt">species</span> in Shenyang urban forest were displayed in their leaf morphology and size, which decreased in the sequence of Lespedeza cyrtobotrya > Syringa oblata > Sophora japonica > Populus alba > Cornus alba > Lonicera maackii > Ligustrum obtusifolium > Fraxinus mandshurica > Prunus padus > Phellodondron amurense. As for the leaf area, it was decreased in the order of S. oblata > P. alba > P. amurense > P. padus > F. mandshurica > C. alba > L. cyrtobotrya > L. maackii > S. japonica > L. obtusifolium. The relationships of leaf length with leaf width, perimeter and area accorded with the model of y = ax(k), and the growth trend belonged to allometic type. The k value between leaf length and width of all test <span class="hlt">tree</span> <span class="hlt">species</span> except P. alba was lower than 1, and that between leaf length and perimeter was > 1 for P. amuresne, approximately 1 for P. alba, and < 1 for other <span class="hlt">tree</span> <span class="hlt">species</span>. As for the k value between leaf length and area, it was > 1 for all the <span class="hlt">tree</span> <span class="hlt">species</span>, with that of P. alba being 2. 1028. The increasing rate of leaf area was about 2 times higher than that of leaf length. An optimum regression assessment model of the 10 <span class="hlt">tree</span> <span class="hlt">species</span> leaf area was built and tested. PMID:17269315</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25141305','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25141305"><span id="translatedtitle">Positive effects of plant genotypic and <span class="hlt">species</span> diversity on anti-herbivore defenses in a tropical <span class="hlt">tree</span> <span class="hlt">species</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Moreira, Xoaquín; Abdala-Roberts, Luis; Parra-Tabla, Víctor; Mooney, Kailen A</p> <p>2014-01-01</p> <p>Despite increasing evidence that plant intra- and inter-specific diversity increases primary productivity, and that such effect may in turn cascade up to influence herbivores, there is little information about plant diversity effects on plant anti-herbivore defenses, the relative importance of different sources of plant diversity, and the mechanisms for such effects. For example, increased plant growth at high diversity may lead to reduced investment in defenses via growth-defense trade-offs. Alternatively, positive effects of plant diversity on plant growth may lead to increased herbivore abundance which in turn leads to a greater investment in plant defenses. The magnitude of trait variation underlying diversity effects is usually greater among <span class="hlt">species</span> than among genotypes within a given <span class="hlt">species</span>, so plant <span class="hlt">species</span> diversity effects on resource use by producers as well as on higher trophic levels should be stronger than genotypic diversity effects. Here we compared the relative importance of plant genotypic and <span class="hlt">species</span> diversity on anti-herbivore defenses and whether such effects are mediated indirectly via diversity effects on plant growth and/or herbivore damage. To this end, we performed a large-scale field experiment where we manipulated genotypic diversity of big-leaf mahogany (Swietenia macrophylla) and <span class="hlt">tree</span> <span class="hlt">species</span> diversity, and measured effects on mahogany growth, damage by the stem-boring specialist caterpillar Hypsipyla grandella, and defensive traits (polyphenolics and condensed tannins in stem and leaves). We found that both forms of plant diversity had positive effects on stem (but not leaf) defenses. However, neither source of diversity influenced mahogany growth, and diversity effects on defenses were not mediated by either growth-defense trade-offs or changes in stem-borer damage. Although the mechanism(s) of diversity effects on plant defenses are yet to be determined, our study is one of the few to test for and show producer diversity effects on plant chemical defenses. PMID:25141305</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4139366','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4139366"><span id="translatedtitle">Positive Effects of Plant Genotypic and <span class="hlt">Species</span> Diversity on Anti-Herbivore Defenses in a Tropical <span class="hlt">Tree</span> <span class="hlt">Species</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Moreira, Xoaquín; Abdala-Roberts, Luis; Parra-Tabla, Víctor; Mooney, Kailen A.</p> <p>2014-01-01</p> <p>Despite increasing evidence that plant intra- and inter-specific diversity increases primary productivity, and that such effect may in turn cascade up to influence herbivores, there is little information about plant diversity effects on plant anti-herbivore defenses, the relative importance of different sources of plant diversity, and the mechanisms for such effects. For example, increased plant growth at high diversity may lead to reduced investment in defenses via growth-defense trade-offs. Alternatively, positive effects of plant diversity on plant growth may lead to increased herbivore abundance which in turn leads to a greater investment in plant defenses. The magnitude of trait variation underlying diversity effects is usually greater among <span class="hlt">species</span> than among genotypes within a given <span class="hlt">species</span>, so plant <span class="hlt">species</span> diversity effects on resource use by producers as well as on higher trophic levels should be stronger than genotypic diversity effects. Here we compared the relative importance of plant genotypic and <span class="hlt">species</span> diversity on anti-herbivore defenses and whether such effects are mediated indirectly via diversity effects on plant growth and/or herbivore damage. To this end, we performed a large-scale field experiment where we manipulated genotypic diversity of big-leaf mahogany (Swietenia macrophylla) and <span class="hlt">tree</span> <span class="hlt">species</span> diversity, and measured effects on mahogany growth, damage by the stem-boring specialist caterpillar Hypsipyla grandella, and defensive traits (polyphenolics and condensed tannins in stem and leaves). We found that both forms of plant diversity had positive effects on stem (but not leaf) defenses. However, neither source of diversity influenced mahogany growth, and diversity effects on defenses were not mediated by either growth-defense trade-offs or changes in stem-borer damage. Although the mechanism(s) of diversity effects on plant defenses are yet to be determined, our study is one of the few to test for and show producer diversity effects on plant chemical defenses. PMID:25141305</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25797923','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25797923"><span id="translatedtitle"><span class="hlt">Species</span> <span class="hlt">tree</span> phylogeny and biogeography of the Neotropical genus Pradosia (Sapotaceae, Chrysophylloideae).</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Terra-Araujo, Mário H; de Faria, Aparecida D; Vicentini, Alberto; Nylinder, Stephan; Swenson, Ulf</p> <p>2015-06-01</p> <p>Recent phylogenetic studies in Sapotaceae have demonstrated that many genera need to be redefined to better correspond to natural groups. The Neotropical genus Pradosia is believed to be monophyletic and includes 26 recognized <span class="hlt">species</span>. Here we reconstruct the generic phylogeny by a <span class="hlt">species-tree</span> approach using (∗)BEAST, 21 recognized <span class="hlt">species</span> (36 accessions), sequence data from three nuclear markers (ITS, ETS, and RPB2), a relaxed lognormal clock model, and a fossil calibration. We explore the evolution of five selected morphological characters, reconstruct the evolution of habitat (white-sand vs. clayish soils) preference, as well as space and time by using a recently developed continuous diffusion model in biogeography. We find Pradosia to be monophyletic in its current circumscription and to have originated in the Amazon basin at ∼47.5Ma. Selected morphological characters are useful to readily distinguish three clades. Preferences to white-sand and/or clay are somewhat important for the majority of <span class="hlt">species</span>, but speciation has not been powered by habitat shifts. Pradosia brevipes is a relative young <span class="hlt">species</span> (∼1.3Ma) that has evolved a unique geoxylic life strategy within Pradosia and is restricted to savannahs. Molecular dating and phylogenetic pattern indicate that Pradosia reached the Brazilian Atlantic coast at least three times: at 34.4Ma (P. longipedicellata), at 11.7Ma (P. kuhlmannii), and at 3.9Ma (weakly supported node within the red-flowered clade). PMID:25797923</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/22285658','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22285658"><span id="translatedtitle">Leaves of Lolium multiflorum 'Lema' and tropical <span class="hlt">tree</span> <span class="hlt">species</span> as biomonitors of polycyclic aromatic hydrocarbons.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rinaldi, Mirian C S; Domingos, Marisa; Dias, Ana P L; Esposito, Jéssica B N; Pagliuso, Josmar D</p> <p>2012-05-01</p> <p>This study extends the current knowledge regarding the use of plants for the passive accumulation of anthropogenic PAHs that are present in the atmospheric total suspended particles (TSP) in the tropics and sub-tropics. It is of major relevance because the anthropic emissions of TSP containing PAHs are significant in these regions, but their monitoring is still scarce. We compared the biomonitor efficiency of Lolium multiflorum 'Lema' and tropical <span class="hlt">tree</span> <span class="hlt">species</span> (Tibouchina pulchra and Psidium guajava 'Paluma') that were growing in an intensely TSP-polluted site in Cubatão (SE Brazil), and established the <span class="hlt">species</span> with the highest potential for alternative monitoring of PAHs. PAHs present in the TSP indicated that the region is impacted by various emission sources. L. multiflorum showed a greater efficiency for the accumulation of PAH compounds on their leaves than the tropical <span class="hlt">trees</span>. The linear regression between the logBCF and logKoa revealed that L. multiflorum is an efficient biomonitor of the profile of light and heavy PAHs present in the particulate phase of the atmosphere during dry weather and mild temperatures. The grass should be used only for indicating the PAHs with higher molecular weight in warmer and wetter periods. PMID:22285658</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24631608','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24631608"><span id="translatedtitle">Determinants of stomatal sluggishness in ozone-exposed deciduous <span class="hlt">tree</span> <span class="hlt">species</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hoshika, Yasutomo; Carriero, Giulia; Feng, Zhaozhong; Zhang, Yulong; Paoletti, Elena</p> <p>2014-05-15</p> <p>Our knowledge of ozone effects on dynamic stomatal response is still limited, especially in Asian <span class="hlt">tree</span> <span class="hlt">species</span>. We thus examined ozone effects on steady-state leaf gas exchange and stomatal dynamics in three common <span class="hlt">tree</span> <span class="hlt">species</span> of China (Ailanthus altissima, Fraxinus chinensis and Platanus orientalis). Seedlings were grown and were exposed to three levels of ozone in open-top chambers (42, 69, 100 nmol mol(-1) daylight average, from 09:00 to 18:00). At steady-state, ozone exposure induced an uncoupling of photosynthesis and stomatal conductance, as the former decreased while the latter did not. Dynamic stomatal response was investigated by cutting the leaf petiole after a steady-state stomatal conductance was reached. Ozone exposure increased stomatal sluggishness, i.e., slowed stomatal response after leaf cutting, in the following order of sensitivity, F. chinensis>A. altissima>P. orientalis. A restriction of stomatal ozone flux reduced the ozone-induced sluggishness in P. orientalis. The ozone-induced impairment of stomatal control was better explained by stomatal ozone flux per net photosynthesis rather than by stomatal ozone flux only. This suggests that ozone injury to stomatal control depends both on the amount of ozone entering a leaf and on the capacity for biochemical detoxification or repair. Leaf mass per area and the density of stomata did not affect stomatal sluggishness. PMID:24631608</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014ESASP.724E.124E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014ESASP.724E.124E"><span id="translatedtitle">Comparison of Different EO Sensors for Mapping <span class="hlt">Tree</span> <span class="hlt">Species</span>- A Case Study in Southwest Germany</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>En?le, Fabian; Kattenborn, Teja; Koch, Barbara</p> <p>2014-11-01</p> <p>The variety of different remote sensing sensors and thus the types of data specifications which are available is increasing continuously. Especially the differences in geometric, radiometric and temporal resolutions of different platforms affect their ability for the mapping of forests. These differences hinder the comparability and application of uniform methods of different remotely sensed data across the same region of interest. The quality and quantity of retrieved forest parameters is directly dependent on the data source, and therefore the objective of this project is to analyse the relationship between the data source and its derived parameters. A comparison of different optical EO-data (e.g. spatial resolution and spectral resolution of specific bands) will help to define the optimum data sets to produce a reproducible method to provide additional inputs to the Dragon cooperative project, specifically to method development for woody biomass estimation and biodiversity assessment services. This poster presents the first results on <span class="hlt">tree</span> <span class="hlt">species</span> mapping in a mixed temperate forest by satellite imagery taken from four different sensors. <span class="hlt">Tree</span> <span class="hlt">species</span> addressed in this pilot study are: Scots pine (Pinus sylvestris), sessile oak (Quercus petraea) and red oak (Quercus rubra). The spatial resolution varies from 2m to 30m and the spectral resolutions range from 8bands up to 155bands.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4651791','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4651791"><span id="translatedtitle">Impacts of Different <span class="hlt">Tree</span> <span class="hlt">Species</span> of Different Sizes on Spatial Distribution of Herbaceous Plants in the Nigerian Guinea Savannah Ecological Zone</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Buba, Toma</p> <p>2015-01-01</p> <p>This study was aimed at finding the impacts of different <span class="hlt">tree</span> <span class="hlt">species</span> and individual <span class="hlt">trees</span> of different sizes on <span class="hlt">species</span> richness, diversity, and composition of the herbaceous layer. All the three <span class="hlt">tree</span> <span class="hlt">species</span> have greatly increased <span class="hlt">species</span> richness and diversity both within and outside their crown zones compared with the open grassland. Both <span class="hlt">species</span> richness and diversity were found to be higher under all the three <span class="hlt">tree</span> <span class="hlt">species</span> than outside their crowns, which was in turn higher than the open field. Daniella oliveri has the highest <span class="hlt">species</span> richness and diversity both within and outside its crown zone followed by Vitellaria paradoxa and then Parkia biglobosa. The result also revealed that the same <span class="hlt">tree</span> <span class="hlt">species</span> with different sizes leads to different herbaceous <span class="hlt">species</span> richness, diversity, and composition under and around the <span class="hlt">trees</span>' crowns. P. biglobosa and V. paradoxa <span class="hlt">trees</span> with smaller sizes showed higher <span class="hlt">species</span> richness and diversity under their crowns than the bigger ones. The dissimilarity of <span class="hlt">species</span> composition differs between the inside and outside crown zones of the individuals of the same <span class="hlt">tree</span> <span class="hlt">species</span> and among the different <span class="hlt">trees</span> <span class="hlt">species</span> and the open field. PMID:26618024</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26618024','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26618024"><span id="translatedtitle">Impacts of Different <span class="hlt">Tree</span> <span class="hlt">Species</span> of Different Sizes on Spatial Distribution of Herbaceous Plants in the Nigerian Guinea Savannah Ecological Zone.