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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.

    PubMed

    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. PMID:22555388

  2. 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.

  3. 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.

  4. In vitro propagation, micromorphological studies and ex vitro rooting of cannon ball tree (Couroupita guianensis aubl.): a multipurpose threatened species.

    PubMed

    Shekhawat, Mahipal S; Manokari, M

    2016-01-01

    In vitro propagation methods using seeds and nodal segments of a 21-year old Couroupita guianensis - a medicinally important but threatened tree have been developed. Hundred percent of the seeds germinated on half strength Murashige and Skoog (MS) medium with 2.0 mg l(-1) indole-3 butyric acid (IBA). Nodal segments were found most suitable for the establishment of cultures. About 90 % explants responded and 4.1 ± 0.23 shoots per node were induced after five weeks of inoculation on MS medium +4.0 mg l(-1) 6-benzylaminopurine (BAP). Further shoot multiplication was achieved by repeated transfer of mother explants and subculturing of in vitro produced shoots on fresh medium. Maximum number (8.2 ± 0.17) of shoots were regenerated on MS medium with 1.0 mg l(-1) each of BAP and Kinetin (Kin) + 0.5 mg l(-1) α-naphthalene acetic acid (NAA) with additives (50 mg l(-1) of ascorbic acid and 25 mg l(-1) each of adenine sulphate, L-arginine and citric acid). The multiplied shoots rooted (4.3 ± 0.26 roots/shoot) on half strength MS medium with 2.5 mg l(-1) IBA. All the shoots were rooted ex vitro when pulse treated with 400 mg l(-1) of IBA for five min with an average of 7.3 ± 0.23 roots per shoot. Nearly 86 % of these plantlets were acclimatized within 7-8 weeks and successfully transferred in the field. Biologically significant developmental changes were observed during acclimation particularly in leaf micromorphology in terms of changes in stomata, veins and vein-islets, and trichomes. This study helps in understanding the response by the plants towards outer environmental conditions during acclimatization. This is the first report on micropropagation of C. guianensis, which could be used for the large-scale multiplication, restoration and conservation of germplasm of this threatened and medicinally important tree. PMID:27186027

  5. Assessing the extent of "conflict of use" in multipurpose tropical forest trees: a regional view.

    PubMed

    Herrero-Jáuregui, Cristina; Guariguata, Manuel R; Cárdenas, Dairon; Vilanova, Emilio; Robles, Marco; Licona, Juan Carlos; Nalvarte, Walter

    2013-11-30

    In the context of multiple forest management, multipurpose tree species which provide both timber and non-timber forest products (NTFP), present particular challenges as the potential of conflicting use for either product may be high. One key aspect is that the magnitude of conflict of use can be location specific, thus adding complexity to policy development. This paper focuses on the extent to which the potential for conflict of use in multipurpose tree species varies across the Amazonian lowland forests shared by Peru, Bolivia, Colombia, Ecuador and Venezuela, emphasizing the economic dimension of conflict. Based on a review of the current normative and regulatory aspects of timber and NTFP extraction in the five countries, the paper also briefly discusses the opportunities and constraints for harmonization of timber and NTFP management of multipurpose species across the region. It was found that about half of the 336 timber species reviewed across the five countries also have non-timber uses. Eleven timber species are multipurpose in all five countries: Calophyllum brasiliense, Cedrela odorata, Ceiba pentandra, Clarisia racemosa, Ficus insipida, Jacaranda copaia, Schefflera morototoni, Simarouba amara and Terminalia amazonia. Seven other multipurpose species occurred only in either Venezuela (Tabebuia impetiginosa, Spondias mombin, Pentaclethra macroloba, Copaifera officinalis, Chlorophora tinctoria, Carapa guianensis) or Ecuador (Tabebuia chrysantha). Four multipurpose tree species presented the highest potential of conflict of use across the region: Dipteryx odorata, Tabebuia serratifolia, Hymenaea courbaril and Myroxylon balsamum yet these were not evenly distributed across all five countries. None of the five studied countries have specific legislation to promote sustainable use of any of the multipurpose species reported here and thus mitigate potential conflict of use; nor documented management options for integration or else segregation of both their

  6. 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

  7. 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

  8. Reproductive traits affect the rescue of valuable and endangered multipurpose tropical trees.

    PubMed

    Sinébou, Viviane; Quinet, Muriel; Ahohuendo, Bonaventure C; Jacquemart, Anne-Laure

    2016-01-01

    Conservation strategies are urgently needed in Tropical areas for widely used tree species. Increasing numbers of species are threatened by overexploitation and their recovery might be poor due to low reproductive success and poor regeneration rates. One of the first steps in developing any conservation policy should be an assessment of the reproductive biology of species that are threatened by overexploitation. This work aimed to study the flowering biology, pollination and breeding system of V. doniana, a multipurpose threatened African tree, as one step in assessing the development of successful conservation strategies. To this end, we studied (1) traits directly involved in pollinator attraction like flowering phenology, flower numbers and morphology, and floral rewards; (2) abundance, diversity and efficiency of flower visitors; (3) breeding system, through controlled hand-pollination experiments involving exclusion of pollinators and pollen from different sources; and (4) optimal conditions for seed germination. The flowering phenology was asynchronous among inflorescences, trees and sites. The flowers produced a large quantity of pollen and nectar with high sugar content. Flowers attracted diverse and abundant visitors, counting both insects and birds, and efficient pollinators included several Hymenoptera species. We detected no spontaneous self-pollination, indicating a total dependence on pollen vectors. Vitex doniana is self-compatible and no inbreeding depression occurred in the first developmental stages. After extraction of the seed from the fruit, seed germination did not require any particular conditions or pre-treatments and the seeds showed high germination rates. These pollination and breeding characteristics as well as germination potential offer the required conditions to develop successful conservation strategies. Protection, cultivation and integration in agroforestry systems are required to improve the regeneration of the tree. PMID:27354660

  9. Reproductive traits affect the rescue of valuable and endangered multipurpose tropical trees

    PubMed Central

    Sinébou, Viviane; Quinet, Muriel; Ahohuendo, Bonaventure C.; Jacquemart, Anne-Laure

    2016-01-01

    Conservation strategies are urgently needed in Tropical areas for widely used tree species. Increasing numbers of species are threatened by overexploitation and their recovery might be poor due to low reproductive success and poor regeneration rates. One of the first steps in developing any conservation policy should be an assessment of the reproductive biology of species that are threatened by overexploitation. This work aimed to study the flowering biology, pollination and breeding system of V. doniana, a multipurpose threatened African tree, as one step in assessing the development of successful conservation strategies. To this end, we studied (1) traits directly involved in pollinator attraction like flowering phenology, flower numbers and morphology, and floral rewards; (2) abundance, diversity and efficiency of flower visitors; (3) breeding system, through controlled hand-pollination experiments involving exclusion of pollinators and pollen from different sources; and (4) optimal conditions for seed germination. The flowering phenology was asynchronous among inflorescences, trees and sites. The flowers produced a large quantity of pollen and nectar with high sugar content. Flowers attracted diverse and abundant visitors, counting both insects and birds, and efficient pollinators included several Hymenoptera species. We detected no spontaneous self-pollination, indicating a total dependence on pollen vectors. Vitex doniana is self-compatible and no inbreeding depression occurred in the first developmental stages. After extraction of the seed from the fruit, seed germination did not require any particular conditions or pre-treatments and the seeds showed high germination rates. These pollination and breeding characteristics as well as germination potential offer the required conditions to develop successful conservation strategies. Protection, cultivation and integration in agroforestry systems are required to improve the regeneration of the tree. PMID:27354660

  10. 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 ...

  11. Transcriptomic Analysis of Multipurpose Timber Yielding Tree Neolamarckia cadamba during Xylogenesis Using RNA-Seq

    PubMed Central

    Zhao, Xianhai; Que, Qingmin; Li, Pei; Huang, Hao; Deng, Xiaomei; Singh, Sunil Kumar; Wu, Ai-Min; Chen, Xiaoyang

    2016-01-01

    Neolamarckia cadamba is a fast-growing tropical hardwood tree that is used extensively for plywood and pulp production, light furniture fabrication, building materials, and as a raw material for the preparation of certain indigenous medicines. Lack of genomic resources hampers progress in the molecular breeding and genetic improvement of this multipurpose tree species. In this study, transcriptome profiling of differentiating stems was performed to understand N. cadamba xylogenesis. The N. cadamba transcriptome was sequenced using Illumina paired-end sequencing technology. This generated 42.49 G of raw data that was then de novo assembled into 55,432 UniGenes with a mean length of 803.2bp. Approximately 47.8% of the UniGenes (26,487) were annotated against publically available protein databases, among which 21,699 and 7,754 UniGenes were assigned to Gene Ontology categories (GO) and Clusters of Orthologous Groups (COG), respectively. 5,589 UniGenes could be mapped onto 116 pathways using the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway database. Among 6,202 UniGenes exhibiting differential expression during xylogenesis, 1,634 showed significantly higher levels of expression in the basal and middle stem segments compared to the apical stem segment. These genes included NAC and MYB transcription factors related to secondary cell wall biosynthesis, genes related to most metabolic steps of lignin biosynthesis, and CesA genes involved in cellulose biosynthesis. This study lays the foundation for further screening of key genes associated with xylogenesis in N. cadamba as well as enhancing our understanding of the mechanism of xylogenesis in fast-growing trees. PMID:27438485

  12. Transcriptomic Analysis of Multipurpose Timber Yielding Tree Neolamarckia cadamba during Xylogenesis Using RNA-Seq.

    PubMed

    Ouyang, Kunxi; Li, Juncheng; Zhao, Xianhai; Que, Qingmin; Li, Pei; Huang, Hao; Deng, Xiaomei; Singh, Sunil Kumar; Wu, Ai-Min; Chen, Xiaoyang

    2016-01-01

    Neolamarckia cadamba is a fast-growing tropical hardwood tree that is used extensively for plywood and pulp production, light furniture fabrication, building materials, and as a raw material for the preparation of certain indigenous medicines. Lack of genomic resources hampers progress in the molecular breeding and genetic improvement of this multipurpose tree species. In this study, transcriptome profiling of differentiating stems was performed to understand N. cadamba xylogenesis. The N. cadamba transcriptome was sequenced using Illumina paired-end sequencing technology. This generated 42.49 G of raw data that was then de novo assembled into 55,432 UniGenes with a mean length of 803.2bp. Approximately 47.8% of the UniGenes (26,487) were annotated against publically available protein databases, among which 21,699 and 7,754 UniGenes were assigned to Gene Ontology categories (GO) and Clusters of Orthologous Groups (COG), respectively. 5,589 UniGenes could be mapped onto 116 pathways using the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway database. Among 6,202 UniGenes exhibiting differential expression during xylogenesis, 1,634 showed significantly higher levels of expression in the basal and middle stem segments compared to the apical stem segment. These genes included NAC and MYB transcription factors related to secondary cell wall biosynthesis, genes related to most metabolic steps of lignin biosynthesis, and CesA genes involved in cellulose biosynthesis. This study lays the foundation for further screening of key genes associated with xylogenesis in N. cadamba as well as enhancing our understanding of the mechanism of xylogenesis in fast-growing trees. PMID:27438485

  13. STRAW: Species TRee Analysis Web server

    PubMed Central

    Shaw, Timothy I.; Ruan, Zheng; Glenn, Travis C.; Liu, Liang

    2013-01-01

    The coalescent methods for species tree reconstruction are increasingly popular because they can accommodate coalescence and multilocus data sets. Herein, we present STRAW, a web server that offers workflows for reconstruction of phylogenies of species using three species tree methods—MP-EST, STAR and NJst. The input data are a collection of rooted gene trees (for STAR and MP-EST methods) or unrooted gene trees (for NJst). The output includes the estimated species tree, modified Robinson-Foulds distances between gene trees and the estimated species tree and visualization of trees to compare gene trees with the estimated species tree. The web sever is available at http://bioinformatics.publichealth.uga.edu/SpeciesTreeAnalysis/. PMID:23661681

  14. 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

  15. 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 (λn)n ≥ 0, in which tree λn 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

  16. Exact solutions for species tree inference from discordant gene trees.

    PubMed

    Chang, Wen-Chieh; Górecki, Paweł; Eulenstein, Oliver

    2013-10-01

    Phylogenetic analysis has to overcome the grant challenge of inferring accurate species trees from evolutionary histories of gene families (gene trees) that are discordant with the species tree along whose branches they have evolved. Two well studied approaches to cope with this challenge are to solve either biologically informed gene tree parsimony (GTP) problems under gene duplication, gene loss, and deep coalescence, or the classic RF supertree problem that does not rely on any biological model. Despite the potential of these problems to infer credible species trees, they are NP-hard. Therefore, these problems are addressed by heuristics that typically lack any provable accuracy and precision. We describe fast dynamic programming algorithms that solve the GTP problems and the RF supertree problem exactly, and demonstrate that our algorithms can solve instances with data sets consisting of as many as 22 taxa. Extensions of our algorithms can also report the number of all optimal species trees, as well as the trees themselves. To better asses the quality of the resulting species trees that best fit the given gene trees, we also compute the worst case species trees, their numbers, and optimization score for each of the computational problems. Finally, we demonstrate the performance of our exact algorithms using empirical and simulated data sets, and analyze the quality of heuristic solutions for the studied problems by contrasting them with our exact solutions. PMID:24131054

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

    NASA Astrophysics Data System (ADS)

    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.

    2013-06-01

    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 2-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.

  18. 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

  19. Multipurpose dissociation cell for enhanced ETD of intact protein species.

    PubMed

    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

    2013-06-01

    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 2-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

  20. Reconciliation with Non-Binary Species Trees

    PubMed Central

    Vernot, Benjamin; Stolzer, Maureen; Goldman, Aiton

    2008-01-01

    Abstract Reconciliation extracts information from the topological incongruence between gene and species trees to infer duplications and losses in the history of a gene family. The inferred duplication-loss histories provide valuable information for a broad range of biological applications, including ortholog identification, estimating gene duplication times, and rooting and correcting gene trees. While reconciliation for binary trees is a tractable and well studied problem, there are no algorithms for reconciliation with non-binary species trees. Yet a striking proportion of species trees are non-binary. For example, 64% of branch points in the NCBI taxonomy have three or more children. When applied to non-binary species trees, current algorithms overestimate the number of duplications because they cannot distinguish between duplication and incomplete lineage sorting. We present the first algorithms for reconciling binary gene trees with non-binary species trees under a duplication-loss parsimony model. Our algorithms utilize an efficient mapping from gene to species trees to infer the minimum number of duplications in O(|VG| · (kS + hS)) time, where |VG| is the number of nodes in the gene tree, hS is the height of the species tree and kS is the size of its largest polytomy. We present a dynamic programming algorithm which also minimizes the total number of losses. Although this algorithm is exponential in the size of the largest polytomy, it performs well in practice for polytomies with outdegree of 12 or less. We also present a heuristic which estimates the minimal number of losses in polynomial time. In empirical tests, this algorithm finds an optimal loss history 99% of the time. Our algorithms have been implemented in Notung, a robust, production quality, tree-fitting program, which provides a graphical user interface for exploratory analysis and also supports automated, high-throughput analysis of large data sets. PMID:18808330

  1. 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, Szöllősi 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

  2. Reconciliation of Gene and Species Trees

    PubMed Central

    Rusin, L. Y.; Lyubetskaya, E. V.; Gorbunov, K. Y.; Lyubetsky, V. A.