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Buba, Toma</p> <p>2015-01-01</p> <p>This study was aimed at finding the impacts of different <span class="hlt">tree</span> <span class="hlt">species</span> and individual <span class="hlt">trees</span> of different sizes on <span class="hlt">species</span> richness, diversity, and composition of the herbaceous layer. All the three <span class="hlt">tree</span> <span class="hlt">species</span> have greatly increased <span class="hlt">species</span> richness and diversity both within and outside their crown zones compared with the open grassland. Both <span class="hlt">species</span> richness and diversity were found to be higher under all the three <span class="hlt">tree</span> <span class="hlt">species</span> than outside their crowns, which was in turn higher than the open field. Daniella oliveri has the highest <span class="hlt">species</span> richness and diversity both within and outside its crown zone followed by Vitellaria paradoxa and then Parkia biglobosa. The result also revealed that the same <span class="hlt">tree</span> <span class="hlt">species</span> with different sizes leads to different herbaceous <span class="hlt">species</span> richness, diversity, and composition under and around the <span class="hlt">trees</span>' crowns. P. biglobosa and V. paradoxa <span class="hlt">trees</span> with smaller sizes showed higher <span class="hlt">species</span> richness and diversity under their crowns than the bigger ones. The dissimilarity of <span class="hlt">species</span> composition differs between the inside and outside crown zones of the individuals of the same <span class="hlt">tree</span> <span class="hlt">species</span> and among the different <span class="hlt">trees</span> <span class="hlt">species</span> and the open field. PMID:26618024</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JARS....7.3480A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JARS....7.3480A"><span id="translatedtitle">Exploiting machine learning algorithms for <span class="hlt">tree</span> <span class="hlt">species</span> classification in a semiarid woodland using RapidEye image</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Adelabu, Samuel; Mutanga, Onisimo; Adam, Elhadi; Cho, Moses Azong</p> <p>2013-01-01</p> <p>Classification of different <span class="hlt">tree</span> <span class="hlt">species</span> in semiarid areas can be challenging as a result of the change in leaf structure and orientation due to soil moisture constraints. <span class="hlt">Tree</span> <span class="hlt">species</span> mapping is, however, a key parameter for forest management in semiarid environments. In this study, we examined the suitability of 5-band RapidEye satellite data for the classification of five <span class="hlt">tree</span> <span class="hlt">species</span> in mopane woodland of Botswana using machine leaning algorithms with limited training samples.We performed classification using random forest (RF) and support vector machines (SVM) based on EnMap box. The overall accuracies for classifying the five <span class="hlt">tree</span> <span class="hlt">species</span> was 88.75 and 85% for both SVM and RF, respectively. We also demonstrated that the new red-edge band in the RapidEye sensor has the potential for classifying <span class="hlt">tree</span> <span class="hlt">species</span> in semiarid environments when integrated with other standard bands. Similarly, we observed that where there are limited training samples, SVM is preferred over RF. Finally, we demonstrated that the two accuracy measures of quantity and allocation disagreement are simpler and more helpful for the vast majority of remote sensing classification process than the kappa coefficient. Overall, high <span class="hlt">species</span> classification can be achieved using strategically located RapidEye bands integrated with advanced processing algorithms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6619422','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6619422"><span id="translatedtitle">Growth and photosynthesis of seedling of five bottom land <span class="hlt">tree</span> <span class="hlt">species</span> following nutrient enrichment</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Vaitkus, M.R.; Ciravolo, T.G.; McLeod, K.W.; Mavity, E.M.; Novak, K.L. )</p> <p>1993-01-01</p> <p>Land management practices are increasingly focusing on the use of native plant communities to filter wastewater. Nutrient uptake from these effluents may affect overall growth and physiology. We examined the effects of increased nutrient levels on the seedlings of five <span class="hlt">species</span> of bottomland <span class="hlt">trees</span>. Seedlings of Carpinus caroliniana Walter. (hornbeam), Pinus serotina Michaux (pond pine), Acer rubrum L. (red maple), Quercus michauxii Nuttall (swamp chestnut oak), and Q, nigra L. (water oak) were grown outside in full sun under six levels of nutrient enrichment. During the 3rd growing season, height, component biomass, total biomass, net photosynthesis per unit leaf area and foliar nitrogen concentrations were determined. Height and total biomass of all <span class="hlt">species</span> increased from low to high nutrient levels, with A. rubrum and P. serotina exhibiting the highest rates of increase. Biomass and foliar nitrogen relationships suggested differing patterns of nutrient uptake and use among the <span class="hlt">species</span>. Acer rubrum, C. caroliniana and Q. michauxii used all nitrogen taken up for growth. Pinus serotina showed an accumulation of foliar nitrogen with a rapid rate of growth. Wuercus nigra grew more slowly. The effect of nutrient level on net photosynthesis was variable and <span class="hlt">species</span>-specific. Only W. nigra and A. rubrum showed a positive relationship. Net photosynthesis and foliar nitrogen showed no clear relationship among individual <span class="hlt">species</span>, although a regression of all <span class="hlt">species</span> together showed net photosynthesis to be positively correlated to foliar nitrogen. In a natural setting, the biomass response of A. rubrum and P. serotina, along with a corresponding increase height, could give seedlings of these <span class="hlt">species</span> a competitive advantage in capturing light or tolerating floods. Differential responses may thus alter the competitive relationships of these five <span class="hlt">species</span> in nutrient-enriched bottomland forest communities. 37 refs., 4 figs., 3 tabs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012IJBm...56..153F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012IJBm...56..153F"><span id="translatedtitle">Bayesian calibration of the Unified budburst model in six temperate <span class="hlt">tree</span> <span class="hlt">species</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fu, Yongshuo H.; Campioli, Matteo; Demarée, Gaston; Deckmyn, Alex; Hamdi, Rafiq; Janssens, Ivan A.; Deckmyn, Gaby</p> <p>2012-01-01</p> <p>Numerous phenology models developed to predict the budburst date of <span class="hlt">trees</span> have been merged into one Unified model (Chuine, 2000, J. Theor. Biol. 207, 337-347). In this study, we tested a simplified version of the Unified model (Unichill model) on six woody <span class="hlt">species</span>. Budburst and temperature data were available for five sites across Belgium from 1957 to 1995. We calibrated the Unichill model using a Bayesian calibration procedure, which reduced the uncertainty of the parameter coefficients and quantified the prediction uncertainty. The model performance differed among <span class="hlt">species</span>. For two <span class="hlt">species</span> (chestnut and black locust), the model showed good performance when tested against independent data not used for calibration. For the four other <span class="hlt">species</span> (beech, oak, birch, ash), the model performed poorly. Model performance improved substantially for most <span class="hlt">species</span> when using site-specific parameter coefficients instead of across-site parameter coefficients. This suggested that budburst is influenced by local environment and/or genetic differences among populations. Chestnut, black locust and birch were found to be temperature-driven <span class="hlt">species</span>, and we therefore analyzed the sensitivity of budburst date to forcing temperature in those three <span class="hlt">species</span>. Model results showed that budburst advanced with increasing temperature for 1-3 days °C-1, which agreed with the observed trends. In synthesis, our results suggest that the Unichill model can be successfully applied to chestnut and black locust (with both across-site and site-specific calibration) and to birch (with site-specific calibration). For other <span class="hlt">species</span>, temperature is not the only determinant of budburst and additional influencing factors will need to be included in the model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24455122','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24455122"><span id="translatedtitle">Relationship between photosynthetic phosphorus-use efficiency and foliar phosphorus fractions in tropical <span class="hlt">tree</span> <span class="hlt">species</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hidaka, Amane; Kitayama, Kanehiro</p> <p>2013-12-01</p> <p>How plants develop adaptive strategies to efficiently use nutrients on infertile soils is an important topic in plant ecology. It has been suggested that, with decreasing phosphorus (P) availability, plants increase photosynthetic P-use efficiency (PPUE) (i.e., the ratio of instantaneous photosynthetic carbon assimilation rate per unit foliar P). However, the mechanism to increase PPUE remains unclear. In this study, we tested whether high PPUE is explained by an optimized allocation of P in cells among P-containing biochemical compounds (i.e., foliar P fractions). We investigated the relationships among mass-based photosynthetic carbon assimilation rate (A mass), PPUE, total foliar P concentration, and foliar P fractions in 10 <span class="hlt">tree</span> <span class="hlt">species</span> in two tropical montane rain forests with differing soil P availability (five <span class="hlt">species</span> on sedimentary soils and five <span class="hlt">species</span> on P-poorer ultrabasic serpentine soils) on Mount Kinabalu, Borneo. We chemically fractionated foliar P into the following four fractions: metabolic P, lipid P, nucleic acid P, and residual P. A mass was positively correlated with the concentrations of total foliar P and of metabolic P across 10 <span class="hlt">tree</span> <span class="hlt">species</span>. Mean A mass and mean concentrations of total foliar P and of each foliar P fraction were lower on the P-poorer ultrabasic serpentine soils than on the sedimentary soils. There was a negative relationship between the proportion of metabolic P per total P and the proportion of lipid P per total P. PPUE was positively correlated with the ratio of metabolic P to lipid P. High PPUE is explained by the net effect of a relatively greater investment of P into P-containing metabolites and a relatively lesser investment into phospholipids in addition to generally reduced concentrations of all P fractions. We conclude that plants optimize the allocation of P among foliar P fractions for maintaining their productivity and growth and for reducing demand for P as their adaptation to P-poor soils. PMID:24455122</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3892354','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3892354"><span id="translatedtitle">Relationship between photosynthetic phosphorus-use efficiency and foliar phosphorus fractions in tropical <span class="hlt">tree</span> <span class="hlt">species</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hidaka, Amane; Kitayama, Kanehiro</p> <p>2013-01-01</p> <p>How plants develop adaptive strategies to efficiently use nutrients on infertile soils is an important topic in plant ecology. It has been suggested that, with decreasing phosphorus (P) availability, plants increase photosynthetic P-use efficiency (PPUE) (i.e., the ratio of instantaneous photosynthetic carbon assimilation rate per unit foliar P). However, the mechanism to increase PPUE remains unclear. In this study, we tested whether high PPUE is explained by an optimized allocation of P in cells among P-containing biochemical compounds (i.e., foliar P fractions). We investigated the relationships among mass-based photosynthetic carbon assimilation rate (Amass), PPUE, total foliar P concentration, and foliar P fractions in 10 <span class="hlt">tree</span> <span class="hlt">species</span> in two tropical montane rain forests with differing soil P availability (five <span class="hlt">species</span> on sedimentary soils and five <span class="hlt">species</span> on P-poorer ultrabasic serpentine soils) on Mount Kinabalu, Borneo. We chemically fractionated foliar P into the following four fractions: metabolic P, lipid P, nucleic acid P, and residual P. Amass was positively correlated with the concentrations of total foliar P and of metabolic P across 10 <span class="hlt">tree</span> <span class="hlt">species</span>. Mean Amass and mean concentrations of total foliar P and of each foliar P fraction were lower on the P-poorer ultrabasic serpentine soils than on the sedimentary soils. There was a negative relationship between the proportion of metabolic P per total P and the proportion of lipid P per total P. PPUE was positively correlated with the ratio of metabolic P to lipid P. High PPUE is explained by the net effect of a relatively greater investment of P into P-containing metabolites and a relatively lesser investment into phospholipids in addition to generally reduced concentrations of all P fractions. We conclude that plants optimize the allocation of P among foliar P fractions for maintaining their productivity and growth and for reducing demand for P as their adaptation to P-poor soils. PMID:24455122</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/22689942','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22689942"><span id="translatedtitle">Rapidly growing tropical <span class="hlt">trees</span> mobilize remarkable amounts of nitrogen, in ways that differ surprisingly among <span class="hlt">species</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Russell, Ann E; Raich, James W</p> <p>2012-06-26</p> <p>Fast-growing forests such as tropical secondary forests can accumulate large amounts of carbon (C), and thereby play an important role in the atmospheric CO(2) balance. Because nitrogen (N) cycling is inextricably linked with C cycling, the question becomes: Where does the N come from to match high rates of C accumulation? In unique experimental 16-y-old plantations established in abandoned pasture in lowland Costa Rica, we used a mass-balance approach to quantify N accumulation in vegetation, identify sources of N, and evaluate differences among <span class="hlt">tree</span> <span class="hlt">species</span> in N cycling. The replicated design contained four broad-leaved evergreen <span class="hlt">tree</span> <span class="hlt">species</span> growing under similar environmental conditions. Nitrogen uptake was rapid, reaching 409 (± 30) kg · ha(-1) · y(-1), double the rate reported from a Puerto Rican forest and greater than four times that observed at Hubbard Brook Forest (New Hampshire, USA). Nitrogen amassed in vegetation was 874 (± 176) kg · ha(-1), whereas net losses of soil N (0-100 cm) varied from 217 (±146) to 3,354 (± 915) kg · ha(-1) (P = 0.018) over 16 y. Soil C:N, ?(13)C values, and N budgets indicated that soil was the main source of biomass N. In Vochysia guatemalensis, however, N fixation contributed >60 kg · ha(-1) · y(-1). All <span class="hlt">species</span> apparently promoted soil N turnover, such that the soil N mean residence time was 32-54 y, an order of magnitude lower than the global mean. High rates of N uptake were associated with substantial N losses in three of the <span class="hlt">species</span>, in which an average of 1.6 g N was lost for every gram of N accumulated in biomass. PMID:22689942</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25826446','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25826446"><span id="translatedtitle">Stand competition determines how different <span class="hlt">tree</span> <span class="hlt">species</span> will cope with a warming climate.