    2014-01-01

    The first part of the paper briefly overviews the problem of gene and species trees reconciliation with the focus on defining and algorithmic construction of the evolutionary scenario. Basic ideas are discussed for the aspects of mapping definitions, costs of the mapping and evolutionary scenario, imposing time scales on a scenario, incorporating horizontal gene transfers, binarization and reconciliation of polytomous trees, and construction of species trees and scenarios. The review does not intend to cover the vast diversity of literature published on these subjects. Instead, the authors strived to overview the problem of the evolutionary scenario as a central concept in many areas of evolutionary research. The second part provides detailed mathematical proofs for the solutions of two problems: (i) inferring a gene evolution along a species tree accounting for various types of evolutionary events and (ii) trees reconciliation into a single species tree when only gene duplications and losses are allowed. All proposed algorithms have a cubic time complexity and are mathematically proved to find exact solutions. Solving algorithms for problem (ii) can be naturally extended to incorporate horizontal transfers, other evolutionary events, and time scales on the species tree. PMID:24800245

  3. 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

  4. 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

  5. Region effects influence local tree species diversity

    PubMed Central

    Ricklefs, Robert E.; He, Fangliang

    2016-01-01

    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

  6. 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

  7. Profiling glucosinolates and phenolics in vegetative and reproductive tissues of the multi-purpose trees Moringa oleifera L. (horseradish tree) and Moringa stenopetala L.

    PubMed

    Bennett, Richard N; Mellon, Fred A; Foidl, Nikolaus; Pratt, John H; Dupont, M Susan; Perkins, Lionel; Kroon, Paul A

    2003-06-01

    Moringa species are important multi-purpose tropical crops, as human foods and for medicine and oil production. There has been no previous comprehensive analysis of the secondary metabolites in Moringa species. Tissues of M. oleifera from a wide variety of sources and M. stenopetala from a single source were analyzed for glucosinolates and phenolics (flavonoids, anthocyanins, proanthocyanidins, and cinnamates). M. oleifera and M. stenopetala seeds only contained 4-(alpha-l-rhamnopyranosyloxy)-benzylglucosinolate at high concentrations. Roots of M. oleifera and M. stenopetala had high concentrations of both 4-(alpha-l-rhamnopyranosyloxy)-benzylglucosinolate and benzyl glucosinolate. Leaves from both species contained 4-(alpha-l-rhamnopyranosyloxy)-benzylglucosinolate and three monoacetyl isomers of this glucosinolate. Only 4-(alpha-l-rhamnopyranosyloxy)-benzylglucosinolate was detected in M. oleifera bark tissue. M. oleifera leaves contained quercetin-3-O-glucoside and quercetin-3-O-(6' '-malonyl-glucoside), and lower amounts of kaempferol-3-O-glucoside and kaempferol-3-O-(6' '-malonyl-glucoside). M. oleifera leaves also contained 3-caffeoylquinic acid and 5-caffeoylquinic acid. Leaves of M. stenopetala contained quercetin 3-O-rhamnoglucoside (rutin) and 5-caffeoylquinic acid. Neither proanthocyanidins nor anthocyanins were detected in any of the tissues of either species. PMID:12769522

  8. 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

  9. 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

  10. The probability of topological concordance of gene trees and species trees.

    PubMed

    Rosenberg, Noah A

    2002-03-01

    The concordance of gene trees and species trees is reconsidered in detail, allowing for samples of arbitrary size to be taken from the species. A sense of concordance for gene tree and species tree topologies is clarified, such that if the "collapsed gene tree" produced by a gene tree has the same topology as the species tree, the gene tree is said to be topologically concordant with the species tree. The term speciodendric is introduced to refer to genes whose trees are topologically concordant with species trees. For a given three-species topology, probabilities of each of the three possible collapsed gene tree topologies are given, as are probabilities of monophyletic concordance and concordance in the sense of N. Takahata (1989), Genetics 122, 957-966. Increasing the sample size is found to increase the probability of topological concordance, but a limit exists on how much the topological concordance probability can be increased. Suggested sample sizes beyond which this probability can be increased only minimally are given. The results are discussed in terms of implications for molecular studies of phylogenetics and speciation. PMID:11969392

  11. Exploring tree species signature using waveform LiDAR data

    NASA Astrophysics Data System (ADS)

    Zhou, T.; Popescu, S. C.; Krause, K.

    2015-12-01

    Successful classification of tree species with waveform LiDAR data would be of considerable value to estimate the biomass stocks and changes in forests. Current approaches emphasize converting the full waveform data into discrete points to get larger amount of parameters and identify tree species using several discrete-points variables. However, ignores intensity values and waveform shapes which convey important structural characteristics. The overall goal of this study was to employ the intensity and waveform shape of individual tree as the waveform signature to detect tree species. The data was acquired by the National Ecological Observatory Network (NEON) within 250*250 m study area located in San Joaquin Experimental Range. Specific objectives were to: (1) segment individual trees using the smoothed canopy height model (CHM) derived from discrete LiDAR points; (2) link waveform LiDAR with above individual tree boundaries to derive sample signatures of three tree species and use these signatures to discriminate tree species in a large area; and (3) compare tree species detection results from discrete LiDAR data and waveform LiDAR data. An overall accuracy of the segmented individual tree of more than 80% was obtained. The preliminary results show that compared with the discrete LiDAR data, the waveform LiDAR signature has a higher potential for accurate tree species classification.

  12. 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

  13. 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

  14. Tree species richness affecting fine root biomass in European forests

    NASA Astrophysics Data System (ADS)

    Finér, Leena; Domisch, Timo; Vesterdal, Lars; Dawud, Seid M.; Raulund-Rasmussen, Karsten

    2016-04-01

    Fine roots are an important factor in the forest carbon cycle, contributing significantly to below-ground biomass and soil carbon storage. Therefore it is essential to understand the role of the forest structure, indicated by tree species diversity in controlling below-ground biomass and managing the carbon pools of forest soils. We studied how tree species richness would affect fine root biomass and its distribution in the soil profile and biomass above- and below-ground allocation patterns of different tree species. Our main hypothesis was that increasing tree species richness would lead to below-ground niche differentiation and more efficient soil exploitation by the roots, resulting in a higher fine root biomass in the soil. We sampled fine roots of trees and understorey vegetation in six European forest types in Finland, Poland, Germany, Romania, Italy and Spain, representing boreal, temperate and Mediterranean forests, established within the FunDivEUROPE project for studying the effects of tree species diversity on forest functioning. After determining fine root biomasses, we identified the percentages of different tree species in the fine root samples using the near infrared reflectance spectroscopy (NIRS) method. Opposite to our hypothesis we did not find any general positive relationship between tree species richness and fine root biomass. A weak positive response found in Italy and Spain seemed to be related to dry environmental conditions during Mediterranean summers. At the Polish site where we could sample deeper soil layers (down to 40 cm), we found more tree fine roots in the deeper layers under species-rich forests, as compared to the monocultures, indicating the ability of trees to explore more resources and to increase soil carbon stocks. Tree species richness did not affect biomass allocation patterns between above- and below-ground parts of the trees.

  15. Inferring optimal species trees under gene duplication and loss.

    PubMed

    Bayzid, M S; Mirarab, S; Warnow, T

    2013-01-01

    Species tree estimation from multiple markers is complicated by the fact that gene trees can differ from each other (and from the true species tree) due to several biological processes, one of which is gene duplication and loss. Local search heuristics for two NP-hard optimization problems - minimize gene duplications (MGD) and minimize gene duplications and losses (MGDL) - are popular techniques for estimating species trees in the presence of gene duplication and loss. In this paper, we present an alternative approach to solving MGD and MGDL from rooted gene trees. First, we characterize each tree in terms of its "subtree-bipartitions" (a concept we introduce). Then we show that the MGD species tree is defined by a maximum weight clique in a vertex-weighted graph that can be computed from the subtree-bipartitions of the input gene trees, and the MGDL species tree is defined by a minimum weight clique in a similarly constructed graph. We also show that these optimal cliques can be found in polynomial time in the number of vertices of the graph using a dynamic programming algorithm (similar to that of Hallett and Lagergren(1)), because of the special structure of the graphs. Finally, we show that a constrained version of these problems, where the subtree-bipartitions of the species tree are drawn from the subtree-bipartitions of the input gene trees, can be solved in time that is polynomial in the number of gene trees and taxa. We have implemented our dynamic programming algorithm in a publicly available software tool, available at http://www.cs.utexas.edu/users/phylo/software/dynadup/. PMID:23424130

  16. Inconsistency of Species Tree Methods under Gene Flow.

    PubMed

    Solís-Lemus, Claudia; Yang, Mengyao; Ané, Cécile

    2016-09-01

    Coalescent-based methods are now broadly used to infer evolutionary relationships between groups of organisms under the assumption that incomplete lineage sorting (ILS) is the only source of gene tree discordance. Many of these methods are known to consistently estimate the species tree when all their assumptions are met. Nonetheless, little work has been done to test the robustness of such methods to violations of their assumptions. Here, we study the performance of two of the most efficient coalescent-based methods, ASTRAL and NJst, in the presence of gene flow. Gene flow violates the assumption that ILS is the sole source of gene tree conflict. We find anomalous gene trees on three-taxon rooted trees and on four-taxon unrooted trees. These anomalous trees do not exist under ILS only, but appear because of gene flow. Our simulations show that species tree methods (and concatenation) may reconstruct the wrong evolutionary history, even from a very large number of well-reconstructed gene trees. In other words, species tree methods can be inconsistent under gene flow. Our results underline the need for methods like PhyloNet, to account simultaneously for ILS and gene flow in a unified framework. Although much slower, PhyloNet had better accuracy and remained consistent at high levels of gene flow. PMID:27151419

  17. 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

  18. 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.

  19. 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 κ = 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

  20. Soil nutrients influence spatial distributions of tropical tree species

    PubMed Central

    John, Robert; Dalling, James W.; Harms, Kyle E.; Yavitt, Joseph B.; Stallard, Robert F.; Mirabello, Matthew; Hubbell, Stephen P.; Valencia, Renato; Navarrete, Hugo; Vallejo, Martha; Foster, Robin 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 (<104 km2) and regional scales. At local scales (<1 km2), however, habitat factors and species distributions show comparable spatial aggregation, making it difficult to disentangle the importance of niche and dispersal processes. In this article, we test soil resource-based niche assembly at a local scale, using species and soil nutrient distributions obtained at high spatial resolution in three diverse neotropical forest plots in Colombia (La Planada), Ecuador (Yasuni), and Panama (Barro Colorado Island). Using spatial distribution maps of >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. PMID:17215353

  1. Tree Species Classification By Multiseasonal High Resolution Satellite Data

    NASA Astrophysics Data System (ADS)

    Elatawneh, Alata; Wallner, Adelheid; Straub, Christoph; Schneider, Thomas; Knoke, Thomas

    2013-12-01

    Accurate forest tree species mapping is a fundamental issue for sustainable forest management and planning. Forest tree species mapping with the means of remote sensing data is still a topic to be investigated. The Bavaria state institute of forestry is investigating the potential of using digital aerial images for forest management purposes. However, using aerial images is still cost- and time-consuming, in addition to their acquisition restrictions. The new space-born sensor generations such as, RapidEye, with a very high temporal resolution, offering multiseasonal data have the potential to improve the forest tree species mapping. In this study, we investigated the potential of multiseasonal RapidEye data for mapping tree species in a Mid European forest in Southern Germany. The RapidEye data of level A3 were collected on ten different dates in the years 2009, 2010 and 2011. For data analysis, a model was developed, which combines the Spectral Angle Mapper technique with a 10-fold- cross-validation. The analysis succeeded to differentiate four tree species; Norway spruce (Picea abies L.), Silver Fir (Abies alba Mill.), European beech (Fagus sylvatica) and Maple (Acer pseudoplatanus). The model success was evaluated using digital aerial images acquired in the year 2009 and inventory point records from 2008/09 inventory. Model results of the multiseasonal RapidEye data analysis achieved an overall accuracy of 76%. However, the success of the model was evaluated only for all the identified species and not for the individual.

  2. 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.

  3. Widespread Discordance of Gene Trees with Species Tree in Drosophila: Evidence for Incomplete Lineage Sorting

    PubMed Central

    Pollard, Daniel A; Eisen, Michael B

    2006-01-01

    The phylogenetic relationship of the now fully sequenced species Drosophila erecta and D. yakuba with respect to the D. melanogaster species complex has been a subject of controversy. All three possible groupings of the species have been reported in the past, though recent multi-gene studies suggest that D. erecta and D. yakuba are sister species. Using the whole genomes of each of these species as well as the four other fully sequenced species in the subgenus Sophophora, we set out to investigate the placement of D. erecta and D. yakuba in the D. melanogaster species group and to understand the cause of the past incongruence. Though we find that the phylogeny grouping D. erecta and D. yakuba together is the best supported, we also find widespread incongruence in nucleotide and amino acid substitutions, insertions and deletions, and gene trees. The time inferred to span the two key speciation events is short enough that under the coalescent model, the incongruence could be the result of incomplete lineage sorting. Consistent with the lineage-sorting hypothesis, substitutions supporting the same tree were spatially clustered. Support for the different trees was found to be linked to recombination such that adjacent genes support the same tree most often in regions of low recombination and substitutions supporting the same tree are most enriched roughly on the same scale as linkage disequilibrium, also consistent with lineage sorting. The incongruence was found to be statistically significant and robust to model and species choice. No systematic biases were found. We conclude that phylogenetic incongruence in the D. melanogaster species complex is the result, at least in part, of incomplete lineage sorting. Incomplete lineage sorting will likely cause phylogenetic incongruence in many comparative genomics datasets. Methods to infer the correct species tree, the history of every base in the genome, and comparative methods that control for and/or utilize this

  4. 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…

  5. Geographical Range and Local Abundance of Tree Species in China

    PubMed Central

    Ren, Haibao; Condit, Richard; Chen, Bin; Mi, Xiangcheng; Cao, Min; Ye, Wanhui; Hao, Zhanqing; Ma, Keping

    2013-01-01

    Most studies on the geographical distribution of species have utilized a few well-known taxa in Europe and North America, with little research in China and its wide range of climate and forest types. We assembled large datasets to quantify the geographic ranges of tree species in China and to test several biogeographic hypotheses: 1) whether locally abundant species tend to be geographically widespread; 2) whether species are more abundant towards their range-centers; and 3) how abundances are correlated between sites. Local abundances of 651 species were derived from four tree plots of 20–25 ha where all individuals ≥1 cm in stem diameter were mapped and identified taxonomically. Range sizes of these species across China were then estimated from over 460,000 geo-referenced records; a Bayesian approach was used, allowing careful measures of error of each range estimate. The log-transformed range sizes had a bell-shaped distribution with a median of 703,000 km2, and >90% of 651 species had ranges >105 km2. There was no relationship between local abundance and range size, and no evidence for species being more abundant towards their range-centers. Finally, species’ abundances were positively correlated between sites. The widespread nature of most tree species in China suggests few are vulnerable to global extinction, and there is no indication of the double-peril that would result if rare species also had narrow ranges. PMID:24130772