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fernández-de-Uña, Laura; Cañellas, Isabel; Gea-Izquierdo, Guillermo</p> <p>2015-01-01</p> <p>Plant-plant interactions influence how forests cope with climate and contribute to modulate <span class="hlt">species</span> response to future climate scenarios. We analysed the functional relationships between growth, climate and competition for Pinus sylvestris, Quercus pyrenaica and Quercus faginea to investigate how stand competition modifies forest sensitivity to climate and simulated how annual growth rates of these <span class="hlt">species</span> with different drought tolerance would change throughout the 21st century. Dendroecological data from stands subjected to thinning were modelled using a novel multiplicative nonlinear approach to overcome biases related to the general assumption of a linear relationship between covariates and to better mimic the biological relationships involved. Growth always decreased exponentially with increasing competition, which explained more growth variability than climate in Q. faginea and P. sylvestris. The effect of precipitation was asymptotic in all cases, while the relationship between growth and temperature reached an optimum after which growth declined with warmer temperatures. Our growth projections indicate that the less drought-tolerant P. sylvestris would be more negatively affected by climate change than the studied sub-Mediterranean oaks. Q. faginea and P. sylvestris mean growth would decrease under all the climate change scenarios assessed. However, P. sylvestris growth would decline regardless of the competition level, whereas this decrease would be offset by reduced competition in Q. faginea. Conversely, Q. pyrenaica growth would remain similar to current rates, except for the warmest scenario. Our models shed light on the nature of the <span class="hlt">species</span>-specific interaction between climate and competition and yield important implications for management. Assuming that individual growth is directly related to <span class="hlt">tree</span> performance, <span class="hlt">trees</span> under low competition would better withstand the warmer conditions predicted under climate change scenarios but in a variable manner depending on the <span class="hlt">species</span>. Thinning following an exponential rule may be desirable to ensure long-term conservation of high-density Mediterranean woodlands, particularly in drought-limited sites. PMID:25826446</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4380403','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4380403"><span id="translatedtitle">Stand Competition Determines How Different <span class="hlt">Tree</span> <span class="hlt">Species</span> Will Cope with a Warming Climate</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Fernández-de-Uña, Laura; Cañellas, Isabel; Gea-Izquierdo, Guillermo</p> <p>2015-01-01</p> <p>Plant-plant interactions influence how forests cope with climate and contribute to modulate <span class="hlt">species</span> response to future climate scenarios. We analysed the functional relationships between growth, climate and competition for Pinus sylvestris, Quercus pyrenaica and Quercus faginea to investigate how stand competition modifies forest sensitivity to climate and simulated how annual growth rates of these <span class="hlt">species</span> with different drought tolerance would change throughout the 21st century. Dendroecological data from stands subjected to thinning were modelled using a novel multiplicative nonlinear approach to overcome biases related to the general assumption of a linear relationship between covariates and to better mimic the biological relationships involved. Growth always decreased exponentially with increasing competition, which explained more growth variability than climate in Q. faginea and P. sylvestris. The effect of precipitation was asymptotic in all cases, while the relationship between growth and temperature reached an optimum after which growth declined with warmer temperatures. Our growth projections indicate that the less drought-tolerant P. sylvestris would be more negatively affected by climate change than the studied sub-Mediterranean oaks. Q. faginea and P. sylvestris mean growth would decrease under all the climate change scenarios assessed. However, P. sylvestris growth would decline regardless of the competition level, whereas this decrease would be offset by reduced competition in Q. faginea. Conversely, Q. pyrenaica growth would remain similar to current rates, except for the warmest scenario. Our models shed light on the nature of the <span class="hlt">species</span>-specific interaction between climate and competition and yield important implications for management. Assuming that individual growth is directly related to <span class="hlt">tree</span> performance, <span class="hlt">trees</span> under low competition would better withstand the warmer conditions predicted under climate change scenarios but in a variable manner depending on the <span class="hlt">species</span>. Thinning following an exponential rule may be desirable to ensure long-term conservation of high-density Mediterranean woodlands, particularly in drought-limited sites. PMID:25826446</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25694041','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25694041"><span id="translatedtitle">Photosynthetic capacity of tropical montane <span class="hlt">tree</span> <span class="hlt">species</span> in relation to leaf nutrients, successional strategy and growth temperature.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dusenge, Mirindi Eric; Wallin, Göran; GÃ¥rdesten, Johanna; Niyonzima, Felix; Adolfsson, Lisa; Nsabimana, Donat; Uddling, Johan</p> <p>2015-04-01</p> <p>Photosynthetic capacity of <span class="hlt">tree</span> leaves is typically positively related to nutrient content and little affected by changes in growth temperature. These relationships are, however, often poorly supported for tropical <span class="hlt">trees</span>, for which interspecific differences may be more strongly controlled by within-leaf nutrient allocation than by absolute leaf nutrient content, and little is known regarding photosynthetic acclimation to temperature. To explore the influence of leaf nutrient status, successional strategy and growth temperature on the photosynthetic capacity of tropical <span class="hlt">trees</span>, we collected data on photosynthetic, chemical and morphological leaf traits of ten <span class="hlt">tree</span> <span class="hlt">species</span> in Rwanda. Seven <span class="hlt">species</span> were studied in a forest plantation at mid-altitude (~1,700 m), whereas six <span class="hlt">species</span> were studied in a cooler montane rainforest at higher altitude (~2,500 m). Three <span class="hlt">species</span> were common to both sites, and, in the montane rainforest, three pioneer <span class="hlt">species</span> and three climax <span class="hlt">species</span> were investigated. Across <span class="hlt">species</span>, interspecific variation in photosynthetic capacity was not related to leaf nutrient content. Instead, this variation was related to differences in within-leaf nitrogen allocation, with a tradeoff between investments into compounds related to photosynthetic capacity (higher in pioneer <span class="hlt">species</span>) versus light-harvesting compounds (higher in climax <span class="hlt">species</span>). Photosynthetic capacity was significantly lower at the warmer site at 1,700 m altitude. We conclude that (1) within-leaf nutrient allocation is more important than leaf nutrient content per se in controlling interspecific variation in photosynthetic capacity among <span class="hlt">tree</span> <span class="hlt">species</span> in tropical Rwanda, and that (2) tropical montane rainforest <span class="hlt">species</span> exhibit decreased photosynthetic capacity when grown in a warmer environment. PMID:25694041</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26581110','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26581110"><span id="translatedtitle">Nature and Age of Neighbours Matter: Interspecific Associations among <span class="hlt">Tree</span> <span class="hlt">Species</span> Exist and Vary across Life Stages in Tropical Forests.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ledo, Alicia</p> <p>2015-01-01</p> <p>Detailed information about interspecific spatial associations among tropical <span class="hlt">tree</span> <span class="hlt">species</span> is scarce, and hence the ecological importance of those associations may have been underestimated. However, they can play a role in community assembly and <span class="hlt">species</span> diversity maintenance. This study investigated the spatial dependence between pairs of <span class="hlt">species</span>. First, the spatial associations (spatial attraction and spatial repulsion) that arose between <span class="hlt">species</span> were examined. Second, different sizes of <span class="hlt">trees</span> were considered in order to evaluate whether the spatial relationships between <span class="hlt">species</span> are constant or vary during the lifetime of individuals. Third, the consistency of those spatial associations with the <span class="hlt">species</span>-habitat associations found in previous studies was assessed. Two different tropical ecosystems were investigated: a montane cloud forest and a lowland moist forest. The results showed that spatial associations among <span class="hlt">species</span> exist, and these vary among life stages and <span class="hlt">species</span>. The rarity of negative spatial interactions suggested that exclusive competition was not common in the studied forests. On the other hand, positive interactions were common, and the results of this study strongly suggested that habitat associations were not the only cause of spatial attraction among <span class="hlt">species</span>. If this is true, habitat associations and density dependence are not the only mechanisms that explain <span class="hlt">species</span> distribution and diversity; other ecological interactions, such as facilitation among <span class="hlt">species</span>, may also play a role. These spatial associations could be important in the assembly of tropical <span class="hlt">tree</span> communities and forest succession, and should be taken into account in future studies. PMID:26581110</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4651535','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4651535"><span id="translatedtitle">Nature and Age of Neighbours Matter: Interspecific Associations among <span class="hlt">Tree</span> <span class="hlt">Species</span> Exist and Vary across Life Stages in Tropical Forests</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ledo, Alicia</p> <p>2015-01-01</p> <p>Detailed information about interspecific spatial associations among tropical <span class="hlt">tree</span> <span class="hlt">species</span> is scarce, and hence the ecological importance of those associations may have been underestimated. However, they can play a role in community assembly and <span class="hlt">species</span> diversity maintenance. This study investigated the spatial dependence between pairs of <span class="hlt">species</span>. First, the spatial associations (spatial attraction and spatial repulsion) that arose between <span class="hlt">species</span> were examined. Second, different sizes of <span class="hlt">trees</span> were considered in order to evaluate whether the spatial relationships between <span class="hlt">species</span> are constant or vary during the lifetime of individuals. Third, the consistency of those spatial associations with the <span class="hlt">species</span>-habitat associations found in previous studies was assessed. Two different tropical ecosystems were investigated: a montane cloud forest and a lowland moist forest. The results showed that spatial associations among <span class="hlt">species</span> exist, and these vary among life stages and <span class="hlt">species</span>. The rarity of negative spatial interactions suggested that exclusive competition was not common in the studied forests. On the other hand, positive interactions were common, and the results of this study strongly suggested that habitat associations were not the only cause of spatial attraction among <span class="hlt">species</span>. If this is true, habitat associations and density dependence are not the only mechanisms that explain <span class="hlt">species</span> distribution and diversity; other ecological interactions, such as facilitation among <span class="hlt">species</span>, may also play a role. These spatial associations could be important in the assembly of tropical <span class="hlt">tree</span> communities and forest succession, and should be taken into account in future studies. PMID:26581110</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011BGeo....8.2535C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011BGeo....8.2535C"><span id="translatedtitle">Stand age and <span class="hlt">tree</span> <span class="hlt">species</span> affect N2O and CH4 exchange from afforested soils</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Christiansen, J. R.; Gundersen, P.</p> <p>2011-09-01</p> <p>Afforestation of former agricultural land is a means to mitigate anthropogenic greenhouse gas emissions. The objectives of this study were (1) to assess the effect of oak (Quercus robur) and Norway spruce (Picea abies [L.] Karst.) stands of different stand ages (13-17 and 40 years after afforestation, respectively) on N2O and CH4 exchange from the soil under these <span class="hlt">species</span> and (2) identify the environmental factors responsible for the differences in gas exchange between <span class="hlt">tree</span> <span class="hlt">species</span> of different ages. N2O and CH4 fluxes (mean ± SE) were measured for two years at an afforested site. No <span class="hlt">species</span> difference was documented for N2O emission (oak: 4.2 ± 0.7 ?g N2O-N m-2 h-1, spruce: 4.0 ± 1 ?g N2O-N m-2 h-1) but the youngest stands (1.9 ± 0.3 ?g N2O-N m-2 h-1) emitted significantly less N2O than older stands (6.3 ± 1.2 ?g N2O-N m-2 h-1). CH4 exchange did not differ significantly between <span class="hlt">tree</span> <span class="hlt">species</span> (oak: -8.9 ± 0.9, spruce: -7.7 ± 1) or stand age (young: -7.3 ± 0.9 ?g CH4-C m-2 h-1, old: -9.4 ± 1 ?g CH4-C m-2 h-1) but interacted significantly; CH4 oxidation in the soil increased with stand age in oak and decreased with age for soils under Norway spruce. We conclude that the exchange of N2O and CH4 from the forest soil undergoes a quick and significant transition in the first four decades after planting in both oak and Norway spruce. These changes are related to (1) increased soil N availability over time as a result of less demand for N by <span class="hlt">trees</span> in turn facilitating higher N2O production in older stands and (2) decreasing bulk density and increased gas diffusivity in the top soil over time facilitating better exchange of N2O and CH4 with the atmosphere.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25224379','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25224379"><span id="translatedtitle">Where to nest? Ecological determinants of chimpanzee nest abundance and distribution at the habitat and <span class="hlt">tree</span> <span class="hlt">species</span> scale.