  6. 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

  7. Is tree species diversity or tree species identity the most important driver of European forest soil carbon stocks?

    NASA Astrophysics Data System (ADS)

    Vesterdal, Lars; Muhie Dawud, Seid; Raulund-Rasmussen, Karsten; Finér, Leena; Domisch, Timo

    2016-04-01

    Land management includes the selection of specific tree species and tree species mixtures for European forests. Studies of functional species diversity effects have reported positive effects for aboveground carbon (C) sequestration, but the question remains whether higher soil C stocks could also result from belowground niche differentiation including more efficient root exploitation of soils. We studied topsoil C stocks in tree species diversity gradients established within the FunDivEurope project to explore biodiversity-ecosystem functioning relationships in six European forest types in Finland, Poland, Germany, Romania, Spain and Italy. In the Polish forest type we extended the sampling to also include subsoils. We found consistent but modest effects of species diversity on total soil C stocks (forest floor and 0-20 cm) across the six European forest types. Carbon stocks in the forest floor alone and in the combined forest floor and mineral soil layers increased with increasing tree species diversity. In contrast, there was a strong effect of species identity (broadleaf vs. conifer) and its interaction with site-related factors. Within the Polish forest type we sampled soils down to 40 cm and found that species identity was again the main factor explaining total soil C stock. However, species diversity increased soil C stocks in deeper soil layers (20-40 cm), while species identity influenced C stocks significantly within forest floors and the 0-10 cm layer. Root biomass increased with diversity in 30-40 cm depth, and a positive relationship between C stocks and root biomass in the 30-40 cm layer suggested that belowground niche complementarity could be a driving mechanism for higher root carbon input and in turn a deeper distribution of C in diverse forests. We conclude that total C stocks are mainly driven by tree species identity. However, modest positive diversity effects were detected at the European scale, and stronger positive effects on subsoil C stocks

  8. Multilocus inference of species trees and DNA barcoding.

    PubMed

    Mallo, Diego; Posada, David

    2016-09-01

    The unprecedented amount of data resulting from next-generation sequencing has opened a new era in phylogenetic estimation. Although large datasets should, in theory, increase phylogenetic resolution, massive, multilocus datasets have uncovered a great deal of phylogenetic incongruence among different genomic regions, due both to stochastic error and to the action of different evolutionary process such as incomplete lineage sorting, gene duplication and loss and horizontal gene transfer. This incongruence violates one of the fundamental assumptions of the DNA barcoding approach, which assumes that gene history and species history are identical. In this review, we explain some of the most important challenges we will have to face to reconstruct the history of species, and the advantages and disadvantages of different strategies for the phylogenetic analysis of multilocus data. In particular, we describe the evolutionary events that can generate species tree-gene tree discordance, compare the most popular methods for species tree reconstruction, highlight the challenges we need to face when using them and discuss their potential utility in barcoding. Current barcoding methods sacrifice a great amount of statistical power by only considering one locus, and a transition to multilocus barcodes would not only improve current barcoding methods, but also facilitate an eventual transition to species-tree-based barcoding strategies, which could better accommodate scenarios where the barcode gap is too small or inexistent.This article is part of the themed issue 'From DNA barcodes to biomes'. PMID:27481787

  9. tropiTree: an NGS-based EST-SSR resource for 24 tropical tree species.

    PubMed

    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

  10. 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

  11. Gene trees versus species trees: reassessing life-history evolution in a freshwater fish radiation.

    PubMed

    Waters, Jonathan M; Rowe, Diane L; Burridge, Christopher P; Wallis, Graham P

    2010-10-01

    Mechanisms of speciation are best understood in the context of phylogenetic relationships and as such have often been inferred from single gene trees, typically those derived from mitochondrial DNA (mtDNA) markers. Recent studies, however, have noted the potential for phylogenetic discordance between gene trees and underlying species trees (e.g., due to stochastic lineage sorting, introgression, or selection). Here, we employ a variety of nuclear DNA loci to reassess evolutionary relationships within a recent freshwater fish radiation to reappraise modes of speciation. New Zealand's freshwater-limited Galaxias vulgaris complex is thought to have evolved from G. brevipinnis, a widespread migratory species that retains a plesiomorphic marine juvenile phase. A well-resolved tree, based on four mtDNA regions, previously suggested that marine migratory ability has been lost on 3 independent occasions in the evolution of this species flock (assuming that loss of diadromy is irreversible). Here, we use pseudogene (galaxiid Numt: 1801 bp), intron (S: 903 bp), and exon (RAG-1: 1427 bp) markers, together with mtDNA, to reevaluate this hypothesis of parallel evolution. Interestingly, partitioned Bayesian analysis of concatenated nuclear sequences (3141 bp) and concatenated nuclear and mtDNA (4770 bp) both recover phylogenies implying a single loss of diadromy, not three parallel losses as previously inferred from mtDNA alone. This phylogenetic result is reinforced by a multilocus analysis performed using Bayesian estimation of species trees (BEST) software that estimates the posterior distribution of species trees under a coalescent model. We discuss factors that might explain the apparently misleading phylogenetic inferences generated by mtDNA. PMID:20603441

  12. Nitrogen Addition Enhances Drought Sensitivity of Young Deciduous Tree Species

    PubMed Central

    Dziedek, Christoph; Härdtle, Werner; von Oheimb, Goddert; Fichtner, Andreas

    2016-01-01

    Understanding how trees respond to global change drivers is central to predict changes in forest structure and functions. Although there is evidence on the mode of nitrogen (N) and drought (D) effects on tree growth, our understanding of the interplay of these factors is still limited. Simultaneously, as mixtures are expected to be less sensitive to global change as compared to monocultures, we aimed to investigate the combined effects of N addition and D on the productivity of three tree species (Fagus sylvatica, Quercus petraea, Pseudotsuga menziesii) in relation to functional diverse species mixtures using data from a 4-year field experiment in Northwest Germany. Here we show that species mixing can mitigate the negative effects of combined N fertilization and D events, but the community response is mainly driven by the combination of certain traits rather than the tree species richness of a community. For beech, we found that negative effects of D on growth rates were amplified by N fertilization (i.e., combined treatment effects were non-additive), while for oak and fir, the simultaneous effects of N and D were additive. Beech and oak were identified as most sensitive to combined N+D effects with a strong size-dependency observed for beech, suggesting that the negative impact of N+D becomes stronger with time as beech grows larger. As a consequence, the net biodiversity effect declined at the community level, which can be mainly assigned to a distinct loss of complementarity in beech-oak mixtures. This pattern, however, was not evident in the other species-mixtures, indicating that neighborhood composition (i.e., trait combination), but not tree species richness mediated the relationship between tree diversity and treatment effects on tree growth. Our findings point to the importance of the qualitative role (‘trait portfolio’) that biodiversity play in determining resistance of diverse tree communities to environmental changes. As such, they provide

  13. Nitrogen Addition Enhances Drought Sensitivity of Young Deciduous Tree Species.

    PubMed

    Dziedek, Christoph; Härdtle, Werner; von Oheimb, Goddert; Fichtner, Andreas

    2016-01-01

    Understanding how trees respond to global change drivers is central to predict changes in forest structure and functions. Although there is evidence on the mode of nitrogen (N) and drought (D) effects on tree growth, our understanding of the interplay of these factors is still limited. Simultaneously, as mixtures are expected to be less sensitive to global change as compared to monocultures, we aimed to investigate the combined effects of N addition and D on the productivity of three tree species (Fagus sylvatica, Quercus petraea, Pseudotsuga menziesii) in relation to functional diverse species mixtures using data from a 4-year field experiment in Northwest Germany. Here we show that species mixing can mitigate the negative effects of combined N fertilization and D events, but the community response is mainly driven by the combination of certain traits rather than the tree species richness of a community. For beech, we found that negative effects of D on growth rates were amplified by N fertilization (i.e., combined treatment effects were non-additive), while for oak and fir, the simultaneous effects of N and D were additive. Beech and oak were identified as most sensitive to combined N+D effects with a strong size-dependency observed for beech, suggesting that the negative impact of N+D becomes stronger with time as beech grows larger. As a consequence, the net biodiversity effect declined at the community level, which can be mainly assigned to a distinct loss of complementarity in beech-oak mixtures. This pattern, however, was not evident in the other species-mixtures, indicating that neighborhood composition (i.e., trait combination), but not tree species richness mediated the relationship between tree diversity and treatment effects on tree growth. Our findings point to the importance of the qualitative role ('trait portfolio') that biodiversity play in determining resistance of diverse tree communities to environmental changes. As such, they provide further

  14. 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

  15. Multilocus inference of species trees and DNA barcoding

    PubMed Central

    2016-01-01

    The unprecedented amount of data resulting from next-generation sequencing has opened a new era in phylogenetic estimation. Although large datasets should, in theory, increase phylogenetic resolution, massive, multilocus datasets have uncovered a great deal of phylogenetic incongruence among different genomic regions, due both to stochastic error and to the action of different evolutionary process such as incomplete lineage sorting, gene duplication and loss and horizontal gene transfer. This incongruence violates one of the fundamental assumptions of the DNA barcoding approach, which assumes that gene history and species history are identical. In this review, we explain some of the most important challenges we will have to face to reconstruct the history of species, and the advantages and disadvantages of different strategies for the phylogenetic analysis of multilocus data. In particular, we describe the evolutionary events that can generate species tree—gene tree discordance, compare the most popular methods for species tree reconstruction, highlight the challenges we need to face when using them and discuss their potential utility in barcoding. Current barcoding methods sacrifice a great amount of statistical power by only considering one locus, and a transition to multilocus barcodes would not only improve current barcoding methods, but also facilitate an eventual transition to species-tree-based barcoding strategies, which could better accommodate scenarios where the barcode gap is too small or inexistent. This article is part of the themed issue ‘From DNA barcodes to biomes’. PMID:27481787

  16. 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

  17. 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

  18. A multigene species tree for Western Mediterranean painted frogs (Discoglossus).

    PubMed

    Pabijan, Maciej; Crottini, Angelica; Reckwell, Dennis; Irisarri, Iker; Hauswaldt, J Susanne; Vences, Miguel

    2012-09-01

    Painted frogs (Discoglossus) are an anuran clade that originated in the Upper Miocene. Extant species are morphologically similar and have a circum-Mediterranean distribution. We assembled a multilocus dataset from seven nuclear and four mitochondrial genes for several individuals of all but one of the extant species and reconstructed a robust phylogeny by applying a coalescent-based species-tree method and a concatenation approach, both of which gave congruent results. The earliest phylogenetic split within Discoglossus separates D. montalentii from a clade comprising all other species. Discoglossus montalentii is monophyletic for haplotype variation at all loci and has distinct morphological, bioacoustic and karyotypic characters. We find moderate support for a sister-group relationship between the Iberian taxa and the Moroccan D. scovazzi, and high support for a D. pictus -D. sardus clade distributed around the Tyrrhenian basin. Topological discordance among gene trees during the speciation of D. galganoi, D. scovazzi, D. pictus and D. sardus is interpreted as the consequence of nearly simultaneous, vicariant diversification. The timing of these events is unclear, but possibly coincided with the final geotectonic rearrangement of the Western Mediterranean in the Middle Miocene or later during the Messinian salinity crisis. The Iberian taxa D. galganoi galganoi and D. g. jeanneae are reciprocally monophyletic in mitochondrial DNA but not in nuclear gene trees, and are therefore treated as subspecies of D. galganoi. PMID:22641173

  19. Diversification rates and species richness across the Tree of Life.

    PubMed

    Scholl, Joshua P; Wiens, John J

    2016-09-14

    Species richness varies dramatically among clades across the Tree of Life, by over a million-fold in some cases (e.g. placozoans versus arthropods). Two major explanations for differences in richness among clades are the clade-age hypothesis (i.e. species-rich clades are older) and the diversification-rate hypothesis (i.e. species-rich clades diversify more rapidly, where diversification rate is the net balance of speciation and extinction over time). Here, we examine patterns of variation in diversification rates across the Tree of Life. We address how rates vary across higher taxa, whether rates within higher taxa are related to the subclades within them, and how diversification rates of clades are related to their species richness. We find substantial variation in diversification rates, with rates in plants nearly twice as high as in animals, and rates in some eukaryotes approximately 10-fold faster than prokaryotes. Rates for each kingdom-level clade are then significantly related to the subclades within them. Although caution is needed when interpreting relationships between diversification rates and richness, a positive relationship between the two is not inevitable. We find that variation in diversification rates seems to explain most variation in richness among clades across the Tree of Life, in contrast to the conclusions of previous studies. PMID:27605507

  20. 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.

  1. 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.

  2. 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

  3. Relating tree growth to rainfall in Bolivian rain forests: a test for six species using tree ring analysis.

    PubMed

    Brienen, Roel J W; Zuidema, Pieter A

    2005-11-01

    Many tropical regions show one distinct dry season. Often, this seasonality induces cambial dormancy of trees, particularly if these belong to deciduous species. This will often lead to the formation of annual rings. The aim of this study was to determine whether tree species in the Bolivian Amazon region form annual rings and to study the influence of the total amount and seasonal distribution of rainfall on diameter growth. Ring widths were measured on stem discs of a total of 154 trees belonging to six rain forest species. By correlating ring width and monthly rainfall data we proved the annual character of the tree rings for four of our study species. For two other species the annual character was proved by counting rings on trees of known age and by radiocarbon dating. The results of the climate-growth analysis show a positive relationship between tree growth and rainfall in certain periods of the year, indicating that rainfall plays a major role in tree growth. Three species showed a strong relationship with rainfall at the beginning of the rainy season, while one species is most sensitive to the rainfall at the end of the previous growing season. These results clearly demonstrate that tree ring analysis can be successfully applied in the tropics and that it is a promising method for various research disciplines. PMID:16012820

  4. 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

  5. Lianas suppress seedling growth and survival of 14 tree species in a Panamanian tropical forest.

    PubMed

    Martínez-Izquierdo, Laura; García, María M; Powers, Jennifer S; Schnitzer, Stefan A

    2016-01-01

    Lianas are a common plant growth form in tropical forests, where they compete intensely with trees, decreasing tree recruitment, growth, and survival. If the detrimental effects of lianas vary significantly with tree species identity, as is often assumed, then lianas may influence tree species diversity and community composition. Furthermore, recent studies have shown that liana abundance and biomass are increasing relative to trees in neotropical forests, which will likely magnify the detrimental effects of lianas and may ultimately alter tree species diversity, relative abundances, and community composition. Few studies, however, have tested the responses of multiple tree species to the presence of lianas in robust, well-replicated experiments. We tested the hypotheses that lianas reduce tree seedling growth and survival, and that the effect of lianas varies with tree species identity. We used a large-scale liana removal experiment in Central Panama in which we planted 14 replicate seedlings of 14 different tree species that varied in shade tolerance in each of 16 80 x 80 m plots (eight liana-removal and eight unmanipulated controls; 3136 total seedlings). Over a nearly two-yr period, we found that tree seedlings survived 75% more, grew 300% taller, and had twice the aboveground biomass in liana-removal plots than seedlings in control plots, consistent with strong competition between lianas and tree seedlings. There were no significant differences in the response of tree species to liana competition (i.e., there was no species by treatment interaction), indicating that lianas had a similar negative effect on all 14 tree species. Furthermore, the effect of lianas did not vary with tree species shade tolerance classification, suggesting that the liana effect was not solely based on light. Based on these findings, recently observed increases in liana abundance in neotropical forests will substantially reduce tree regeneration, but will not significantly alter

  6. 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

  7. 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

  8. 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.

  9. 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

  10. 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.

  11. Consistency and inconsistency of consensus methods for inferring species trees from gene trees in the presence of ancestral population structure.

    PubMed

    DeGiorgio, Michael; Rosenberg, Noah A

    2016-08-01

    In the last few years, several statistically consistent consensus methods for species tree inference have been devised that are robust to the gene tree discordance caused by incomplete lineage sorting in unstructured ancestral populations. One source of gene tree discordance that has only recently been identified as a potential obstacle for phylogenetic inference is ancestral population structure. In this article, we describe a general model of ancestral population structure, and by relying on a single carefully constructed example scenario, we show that the consensus methods Democratic Vote, STEAC, STAR, R(∗) Consensus, Rooted Triple Consensus, Minimize Deep Coalescences, and Majority-Rule Consensus are statistically inconsistent under the model. We find that among the consensus methods evaluated, the only method that is statistically consistent in the presence of ancestral population structure is GLASS/Maximum Tree. We use simulations to evaluate the behavior of the various consensus methods in a model with ancestral population structure, showing that as the number of gene trees increases, estimates on the basis of GLASS/Maximum Tree approach the true species tree topology irrespective of the level of population structure, whereas estimates based on the remaining methods only approach the true species tree topology if the level of structure is low. However, through simulations using species trees both with and without ancestral population structure, we show that GLASS/Maximum Tree performs unusually poorly on gene trees inferred from alignments with little information. This practical limitation of GLASS/Maximum Tree together with the inconsistency of other methods prompts the need for both further testing of additional existing methods and development of novel methods under conditions that incorporate ancestral population structure. PMID:27086043

  12. Neogene origins and implied warmth tolerance of Amazon tree species

    PubMed Central

    Dick, Christopher W; Lewis, Simon L; Maslin, Mark; Bermingham, Eldredge

    2013-01-01

    Tropical rain forest has been a persistent feature in South America for at least 55 million years. The future of the contemporary Amazon forest is uncertain, however, as the region is entering conditions with no past analogue, combining rapidly increasing air temperatures, high atmospheric carbon dioxide concentrations, possible extreme droughts, and extensive removal and modification by humans. Given the long-term Cenozoic cooling trend, it is unknown whether Amazon forests can tolerate air temperature increases, with suggestions that lowland forests lack warm-adapted taxa, leading to inevitable species losses. In response to this uncertainty, we posit a simple hypothesis: the older the age of a species prior to the Pleistocene, the warmer the climate it has previously survived, with Pliocene (2.6–5 Ma) and late-Miocene (8–10 Ma) air temperature across Amazonia being similar to 2100 temperature projections under low and high carbon emission scenarios, respectively. Using comparative phylogeographic analyses, we show that 9 of 12 widespread Amazon tree species have Pliocene or earlier lineages (>2.6 Ma), with seven dating from the Miocene (>5.6 Ma) and three >8 Ma. The remarkably old age of these species suggest that Amazon forests passed through warmth similar to 2100 levels and that, in the absence of other major environmental changes, near-term high temperature-induced mass species extinction is unlikely. PMID:23404439

  13. Evaluating Summary Methods for Multilocus Species Tree Estimation in the Presence of Incomplete Lineage Sorting.

    PubMed

    Mirarab, Siavash; Bayzid, Md Shamsuzzoha; Warnow, Tandy

    2016-05-01

    Species tree estimation is complicated by processes, such as gene duplication and loss and incomplete lineage sorting (ILS), that cause discordance between gene trees and the species tree. Furthermore, while concatenation, a traditional approach to tree estimation, has excellent performance under many conditions, the expectation is that the best accuracy will be obtained through the use of species tree estimation methods that are specifically designed to address gene tree discordance. In this article, we report on a study to evaluate MP-EST-one of the most popular species tree estimation methods designed to address ILS-as well as concatenation under maximum likelihood, the greedy consensus, and two supertree methods (Matrix Representation with Parsimony and Matrix Representation with Likelihood). Our study shows that several factors impact the absolute and relative accuracy of methods, including the number of gene trees, the accuracy of the estimated gene trees, and the amount of ILS. Concatenation can be more accurate than the best summary methods in some cases (mostly when the gene trees have poor phylogenetic signal or when the level of ILS is low), but summary methods are generally more accurate than concatenation when there are an adequate number of sufficiently accurate gene trees. Our study suggests that coalescent-based species tree methods may be key to estimating highly accurate species trees from multiple loci. PMID:25164915

  14. The complex biogeographic history of a widespread tropical tree species.

    PubMed

    Dick, Christopher W; Heuertz, Myriam

    2008-11-01

    Many tropical forest tree species have broad geographic ranges, and fossil records indicate that population disjunctions in some species were established millions of years ago. Here we relate biogeographic history to patterns of population differentiation, mutational and demographic processes in the widespread rainforest tree Symphonia globulifera using ribosomal (ITS) and chloroplast DNA sequences and nuclear microsatellite (nSSR) loci. Fossil records document sweepstakes dispersal origins of Neotropical S. globulifera populations from Africa during the Miocene. Despite historical long-distance gene flow, nSSR differentiation across 13 populations from Costa Rica, Panama, Ecuador (east and west of Andes) and French Guiana was pronounced (F(ST)= 0.14, R(ST)= 0.39, P < 0.001) and allele-size mutations contributed significantly (R(ST) > F(ST)) to the divergences between cis- and trans-Andean populations. Both DNA sequence and nSSR data reflect contrasting demographic histories in lower Mesoamerica and Amazonia. Amazon populations show weak phylogeographic structure and deviation from drift-mutation equilibrium indicating recent population expansion. In Mesoamerica, genetic drift was strong and contributed to marked differentiation among populations. The genetic structure of S. globulifera contains fingerprints of drift-dispersal processes and phylogeographic footprints of geological uplifts and sweepstakes dispersal. PMID:18764917

  15. Firewood crops: shrub and tree species for energy production

    SciTech Connect

    Not Available

    1980-01-01

    In the face of global concern over the dwindling supply of fuelwood, the rate of forest decimation to provide basic human necessities in developing countries is alarming. We must look upon woody plants as renewable resources that, if effectively managed, could alleviate the problem not only for the present,but for posterity. This report suggests potential significant fuelwood species for introduction to suitable environments, although it does not suggest a solution for the fuelwood crisis. The emphasis is on species suitable for individual crops, but species suited to plantation cultivation for fueling small industrial factories, electric generators, and crop driers are also considered. Most of the plants are little known in traditional forest production. Some are woody shrubs rather than trees, but all are aggressive and quick growing. They should be introduced with care in areas where the climate and soil conditions are not harsh. The substitution of well-designed stoves, kilns, or boilers could improve fuel efficiency. Each species is illustrated with photographs and diagrams. (Refs. 420).

  16. 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

  17. 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.

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

    PubMed

    Gamfeldt, Lars; Snäll, Tord; Bagchi, Robert; Jonsson, Micael; Gustafsson, Lena; Kjellander, Petter; Ruiz-Jaen, María C; Fröberg, Mats; Stendahl, Johan; Philipson, Christopher D; Mikusiński, 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 km(2), 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

  19. 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.; Mikusiński, 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

  20. Temporal changes of soil respiration under different tree species.

    PubMed

    Akburak, Serdar; Makineci, Ender

    2013-04-01

    Soil respiration rates were measured monthly (from April 2007 to March 2008) under four adjacent coniferous plantation sites [Oriental spruce (Picea orientalis L.), Austrian pine (Pinus nigra Arnold), Turkish fir (Abies bornmulleriana L.), and Scots pine (Pinus sylvestris L.)] and adjacent natural Sessile oak forest (Quercus petraea L.) in Belgrad Forest-Istanbul/Turkey. Also, soil moisture, soil temperature, and fine root biomass were determined to identify the underlying environmental variables among sites which are most likely causing differences in soil respiration. Mean annual soil moisture was determined to be between 6.3 % and 8.1 %, and mean annual temperature ranged from 13.0°C to 14.2°C under all species. Mean annual fine root biomass changed between 368.09 g/m(2) and 883.71 g/m(2) indicating significant differences among species. Except May 2007, monthly soil respiration rates show significantly difference among species. However, focusing on tree species, differences of mean annual respiration rates did not differ significantly. Mean annual soil respiration ranged from 0.56 to 1.09 g C/m(2)/day. The highest rates of soil respiration reached on autumn months and the lowest rates were determined on summer season. Soil temperature, soil moisture, and fine root biomass explain mean annual soil respiration rates at the highest under Austrian pine (R (2) = 0.562) and the lowest (R (2) = 0.223) under Turkish fir. PMID:22828980

  1. 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

  2. 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.

  3. 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

  4. 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

    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

  5. 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

  6. A Bayesian Supertree Model for Genome-Wide Species Tree Reconstruction

    PubMed Central

    De Oliveira Martins, Leonardo; Mallo, Diego; Posada, David

    2016-01-01

    Current phylogenomic data sets highlight the need for species tree methods able to deal with several sources of gene tree/species tree incongruence. At the same time, we need to make most use of all available data. Most species tree methods deal with single processes of phylogenetic discordance, namely, gene duplication and loss, incomplete lineage sorting (ILS) or horizontal gene transfer. In this manuscript, we address the problem of species tree inference from multilocus, genome-wide data sets regardless of the presence of gene duplication and loss and ILS therefore without the need to identify orthologs or to use a single individual per species. We do this by extending the idea of Maximum Likelihood (ML) supertrees to a hierarchical Bayesian model where several sources of gene tree/species tree disagreement can be accounted for in a modular manner. We implemented this model in a computer program called guenomu whose inputs are posterior distributions of unrooted gene tree topologies for multiple gene families, and whose output is the posterior distribution of rooted species tree topologies. We conducted extensive simulations to evaluate the performance of our approach in comparison with other species tree approaches able to deal with more than one leaf from the same species. Our method ranked best under simulated data sets, in spite of ignoring branch lengths, and performed well on empirical data, as well as being fast enough to analyze relatively large data sets. Our Bayesian supertree method was also very successful in obtaining better estimates of gene trees, by reducing the uncertainty in their distributions. In addition, our results show that under complex simulation scenarios, gene tree parsimony is also a competitive approach once we consider its speed, in contrast to more sophisticated models. PMID:25281847

  7. 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

  8. 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

  9. 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

  10. 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

  11. 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

  12. 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, ...

  13. 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....

  14. Fire controls population structure in four dominant tree species in a tropical savanna.

    PubMed

    Lehmann, Caroline E R; Prior, Lynda D; Bowman, David M J S

    2009-09-01

    The persistence of mesic savannas has been theorised as being dependent on disturbances that restrict the number of juveniles growing through the sapling size class to become fire-tolerant trees. We analysed the population structures of four dominant tropical savanna tree species from 30 locations in Kakadu National Park (KNP), northern Australia. We found that across KNP as a whole, the population size structures of these species do not exhibit recruitment bottlenecks. However, individual stands had multimodal size-class distributions and mixtures of tree species consistent with episodic and individualistic recruitment of co-occurring tree species. Using information theory and multimodel inference, we examined the relative importance of fire frequency, stand basal area and elevation difference between a site and permanent water in explaining variations in the proportion of sapling to adult stems in four dominant tree species. This showed that the proportion of the tree population made up of saplings was negatively related to both fire frequencies and stand basal area. Overall, fire frequency has density-dependent effects in the regulation of the transition of saplings to trees in this Australian savanna, due to interactions with stem size, regeneration strategies, growth rates and tree-tree competition. Although stable at the regional scale, the spatiotemporal variability of fire can result in structural and floristic diversity of savanna tree populations. PMID:19629532

  15. Indicator species of essential forest tree species in the Burdur district.

    PubMed

    Negiz, Mehmet Güvenç; Eser, Yunus; Kuzugüdenll, Emre; Izkan, Kürşad

    2015-01-01

    The forests of Burdur district for long have been subjected to over grazing and individual selection. As a result of this, majority of the forest areas in the district were degraded. In the district, afforestation efforts included majority of forestry implementations. It is well known that selecting suitable species plays an important role for achieving afforestation efforts. In this context, knowing the indicator species among the target species would be used in afforestation efforts, studies on the interrelationships between environmental factors and target species distribution is vital for selecting suitable species for a given area. In this study, Anatolian Black pine (Pinus nigra), Red pine (Pinus brutia), Crimean juniper (Juniperus excelsa) and Taurus cedar (Cedrus libani), essential tree species, were considered as target species. The data taken from 100 sample plots in Burdur district was used. Interspecific correlation analysis was performed to determine the positive and negative indicator species among each of the target species. As a result of ICA, 2 positive (Berberis crataegina, Juniperus oxycedrus), 2 negative (Phillyrea latifolia, Quercus coccifera) for Crimean Juniper, I positive (Juniperus oxycedrus), 3 negative (Onopordium acanthium, Fraxinus ornus, Phillyrea latifolia) for Anatolian black pine, 3 positive (Paliurus spina-christi, Quercus coccifer, Crataegus orientalis), 2 negative (Berberis crataegina, Astragalus nanus) for Red pine and 3 positive (Berberis crataegina, Rhamnus oleoides, Astragalus prusianus) 2 negative (Paliurus spina-christi, Quercus cerris) for Taurus cedarwere defined as indicator plant species. In this way, practical information was obtained for selecting the most suitable species, among the target species, for afforestation efforts in Burdur district. PMID:26591889

  16. 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

  17. 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

  18. 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

  19. 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

  20. The relationship between species diversity and genetic structure in the rare Picea chihuahuana tree species community, Mexico.