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Carvalho, Joana S; Meyer, Christoph F J; Vicente, Luis; Marques, Tiago A</p> <p>2015-02-01</p> <p>Conversion of forests to anthropogenic land-uses increasingly subjects chimpanzee populations to habitat changes and concomitant alterations in the plant resources available to them for nesting and feeding. Based on nest count surveys conducted during the dry season, we investigated nest <span class="hlt">tree</span> <span class="hlt">species</span> selection and the effect of vegetation attributes on nest abundance of the western chimpanzee, Pan troglodytes verus, at Lagoas de Cufada Natural Park (LCNP), Guinea-Bissau, a forest-savannah mosaic widely disturbed by humans. Further, we assessed patterns of nest height distribution to determine support for the anti-predator hypothesis. A zero-altered generalized linear mixed model showed that nest abundance was negatively related to floristic diversity (exponential form of the Shannon index) and positively with the availability of smaller-sized <span class="hlt">trees</span>, reflecting characteristics of dense-canopy forest. A positive correlation between nest abundance and floristic richness (number of plant <span class="hlt">species</span>) and composition indicated that <span class="hlt">species</span>-rich open habitats are also important in nest site selection. Restricting this analysis to feeding <span class="hlt">trees</span>, nest abundance was again positively associated with the availability of smaller-sized <span class="hlt">trees</span>, further supporting the preference for nesting in food <span class="hlt">tree</span> <span class="hlt">species</span> from dense forest. Nest <span class="hlt">tree</span> <span class="hlt">species</span> selection was non-random, and oil palms were used at a much lower proportion (10%) than previously reported from other study sites in forest-savannah mosaics. While this study suggests that human disturbance may underlie the exclusive arboreal nesting at LCNP, better quantitative data are needed to determine to what extent the construction of elevated nests is in fact a response to predators able to climb <span class="hlt">trees</span>. Given the importance of LCNP as refuge for Pan t. verus our findings can improve conservation decisions for the management of this important umbrella <span class="hlt">species</span> as well as its remaining suitable habitats. PMID:25224379</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4012946','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4012946"><span id="translatedtitle">Development of Rapidly Evolving Intron Markers to Estimate Multilocus <span class="hlt">Species</span> <span class="hlt">Trees</span> of Rodents</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Rodríguez-Prieto, Ana; Igea, Javier; Castresana, Jose</p> <p>2014-01-01</p> <p>One of the major challenges in the analysis of closely related <span class="hlt">species</span>, speciation and phylogeography is the identification of variable sequence markers that allow the determination of genealogical relationships in multiple genomic regions using coalescent and <span class="hlt">species</span> <span class="hlt">tree</span> approaches. Rodent <span class="hlt">species</span> represent nearly half of the mammalian diversity, but so far no systematic study has been carried out to detect suitable informative markers for this group. Here, we used a bioinformatic pipeline to extract intron sequences from rodent genomes available in databases and applied a series of filters that allowed the identification of 208 introns that adequately fulfilled several criteria for these studies. The main required characteristics of the introns were that they had the maximum possible mutation rates, that they were part of single-copy genes, that they had an appropriate sequence length for amplification, and that they were flanked by exons with suitable regions for primer design. In addition, in order to determine the validity of this approach, we chose ten of these introns for primer design and tested them in a panel of eleven rodent <span class="hlt">species</span> belonging to different representative families. We show that all these introns can be amplified in the majority of <span class="hlt">species</span> and that, overall, 79% of the amplifications worked with minimum optimization of the annealing temperature. In addition, we confirmed for a pair of sister <span class="hlt">species</span> the relatively high level of sequence divergence of these introns. Therefore, we provide here a set of adequate intron markers that can be applied to different <span class="hlt">species</span> of Rodentia for their use in studies that require significant sequence variability. PMID:24804779</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5126788','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5126788"><span id="translatedtitle">Biomass production of Prosopis <span class="hlt">species</span> (mesquite), leucaena, and other leguminous <span class="hlt">trees</span> grown under heat/drought stress</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Felker, P.; Cannell, G.H.; Clark, P.R.; Osborn, J.F.; Nash, P.</p> <p>1983-01-01</p> <p>Leguminous <span class="hlt">trees</span> were examined for use on hot/arid lands in field trials in the Califronia Imperial Valley where July daily maximum temperatures are 42/sup 0/C (108/sup 0/F). Two field trials were carried out to rank 55 accessions in biomass per <span class="hlt">tree</span> and to evaluate biomass production per unit area with four of the more productive accessions identified in earlier trials. The trial with 55 accessions compared Prosopis (mesquite) to widely recommended <span class="hlt">species</span> for arid lands such as Leucaena leucocephala (K-8), Parkinsonia aculeata, and Prosopis tamarugo and to other drought adapted <span class="hlt">tree</span> legume <span class="hlt">species</span> of California/Arizona deserts such as Cercidium fluoridium and Olneya tesota. Prosopis selections were identified that had greater productivity than either Leucaena leucocephala (K-8) or Parkinsonia aculeata. The mean ovendry biomass per accession ranged from 0.2 kg/<span class="hlt">tree</span> for Prosopis tamarugo to 29 kg/<span class="hlt">tree</span> for P. alba (0166) when measured 2 years from germination in the greenhouse. Clones were obtained from <span class="hlt">trees</span> in this trial which had 45-56 kg/<span class="hlt">tree</span> (ovendry) in two seasons. The plots designed to measure biomass production per unit area were on a 1.5 m spacing and had productivities of 7, 11.2, 14.3, and 14.5 ovendry T ha/sup -1/ yr/sup -1/ for P. glandulosa var torreyana (0001), P. alba (0163), P. chilensis (0009), and P. alba (0039), respectively, when measured 2 years from germination in the greenhouse.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5266099','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5266099"><span id="translatedtitle">Biomass production of Prosopis <span class="hlt">species</span> (mesquite), Leucaena, and other leguminous <span class="hlt">trees</span> grown under heat/drought stress</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Felker, P.; Cannell, G.H.; Clark, P.R.; Osborn, J.F.; Nash, P.</p> <p>1983-09-01</p> <p>Leguminous <span class="hlt">trees</span> were examined for use of hot/arid lands in field trials in the California Imperial Valley where July daily maximum temperatures are 42 degrees C (108 degrees F). Two field trials were carried out to rank 55 accessions in biomass per <span class="hlt">tree</span> and to evaluate biomass production per unit area with four of the more productive accessions identified in earlier trials. The trial with 55 accessions compared Prosopis (mesquite) to widely recommended <span class="hlt">species</span> for arid lands such as Leucaena leucocephala (K-8), Parkinsonia aculeata, and Prosopis tamarugo and to other drought adapted <span class="hlt">tree</span> legume <span class="hlt">species</span> of California/Arizona deserts such as Cercidium floridium and Olneya tesota. Prosopis selections were identified that had greater productivity than either Leucaena leucocephala (K-8) or Parkinsonia aculeata. The mean oven-dry biomass per accession ranged from 0.2 kg/<span class="hlt">tree</span> for Prosospis tamarugo to 29 kg/<span class="hlt">tree</span> for P. alba (0166) when measured 2 years from germination in the greenhouse. Clones were obtained from <span class="hlt">trees</span> in this trial which had 45-56 kg/<span class="hlt">tree</span> (oven-dry) in two seasons. The plots designed to measure biomass production per unit area were on a 1.5 m spacing and had productivities of 7, 11.2, 14.3, and 14.5 oven-dry T ha-1 yr-1 for P. glandulosa var torreyana (0001), P. alba (0163), P. chilensis (0009), and P. alba(0039), respectively, when measured 2 years from germination in the greenhouse. 30 references</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4123702','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4123702"><span id="translatedtitle">Stochastically driven adult–recruit associations of <span class="hlt">tree</span> <span class="hlt">species</span> on Barro Colorado Island</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Getzin, Stephan; Wiegand, Thorsten; Hubbell, Stephen P.</p> <p>2014-01-01</p> <p>The spatial placement of recruits around adult conspecifics represents the accumulated outcome of several pattern-forming processes and mechanisms such as primary and secondary seed dispersal, habitat associations or Janzen–Connell effects. Studying the adult–recruit relationship should therefore allow the derivation of specific hypotheses on the processes shaping population and community dynamics. We analysed adult–recruit associations for 65 <span class="hlt">tree</span> <span class="hlt">species</span> taken from six censuses of the 50 ha neotropical forest plot on Barro Colorado Island (BCI), Panama. We used point pattern analysis to test, at a range of neighbourhood scales, for spatial independence between recruits and adults, to assess the strength and type of departure from independence, and its relationship with <span class="hlt">species</span> properties. Positive associations expected to prevail due to dispersal limitation occurred only in 16% of all cases; instead a majority of <span class="hlt">species</span> showed spatial independence (≈73%). Independence described the placement of recruits around conspecific adults in good approximation, although we found weak and noisy signals of <span class="hlt">species</span> properties related to seed dispersal. We hypothesize that spatial mechanisms with strong stochastic components such as animal seed dispersal overpower the pattern-forming effects of dispersal limitation, density dependence and habitat association, or that some of the pattern-forming processes cancel out each other. PMID:25030984</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/10540979','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/10540979"><span id="translatedtitle">Proximate composition and mineral content of two edible <span class="hlt">species</span> of Cnidoscolus (<span class="hlt">tree</span> spinach).</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kuti, J O; Kuti, H O</p> <p>1999-01-01</p> <p>Proximate composition and mineral content of raw and cooked leaves of two edible <span class="hlt">tree</span> spinach <span class="hlt">species</span> (Cnidoscolus chayamansa and C. aconitifolius), known locally as 'chaya', were determined and compared with that of a traditional green vegetable, spinach (Spinicia oleraceae). Results of the study indicated that the edible leafy parts of the two chaya <span class="hlt">species</span> contained significantly (p<0.05) greater amounts of crude protein, crude fiber, Ca, K, Fe, ascorbic acid and beta-carotene than the spinach leaf. However, no significant (p>0.05) differences were found in nutritional composition and mineral content between the chaya <span class="hlt">species</span>, except minor differences in the relative composition of fatty acids, protein and amino acids. Cooking of chaya leaves slightly reduced nutritional composition of both chaya <span class="hlt">species</span>. Cooking is essential prior to consumption to inactivate the toxic hydrocyanic glycosides present in chaya leaves. Based on the results of this study, the edible chaya leaves may be good dietary sources of minerals (Ca, K and Fe) and vitamins (ascorbic acid and beta-carotene). PMID:10540979</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4689444','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4689444"><span id="translatedtitle">Preliminary Genomic Characterization of Ten Hardwood <span class="hlt">Tree</span> <span class="hlt">Species</span> from Multiplexed Low Coverage Whole Genome Sequencing</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Staton, Margaret; Best, Teodora; Khodwekar, Sudhir; Owusu, Sandra; Xu, Tao; Xu, Yi; Jennings, Tara; Cronn, Richard; Arumuganathan, A. Kathiravetpilla; Coggeshall, Mark; Gailing, Oliver; Liang, Haiying; Romero-Severson, Jeanne; Schlarbaum, Scott; Carlson, John E.</p> <p>2015-01-01</p> <p>Forest health issues are on the rise in the United States, resulting from introduction of alien pests and diseases, coupled with abiotic stresses related to climate change. Increasingly, forest scientists are finding genetic/genomic resources valuable in addressing forest health issues. For a set of ten ecologically and economically important native hardwood <span class="hlt">tree</span> <span class="hlt">species</span> representing a broad phylogenetic spectrum, we used low coverage whole genome sequencing from multiplex Illumina paired ends to economically profile their genomic content. For six <span class="hlt">species</span>, the genome content was further analyzed by flow cytometry in order to determine the nuclear genome size. Sequencing yielded a depth of 0.8X to 7.5X, from which in silico analysis yielded preliminary estimates of gene and repetitive sequence content in the genome for each <span class="hlt">species</span>. Thousands of genomic SSRs were identified, with a clear predisposition toward dinucleotide repeats and AT-rich repeat motifs. Flanking primers were designed for SSR loci for all ten <span class="hlt">species</span>, ranging from 891 loci in sugar maple to 18,167 in redbay. In summary, we have demonstrated that useful preliminary genome information including repeat content, gene content and useful SSR markers can be obtained at low cost and time input from a single lane of Illumina multiplex sequence. PMID:26698853</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4552639','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4552639"><span id="translatedtitle">Influence of <span class="hlt">Tree</span> <span class="hlt">Species</span> Composition and Community Structure on Carbon Density in a Subtropical Forest</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hu, Yanqiu; Su, Zhiyao; Li, Wenbin; Li, Jingpeng; Ke, Xiandong</p> <p>2015-01-01</p> <p>We assessed the impact of <span class="hlt">species</span> composition and stand structure on the spatial variation of forest carbon density using data collected from a 4-ha plot in a subtropical forest in southern China. We found that 1) forest biomass carbon density significantly differed among communities, reflecting a significant effect of community structure and <span class="hlt">species</span> composition on carbon accumulation; 2) soil organic carbon density increased whereas stand biomass carbon density decreased across communities, indicating that different mechanisms might account for the accumulation of stand biomass carbon and soil organic carbon in the subtropical forest; and 3) a small number of <span class="hlt">tree</span> individuals of the medium- and large-diameter class contributed predominantly to biomass carbon accumulation in the community, whereas a large number of seedlings and saplings were responsible for a small proportion of the total forest carbon stock. These findings demonstrate that both biomass carbon and soil carbon density in the subtropical forest are sensitive to <span class="hlt">species</span> composition and community structure, and that heterogeneity in <span class="hlt">species</span> composition and stand structure should be taken into account to ensure accurate forest carbon accounting. PMID:26317523</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/21952957','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21952957"><span id="translatedtitle">Flower-visiting insects of five <span class="hlt">tree</span> <span class="hlt">species</span> in a restored area of semideciduous seasonal forest.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fragoso, F P; Varanda, E M</p> <p>2011-01-01</p> <p>The reinstatement of biodiversity and ecological processes must be the major goal in restoration projects, which requires the establishment of biological interactions in addition to native plant population recovery. Therefore, we assessed the flower visitors of five <span class="hlt">tree</span> <span class="hlt">species</span> in a restored area of Semideciduous Seasonal Forest, in Ribeirão Preto, SP, Brazil. The specimens were collected using entomological net on flowers of Acacia polyphylla, Aegiphila sellowianna, Croton floribundus, Croton urucurana and Schinus terebinthifolius from October 2007 to September 2008. A total of 139 insect <span class="hlt">species</span> belonging to five orders were collected. Hymenoptera was the most diverse order collected. From a total of 37 families, Vespidae (15 <span class="hlt">species</span>), Cabronidae (12), Apidae (10), Halictidae (10), Syrphidae (12), Tachinidae (6) and Hesperidae (7) were the richest ones. Schinus terebinthifolius flowers presented the most abundant and diverse insect visitors (60), suggesting it is an important attractive <span class="hlt">species</span> to the fauna in restoration programs. Our data suggest that mutualistic interactions between some of these plants and their flower-visiting insects may be in a reinstatement process, and will support the design and monitoring of future restoration efforts. PMID:21952957</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26057363','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26057363"><span id="translatedtitle">Leaf reflectance variation along a vertical crown gradient of two deciduous <span class="hlt">tree</span> <span class="hlt">species</span> in a Belgian industrial habitat.