    PubMed

    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

  1. 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

  2. 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

  3. Mortality rates associated with crown health for eastern forest tree species.

    PubMed

    Morin, Randall S; Randolph, KaDonna C; Steinman, Jim

    2015-03-01

    The condition of tree crowns is an important indicator of tree and forest health. Crown conditions have been evaluated during inventories of the US Forest Service Forest Inventory and Analysis (FIA) program since 1999. In this study, remeasured data from 55,013 trees on 2616 FIA plots in the eastern USA were used to assess the probability of survival among various tree species using the suite of FIA crown condition variables. Logistic regression procedures were employed to develop models for predicting tree survival. Results of the regression analyses indicated that crown dieback was the most important crown condition variable for predicting tree survival for all species combined and for many of the 15 individual species in the study. The logistic models were generally successful in representing recent tree mortality responses to multiyear infestations of beech bark disease and hemlock woolly adelgid. Although our models are only applicable to trees growing in a forest setting, the utility of models that predict impending tree mortality goes beyond forest inventory or traditional forestry growth and yield models and includes any application where managers need to assess tree health or predict tree mortality including urban forest, recreation, wildlife, and pest management. PMID:25655130

  4. Independent domestications of cultivated tree peonies from different wild peony species.

    PubMed

    Yuan, Jun-Hui; Cornille, Amandine; Giraud, Tatiana; Cheng, Fang-Yun; Hu, Yong-Hong

    2014-01-01

    An understanding of plant domestication history provides insights into general mechanisms of plant adaptation and diversification and can guide breeding programmes that aim to improve cultivated species. Cultivated tree peonies (genus Paeonia L.) are among the most popular ornamental plants in the world; yet, the history of their domestication is still unresolved. Here, we explored whether the domestication in China of historically cultivated peonies, that is, the common and flare cultivated tree peonies, was a single event or whether independent domestications occurred. We used 14 nuclear microsatellite markers and a comprehensive set of 553 tree peonies collected across China, including common tree peonies, flare tree peonies and the wild species or subspecies that are potential contributors to the cultivated tree peonies, that is, Paeonia rockii ssp. rockii, P. rockii ssp. atava, P. jishanensis and P. decomposita. Assignment methods, a principal component analysis and approximate Bayesian computations provided clear evidence for independent domestications of these common tree and flare tree peonies from two distinct and allopatric wild species, P. jishanensis and P. rockii ssp. atava, respectively. This study provides the first example of independent domestications of cultivated trees from distinct species and locations. This work also yields crucial insight into the history of domestication of one of the most popular woody ornamental plants. The cultivated peonies represent an interesting case of parallel and convergent evolution. The information obtained in this study will be valuable both for improving current tree peony breeding strategies and for understanding the mechanisms of domestication, diversification and adaptation in plants. PMID:24138195

  5. Species tree discordance traces to phylogeographic clade boundaries in North American fence lizards (Sceloporus).

    PubMed

    Leaché, Adam D

    2009-12-01

    I investigated the impacts of phylogeographic sampling decisions on species tree estimation in the Sceloporus undulatus species group, a recent radiation of small, insectivorous lizards connected by parapatric and peripatric distribution across North America, using a variety of species tree inference methods (Bayesian estimation of species trees, Bayesian untangling of concordance knots, and minimize deep coalescences). Phylogenetic analyses of 16 specimens representing 4 putative species within S. "undulatus" using complete (8 loci, >5.5 kb) and incomplete (29 loci, >23.6 kb) nuclear data sets result in species trees that share features with the mitochondrial DNA (mtDNA) genealogy at the phylogeographic level but provide new insights into the evolutionary history of the species group. The concatenated nuclear data and mtDNA data both recover 4 major clades connecting populations across North America; however, instances of discordance are localized at the contact zones between adjacent phylogeographic groups. A random sub-sampling experiment designed to vary the phylogeographic samples included across hundreds of replicate species tree inferences suggests that inaccurate species assignments can result in inferred phylogenetic relationships that are dependent upon which particular populations are used as exemplars to represent species and can lead to increased estimates of effective population size. For the phylogeographic data presented here, reassigning specimens with introgressed mtDNA genomes to their prospective species, or excluding them from the analysis altogether, produces species tree topologies that are distinctly different from analyses that utilize mtDNA-based species assignments. Evolutionary biologists working at the interface of phylogeography and phylogenetics are likely to encounter multiple processes influencing gene trees congruence, which increases the relevance of estimating species trees with multilocus nuclear data and models that accommodate

  6. 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.

  7. 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

  8. 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

  9. Species tree estimation for a deep phylogenetic divergence in the New World monkeys (Primates: Platyrrhini).

    PubMed

    Perez, S Ivan; Klaczko, Julia; dos Reis, Sérgio F

    2012-11-01

    The estimation of a robust phylogeny is a necessary first step in understanding the biological diversification of the platyrrhines. Although the most recent phylogenies are generally robust, they differ from one another in the relationship between Aotus and other genera as well as in the relationship between Pitheciidae and other families. Here, we used coding and non-coding sequences to infer the species tree and embedded gene trees of the platyrrhine genera using the Bayesian Markov chain Monte Carlo method for the multispecies coalescent (*BEAST) for the first time and to compared the results with those of a Bayesian concatenated phylogenetic analysis. Our species tree, based on all available sequences, shows a closer phylogenetic relationship between Atelidae and Cebidae and a closer relationship between Aotus and the Cebidae clade. The posterior probabilities are lower for these conflictive tree nodes compared to those in the concatenated analysis; this finding could be explained by some gene trees showing no concordant topologies between Aotus and the other genera. Moreover, the topology of our species tree also differs from the findings of previous molecular and morphological studies regarding the position of Aotus. The existence of discrepancies between morphological data, gene trees and the species tree is widely reported and can be related to processes such as incomplete lineage sorting or selection. Although these processes are common in species trees with low divergence, they can also occur in species trees with deep and rapid divergence. The sources of the inconsistency of morphological and molecular traits with the species tree could be a main focus of further research on platyrrhines. PMID:22841656

  10. 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

  11. 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 μgC 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.

  12. 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.

  13. Species-environment relationships and vegetation patterns: Effects of spatial scale and tree life-stage

    USGS Publications Warehouse

    Stohlgren, T.J.; Bachand, R.R.; Onami, Y.; Binkley, D.

    1998-01-01

    Do relationships between species and environmental gradients strengthen or weaken with tree life-stage (i.e., small seedlings, large seedlings, saplings, and mature trees)? Strengthened relationships may lead to distinct forest type boundaries, or weakening connections could lead to gradual ecotones and heterogeneous forest landscapes. We quantified the changes in forest dominance (basal area of tree species by life-stage) and environmental factors (elevation, slope, aspect, intercepted photosynthetically active radiation (PAR), summer soil moisture, and soil depth and texture) across 14 forest ecotones (n = 584, 10 m x 10 m plots) in Rocky Mountain National Park, Colorado, U.S.A. Local, ecotone-specific species-environment relationships, based on multiple regression techniques, generally strengthened from the small seedling stage (multiple R2 ranged from 0.00 to 0.26) to the tree stage (multiple R2 ranged from 0.20 to 0.61). At the landscape scale, combined canonical correspondence analysis (CCA) among species and for all tree life-stages suggested that the seedlings of most species became established in lower-elevation, drier sites than where mature trees of the same species dominated. However, conflicting evidence showed that species-environment relationships may weaken with tree life-stage. Seedlings were only found in a subset of plots (habitats) occupied by mature trees of the same species. At the landscape scale, CCA results showed that species-environment relationships weakened somewhat from the small seedling stage (86.4% of the variance explained by the first two axes) to the tree stage (76.6% of variance explained). The basal area of tree species co-occurring with Pinus contorta Doug. ex. Loud declined more gradually than P. contorta basal area declined across ecotones, resulting in less-distinct forest type boundaries. We conclude that broad, gradual ecotones and heterogeneous forest landscapes are created and maintained by: (1) sporadic establishment

  14. Tissue culture and top-fruit tree species.

    PubMed

    Ochatt, S J; Davey, M R; Power, J B

    1990-01-01

    The commercial cultivation of rosaceous fruit trees (e.g., pear, apple, cherry, peach, plum) relies heavily upon the quality and performance of the rootstocks. This is even more the case now that self-rooted scions produce larger trees with a longer juvenile phase (1). It would, therefore, be of special interest for the fruit breeder to have general purpose rootstocks with a wide ecophysiological adaptation and high compatibility coupled with early cropping. In addition, many of the older and highly adapted scion varieties of fruit trees could benefit greatly from the introduction of stable, yet minor changes in their genome. Fruit trees are generally highly heterozygous, outbreeding, and thus are asexually propagated (see Chapter 10 , this vol.). Consequently, genetic improvement is likely to be based on protoplast technology, and achieved mainly through somatic methods, such as somaclonal variation or somatic hybridization. PMID:21390607

  15. 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

  16. Designing mixed species tree plantations for the tropics: balancing ecological attributes of species with landholder preferences in the Philippines.

    PubMed

    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

  17. 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

  18. Concatenation and Species Tree Methods Exhibit Statistically Indistinguishable Accuracy under a Range of Simulated Conditions

    PubMed Central

    Tonini, João; Moore, Andrew; Stern, David; Shcheglovitova, Maryia; Ortí, Guillermo

    2015-01-01

    Phylogeneticists have long understood that several biological processes can cause a gene tree to disagree with its species tree. In recent years, molecular phylogeneticists have increasingly foregone traditional supermatrix approaches in favor of species tree methods that account for one such source of error, incomplete lineage sorting (ILS). While gene tree-species tree discordance no doubt poses a significant challenge to phylogenetic inference with molecular data, researchers have only recently begun to systematically evaluate the relative accuracy of traditional and ILS-sensitive methods. Here, we report on simulations demonstrating that concatenation can perform as well or better than methods that attempt to account for sources of error introduced by ILS. Based on these and similar results from other researchers, we argue that concatenation remains a useful component of the phylogeneticist’s toolbox and highlight that phylogeneticists should continue to make explicit comparisons of results produced by contemporaneous and classical methods. PMID:25901289

  19. 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

  20. 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

  1. Coordination between water transport capacity, biomass growth, metabolic scaling and species stature in co-occurring shrub and tree species.

    PubMed

    Smith, Duncan D; Sperry, John S

    2014-12-01

    The significance of xylem function and metabolic scaling theory begins from the idea that water transport is strongly coupled to growth rate. At the same time, coordination of water transport and growth seemingly should differ between plant functional types. We evaluated the relationships between water transport, growth and species stature in six species of co-occurring trees and shrubs. Within species, a strong proportionality between plant hydraulic conductance (K), sap flow (Q) and shoot biomass growth (G) was generally supported. Across species, however, trees grew more for a given K or Q than shrubs, indicating greater growth-based water-use efficiency (WUE) in trees. Trees also showed slower decline in relative growth rate (RGR) than shrubs, equivalent to a steeper G by mass (M) scaling exponent in trees (0.77-0.98). The K and Q by M scaling exponents were common across all species (0.80, 0.82), suggesting that the steeper G scaling in trees reflects a size-dependent increase in their growth-based WUE. The common K and Q by M exponents were statistically consistent with the 0.75 of ideal scaling theory. A model based upon xylem anatomy and branching architecture consistently predicted the observed K by M scaling exponents but only when deviations from ideal symmetric branching were incorporated. PMID:25041417

  2. 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...

  3. 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

  4. Slope variation and population structure of tree species from different ecological groups in South Brazil.

    PubMed

    Bianchini, Edmilson; Garcia, Cristina C; Pimenta, José A; Torezan, José M D

    2010-09-01

    Size structure and spatial arrangement of 13 abundant tree species were determined in a riparian forest fragment in Paraná State, South Brazil (23°16'S and 51°01'W). The studied species were Aspidosperma polyneuron Müll. Arg., Astronium graveolens Jacq. and Gallesia integrifolia (Spreng) Harms (emergent species); Alseis floribunda Schott, Ruprechtia laxiflora Meisn. and Bougainvillea spectabilis Willd. (shade-intolerant canopy species); Machaerium paraguariense Hassl, Myroxylum peruiferum L. and Chrysophyllum gonocarpum (Mart. & Eichler ex Miq.) Engl. (shade-tolerant canopy species); Sorocea bonplandii (Baill.) Bürger, Trichilia casaretti C. Dc, Trichilia catigua A. Juss. and Actinostemon concolor (Spreng.) Müll. Arg. (understory small trees species). Height and diameter structures and basal area of species were analyzed. Spatial patterns and slope correlation were analyzed by Moran's / spatial autocorrelation coefficient and partial Mantel test, respectively. The emergent and small understory species showed the highest and the lowest variations in height, diameter and basal area. Size distribution differed among emergent species and also among canopy shade-intolerant species. The spatial pattern ranged among species in all groups, except in understory small tree species. The slope was correlated with spatial pattern for A. polyneuron, A. graveolens, A. floribunda, R. laxiflora, M. peruiferum and T. casaretti. The results indicated that most species occurred in specific places, suggesting that niche differentiation can be an important factor in structuring the tree community. PMID:21562693

  5. Method for estimating potential tree-grade distributions for northeastern forest species. Forest Service research paper (Final)

    SciTech Connect

    Yaussy, D.A.

    1993-03-01

    The generalized logistic regression was used to distribute trees into four potential tree grades for 20 northeastern species groups. The potential tree grade is defined as the tree grade based on the length and amount of clear cuttings and defects only, disregarding minimum grading diameter. The algorithms described use site index and tree diameter as the predictive variables, allowing the equations to be incorporated into individual-tree growth and yield simulators such as NE-TWIGS.

  6. 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...

  7. 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…

  8. 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

  9. 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

  10. Mountain landscapes offer few opportunities for high-elevation tree species migration

    USGS Publications Warehouse

    Bell, David M.; Bradford, John B.; Lauenroth, William K.

    2014-01-01

    Climate change is anticipated to alter plant species distributions. Regional context, notably the spatial complexity of climatic gradients, may influence species migration potential. While high-elevation species may benefit from steep climate gradients in mountain regions, their persistence may be threatened by limited suitable habitat as land area decreases with elevation. To untangle these apparently contradictory predictions for mountainous regions, we evaluated the climatic suitability of four coniferous forest tree species of the western United States based on species distribution modeling (SDM) and examined changes in climatically suitable areas under predicted climate change. We used forest structural information relating to tree species dominance, productivity, and demography from an extensive forest inventory system to assess the strength of inferences made with a SDM approach. We found that tree species dominance, productivity, and recruitment were highest where climatic suitability (i.e., probability of species occurrence under certain climate conditions) was high, supporting the use of predicted climatic suitability in examining species risk to climate change. By predicting changes in climatic suitability over the next century, we found that climatic suitability will likely decline, both in areas currently occupied by each tree species and in nearby unoccupied areas to which species might migrate in the future. These trends were most dramatic for high elevation species. Climatic changes predicted over the next century will dramatically reduce climatically suitable areas for high-elevation tree species while a lower elevation species, Pinus ponderosa, will be well positioned to shift upslope across the region. Reductions in suitable area for high-elevation species imply that even unlimited migration would be insufficient to offset predicted habitat loss, underscoring the vulnerability of these high-elevation species to climatic changes.

  11. Mountain landscapes offer few opportunities for high-elevation tree species migration.

    PubMed

    Bell, David M; Bradford, John B; Lauenroth, William K

    2014-05-01

    Climate change is anticipated to alter plant species distributions. Regional context, notably the spatial complexity of climatic gradients, may influence species migration potential. While high-elevation species may benefit from steep climate gradients in mountain regions, their persistence may be threatened by limited suitable habitat as land area decreases with elevation. To untangle these apparently contradictory predictions for mountainous regions, we evaluated the climatic suitability of four coniferous forest tree species of the western United States based on species distribution modeling (SDM) and examined changes in climatically suitable areas under predicted climate change. We used forest structural information relating to tree species dominance, productivity, and demography from an extensive forest inventory system to assess the strength of inferences made with a SDM approach. We found that tree species dominance, productivity, and recruitment were highest where climatic suitability (i.e., probability of species occurrence under certain climate conditions) was high, supporting the use of predicted climatic suitability in examining species risk to climate change. By predicting changes in climatic suitability over the next century, we found that climatic suitability will likely decline, both in areas currently occupied by each tree species and in nearby unoccupied areas to which species might migrate in the future. These trends were most dramatic for high elevation species. Climatic changes predicted over the next century will dramatically reduce climatically suitable areas for high-elevation tree species while a lower elevation species, Pinus ponderosa, will be well positioned to shift upslope across the region. Reductions in suitable area for high-elevation species imply that even unlimited migration would be insufficient to offset predicted habitat loss, underscoring the vulnerability of these high-elevation species to climatic changes. PMID:24353188

  12. 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

  13. 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

  14. Extending the dormant bud cryopreservation method to new tree species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In cryopreservation of germplasm, using dormant winter buds (DB) as source plant material is economically favorable over tissue culture options. Although the DB cryopreservation method has been known for many years, the approach is feasible only for cryopreserving a select number of temperate tree s...