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Khavaninzadeh, Ali Reza; Veroustraete, Frank; Van Wittenberghe, Shari; Verrelst, Jochem; Samson, Roeland</p> <p>2015-09-01</p> <p>The reflectometry of leaf asymmetry is a novel approach in the bio-monitoring of <span class="hlt">tree</span> health in urban or industrial habitats. Leaf asymmetry responds to the degree of environmental pollution and reflects structural changes in a leaf due to environmental pollution. This paper describes the boundary conditions to scale up from leaf to canopy level reflectance, by describing the variability of adaxial and abaxial leaf reflectance, hence leaf asymmetry, along the crown height gradients of two <span class="hlt">tree</span> <span class="hlt">species</span>. Our findings open a research pathway towards bio-monitoring based on the airborne remote sensing of <span class="hlt">tree</span> canopies and their leaf asymmetric properties. PMID:26057363</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011BGD.....8.5729C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011BGD.....8.5729C"><span id="translatedtitle">Stand age and <span class="hlt">tree</span> <span class="hlt">species</span> affect N2O and CH4 exchange from afforested soils</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Christiansen, J. R.; Gundersen, P.</p> <p>2011-06-01</p> <p>Afforestation of former agricultural land is a means to mitigate anthropogenic greenhouse gas emissions. The objectives of this study were to assess the effect of pedunculate oak and Norway Spruce of different stand ages (13-17 and 40 yr after afforestation, respectively) on N2O and CH4 exchange and identify the environmental factors responsible for the differences in gas exchange between <span class="hlt">tree</span> <span class="hlt">species</span> of different ages. N2O and CH4 fluxes (mean ± SE) were measured for two years at an afforested site. No <span class="hlt">species</span> difference was documented for N2O emission (oak: 4.2 ± 0.7 ?g N2O-N m-2 h-1, spruce: 4.0 ± 1 ?g N2O-N m-2 h-1) but the youngest stands (1.9 ± 0.3 ?g N2O-N m-2 h-1) emitted significantly less N2O than older stands (6.3 ± 1.2 ?g N2O-N m-2 h-1). CH4 exchange did not differ significantly between <span class="hlt">tree</span> <span class="hlt">species</span> (oak: -8.9 ± 0.9, spruce: -7.7 ± 1) or stand age (young: -7.3 ± 0.9 ?g CH4-C m-2 h-1, old: -9.4 ± 1 ?g CH4-C m-2 h-1) but interacted significantly; CH4 oxidation increased with age in oak and decreased with age for Norway Spruce. We conclude that the exchange of N2O and CH4 from the forest soil undergoes a quick and significant transition in the first four decades after planting in both oak and Norway Spruce related to physical changes in the top soil and availability of soil N.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/17169898','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/17169898"><span id="translatedtitle">Photosynthetic responses to understory shade and elevated carbon dioxide concentration in four northern hardwood <span class="hlt">tree</span> <span class="hlt">species</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sefcik, Lesley T; Zak, Donald R; Ellsworth, David S</p> <p>2006-12-01</p> <p>Seedling responses to elevated atmospheric CO(2) concentration ([CO(2)]) and solar irradiance were measured over two growing seasons in shade-tolerant Acer saccharum Marsh. and Fagus grandifolia J.F. Ehrh. and shade-intolerant Prunus serotina, a J.F. Ehrh. and Betula papyrifera Marsh. Seedlings were exposed to a factorial combination of [CO2] (ambient and elevated (658 micromol mol-1)) and understory shade (deep and moderate) in open-top chambers placed in a forest understory. The elevated [CO(2)] treatment increased mean light-saturated net photosynthetic rate by 63% in the shade-tolerant <span class="hlt">species</span> and 67% in the shade-intolerant <span class="hlt">species</span>. However, when measured at the elevated [CO(2)], long-term enhancement of photosynthesis was 10% lower than the instantaneous enhancement seen in ambient-[CO(2)]-grown plants (P < 0.021). Overall, growth light environment affected long-term photosynthetic enhancement by elevated [CO(2)]: as the growth irradiance increased, proportional enhancement due to elevated [CO(2)] decreased from 97% for plants grown in deep shade to 47% for plants grown in moderate shade. Results suggest that in N-limited northern temperate forests, <span class="hlt">trees</span> grown in deep shade may display greater photosynthetic gains from a CO(2)-enriched atmosphere than <span class="hlt">trees</span> growing in more moderate shade, because of greater downregulation in the latter environment. If photosynthetic gains by deep-shade-grown plants in response to elevated [CO(2)] translate into improved growth and survival of shade-intolerant <span class="hlt">species</span>, it could alter the future composition and dynamics of successional forest communities. PMID:17169898</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25737134','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25737134"><span id="translatedtitle">Minimizing the cost of translocation failure with decision-<span class="hlt">tree</span> models that predict <span class="hlt">species</span>' behavioral response in translocation sites.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ebrahimi, Mehregan; Ebrahimie, Esmaeil; Bull, C Michael</p> <p>2015-08-01</p> <p>The high number of failures is one reason why translocation is often not recommended. Considering how behavior changes during translocations may improve translocation success. To derive decision-<span class="hlt">tree</span> models for <span class="hlt">species</span>' translocation, we used data on the short-term responses of an endangered Australian skink in 5 simulated translocations with different release conditions. We used 4 different decision-<span class="hlt">tree</span> algorithms (decision <span class="hlt">tree</span>, decision-<span class="hlt">tree</span> parallel, decision stump, and random forest) with 4 different criteria (gain ratio, information gain, gini index, and accuracy) to investigate how environmental and behavioral parameters may affect the success of a translocation. We assumed behavioral changes that increased dispersal away from a release site would reduce translocation success. The <span class="hlt">trees</span> became more complex when we included all behavioral parameters as attributes, but these <span class="hlt">trees</span> yielded more detailed information about why and how dispersal occurred. According to these complex <span class="hlt">trees</span>, there were positive associations between some behavioral parameters, such as fight and dispersal, that showed there was a higher chance, for example, of dispersal among lizards that fought than among those that did not fight. Decision <span class="hlt">trees</span> based on parameters related to release conditions were easier to understand and could be used by managers to make translocation decisions under different circumstances. PMID:25737134</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/19784850','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/19784850"><span id="translatedtitle"><span class="hlt">Tree</span> <span class="hlt">species</span> effects on ecosystem water-use efficiency in a high-elevation, subalpine forest.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Monson, Russell K; Prater, Margaret R; Hu, Jia; Burns, Sean P; Sparks, Jed P; Sparks, Kimberlee L; Scott-Denton, Laura E</p> <p>2010-02-01</p> <p>Ecosystem water-use efficiency (eWUE; the ratio of net ecosystem productivity to evapotranspiration rate) is a complex landscape-scale parameter controlled by both physical and biological processes occurring in soil and plants. Leaf WUE (lWUE; the ratio of leaf CO(2) assimilation rate to transpiration rate) is controlled at short time scales principally by leaf stomatal dynamics and this control varies among plant <span class="hlt">species</span>. Little is known about how leaf-scale variation in lWUE influences landscape-scale variation in eWUE. We analyzed approximately seven thousand 30-min averaged eddy covariance observations distributed across 9 years in order to assess eWUE in two neighboring forest communities. Mean eWUE was 19% lower for the community in which Engelmann spruce and subalpine fir were dominant, compared to the community in which lodgepole pine was dominant. Of that 19% difference, 8% was attributed to residual bias in the analysis that favored periods with slightly drier winds for the spruce-fir community. In an effort to explain the remaining 11% difference, we assessed patterns in lWUE using C isotope ratios. When we focused on bulk tissue from older needles we detected significant differences in lWUE among <span class="hlt">tree</span> <span class="hlt">species</span> and between upper and lower canopy needles. However, when these differences were scaled to reflect vertical and horizontal leaf area distributions within the two communities, they provided no power to explain differences in eWUE that we observed in the eddy covariance data. When we focused only on bulk needle tissue of current-year needles for 3 of the 9 years, we also observed differences in lWUE among <span class="hlt">species</span> and in needles from upper and lower parts of the canopy. When these differences in lWUE were scaled to reflect leaf area distributions within the two communities, we were able to explain 6.3% of the differences in eWUE in 1 year (2006), but there was no power to explain differences in the other 2 years (2003 and 2007). When we examined sugars extracted from needles at 3 different times during the growing season of 2007, we could explain 3.8-6.0% of the differences in eWUE between the two communities, but the difference in eWUE obtained from the eddy covariance record, and averaged over the growing season for this single year, was 32%. Thus, overall, after accounting for <span class="hlt">species</span> effects on lWUE, we could explain little of the difference in eWUE between the two forest communities observed in the eddy covariance record. It is likely that water and C fluxes from soil, understory plants, and non-needle tissues, account for most of the differences observed in the eddy covariance data. For those cases where we could explain some of the difference in eWUE on the basis of <span class="hlt">species</span> effects, we partitioned the scaled patterns in lWUE into two components: a component that is independent of canopy leaf area distribution, and therefore only dependent on <span class="hlt">species</span>-specific differences in needle physiology; and a component that is independent of <span class="hlt">species</span> differences in needle physiology, and only dependent on <span class="hlt">species</span>-specific influences on canopy leaf area distribution. Only the component that is dependent on <span class="hlt">species</span> influences on canopy leaf area distribution, and independent of inherent <span class="hlt">species</span> differences in needle physiology, had potential to explain differences in eWUE between the two communities. Thus, when <span class="hlt">tree</span> <span class="hlt">species</span> effects are important, canopy structure, rather than <span class="hlt">species</span>-specific needle physiology, has more potential to explain patterns in eWUE. PMID:19784850</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4591120','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4591120"><span id="translatedtitle">De Novo Transcriptome Assembly in Firmiana danxiaensis, a <span class="hlt">Tree</span> <span class="hlt">Species</span> Endemic to the Danxia Landform</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Chen, Su-Fang; Li, Ming-Wan; Jing, Hui-Juan; Zhou, Ren-Chao; Yang, Gui-Li; Wu, Wei; Fan, Qiang; Liao, Wen-Bo</p> <p>2015-01-01</p> <p>Many Firmiana <span class="hlt">species</span> are locally endemic, providing an interesting system for studying adaptation and speciation. Among these <span class="hlt">species</span>, F. danxiaensis is a <span class="hlt">tree</span> <span class="hlt">species</span> endemic to Mount Danxia in Guangdong, China, which is an area known for presenting the Danxia landform. How F. danxiaensis could have adapted to the stressful environment of rocky cliffs covered with barren soils in the Danxia landform is still unknown. In this study, we performed de novo assembly of the transcriptome of F. danxiaensis, obtaining 47,221 unigenes with an N50 value of 987 bp. Homology analysis showed that 32,318 of the unigenes presented hits in the NCBI non-redundant database, and 31,857 exhibited significant matches with the protein database of Theobroma cacao. Gene Ontology (GO) annotation showed that hundreds of unigenes participated in responses to various stresses or nutritional starvation, which may help us to understand the adaptation of F. danxiaensis to Danxia landform. Additionally, we found 263 genes related to responses to Cd, partially explaining the high accumulation of Cd observed in Firmiana <span class="hlt">species</span>. The EuKaryotic Orthologous Groups (KOG) and Kyoto Encyclopedia of Genes and Genomes (KEGG) annotations revealed many genes playing roles in the biosynthesis of secondary metabolites and environmental adaptation, which may also contribute to the survivor and success of Firmiana <span class="hlt">species</span> in extreme environments. Based on the obtained transcriptome, we further identified a Firmiana-specific whole-genome duplication event that occurred approximately 20 Mya, which may have provided raw materials for the diversification of Firmiana <span class="hlt">species</span>. PMID:26427005</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26427005','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26427005"><span id="translatedtitle">De Novo Transcriptome Assembly in Firmiana danxiaensis, a <span class="hlt">Tree</span> <span class="hlt">Species</span> Endemic to the Danxia Landform.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chen, Su-Fang; Li, Ming-Wan; Jing, Hui-Juan; Zhou, Ren-Chao; Yang, Gui-Li; Wu, Wei; Fan, Qiang; Liao, Wen-Bo</p> <p>2015-01-01</p> <p>Many Firmiana <span class="hlt">species</span> are locally endemic, providing an interesting system for studying adaptation and speciation. Among these <span class="hlt">species</span>, F. danxiaensis is a <span class="hlt">tree</span> <span class="hlt">species</span> endemic to Mount Danxia in Guangdong, China, which is an area known for presenting the Danxia landform. How F. danxiaensis could have adapted to the stressful environment of rocky cliffs covered with barren soils in the Danxia landform is still unknown. In this study, we performed de novo assembly of the transcriptome of F. danxiaensis, obtaining 47,221 unigenes with an N50 value of 987 bp. Homology analysis showed that 32,318 of the unigenes presented hits in the NCBI non-redundant database, and 31,857 exhibited significant matches with the protein database of Theobroma cacao. Gene Ontology (GO) annotation showed that hundreds of unigenes participated in responses to various stresses or nutritional starvation, which may help us to understand the adaptation of F. danxiaensis to Danxia landform. Additionally, we found 263 genes related to responses to Cd, partially explaining the high accumulation of Cd observed in Firmiana <span class="hlt">species</span>. The EuKaryotic Orthologous Groups (KOG) and Kyoto Encyclopedia of Genes and Genomes (KEGG) annotations revealed many genes playing roles in the biosynthesis of secondary metabolites and environmental adaptation, which may also contribute to the survivor and success of Firmiana <span class="hlt">species</span> in extreme environments. Based on the obtained transcriptome, we further identified a Firmiana-specific whole-genome duplication event that occurred approximately 20 Mya, which may have provided raw materials for the diversification of Firmiana <span class="hlt">species</span>. PMID:26427005</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AcO....36..530R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AcO....36..530R"><span id="translatedtitle">Canopy gaps decrease microbial densities and disease risk for a shade-intolerant <span class="hlt">tree</span> <span class="hlt">species</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Reinhart, Kurt O.; Royo, Alejandro A.; Kageyama, Stacie A.; Clay, Keith</p> <p>2010-11-01</p> <p>Canopy disturbances such as windthrow events have obvious impacts on forest structure and composition aboveground, but changes in soil microbial communities and the consequences of these changes are less understood. We characterized the densities of a soil-borne pathogenic oomycete ( Pythium) and a common saprotrophic zygomycete ( Mortierella) in nine pairs of forest gaps created by windthrows and adjacent forest understories. We determined the levels of Pythium necessary to cause disease by performing pathogenicity experiments using two Pythium <span class="hlt">species</span>, a range of Pythium densities, and two common <span class="hlt">tree</span> <span class="hlt">species</span> ( Acer rubrum and Prunus serotina) from the study sites. Three years post-disturbance, densities of Mortierella remained suppressed in soil from forest gaps compared to levels in intact forest understories while varying across sites and sampling dates. Pythium were infrequently detected likely because of soil handling effects. Expression of disease symptoms increased with increasing inoculum density for seedlings of P. serotina with each Pythium spp. having a similar effect on this <span class="hlt">species</span>. Conversely, A. rubrum appeared resistant to the two <span class="hlt">species</span> of Pythium. These results suggest that Pythium densities at sites where they were detected are sufficient to cause disease and possibly affect establishment of susceptible <span class="hlt">species</span> like P. serotina. Because early seral environments have lower loads of the saprotrophic Mortierella, pathogen loads may follow a similar pattern, causing susceptible <span class="hlt">species</span> to establish more frequently in those habitats than in late-seral forests. Forest disturbances that alter the disease landscape may provide an additional mechanism for explaining succession of temperate forests in addition to the shade-tolerance paradigm.