  15. North American tree squirrels and ground squirrels with overlapping ranges host different Cryptosporidium species and genotypes.

    PubMed

    Stenger, Brianna L S; Clark, Mark E; Kváč, Martin; Khan, Eakalak; Giddings, Catherine W; Prediger, Jitka; McEvoy, John M

    2015-12-01

    Wildlife-associated Cryptosporidium are an emerging cause of cryptosporidiosis in humans. The present study was undertaken to determine the extent to which North American tree squirrels and ground squirrels host zoonotic Cryptosporidium species and genotypes. Fragments of the Cryptosporidium 18S rRNA and actin genes were amplified and sequenced from fecal samples obtained from three tree squirrel and three ground squirrel species. In tree 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 species/genotypes in tree squirrels. Because tree squirrels live in close proximity to humans and are frequently infected with potentially zoonotic Cryptosporidium species/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 species. In contrast to the Cryptosporidium infecting tree squirrels, these species/genotypes appear to be specific for ground squirrels and are not associated with human disease. PMID:26437239

  16. 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.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/cgi-bin/nph-data_query?bibcode=2016JHyd..537....1S&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016JHyd..537....1S&link_type=ABSTRACT"><span id="translatedtitle">Inter- and intra-specific variation in stemflow for evergreen <span class="hlt">species</span> and deciduous <span class="hlt">tree</span> <span class="hlt">species</span> in a subtropical forest</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Su, Lei; Xu, Wenting; Zhao, Changming; Xie, Zongqiang; Ju, Hua</p> <p>2016-06-01</p> <p>Quantification of stemflow is necessary for the assessment of forest ecosystem hydrological effects. Nevertheless, variation of stemflow among plant functional groups is currently not well understood. Stemflow production of co-occurring evergreen broadleaved <span class="hlt">trees</span> (Cyclobalanopsis multinervis and Cyclobalanopsis oxyodon) and deciduous broadleaved <span class="hlt">trees</span> (Fagus engleriana and Quercus serrata var. brevipetiolata) was quantified through field observations in a mixed evergreen and deciduous broadleaved forest. The research results revealed that stemflow increased linearly with increasing rainfall magnitude, with precipitation depths of 6.9, 7.2, 10.0 and 14.8 mm required for the initiation of stemflow for C. multinervis, C. oxyodon, F. engleriana and Q. serrata, respectively. Stemflow percentage and funneling ratio (FR) increased with increasing rainfall in a logarithmic fashion. Stemflow percentage and FR tended to grow rapidly with increasing rainfall magnitude up to a rainfall threshold of 50 mm, above which, further rainfall increases brought about only small increases. For C. multinervis, C. oxyodon, F. engleriana and Q. serrata, FR averaged 19.8, 14.8, 8.9 and 2.8, respectively. The stemflow generating rainfall thresholds for evergreen <span class="hlt">species</span> were smaller than for deciduous <span class="hlt">species</span>. Furthermore, stemflow percentage and FR of the former was greater than the latter. For both evergreen <span class="hlt">species</span> and deciduous <span class="hlt">species</span>, overall funneling ratio (FRs) decreased with increasing basal area. We concluded that: (1) although stemflow partitioning represented a fairly low percentage of gross rainfall in mixed evergreen and deciduous broadleaved forests, it was capable of providing substantial amount of rainwater to <span class="hlt">tree</span> boles; (2) the evergreen <span class="hlt">species</span> were more likely to generate stemflow than deciduous <span class="hlt">species</span>, and directed more intercepted rainwater to the root zone; (3) small <span class="hlt">trees</span> were more productive in funneling stemflow than larger <span class="hlt">trees</span>, which may provide a favorable</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</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=65294418&CFTOKEN=71908534','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=65294418&CFTOKEN=71908534"><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> </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/24233419','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24233419"><span id="translatedtitle">Ozone exposure : Areas of potential ozone risk for selected <span class="hlt">tree</span> <span class="hlt">species</span> in Austria.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Loibl, W; Smidt, S</p> <p>1996-12-01</p> <p>Increased tropospheric ozone concentrations cause damage to both human health and the environment. To assess the exposure of forest areas and selected <span class="hlt">tree</span> <span class="hlt">species</span> to ozone, it is necessary to calculate the ozone exposure distribution. The present article describes the application of an ozone interpolation model to the calculation of the ozone exposure distribution in combination with forest inventory data.The exposure of forest regions to ozone was assessed by means of an AOT40 map (accumulated ozone exposure over a threshold of 40 ppb). The calculation was performed by hourly running of the model during the summer term and accumulation of the patterns that exceeded 40 ppb.The exposure of the primary Austrian <span class="hlt">tree</span> <span class="hlt">species</span> to ozone can be assessed due to the spatial relation of ozone exposure and <span class="hlt">tree</span> <span class="hlt">species</span> patterns. This spatial relation also allows the verification of assumptions concerning ozone-related <span class="hlt">tree</span> damage. PMID:24233419</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015EGUGA..17.8279L&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015EGUGA..17.8279L&link_type=ABSTRACT"><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/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://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4375868','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4375868"><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=pmc">PubMed Central</a></p> <p>Roberts, David R.; Hamann, Andreas</p> <p>2015-01-01</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 (r2 = 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://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/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://www.ncbi.nlm.nih.gov/pubmed/12620063','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/12620063"><span id="translatedtitle">Identification, measurement and interpretation of <span class="hlt">tree</span> rings in woody <span class="hlt">species</span> from mediterranean climates.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cherubini, Paolo; Gartner, Barbara L; Tognetti, Roberto; Bräker, Otto U; Schoch, Werner; Innes, John L</p> <p>2003-02-01</p> <p>We review the literature dealing with mediterranean climate, vegetation, phenology and ecophysiology relevant to the understanding of <span class="hlt">tree</span>-ring formation in mediterranean regions. <span class="hlt">Tree</span> rings have been used extensively in temperate regions to reconstruct responses of forests to past environmental changes. In mediterranean regions, studies of <span class="hlt">tree</span> rings are scarce, despite their potential for understanding and predicting the effects of global change on important ecological processes such as desertification. In mediterranean regions, due to the great spatio-temporal variability of mediterranean environmental conditions, <span class="hlt">tree</span> rings are sometimes not formed. Often, clear seasonality is lacking, and vegetation activity is not always associated with regular dormancy periods. We present examples of <span class="hlt">tree</span>-ring morphology of five <span class="hlt">species</span> (Arbutus unedo, Fraxinus ornus, Quercus cerris, Q. ilex, Q. pubescens) sampled in Tuscany, Italy, focusing on the difficulties we encountered during the dating. We present an interpretation of anomalies found in the wood structure and, more generally, of cambial activity in such environments. Furthermore, we propose a classification of <span class="hlt">tree</span>-ring formation in mediterranean environments. Mediterranean <span class="hlt">tree</span> rings can be dated and used for dendrochronological purposes, but great care should be taken in selecting sampling sites, <span class="hlt">species</span> and sample <span class="hlt">trees</span>. PMID:12620063</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015EGUGA..1712601J&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015EGUGA..1712601J&link_type=ABSTRACT"><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></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/17665219','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/17665219"><span id="translatedtitle">Population structure, physiology and ecohydrological impacts of dioecious riparian <span class="hlt">tree</span> <span class="hlt">species</span> of western 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>Hultine, K R; Bush, S E; West, A G; Ehleringer, J R</p> <p>2007-11-01</p> <p>The global water cycle is intimately linked to vegetation structure and function. Nowhere is this more apparent than in the arid west where riparian forests serve as ribbons of productivity in otherwise mostly unproductive landscapes. Dioecy is common among <span class="hlt">tree</span> <span class="hlt">species</span> that make up western North American riparian forests. There are intrinsic physiological differences between male and female dioecious riparian <span class="hlt">trees</span> that may influence population structure (i.e., the ratio of male to female <span class="hlt">trees</span>) and impact ecohydrology at large scales. In this paper, we review the current literature on sex ratio patterns and physiology of dioecious riparian <span class="hlt">tree</span> <span class="hlt">species</span>. Then develop a conceptual framework of the mechanisms that underlie population structure of dominant riparian <span class="hlt">tree</span> <span class="hlt">species</span>. Finally, we identify linkages between population structure and ecohydrological processes such as evapotranspiration and streamflow. A more thorough understanding of the mechanisms that underlie population structure of dominant riparian <span class="hlt">tree</span> <span class="hlt">species</span> will enable us to better predict global change impacts on vegetation and water cycling at multiple scales. PMID:17665219</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://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://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</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=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> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/12625013','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/12625013"><span id="translatedtitle">[Feasibility to introduce rare <span class="hlt">tree</span> <span class="hlt">species</span> Pinus sibirica into China].</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Liu, Guifeng; Yang, Chuanping; Zhao, Guangyi</p> <p>2002-11-01</p> <p>Pinus sibirica growing mainly in Siberia of Russia is distributed over the Euro-Asia Taiga forest belt. There are many high-quality populations due to a great deal of variations. This kind of <span class="hlt">tree</span> has an advantage of standing up to frigid environment, and can spread out in such places that have cold weather and high altitude. In China, boreal forest is a wide-spreaded type of forest that has the largest area and high volume. For this reason, it is feasible to introduce Pinus sibirica into the region that the condition is suitable. Introducing this kind of <span class="hlt">tree</span> is a strategic project that can improve the structure and quality of our boreal forest. Introducing it can not only meet the demands of improved variety in short time, but also do the experiment of producing edible seeds and build up the developing center of nut, which can be a way of getting rid of poverty of forest region in heavy frigid area where is regarded as infertile area for farming formerly. PMID:12625013</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.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4988811','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4988811"><span id="translatedtitle">Early establishment of <span class="hlt">trees</span> at the alpine treeline: idiosyncratic <span class="hlt">species</span> responses to temperature-moisture interactions</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Loranger, Hannah; Zotz, Gerhard; Bader, Maaike Y.</p> <p>2016-01-01</p> <p>On a global scale, temperature is the main determinant of arctic and alpine treeline position. However on a local scale, treeline form and position vary considerably due to other climatic factors, <span class="hlt">tree</span> <span class="hlt">species</span> ecology and life-stage-dependent responses. For treelines to advance poleward or uphill, the first steps are germination and seedling establishment. These earliest life stages may be major bottlenecks for treeline <span class="hlt">tree</span> populations and will depend differently on climatic conditions than adult <span class="hlt">trees</span>. We investigated the effect of soil temperature and moisture on germination and early seedling survival in a field experiment in the French Alps near the local treeline (2100 m a.s.l.) using passive temperature manipulations and two watering regimes. Five European treeline <span class="hlt">tree</span> <span class="hlt">species</span> were studied: Larix decidua, Picea abies, Pinus cembra, Pinus uncinata and Sorbus aucuparia. In addition, we monitored the germination response of three of these <span class="hlt">species</span> to low temperatures under controlled conditions in growth chambers. The early establishment of these <span class="hlt">trees</span> at the alpine treeline was limited either by temperature or by moisture, the sensitivity to one factor often depending on the intensity of the other. The results showed that the relative importance of the two factors and the direction of the effects are highly <span class="hlt">species</span>-specific, while both factors tend to have consistent effects on both germination and early seedling survival within each <span class="hlt">species</span>. We show that temperature and water availability are both important contributors to establishment patterns of treeline <span class="hlt">trees</span> and hence to <span class="hlt">species</span>-specific forms and positions of alpine treelines. The observed idiosyncratic <span class="hlt">species</span> responses highlight the need for studies including several <span class="hlt">species</span> and life-stages to create predictive power concerning future treeline dynamics. PMID:27402618</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27402618','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27402618"><span id="translatedtitle">Early establishment of <span class="hlt">trees</span> at the alpine treeline: idiosyncratic <span class="hlt">species</span> responses to temperature-moisture interactions.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Loranger, Hannah; Zotz, Gerhard; Bader, Maaike Y</p> <p>2016-01-01</p> <p>On a global scale, temperature is the main determinant of arctic and alpine treeline position. However on a local scale, treeline form and position vary considerably due to other climatic factors, <span class="hlt">tree</span> <span class="hlt">species</span> ecology and life-stage-dependent responses. For treelines to advance poleward or uphill, the first steps are germination and seedling establishment. These earliest life stages may be major bottlenecks for treeline <span class="hlt">tree</span> populations and will depend differently on climatic conditions than adult <span class="hlt">trees</span>. We investigated the effect of soil temperature and moisture on germination and early seedling survival in a field experiment in the French Alps near the local treeline (2100 m a.s.l.) using passive temperature manipulations and two watering regimes. Five European treeline <span class="hlt">tree</span> <span class="hlt">species</span> were studied: Larix decidua, Picea abies, Pinus cembra, Pinus uncinata and Sorbus aucuparia In addition, we monitored the germination response of three of these <span class="hlt">species</span> to low temperatures under controlled conditions in growth chambers. The early establishment of these <span class="hlt">trees</span> at the alpine treeline was limited either by temperature or by moisture, the sensitivity to one factor often depending on the intensity of the other. The results showed that the relative importance of the two factors and the direction of the effects are highly <span class="hlt">species</span>-specific, while both factors tend to have consistent effects on both germination and early seedling survival within each <span class="hlt">species</span>. We show that temperature and water availability are both important contributors to establishment patterns of treeline <span class="hlt">trees</span> and hence to <span class="hlt">species</span>-specific forms and positions of alpine treelines. The observed idiosyncratic <span class="hlt">species</span> responses highlight the need for studies including several <span class="hlt">species</span> and life-stages to create predictive power concerning future treeline dynamics. PMID:27402618</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25377453','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25377453"><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=pubmed">PubMed</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>2014-12-22</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> </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.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3436813','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3436813"><span id="translatedtitle">Inferring duplications, losses, transfers and incomplete lineage sorting with nonbinary <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>Stolzer, Maureen; Lai, Han; Xu, Minli; Sathaye, Deepa; Vernot, Benjamin; Durand, Dannie</p> <p>2012-01-01</p> <p>Motivation: Gene duplication (D), transfer (T), loss (L) and incomplete lineage sorting (I) are crucial to the evolution of gene families and the emergence of novel functions. The history of these events can be inferred via comparison of gene and <span class="hlt">species</span> <span class="hlt">trees</span>, a process called reconciliation, yet current reconciliation algorithms model only a subset of these evolutionary processes. Results: We present an algorithm to reconcile a binary gene <span class="hlt">tree</span> with a nonbinary <span class="hlt">species</span> <span class="hlt">tree</span> under a DTLI parsimony criterion. This is the first reconciliation algorithm to capture all four evolutionary processes driving <span class="hlt">tree</span> incongruence and the first to reconcile non-binary <span class="hlt">species</span> <span class="hlt">trees</span> with a transfer model. Our algorithm infers all optimal solutions and reports complete, temporally feasible event histories, giving the gene and <span class="hlt">species</span> lineages in which each event occurred. It is fixed-parameter tractable, with polytime complexity when the maximum <span class="hlt">species</span> outdegree is fixed. Application of our algorithms to prokaryotic and eukaryotic data show that use of an incomplete event model has substantial impact on the events inferred and resulting biological conclusions. Availability: Our algorithms have been implemented in Notung, a freely available phylogenetic reconciliation software package, available at http://www.cs.cmu.edu/~durand/Notung. Contact: mstolzer@andrew.cmu.edu PMID:22962460</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/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=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/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.treesearch.fs.fed.us/pubs/4893','USGSPUBS'); return false;" href="http://www.treesearch.fs.fed.us/pubs/4893"><span id="translatedtitle">Supplemental planting of early successional <span class="hlt">tree</span> <span class="hlt">species</span> during bottomland hardwood afforestation</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Twedt, D.J.; Wilson, R.R.</p> <p>2002-01-01</p> <p>Reforestation of former bottom land hardwood forests that have been cleared for agriculture (i.e., afforestation) has historically emphasized planting heavy-seeded oaks (Quercus spp.) and pecans (Carya spp.). These <span class="hlt">species</span> are slow to develop vertical forest structure. However, vertical forest structure is key to colonization of afforested sites by forest birds. Although early-successional <span class="hlt">tree</span> <span class="hlt">species</span> often enhance vertical structure, few of these <span class="hlt">species</span> invade afforested sites that are distant from seed sources. Furthermore, many land mangers are reluctant to establish and maintain stands of fast-growing plantation <span class="hlt">trees</span>. Therefore, on 40 afforested bottomland sites, we supplemented heavy-seeded seedlings with 8 patches of fast-growing <span class="hlt">trees</span>: 4 patches of 12 eastern cottonwood (Populus deltoides) stem cuttings and 4 patches of 12 American sycamore (Platanus occidentalis) seedlings. To enhance survival and growth, <span class="hlt">tree</span> patches were subjected to 4 weed control treatments: (1) physical weed barriers, (2) chemical herbicide, (3) both physical and chemical weed control, or (4) no weed control. Overall, first-year survival of cottonwood and sycamore was 25 percent and 47 percent, respectively. Second-year survival of extant <span class="hlt">trees</span> was 52 percent for cottonwood and 77 percent for sycamore. Physical weed barriers increased survival of cottonwoods to 30 percent versus 18 percent survival with no weed control. Similarly, sycamore survival was increased from 49 percent without weed control to 64 percent with physical weed barriers. Chemical weed control adversely impacted sycamore and reduced survival to 35 percent. <span class="hlt">Tree</span> heights did not differ between <span class="hlt">species</span> or among weed control treatments. Girdling of <span class="hlt">trees</span> by deer often destroyed saplings. Thus, little increase in vertical structure was detected between growing seasons. Application of fertilizer and protection via <span class="hlt">tree</span> shelters did not improve survival or vertical development of sycamore or cottonwood.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1461003','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1461003"><span id="translatedtitle">Effects of colonization processes on genetic diversity: differences between annual plants and <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>Austerlitz, F; Mariette, S; Machon, N; Gouyon, P H; Godelle, B</p> <p>2000-01-01</p> <p><span class="hlt">Tree</span> <span class="hlt">species</span> are striking for their high within-population diversity and low among-population differentiation for nuclear genes. In contrast, annual plants show much more differentiation for nuclear genes but much less diversity than <span class="hlt">trees</span>. The usual explanation for this difference is that pollen flow, and therefore gene flow, is much higher for <span class="hlt">trees</span>. This explanation is problematic because it relies on equilibrium hypotheses. Because <span class="hlt">trees</span> have very recently recolonized temperate areas, they have experienced many foundation events, which usually reduce within-population diversity and increase differentiation. Only extremely high levels of gene flow could counterbalance these successive founder effects. We develop a model to study the impact of life cycle of forest <span class="hlt">trees</span>, in particular of the length of their juvenile phase, on genetic diversity and differentiation during the glacial period and the following colonization period. We show that both a reasonably high level of pollen flow and the life-cycle characteristics of <span class="hlt">trees</span> are needed to explain the observed structure of genetic diversity. We also show that gene flow and life cycle both have an impact on maternally inherited cytoplasmic genes, which are characterized both in <span class="hlt">trees</span> and annual <span class="hlt">species</span> by much less diversity and much more differentiation than nuclear genes. PMID:10757772</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://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://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</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/19880241','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/19880241"><span id="translatedtitle">Estimating <span class="hlt">tree</span> bole volume using artificial neural network models for four <span class="hlt">species</span> in Turkey.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ozçelik, Ramazan; Diamantopoulou, Maria J; Brooks, John R; Wiant, Harry V</p> <p>2010-01-01</p> <p><span class="hlt">Tree</span> bole volumes of 89 Scots pine (Pinus sylvestris L.), 96 Brutian pine (Pinus brutia Ten.), 107 Cilicica fir (Abies cilicica Carr.) and 67 Cedar of Lebanon (Cedrus libani A. Rich.) <span class="hlt">trees</span> were estimated using Artificial Neural Network (ANN) models. Neural networks offer a number of advantages including the ability to implicitly detect complex nonlinear relationships between input and output variables, which is very helpful in <span class="hlt">tree</span> volume modeling. Two different neural network architectures were used and produced the Back propagation (BPANN) and the Cascade Correlation (CCANN) Artificial Neural Network models. In addition, <span class="hlt">tree</span> bole volume estimates were compared to other established <span class="hlt">tree</span> bole volume estimation techniques including the centroid method, taper equations, and existing standard volume tables. An overview of the features of ANNs and traditional methods is presented and the advantages and limitations of each one of them are discussed. For validation purposes, actual volumes were determined by aggregating the volumes of measured short sections (average 1 meter) of the <span class="hlt">tree</span> bole using Smalian's formula. The results reported in this research suggest that the selected cascade correlation artificial neural network (CCANN) models are reliable for estimating the <span class="hlt">tree</span> bole volume of the four examined <span class="hlt">tree</span> <span class="hlt">species</span> since they gave unbiased results and were superior to almost all methods in terms of error (%) expressed as the mean of the percentage errors. PMID:19880241</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 κ-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://files.eric.ed.gov/fulltext/EJ1099325.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/EJ1099325.pdf"><span id="translatedtitle"><span class="hlt">Trees</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Al-Khaja, Nawal</p> <p>2007-01-01</p> <p>This is a thematic lesson plan for young learners about palm <span class="hlt">trees</span> and the importance of taking care of them. The two part lesson teaches listening, reading and speaking skills. The lesson includes parts of a <span class="hlt">tree</span>; the modal auxiliary, can; dialogues and a role play activity.</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=4840356','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4840356"><span id="translatedtitle">Warming effects on photosynthesis of subtropical <span class="hlt">tree</span> <span class="hlt">species</span>: a translocation experiment along an altitudinal gradient</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Li, Yiyong; Liu, Juxiu; Zhou, Guoyi; Huang, Wenjuan; Duan, Honglang</p> <p>2016-01-01</p> <p>Ongoing climate warming induced by human activities may have great impacts on <span class="hlt">trees</span>, yet it remains unresolved how subtropical <span class="hlt">tree</span> <span class="hlt">species</span> respond to rising temperature in the field. Here, we used downward translocation to investigate the effects of climate warming on leaf photosynthesis of six common <span class="hlt">tree</span> <span class="hlt">species</span> in subtropical China. During the experimental period between 2012 and 2014, the mean average photosynthetic rates (Asat) under saturating light for Schima superba, Machilus breviflora, Pinus massoniana and Ardisia lindleyana in the warm site were7%, 19%, 20% and 29% higher than those in the control site. In contrast, seasonal Asat for Castanopsis hystrix in the warm site were lower compared to the control site. Changes in Asat in response to translocation were mainly associated with those in leaf stomatal conductance (gs) and photosynthetic capacity (RuBP carboxylation, RuBP regeneration capacity). Our results imply that climate warming could have potential impacts on <span class="hlt">species</span> composition and community structure in subtropical forests. PMID:27102064</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></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27348264','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27348264"><span id="translatedtitle">The role of selected <span class="hlt">tree</span> <span class="hlt">species</span> in industrial sewage sludge/flotation tailing management.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mleczek, Mirosław; Rutkowski, Paweł; Niedzielski, Przemysław; Goliński, Piotr; Gąsecka, Monika; Kozubik, Tomisław; Dąbrowski, Jędrzej; Budzyńska, Sylwia; Pakuła, Jarosław</p> <p>2016-11-01</p> <p>The aim of the study was to estimate the ability of ten <span class="hlt">tree</span> and bush <span class="hlt">species</span> to tolerate and accumulate Cd, Cu, Pb, Zn, and As <span class="hlt">species</span> [As(III), As(V), and total organic arsenic] in industrial sewage sludge extremely contaminated with arsenic (almost 27.5 g kg(-1)) in a pot experiment. The premise being that it will then be possible to select the most promising <span class="hlt">tree</span>/bush <span class="hlt">species</span>, able to grow in the vicinity of dams where sewage sludge/flotation tailings are used as landfill. Six of the ten tested <span class="hlt">tree</span> <span class="hlt">species</span> were able to grow on the sludge. The highest content of total As was observed in Betula pendula roots (30.0 ± 1.3 mg kg(-1) DW), where the dominant As <span class="hlt">species</span> was the toxic As(V). The highest biomass of Quercus Q1 robur (77.3 § 2.6 g) and Acer platanoides (76.0 § 4.9 g) was observed. A proper planting of selected <span class="hlt">tree</span> <span class="hlt">species</span> that are able to thrive on sewage sludge/flotation tailings could be an interesting and promising way to protect dams. By utilizing differences in their root systems and water needs, we will be able to reduce the risk of fatal environmental disasters. PMID:27348264</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://www.ncbi.nlm.nih.gov/pubmed/25058660','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25058660"><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=pubmed">PubMed</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://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> </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/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://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; Szöllősi, 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</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4407066','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4407066"><span id="translatedtitle">How <span class="hlt">tree</span> <span class="hlt">species</span> fill geographic and ecological space in eastern 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>Ricklefs, Robert E.</p> <p>2015-01-01</p> <p>Background and Aims Ecologists broadly accept that the number of <span class="hlt">species</span> present within a region balances regional processes of immigration and speciation against competitive and other interactions between populations that limit distribution and constrain diversity. Although ecological theory has, for a long time, addressed the premise that ecological space can be filled to ‘capacity’ with <span class="hlt">species</span>, only with the availability of time-calibrated phylogenies has it been possible to test the hypothesis that diversification slows as the number of <span class="hlt">species</span> in a region increases. Focusing on the deciduous <span class="hlt">trees</span> of eastern North America, this study tested predictions from competition theory concerning the distribution and abundance of <span class="hlt">species</span>. Methods Local assemblages of <span class="hlt">trees</span> tabulated in a previous study published in 1950 were analysed. Assemblages were ordinated with respect to <span class="hlt">species</span> composition by non-metric multidimensional scaling (NMS). Distributions of <span class="hlt">trees</span> were analysed by taxonomically nested analysis of variance, discriminant analysis based on NMS scores, and canonical correlation analysis of NMS scores and Bioclim climate variables. Key Results Most of the variance in <span class="hlt">species</span> abundance and distribution was concentrated among closely related (i.e. congeneric) <span class="hlt">species</span>, indicating evolutionary lability. <span class="hlt">Species</span> distribution and abundance were unrelated to the number of close relatives, suggesting that competitive effects are diffuse. Distances between pairs of congeneric <span class="hlt">species</span> in NMS space did not differ significantly from distances between more distantly related <span class="hlt">species</span>, in contrast to the predictions of both competitive habitat partitioning and ecological sorting of <span class="hlt">species</span>. Conclusions Eastern deciduous forests of North America do not appear to be saturated with <span class="hlt">species</span>. The distributions and abundances of individual <span class="hlt">species</span> provide little evidence of being shaped by competition from related (i.e. ecologically similar) <span class="hlt">species</span> and, by inference, that</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014EnMan..53..783S&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014EnMan..53..783S&link_type=ABSTRACT"><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/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://www.ncbi.nlm.nih.gov/pubmed/21362638','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21362638"><span id="translatedtitle">Detecting phylogenetic breakpoints and discordance from genome-wide alignments for <span class="hlt">species</span> <span class="hlt">tree</span> reconstruction.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ané, Cécile</p> <p>2011-01-01</p> <p>With the easy acquisition of sequence data, it is now possible to obtain and align whole genomes across multiple related <span class="hlt">species</span> or populations. In this work, I assess the performance of a statistical method to reconstruct the whole distribution of phylogenetic <span class="hlt">trees</span> along the genome, estimate the proportion of the genome for which a given clade is true, and infer a concordance <span class="hlt">tree</span> that summarizes the dominant vertical inheritance pattern. There are two main issues when dealing with whole-genome alignments, as opposed to multiple genes: the size of the data and the detection of recombination breakpoints. These breakpoints partition the genomic alignment into phylogenetically homogeneous loci, where sites within a given locus all share the same phylogenetic <span class="hlt">tree</span> topology. To delimitate these loci, I describe here a method based on the minimum description length (MDL) principle, implemented with dynamic programming for computational efficiency. Simulations show that combining MDL partitioning with Bayesian concordance analysis provides an efficient and robust way to estimate both the vertical inheritance signal and the horizontal phylogenetic signal. The method performed well both in the presence of incomplete lineage sorting and in the presence of horizontal gene transfer. A high level of systematic bias was found here, highlighting the need for good individual <span class="hlt">tree</span> building methods, which form the basis for more elaborate gene <span class="hlt">tree/species</span> <span class="hlt">tree</span> reconciliation methods. PMID:21362638</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</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23376521','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23376521"><span id="translatedtitle">Forest floor leachate fluxes under six different <span class="hlt">tree</span> <span class="hlt">species</span> on a metal contaminated site.