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AcO....70...10F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AcO....70...10F"><span id="translatedtitle">Interspecific variation in resistance of two host <span class="hlt">tree</span> <span class="hlt">species</span> to spruce budworm</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fuentealba, Alvaro; Bauce, Éric</p> <p>2016-01-01</p> <p>Woody plants regularly sustain biomass losses to herbivorous insects. Consequently, they have developed various resistance mechanisms to cope with insect attack. However, these mechanisms of defense and how they are affected by resource availability are not well understood. The present study aimed at evaluating and comparing the natural resistance (antibiosis and tolerance) of balsam fir (Abies balsamea [L.] Mill.) and white spruce (Picea glauca [Moench) Voss] to spruce budworm, Choristoneura fumiferana (Clem.), and how drainage site quality as a component of resource availability affects the expression of resistance over time (6 years). Our results showed that there are differences in natural resistance between the two <span class="hlt">tree</span> <span class="hlt">species</span> to spruce budworm, but it was not significantly affected by drainage quality. Balsam fir exhibited higher foliar toxic secondary compounds concentrations than white spruce in all drainage classes, resulting in lower male pupal mass, survival and longer male developmental time. This, however, did not prevent spruce budworm from consuming more foliage in balsam fir than in white spruce. This response suggests that either natural levels of measured secondary compounds do not provide sufficient toxicity to reduce defoliation, or spruce budworm has developed compensatory mechanisms, which allow it to utilize food resources more efficiently or minimize the toxic effects that are produced by its host's defensive compounds. Larvae exhibited lower pupal mass and higher mortality in rapidly drained and subhygric sites. Drainage class also affected the amount of foliage destroyed but its impact varied over the years and was probably influenced by climatic variables. These results demonstrate the complexity of predicting the effect of resource availability on <span class="hlt">tree</span> defenses, especially when other confounding environmental factors can affect <span class="hlt">tree</span> resource allocation and utilization.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4571104','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4571104"><span id="translatedtitle">Leaf economics of evergreen and deciduous <span class="hlt">tree</span> <span class="hlt">species</span> along an elevational gradient in a subtropical mountain</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Bai, Kundong; He, Chengxin; Wan, Xianchong; Jiang, Debing</p> <p>2015-01-01</p> <p>The ecophysiological mechanisms underlying the pattern of bimodal elevational distribution of evergreen <span class="hlt">tree</span> <span class="hlt">species</span> remain incompletely understood. Here we used leaf economics spectrum (LES) theory to explain such patterns. We measured leaf economic traits and constructed an LES for the co-existing 19 evergreen and 15 deciduous <span class="hlt">species</span> growing in evergreen broad-leaved forest at low elevation, beech-mixed forest at middle elevation and hemlock-mixed forest at high elevation in Mao'er Mountain, Guangxi, Southern China (25°50′N, 110°49′E). Leaf economic traits presented low but significant phylogenetic signal, suggesting trait similarity between closely related <span class="hlt">species</span>. After considering the effects of phylogenetic history, deciduous <span class="hlt">species</span> in general showed a more acquisitive leaf strategy with a higher ratio of leaf water to dry mass, higher leaf nitrogen and phosphorous contents, higher photosynthetic and respiratory rates and greater photosynthetic nitrogen-use efficiency. In contrast, evergreen <span class="hlt">species</span> exhibited a more conservative leaf strategy with higher leaf mass per area, greater construction costs and longer leaf life span. With the elevation-induced decreases of temperature and soil fertility, both evergreen and deciduous <span class="hlt">species</span> showed greater resource conservation, suggesting the increasing importance of environmental filtering to community assembly with increasing elevation. We found close inter-specific correlations between leaf economic traits, suggesting that there are strong genetic constraints limiting the independent evolution of LES traits. Phylogenetic signal increased with decreasing evolutionary rate across leaf economic traits, suggesting that genetic constraints are important for the process of trait evolution. We found a significantly positive relationship between primary axis <span class="hlt">species</span> score (PASS) distance and phylogenetic distance across <span class="hlt">species</span> pairs and an increasing average PASS distance between evergreen and deciduous <span class="hlt">species</span> with increasing elevation, implying that the frequency of distantly related evergreen and deciduous pairs with wide spreading of leaf economic values increases with increasing elevation. Our findings thus suggest that elevation acts as an environmental filter to both select the locally adapted evergreen and deciduous <span class="hlt">species</span> with sufficient phylogenetic variation and regulate their distribution along the elevational gradient based on their coordinated spreading of phylogenetic divergence and leaf economic variation. PMID:26056133</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26056133','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26056133"><span id="translatedtitle">Leaf economics of evergreen and deciduous <span class="hlt">tree</span> <span class="hlt">species</span> along an elevational gradient in a subtropical mountain.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bai, Kundong; He, Chengxin; Wan, Xianchong; Jiang, Debing</p> <p>2015-01-01</p> <p>The ecophysiological mechanisms underlying the pattern of bimodal elevational distribution of evergreen <span class="hlt">tree</span> <span class="hlt">species</span> remain incompletely understood. Here we used leaf economics spectrum (LES) theory to explain such patterns. We measured leaf economic traits and constructed an LES for the co-existing 19 evergreen and 15 deciduous <span class="hlt">species</span> growing in evergreen broad-leaved forest at low elevation, beech-mixed forest at middle elevation and hemlock-mixed forest at high elevation in Mao'er Mountain, Guangxi, Southern China (25°50'N, 110°49'E). Leaf economic traits presented low but significant phylogenetic signal, suggesting trait similarity between closely related <span class="hlt">species</span>. After considering the effects of phylogenetic history, deciduous <span class="hlt">species</span> in general showed a more acquisitive leaf strategy with a higher ratio of leaf water to dry mass, higher leaf nitrogen and phosphorous contents, higher photosynthetic and respiratory rates and greater photosynthetic nitrogen-use efficiency. In contrast, evergreen <span class="hlt">species</span> exhibited a more conservative leaf strategy with higher leaf mass per area, greater construction costs and longer leaf life span. With the elevation-induced decreases of temperature and soil fertility, both evergreen and deciduous <span class="hlt">species</span> showed greater resource conservation, suggesting the increasing importance of environmental filtering to community assembly with increasing elevation. We found close inter-specific correlations between leaf economic traits, suggesting that there are strong genetic constraints limiting the independent evolution of LES traits. Phylogenetic signal increased with decreasing evolutionary rate across leaf economic traits, suggesting that genetic constraints are important for the process of trait evolution. We found a significantly positive relationship between primary axis <span class="hlt">species</span> score (PASS) distance and phylogenetic distance across <span class="hlt">species</span> pairs and an increasing average PASS distance between evergreen and deciduous <span class="hlt">species</span> with increasing elevation, implying that the frequency of distantly related evergreen and deciduous pairs with wide spreading of leaf economic values increases with increasing elevation. Our findings thus suggest that elevation acts as an environmental filter to both select the locally adapted evergreen and deciduous <span class="hlt">species</span> with sufficient phylogenetic variation and regulate their distribution along the elevational gradient based on their coordinated spreading of phylogenetic divergence and leaf economic variation. PMID:26056133</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3568837','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3568837"><span id="translatedtitle">Multiple evolutionary processes drive the patterns of genetic differentiation in a forest <span class="hlt">tree</span> <span class="hlt">species</span> complex</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Jones, Rebecca C; Steane, Dorothy A; Lavery, Martyn; Vaillancourt, René E; Potts, Brad M</p> <p>2013-01-01</p> <p>Forest <span class="hlt">trees</span> frequently form <span class="hlt">species</span> complexes, complicating taxonomic classification and gene pool management. This is certainly the case in Eucalyptus, and well exemplified by the Eucalyptus globulus complex. This ecologically and economically significant complex comprises four taxa (sspp. bicostata, globulus, maidenii, pseudoglobulus) that are geographically and morphologically distinct, but linked by extensive “intergrade” populations. To resolve their genetic affinities, nine microsatellites were used to genotype 1200 <span class="hlt">trees</span> from throughout the natural range of the complex in Australia, representing 33 morphological core and intergrade populations. There was significant spatial genetic structure (FST = 0.10), but variation was continuous. High genetic diversity in southern ssp. maidenii indicates that this region is the center of origin. Genetic diversity decreases and population differentiation increases with distance from this area, suggesting that drift is a major evolutionary process. Many of the intergrade populations, along with other populations morphologically classified as ssp. pseudoglobulus or ssp. globulus, belong to a “cryptic genetic entity” that is genetically and geographically intermediate between core ssp. bicostata, ssp. maidenii, and ssp. globulus. Geography, rather than morphology, therefore, is the best predictor of overall genetic affinities within the complex and should be used to classify germplasm into management units for conservation and breeding purposes. PMID:23403692</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24583020','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24583020"><span id="translatedtitle"><span class="hlt">Species</span> <span class="hlt">tree</span> estimation of North American chorus frogs (Hylidae: Pseudacris) with parallel tagged amplicon sequencing.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Barrow, Lisa N; Ralicki, Hannah F; Emme, Sandra A; Lemmon, Emily Moriarty</p> <p>2014-06-01</p> <p>The field of phylogenetics is changing rapidly with the application of high-throughput sequencing to non-model organisms. Cost-effective use of this technology for phylogenetic studies, which often include a relatively small portion of the genome but several taxa, requires strategies for genome partitioning and sequencing multiple individuals in parallel. In this study we estimated a multilocus phylogeny for the North American chorus frog genus Pseudacris using anonymous nuclear loci that were recently developed using a reduced representation library approach. We sequenced 27 nuclear loci and three mitochondrial loci for 44 individuals on 1/3 of an Illumina MiSeq run, obtaining 96.5% of the targeted amplicons at less than 20% of the cost of traditional Sanger sequencing. We found heterogeneity among gene <span class="hlt">trees</span>, although four major clades (Trilling Frog, Fat Frog, crucifer, and West Coast) were consistently supported, and we resolved the relationships among these clades for the first time with strong support. We also found discordance between the mitochondrial and nuclear datasets that we attribute to mitochondrial introgression and a possible selective sweep. Bayesian concordance analysis in BUCKy and <span class="hlt">species</span> <span class="hlt">tree</span> analysis in (*)BEAST produced largely similar topologies, although we identify taxa that require additional investigation in order to clarify taxonomic and geographic range boundaries. Overall, we demonstrate the utility of a reduced representation library approach for marker development and parallel tagged sequencing on an Illumina MiSeq for phylogenetic studies of non-model organisms. PMID:24583020</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/18203858','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/18203858"><span id="translatedtitle">The exotic legume <span class="hlt">tree</span> <span class="hlt">species</span> Acacia holosericea alters microbial soil functionalities and the structure of the arbuscular mycorrhizal community.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Remigi, P; Faye, A; Kane, A; Deruaz, M; Thioulouse, J; Cissoko, M; Prin, Y; Galiana, A; Dreyfus, B; Duponnois, R</p> <p>2008-03-01</p> <p>The response of microbial functional diversity as well as its resistance to stress or disturbances caused by the introduction of an exotic <span class="hlt">tree</span> <span class="hlt">species</span>, Acacia holosericea, ectomycorrhized or not with Pisolithus albus, was examined. The results show that this ectomycorrhizal fungus promotes drastically the growth of this fast-growing <span class="hlt">tree</span> <span class="hlt">species</span> in field conditions after 7 years of plantation. Compared to the crop soil surrounding the A. holosericea plantation, this exotic <span class="hlt">tree</span> <span class="hlt">species</span>, associated or not with the ectomycorrhizal symbiont, induced strong modifications in soil microbial functionalities (assessed by measuring the patterns of in situ catabolic potential of microbial communities) and reduced soil resistance in response to increasing stress or disturbance (salinity, temperature, and freeze-thaw and wet-dry cycles). In addition, A. holosericea strongly modified the structure of arbuscular mycorrhizal fungus communities. These results show clearly that exotic plants may be responsible for important changes in soil microbiota affecting the structure and functions of microbial communities. PMID:18203858</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2258654','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2258654"><span id="translatedtitle">The Exotic Legume <span class="hlt">Tree</span> <span class="hlt">Species</span> Acacia holosericea Alters Microbial Soil Functionalities and the Structure of the Arbuscular Mycorrhizal Community▿</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Remigi, P.; Faye, A.; Kane, A.; Deruaz, M.; Thioulouse, J.; Cissoko, M.; Prin, Y.; Galiana, A.; Dreyfus, B.; Duponnois, R.</p> <p>2008-01-01</p> <p>The response of microbial functional diversity as well as its resistance to stress or disturbances caused by the introduction of an exotic <span class="hlt">tree</span> <span class="hlt">species</span>, Acacia holosericea, ectomycorrhized or not with Pisolithus albus, was examined. The results show that this ectomycorrhizal fungus promotes drastically the growth of this fast-growing <span class="hlt">tree</span> <span class="hlt">species</span> in field conditions after 7 years of plantation. Compared to the crop soil surrounding the A. holosericea plantation, this exotic <span class="hlt">tree</span> <span class="hlt">species</span>, associated or not with the ectomycorrhizal symbiont, induced strong modifications in soil microbial functionalities (assessed by measuring the patterns of in situ catabolic potential of microbial communities) and reduced soil resistance in response to increasing stress or disturbance (salinity, temperature, and freeze-thaw and wet-dry cycles). In addition, A. holosericea strongly modified the structure of arbuscular mycorrhizal fungus communities. These results show clearly that exotic plants may be responsible for important changes in soil microbiota affecting the structure and functions of microbial communities. PMID:18203858</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15..577W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15..577W"><span id="translatedtitle">Assessing the contribution of leaf respiration to the carbon economy of tropical rainforest <span class="hlt">tree</span> <span class="hlt">species</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Weerasinghe, Lasantha; Creek, Danielle; Crous, Kristine; Xiang, Shuang; Atkin, Owen</p> <p>2013-04-01</p> <p>Tropical rainforests are among the most important biomes in terms of annual primary productivity; hence, assessing their sensitivity to potential shifts in global and regional temperatures patterns is a necessary step to model future local, regional, and global carbon cycling. However, how the changes in future climate including increased temperatures in short- and long-term basis might impact on the carbon cycling in these tropical rainforests is little studied and remain poorly understood. Given this, this study examined the impact of short and long term changes in temperature on leaf respiration in tropical lowland rainforest located in Far North Queensland, Australia. We quantified how leaf respiration responded to short-term changes in temperature and associated leaf chemical and structural traits in 16 tropical rainforest <span class="hlt">tree</span> <span class="hlt">species</span> at two canopy heights; upper and lower level of the <span class="hlt">tree</span> canopy. Further we measured rates of photosynthesis (A) and leaf respiration (R) both in the dark and light, and relationships between those traits and associated leaf structural and chemical traits. Four of these <span class="hlt">species</span> were subsequently exposed to three different growth temperatures of 25° C, 30° C and 35° C under controlled environment conditions and ability of leaf respiration to acclimate to new temperature regimes was examined. In the field, upper canopy leaves showed higher rates of leaf respiration in darkness and in light than lower canopy leaves at a given set temperature (28° C). Moreover, at any given leaf mass per unit area (LMA), leaf nitrogen [N] and leaf phosphorus [P] value, rates of respiration were higher in upper canopy leaves (compared to lower canopy leaves). The short-term temperature sensitivity of leaf respiration (Q10) was found to be constant around 1.89 at 25° C irrespective of <span class="hlt">species</span> or canopy position. Three out of four <span class="hlt">species</span> subjected to different long-term growth temperatures under control environment conditions exhibited some ability to acclimate; acclimation resulted in homeostasis of leaf respiration measured at the prevailing growth temperatures. In conclusion, our findings highlight the importance of canopy position in determining rates of leaf respiration in this tropical forest, the ability of tropical rainforest <span class="hlt">species</span> to acclimate to changes in temperature in future warmer world, and appropriateness of current climate models using Q10 of 2 to describe temperature sensitivity of leaf respiration for this forest type. Key words: Respiration, carbon cycle, acclimation, tropical rain forests</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5301570','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5301570"><span id="translatedtitle">Comparison of elemental concentrations in the wood of three <span class="hlt">tree</span> <span class="hlt">species</span> growing adjacent to an inactive chromium smelter</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bowers, L.J.; Melhuish, J.H. Jr.</p> <p>1988-03-01</p> <p>Studies of plant tissues have been conducted to determine the degree and spatial extent of point source pollutants. Differences in accumulation rates among <span class="hlt">species</span> have been used to identify plants which are good bioindicators of the status of specific elements in soils. A preponderance of these plant studies have used herbaceous plants or the leaves of woody plants. However, it is the woody <span class="hlt">tree</span> bole which provides long-term storage of elements dispersed by anthropogenic sources of pollution. Recent research indicates that the growth rings of <span class="hlt">trees</span> may provide a temporal history of heavy metal deposition in the environment. Additional information is needed about differences in the elemental concentration found in <span class="hlt">tree</span> rings which may be related to <span class="hlt">species</span> differences if <span class="hlt">tree</span> rings are to be used to monitor metal deposition. Seventeen elements were measured in wood samples taken from three <span class="hlt">tree</span> <span class="hlt">species</span> growing approximately 1.2 km from an inactive chromium smelter. The <span class="hlt">species</span> sampled were: baldcypress (Taxodium distichum L. Rich.), loblolly pine (Pinus taeda L.), and Southern red oak (Quercus falcata L. Michx.).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..12.6286B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..12.6286B"><span id="translatedtitle">Heterogeneity of net precipitation due to <span class="hlt">tree</span> <span class="hlt">species</span> and edge effect in a semi arid cloud forest in Dhofar, Oman</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bawain, Abdullah; Friesen, Jan; Hildebrandt, Anke</p> <p>2010-05-01</p> <p>The cloud forests of the Dhofar mountains in Oman are one of few water limited seasonal cloud forests in the world. Because of the dry conditions (annual rainfall is only 114-252 mm depending on the location), cloud water interception by <span class="hlt">tree</span> canopies (horizontal precipitation) is believed to play a major role for survival of the forest. Being the only green belt in the region, these ecosystems are under considerable pressure from animal feeding on <span class="hlt">tree</span> canopies. In order to protect the Dhofar cloud forest from overgrazing and degradation a number of fenced forest enclosures have been established. Many of the originally established enclosures, however, did not survive and degraded similar to the enclosure surroundings. Our research focuses on the distribution of net precipitation (total water received below the <span class="hlt">tree</span> canopies), as a function of throughfall, stemflow, and, horizontal precipitation within one of the few successful forest enclosures at Tawi Attair. Based on intensive measurements of throughfall, stemflow, fog, and rainfall water our work shows that the heterogeneity of net precipitation is linked to <span class="hlt">tree</span> <span class="hlt">species</span> and <span class="hlt">tree</span> positioning within the enclosure. We demonstrate the contribution of both stemflow and throughfall for two different <span class="hlt">tree</span> <span class="hlt">species</span>, Pithicellobium dulce and Leucaenia leucacephala, as well as for different sectors within the enclosure. For stemflow results show significantly higher amounts for <span class="hlt">trees</span> situated at the enclosure fence as well as significant differences between the two <span class="hlt">tree</span> <span class="hlt">species</span>. For throughfall the results were less pronounced but still show significant differences between different sectors. Generally, stemflow was considerable in all sectors, and is believed to contribute significantly to ground water recharge in this region. The work contributes to the understanding of these water limited seasonal cloud forests and to the future design of successful forest enclosures in the Dhofar mountains.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4586421','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4586421"><span id="translatedtitle">Photoinhibition of photosystem I under high light in the shade-established tropical <span class="hlt">tree</span> <span class="hlt">species</span> Psychotria rubra</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Huang, Wei; Zhang, Shi-Bao; Zhang, Jiao-Lin; Hu, Hong</p> <p>2015-01-01</p> <p>The photosynthetic sensitivity to high light differs among understory plants of shade- and sun- established <span class="hlt">tree</span> <span class="hlt">species</span>. Shade-established <span class="hlt">tree</span> <span class="hlt">species</span> are sensitive to high light but the underlying photosynthetic mechanism has not been fully resolved. In the present study, we examined the responses of photosystem I (PSI) and photosystem II (PSII) to high light in shade leaves of a shade-established <span class="hlt">tree</span> <span class="hlt">species</span> Psychotria rubra and a sun-established <span class="hlt">tree</span> <span class="hlt">species</span> Pometia tomentosa. After exposure to 2000 μmol photons m–2 s–1 for 2 h, the maximum photo-oxidizable P700 (Pm) decreased by 40 and 9% in P. rubra and P. tomentosa, respectively. These results indicate that the shade-established <span class="hlt">species</span> P. rubra is incapable of protecting PSI under high light. Strong photoinhibition of PSII under high light led to large depression of electron transfer from PSII to PSI and then prevented further photodamage to PSI. During the high light treatment of 2000 μmol photons m–2 s–1, PSI photoinhibition in P. rubra was accompanied with high levels of cyclic electron flow (CEF) and P700 oxidation ratio. Therefore, we propose that PSI photoinhibition under high light in P. rubra is dependent on electron transfer from PSII to PSI, and CEF is unlikely to play a major role in photoprotection for PSI in P. rubra. These findings suggest that photoinhibition of PSI is another important mechanism underlying why shade-established <span class="hlt">species</span> cannot survive under high light. PMID:26483816</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EnMan..52..851S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EnMan..52..851S"><span id="translatedtitle">Using Data From Seed-Dispersal Modelling to Manage Invasive <span class="hlt">Tree</span> <span class="hlt">Species</span>: The Example of Fraxinus pennsylvanica Marshall in Europe</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schmiedel, Doreen; Huth, Franka; Wagner, Sven</p> <p>2013-10-01</p> <p>Management strategies to control invasive <span class="hlt">species</span> need information about dispersal distances to predict establishment potential. Fraxinus pennsylvanica is a North American anemochorous <span class="hlt">tree</span> <span class="hlt">species</span> that is invasive in many Central European floodplain forests. To predict seed-dispersal potential, the stochastic model WaldStat was used, which enables different options for directionality (isotropic and anisotropic) to be simulated. In this article, we (1) show empirical results of fructification and seed dispersal for this <span class="hlt">tree</span> <span class="hlt">species</span>. The model predicts approximately 250,000 seeds for one F. pennsylvanica <span class="hlt">tree</span>. These results were used to (2) calculate <span class="hlt">species</span>-specific dispersal distances and effects of wind direction. To consider the influence of wind on dispersal potential of the <span class="hlt">tree</span> <span class="hlt">species</span>, long-distance dispersal (LDD [95th percentile dispersal distance]) was calculated. Mean dispersal distances varied between 47 and 66 m. LDD values modelled along the main wind direction ranged from 60 to 150 m. Seed production, dispersal distance, and direction data were (3) incorporated into theoretical management scenarios for forest ecosystems. Finally (4), we discuss management options and the practical relevance of model scenarios in relation to the accuracy of spatial dispersal predictions. Further analyses should be focused on possible, well-adapted management concepts at stand level that could restrict the potential spread of invasive <span class="hlt">species</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23974901','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23974901"><span id="translatedtitle">Using data from seed-dispersal modelling to manage invasive <span class="hlt">tree</span> <span class="hlt">species</span>: the example of Fraxinus pennsylvanica Marshall in Europe.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Schmiedel, Doreen; Huth, Franka; Wagner, Sven</p> <p>2013-10-01</p> <p>Management strategies to control invasive <span class="hlt">species</span> need information about dispersal distances to predict establishment potential. Fraxinus pennsylvanica is a North American anemochorous <span class="hlt">tree</span> <span class="hlt">species</span> that is invasive in many Central European floodplain forests. To predict seed-dispersal potential, the stochastic model WaldStat was used, which enables different options for directionality (isotropic and anisotropic) to be simulated. In this article, we (1) show empirical results of fructification and seed dispersal for this <span class="hlt">tree</span> <span class="hlt">species</span>. The model predicts approximately 250,000 seeds for one F. pennsylvanica <span class="hlt">tree</span>. These results were used to (2) calculate <span class="hlt">species</span>-specific dispersal distances and effects of wind direction. To consider the influence of wind on dispersal potential of the <span class="hlt">tree</span> <span class="hlt">species</span>, long-distance dispersal (LDD [95th percentile dispersal distance]) was calculated. Mean dispersal distances varied between 47 and 66 m. LDD values modelled along the main wind direction ranged from 60 to 150 m. Seed production, dispersal distance, and direction data were (3) incorporated into theoretical management scenarios for forest ecosystems. Finally (4), we discuss management options and the practical relevance of model scenarios in relation to the accuracy of spatial dispersal predictions. Further analyses should be focused on possible, well-adapted management concepts at stand level that could restrict the potential spread of invasive <span class="hlt">species</span>. PMID:23974901</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2846086','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2846086"><span id="translatedtitle">HIERARCHICAL SPATIAL MODELS FOR PREDICTING <span class="hlt">TREE</span> <span class="hlt">SPECIES</span> ASSEMBLAGES ACROSS LARGE DOMAINS</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Banerjee, Sudipto; McRoberts, Ronald E.</p> <p>2009-01-01</p> <p>Spatially explicit data layers of <span class="hlt">tree</span> <span class="hlt">species</span> assemblages, referred to as forest types or forest type groups, are a key component in large-scale assessments of forest sustainability, biodiversity, timber biomass, carbon sinks and forest health monitoring. This paper explores the utility of coupling georeferenced national forest inventory (NFI) data with readily available and spatially complete environmental predictor variables through spatially-varying multinomial logistic regression models to predict forest type groups across large forested landscapes. These models exploit underlying spatial associations within the NFI plot array and the spatially-varying impact of predictor variables to improve the accuracy of forest type group predictions. The richness of these models incurs onerous computational burdens and we discuss dimension reducing spatial processes that retain the richness in modeling. We illustrate using NFI data from Michigan, USA, where we provide a comprehensive analysis of this large study area and demonstrate improved prediction with associated measures of uncertainty. PMID:20352037</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/18819601','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/18819601"><span id="translatedtitle">An appropriate plot area for analyzing canopy cover and <span class="hlt">tree</span> <span class="hlt">species</span> richness in Zagros forests.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Adeli, Kamran; Fallah, Asghar; Kooch, Yahya</p> <p>2008-01-01</p> <p>In order to make the sampling procedure more efficient and more accurate to study the <span class="hlt">tree</span> <span class="hlt">species</span> richness and canopy cover, the appropriate plot size was calculated in the this study. The sampling was carried out using 48 four-hectare plots, each with 13 sub-plots of different plot sizes and 7 one-hectare plots, each with 7 sub-plots. The result of this study showed that 300 ARE plot size was determined as the best area for 1-5% density class, 125 ARE plots for 5-10% class, 150 ARE for 10-25% class, 100 ARE for 25-50% class and 75 ARE plot size to sample >50% density class, in 95% confidence level. Consequently, using 100 ARE sampling plots is suggested for all density classes in central Zagros forests. PMID:18819601</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25319714','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25319714"><span id="translatedtitle">Effects of tannin source and concentration from <span class="hlt">tree</span> leaves on two <span class="hlt">species</span> of tadpoles.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Earl, Julia E; Semlitsch, Raymond D</p> <p>2015-01-01</p> <p>Vegetation in and around freshwater ecosystems can affect aquatic organisms through the production of secondary compounds, which are retained in leaves after senescence and are biologically active. Tannins can be toxic to tadpoles, but the plant source of tannins and tannin concentration have been confounded in experimental designs in previous studies. To examine the effects of the concentration and source of tannins (<span class="hlt">tree</span> <span class="hlt">species</span>), we examined the effects of 4 factors on tadpole survival, growth, and development: tannin source (red oak [Quercus rubra], white oak [Quercus alba], or sugar maple [Acer saccharum]); tannin concentration (including a control); diet protein level; and tadpole <span class="hlt">species</span> (American toad [Anaxyrus americanus] and spring peepers [Pseudacris crucifer]). Tannin source and concentration affected spring peeper survival, but American toads had uniformly high survival. Spring peepers had a lower survival rate in high tannin concentrations of oak leachate but a high survival rate in both concentrations of sugar maple leachate. These differences in survival did not correspond with changes in dissolved oxygen, and no effect of dietary protein level on tadpole performance was observed. The presence of plant leachate resulted in increased tadpole growth in both <span class="hlt">species</span>, but the mechanism for this finding is unclear. The results of the present study show that tannin concentration and source are important factors for tadpole performance, adding further evidence that plant chemistry can affect aquatic organisms. PMID:25319714</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26466879','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26466879"><span id="translatedtitle">Backbone <span class="hlt">tree</span> for Chaetothyriales with four new <span class="hlt">species</span> of Minimelanolocus from aquatic habitats.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Liu, Xiao-Ying; Udayanga, Dhanushka; Luo, Zong-Long; Chen, Li-Jiao; Zhou, De-Qun; Su, Hong Yan; Hyde, Kevin D</p> <p>2015-11-01</p> <p>We are studying the freshwater lignicolous fungi along a north-south latitudinal gradient in Asia. In this paper, fresh collections of Minimelanolocus from submerged wood in streams in Yunnan Province, China are characterised based on morphology and molecular phylogeny based on three rDNA regions: 18S (SSU), ITS1-5.8S-ITS2 (ITS) and 28S nuclear rDNA (LSU). The phylogenetic analysis of combined LSU and SSU sequence data and a separate analysis of ITS placed the isolates within the family Herpotrichiellaceae, order Chaetothyriales. An updated phylogenetic backbone <span class="hlt">tree</span> for Chaetothyriales is provided with available ex-type and additional isolates. One of the isolates collected was identified as Minimelanolocus obscurus based on morphology and molecular data. Minimelanolocus aquaticus, M. asiaticus, M. curvatus and M. melanicus are described as new <span class="hlt">species</span> considering the interspecific ITS variability and morphology. The phylogenetic placement of Minimelanolocus in Chaetothyriales is novel and provides new sequence data for the genus as a distinct lineage in Chaetothyriales. The conidial characters of all the known <span class="hlt">species</span> in the genus are summarized. Descriptions and illustrations are provided for the five <span class="hlt">species</span> of Minimelanolocus with notes on their taxonomy and phylogeny. PMID:26466879</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/12358465','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/12358465"><span id="translatedtitle">Extractives content in cooperage oak wood during natural seasoning and toasting; influence of <span class="hlt">tree</span> <span class="hlt">species</span>, geographic location, and single-<span class="hlt">tree</span> effects.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Doussot, Franck; De Jéso, Bernard; Quideau, Stéphane; Pardon, Patrick</p> <p>2002-10-01</p> <p>The chemical composition of cooperage oak wood is highly variable, depending upon the <span class="hlt">tree</span> <span class="hlt">species</span> (Quercus robur L. versus Quercus petraea Liebl.), its geographic location, and the single-<span class="hlt">tree</span> effect. In the process of cask-making, natural seasoning and toasting contribute strongly to the modification of the oak wood chemical composition and therefore influence wine cooperaging. HPLC and GC quantification of ellagitannins and volatile compounds such as whiskey-lactones, eugenol, and vanillin over a sample set of 61 pedunculate oaks and 72 sessile oaks originating from six different forests showed that natural drying leads to a decrease of the ellagitannins and total extractives content level and a quasi constant level of the volatile compounds. Toasting (medium type) drastically enhanced the loss of ellagitannins and the gain in volatile compounds. Statistical treatment showed that the <span class="hlt">species</span> effect remained significant throughout the process of drying and toasting, but not the provenance. The poor correlation with ring width of extractives levels measured on fresh timber remained unchanged as did the single-<span class="hlt">tree</span> effect, with high variability found for all chemical parameters. These results provide further evidence that cooperage oak selection should not be based solely on the wood grain or the provenance but rather on a <span class="hlt">species</span>-provenance combination. PMID:12358465</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25772799','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25772799"><span id="translatedtitle">Multi-locus <span class="hlt">tree</span> and <span class="hlt">species</span> <span class="hlt">tree</span> approaches toward resolving a complex clade of downy mildews (Straminipila, Oomycota), including pathogens of beet and spinach.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Choi, Young-Joon; Klosterman, Steven J; Kummer, Volker; Voglmayr, Hermann; Shin, Hyeon-Dong; Thines, Marco</p> <p>2015-05-01</p> <p>Accurate <span class="hlt">species</span> determination of plant pathogens is a prerequisite for their control and quarantine, and further for assessing their potential threat to crops. The family Peronosporaceae (Straminipila; Oomycota) consists of obligate biotrophic pathogens that cause downy mildew disease on angiosperms, including a large number of cultivated plants. In the largest downy mildew genus Peronospora, a phylogenetically complex clade includes the economically important downy mildew pathogens of spinach and beet, as well as the type <span class="hlt">species</span> of the genus Peronospora. To resolve this complex clade at the <span class="hlt">species</span> level and to infer evolutionary relationships among them, we used multi-locus phylogenetic analysis and <span class="hlt">species</span> <span class="hlt">tree</span> estimation. Both approaches discriminated all nine currently accepted <span class="hlt">species</span> and revealed four previously unrecognized lineages, which are specific to a host genus or <span class="hlt">species</span>. This is in line with a narrow <span class="hlt">species</span> concept, i.e. that a downy mildew <span class="hlt">species</span> is associated with only a particular host plant genus or <span class="hlt">species</span>. Instead of applying the dubious name Peronospora farinosa, which has been proposed for formal rejection, our results provide strong evidence that Peronospora schachtii is an independent <span class="hlt">species</span> from lineages on Atriplex and apparently occurs exclusively on Beta vulgaris. The members of the clade investigated, the Peronospora rumicis clade, associate with three different host plant families, Amaranthaceae, Caryophyllaceae, and Polygonaceae, suggesting that they may have speciated following at least two recent inter-family host shifts, rather than contemporary cospeciation with the host plants. PMID:25772799</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22320362','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22320362"><span id="translatedtitle">High field electron paramagnetic resonance spectroscopy under ultrahigh vacuum conditions—A <span class="hlt">multipurpose</span> machine to study paramagnetic <span class="hlt">species</span> on well defined single crystal surfaces</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Rocker, J.; Cornu, D.; Kieseritzky, E.; Hänsel-Ziegler, W.; Freund, H.-J.; Seiler, A.; Bondarchuk, O.</p> <p>2014-08-01</p> <p>A new ultrahigh vacuum (UHV) electron paramagnetic resonance (EPR) spectrometer operating at 94 GHz to investigate paramagnetic centers on single crystal surfaces is described. It is particularly designed to study paramagnetic centers on well-defined model catalysts using epitaxial thin oxide films grown on metal single crystals. The EPR setup is based on a commercial Bruker E600 spectrometer, which is adapted to ultrahigh vacuum conditions using a home made Fabry Perot resonator. The key idea of the resonator is to use the planar metal single crystal required to grow the single crystalline oxide films as one of the mirrors of the resonator. EPR spectroscopy is solely sensitive to paramagnetic <span class="hlt">species</span>, which are typically minority <span class="hlt">species</span> in such a system. Hence, additional experimental characterization tools are required to allow for a comprehensive investigation of the surface. The apparatus includes a preparation chamber hosting equipment, which is required to prepare supported model catalysts. In addition, surface characterization tools such as low energy electron diffraction (LEED)/Auger spectroscopy, temperature programmed desorption (TPD), and infrared reflection absorption spectroscopy (IRAS) are available to characterize the surfaces. A second chamber used to perform EPR spectroscopy at 94 GHz has a room temperature scanning tunneling microscope attached to it, which allows for real space structural characterization. The heart of the UHV adaptation of the EPR experiment is the sealing of the Fabry-Perot resonator against atmosphere. To this end it is possible to use a thin sapphire window glued to the backside of the coupling orifice of the Fabry Perot resonator. With the help of a variety of stabilization measures reducing vibrations as well as thermal drift it is possible to accumulate data for a time span, which is for low temperature measurements only limited by the amount of liquid helium. Test measurements show that the system can detect paramagnetic <span class="hlt">species</span> with a density of approximately 5 × 10{sup 11} spins/cm{sup 2}, which is comparable to the limit obtained for the presently available UHV-EPR spectrometer operating at 10 GHz (X-band). Investigation of electron trapped centers in MgO(001) films shows that the increased resolution offered by the experiments at W-band allows to identify new paramagnetic <span class="hlt">species</span>, that cannot be differentiated with the currently available methodology.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25173280','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25173280"><span id="translatedtitle">High field electron paramagnetic resonance spectroscopy under ultrahigh vacuum conditions--a <span class="hlt">multipurpose</span> machine to study paramagnetic <span class="hlt">species</span> on well defined single crystal surfaces.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rocker, J; Cornu, D; Kieseritzky, E; Seiler, A; Bondarchuk, O; Hänsel-Ziegler, W; Risse, T; Freund, H-J</p> <p>2014-08-01</p> <p>A new ultrahigh vacuum (UHV) electron paramagnetic resonance (EPR) spectrometer operating at 94 GHz to investigate paramagnetic centers on single crystal surfaces is described. It is particularly designed to study paramagnetic centers on well-defined model catalysts using epitaxial thin oxide films grown on metal single crystals. The EPR setup is based on a commercial Bruker E600 spectrometer, which is adapted to ultrahigh vacuum conditions using a home made Fabry Perot resonator. The key idea of the resonator is to use the planar metal single crystal required to grow the single crystalline oxide films as one of the mirrors of the resonator. EPR spectroscopy is solely sensitive to paramagnetic <span class="hlt">species</span>, which are typically minority <span class="hlt">species</span> in such a system. Hence, additional experimental characterization tools are required to allow for a comprehensive investigation of the surface. The apparatus includes a preparation chamber hosting equipment, which is required to prepare supported model catalysts. In addition, surface characterization tools such as low energy electron diffraction (LEED)/Auger spectroscopy, temperature programmed desorption (TPD), and infrared reflection absorption spectroscopy (IRAS) are available to characterize the surfaces. A second chamber used to perform EPR spectroscopy at 94 GHz has a room temperature scanning tunneling microscope attached to it, which allows for real space structural characterization. The heart of the UHV adaptation of the EPR experiment is the sealing of the Fabry-Perot resonator against atmosphere. To this end it is possible to use a thin sapphire window glued to the backside of the coupling orifice of the Fabry Perot resonator. With the help of a variety of stabilization measures reducing vibrations as well as thermal drift it is possible to accumulate data for a time span, which is for low temperature measurements only limited by the amount of liquid helium. Test measurements show that the system can detect paramagnetic <span class="hlt">species</span> with a density of approximately 5 × 10(11) spins/cm(2), which is comparable to the limit obtained for the presently available UHV-EPR spectrometer operating at 10 GHz (X-band). Investigation of electron trapped centers in MgO(001) films shows that the increased resolution offered by the experiments at W-band allows to identify new paramagnetic <span class="hlt">species</span>, that cannot be differentiated with the currently available methodology. PMID:25173280</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014RScI...85h3903R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014RScI...85h3903R"><span id="translatedtitle">High field electron paramagnetic resonance spectroscopy under ultrahigh vacuum conditions—A <span class="hlt">multipurpose</span> machine to study paramagnetic <span class="hlt">species</span> on well defined single crystal surfaces</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rocker, J.; Cornu, D.; Kieseritzky, E.; Seiler, A.; Bondarchuk, O.; Hänsel-Ziegler, W.; Risse, T.; Freund, H.-J.</p> <p>2014-08-01</p> <p>A new ultrahigh vacuum (UHV) electron paramagnetic resonance (EPR) spectrometer operating at 94 GHz to investigate paramagnetic centers on single crystal surfaces is described. It is particularly designed to study paramagnetic centers on well-defined model catalysts using epitaxial thin oxide films grown on metal single crystals. The EPR setup is based on