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Van Nevel, Lotte; Mertens, Jan; De Schrijver, An; Baeten, Lander; De Neve, Stefaan; Tack, Filip M G; Meers, Erik; Verheyen, Kris</p> <p>2013-03-01</p> <p><span class="hlt">Trees</span> play an important role in the biogeochemical cycling of metals, although the influence of different <span class="hlt">tree</span> <span class="hlt">species</span> on the mobilization of metals is not yet clear. This study examined effects of six <span class="hlt">tree</span> <span class="hlt">species</span> on fluxes of Cd, Zn, DOC, H(+) and base cations in forest floor leachates on a metal polluted site in Belgium. Forest floor leachates were sampled with zero-tension lysimeters in a 12-year-old post-agricultural forest on a sandy soil. The <span class="hlt">tree</span> <span class="hlt">species</span> included were silver birch (Betula pendula), oak (Quercus robur and Q. petraea), black locust (Robinia pseudoacacia), aspen (Populus tremula), Scots pine (Pinus sylvestris) and Douglas fir (Pseudotsuga menziesii). We show that total Cd fluxes in forest floor leachate under aspen were slightly higher than those in the other <span class="hlt">species</span>' leachates, yet the relative differences between the <span class="hlt">species</span> were considerably smaller when looking at dissolved Cd fluxes. The latter was probably caused by extremely low H(+) amounts leaching from aspen's forest floor. No <span class="hlt">tree</span> <span class="hlt">species</span> effect was found for Zn leachate fluxes. We expected higher metal leachate fluxes under aspen as its leaf litter was significantly contaminated with Cd and Zn. We propose that the low amounts of Cd and Zn leaching under aspen's forest floor were possibly caused by high activity of soil biota, for example burrowing earthworms. Furthermore, our results reveal that Scots pine and oak were characterized by high H(+) and DOC fluxes as well as low base cation fluxes in their forest floor leachates, implying that those <span class="hlt">species</span> might enhance metal mobilization in the soil profile and thus bear a potential risk for belowground metal dispersion. PMID:23376521</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27220216','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27220216"><span id="translatedtitle">Interspecific variation in growth responses to climate and competition of five eastern <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>Rollinson, Christine R; Kaye, Margot W; Canham, Charles D</p> <p>2016-04-01</p> <p>Climate and competition are often presented from two opposing views of the dominant driver of individual <span class="hlt">tree</span> growth and <span class="hlt">species</span> distribution in temperate forests, such as those in the eastern United States. Previous studies have provided abundant evidence indicating that both factors influence <span class="hlt">tree</span> growth, and we argue that these effects are not independent of one another and rather that interactions between climate, competition, and size best describe <span class="hlt">tree</span> growth. To illustrate this point, we describe the growth responses of five common eastern <span class="hlt">tree</span> <span class="hlt">species</span> to interacting effects of temperature, precipitation, competition, and individual size using maximum likelihood estimation. Models that explicitly include interactions among these four factors explained over half of the variance in annual growth for four out of five <span class="hlt">species</span> using annual climate. Expanding temperature and precipitation analyses to include seasonal interactions resulted in slightly improved models with a mean R2 of 0.61 (SD 0.10). Growth responses to individual factors as well their interactions varied greatly among <span class="hlt">species</span>. For example, growth sensitivity to temperature for Quercus rubra increased with maximum annual precipitation, but other <span class="hlt">species</span> showed no change in sensitivity or slightly reduced annual growth. Our results also indicate that three-way interactions among individual stem size, competition, and temperature may determine which of the five co-occurring <span class="hlt">species</span> in our study could have the highest growth rate in a given year. Continued consideration and quantification of interactions among climate, competition, and individual-based characteristics are likely to increase understanding of key biological processes such as <span class="hlt">tree</span> growth. Greater parameterization of interactions between traditionally segregated factors such as climate and competition may also help build a framework to reconcile drivers of individual-based processes such as growth with larger-scale patterns of <span class="hlt">species</span></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://adsabs.harvard.edu/abs/2015AGUFM.B43C0563C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.B43C0563C"><span id="translatedtitle">A Section-based Method For <span class="hlt">Tree</span> <span class="hlt">Species</span> Classification Using Airborne LiDAR Discrete Points In Urban Areas</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chunjing, Y. C.; Hui, T.; Zhongjie, R.; Guikai, B.</p> <p>2015-12-01</p> <p>As a new approach to forest inventory utilizing, LiDAR remote sensing has become an important research issue in the past. Lidar researches initially concentrate on the investigation for mapping forests at the <span class="hlt">tree</span> level and identifying important structural parameters, such as <span class="hlt">tree</span> height, crown size, crown base height, individual <span class="hlt">tree</span> <span class="hlt">species</span>, and stem volume etc. But for the virtual city visualization and mapping, the traditional methods of <span class="hlt">tree</span> classification can't satisfy the more complex conditions. Recently, the advanced LiDAR technology has generated new full waveform scanners that provide a higher point density and additional information about the reflecting characteristics of <span class="hlt">trees</span>. Subsequently, it was demonstrated that it is feasible to detect individual overstorey <span class="hlt">trees</span> in forests and classify <span class="hlt">species</span>. But the important issues like the calibration and the decomposition of full waveform data with a series of Gaussian functions usually take a lot of works. What's more, the detection and classification of vegetation results relay much on the prior outcomes. From all above, the section-based method for <span class="hlt">tree</span> <span class="hlt">species</span> classification using small footprint and high sampling density lidar data is proposed in this paper, which can overcome the <span class="hlt">tree</span> <span class="hlt">species</span> classification issues in urban areas. More specific objectives are to: (1)use local maximum height decision and four direction sections certification methods to get the precise locations of the <span class="hlt">trees</span>;(2) develop new lidar-derived features processing techniques for characterizing the section structure of individual <span class="hlt">tree</span> crowns;(3) investigate several techniques for filtering and analyzing vertical profiles of individual <span class="hlt">trees</span> to classify the <span class="hlt">trees</span>, and using the expert decision skills based on percentile analysis;(4) assess the accuracy of estimating <span class="hlt">tree</span> <span class="hlt">species</span> for each <span class="hlt">tree</span>, and (5) investigate which type of lidar data, point frequency or intensity, provides the most accurate estimate of <span class="hlt">tree</span> <span class="hlt">species</span></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://www.ncbi.nlm.nih.gov/pubmed/22864803','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22864803"><span id="translatedtitle">The abundance and diversity of legume-nodulating rhizobia in 28-year-old plantations of tropical, subtropical, and exotic <span class="hlt">tree</span> <span class="hlt">species</span>: a case study from the Forest Reserve of Bandia, Senegal.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sene, Godar; Thiao, Mansour; Samba-Mbaye, Ramatoulaye; Khasa, Damase; Kane, Aboubacry; Mbaye, Mame Samba; Beaulieu, Marie-Ève; Manga, Anicet; Sylla, Samba Ndao</p> <p>2013-01-01</p> <p>Several fast-growing and <span class="hlt">multipurpose</span> <span class="hlt">tree</span> <span class="hlt">species</span> have been widely used in West Africa to both reverse the tendency of land degradation and restore soil productivity. Although beneficial effects have been reported on soil stabilization, there still remains a lack of information about their impact on soil microorganisms. Our investigation has been carried out in exotic and native <span class="hlt">tree</span> plantations of 28 years and aimed to survey and compare the abundance and genetic diversity of natural legume-nodulating rhizobia (LNR). The study of LNR is supported by the phylogenetic analysis which clustered the isolates into three genera: Bradyrhizobium, Mesorhizobium, and Sinorhizobium. The results showed close positive correlations between the sizes of LNR populations estimated both in the dry and rainy seasons and the presence of legume <span class="hlt">tree</span> hosts. There were significant increases in Rhizobium spp. population densities in response to planting with Acacia spp., and high genetic diversities and richness of genotypes were fittest in these <span class="hlt">tree</span> plantations. This suggests that enrichment of soil Rhizobium spp. populations is host specific. The results indicated also that <span class="hlt">species</span> of genera Mesorhizobium and Sinorhizobium were lacking in plantations of non-host <span class="hlt">species</span>. By contrast, there was a widespread distribution of Bradyrhizobium spp. strains across the <span class="hlt">tree</span> plantations, with no evident specialization in regard to plantation type. Finally, the study provides information about the LNR communities associated with a range of old <span class="hlt">tree</span> plantations and some aspects of their relationships to soil factors, which may facilitate the management of man-made forest systems that target ecosystem rehabilitation and preservation of soil biota. PMID:22864803</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013EnMan..51..524M&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013EnMan..51..524M&link_type=ABSTRACT"><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> <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://www.ncbi.nlm.nih.gov/pubmed/27490180','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27490180"><span id="translatedtitle">Direct vs. Microclimate-Driven Effects of <span class="hlt">Tree</span> <span class="hlt">Species</span> Diversity on Litter Decomposition in Young Subtropical Forest Stands.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Seidelmann, Katrin N; Scherer-Lorenzen, Michael; Niklaus, Pascal A</p> <p>2016-01-01</p> <p>Effects of <span class="hlt">tree</span> <span class="hlt">species</span> diversity on decomposition can operate via a multitude of mechanism, including alterations of microclimate by the forest canopy. Studying such effects in natural settings is complicated by the fact that topography also affects microclimate and thus decomposition, so that effects of diversity are more difficult to isolate. Here, we quantified decomposition rates of standard litter in young subtropical forest stands, separating effects of canopy <span class="hlt">tree</span> <span class="hlt">species</span> richness and topography, and quantifying their direct and micro-climate-mediated components. Our litterbag study was carried out at two experimental sites of a biodiversity-ecosystem functioning field experiment in south-east China (BEF-China). The field sites display strong topographical heterogeneity and were planted with <span class="hlt">tree</span> communities ranging from monocultures to mixtures of 24 native subtropical <span class="hlt">tree</span> <span class="hlt">species</span>. Litter bags filled with senescent leaves of three native <span class="hlt">tree</span> <span class="hlt">species</span> were placed from Nov. 2011 to Oct. 2012 on 134 plots along the <span class="hlt">tree</span> <span class="hlt">species</span> diversity gradient. Topographic features were measured for all and microclimate in a subset of plots. Stand <span class="hlt">species</span> richness, topography and microclimate explained important fractions of the variations in litter decomposition rates, with diversity and topographic effects in part mediated by microclimatic changes. <span class="hlt">Tree</span> stands were 2-3 years old, but nevertheless <span class="hlt">tree</span> <span class="hlt">species</span> diversity explained more variation (54.3%) in decomposition than topography (7.7%). <span class="hlt">Tree</span> <span class="hlt">species</span> richness slowed litter decomposition, an effect that slightly depended on litter <span class="hlt">species</span> identity. A large part of the variance in decomposition was explained by <span class="hlt">tree</span> <span class="hlt">species</span> composition, with the presence of three <span class="hlt">tree</span> <span class="hlt">species</span> playing a significant role. Microclimate explained 31.4% of the variance in decomposition, and was related to lower soil moisture. Within this microclimate effect, <span class="hlt">species</span> diversity (without composition) explained 8.9% and topography 34.4% of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4973968','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4973968"><span id="translatedtitle">Direct vs. Microclimate-Driven Effects of <span class="hlt">Tree</span> <span class="hlt">Species</span> Diversity on Litter Decomposition in Young Subtropical Forest Stands</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Seidelmann, Katrin N.; Scherer-Lorenzen, Michael; Niklaus, Pascal A.</p> <p>2016-01-01</p> <p>Effects of <span class="hlt">tree</span> <span class="hlt">species</span> diversity on decomposition can operate via a multitude of mechanism, including alterations of microclimate by the forest canopy. Studying such effects in natural settings is complicated by the fact that topography also affects microclimate and thus decomposition, so that effects of diversity are more difficult to isolate. Here, we quantified decomposition rates of standard litter in young subtropical forest stands, separating effects of canopy <span class="hlt">tree</span> <span class="hlt">species</span> richness and topography, and quantifying their direct and micro-climate-mediated components. Our litterbag study was carried out at two experimental sites of a biodiversity-ecosystem functioning field experiment in south-east China (BEF-China). The field sites display strong topographical heterogeneity and were planted with <span class="hlt">tree</span> communities ranging from monocultures to mixtures of 24 native subtropical <span class="hlt">tree</span> <span class="hlt">species</span>. Litter bags filled with senescent leaves of three native <span class="hlt">tree</span> <span class="hlt">species</span> were placed from Nov. 2011 to Oct. 2012 on 134 plots along the <span class="hlt">tree</span> <span class="hlt">species</span> diversity gradient. Topographic features were measured for all and microclimate in a subset of plots. Stand <span class="hlt">species</span> richness, topography and microclimate explained important fractions of the variations in litter decomposition rates, with diversity and topographic effects in part mediated by microclimatic changes. <span class="hlt">Tree</span> stands were 2–3 years old, but nevertheless <span class="hlt">tree</span> <span class="hlt">species</span> diversity explained more variation (54.3%) in decomposition than topography (7.7%). <span class="hlt">Tree</span> <span class="hlt">species</span> richness slowed litter decomposition, an effect that slightly depended on litter <span class="hlt">species</span> identity. A large part of the variance in decomposition was explained by <span class="hlt">tree</span> <span class="hlt">species</span> composition, with the presence of three <span class="hlt">tree</span> <span class="hlt">species</span> playing a significant role. Microclimate explained 31.4% of the variance in decomposition, and was related to lower soil moisture. Within this microclimate effect, <span class="hlt">species</span> diversity (without composition) explained 8.9% and topography 34.4% of</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</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</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://www.ncbi.nlm.nih.gov/pubmed/21691855','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21691855"><span id="translatedtitle"><span class="hlt">Tree</span> <span class="hlt">species</span> identity and interactions with neighbors determine nutrient leaching in model 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>Ewel, John J; Bigelow, Seth W</p> <p>2011-12-01</p> <p>An ecosystem containing a mixture of <span class="hlt">species</span> that differ in phenology, morphology, and physiology might be expected to resist leaching of soil nutrients to a greater extent than one composed of a single <span class="hlt">species</span>. We tested the effects of <span class="hlt">species</span> identity and plant-life-form richness on nutrient leaching at a lowland tropical site where deep infiltration averages >2 m year(-1). Three indigenous <span class="hlt">tree</span> <span class="hlt">species</span> with contrasting leafing phenologies (evergreen, dry-season deciduous, and wet-season deciduous) were grown in monoculture and together with two other life-forms with which they commonly occur in tropical forests: a palm and a giant, perennial herb. To calculate nutrient leaching over an 11-year period, concentrations of nutrients in soil water were multiplied by drainage rates estimated from a water balance. The effect of plant-life-form richness on retention differed according to <span class="hlt">tree</span> <span class="hlt">species</span> identity and nutrient. Nitrate retention was greater in polycultures of the dry-season deciduous <span class="hlt">tree</span> <span class="hlt">species</span> (mean of 7.4 kg ha(-1) year(-1) of NO(3)-N lost compared to 12.7 in monoculture), and calcium and magnesium retention were greater in polycultures of the evergreen and wet-season deciduous <span class="hlt">tree</span> <span class="hlt">species</span>. Complementary use of light led to intensification of soil exploitation by roots, the main agent responsible for enhanced nutrient retention in some polycultures. Other mechanisms included differences in nutrient demand among <span class="hlt">species</span>, and avoidance of catastrophic failure due to episodic weather events or pest outbreaks. Even unrealistically simple multi-life-form mimics of tropical forest can safeguard a site's nutrient capital if careful attention is paid to <span class="hlt">species</span>' characteristics and temporal changes in interspecific interactions. PMID:21691855</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..1810323K&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..1810323K&link_type=ABSTRACT"><span id="translatedtitle">Investigating the limitations of <span class="hlt">tree</span> <span class="hlt">species</span> classification using the Combined Cluster and Discriminant Analysis method for low density ALS data from a dense forest region in Aggtelek (Hungary)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Koma, Zsófia; Deák, Márton; Kovács, József; Székely, Balázs; Kelemen, Kristóf; Standovár, Tibor</p> <p>2016-04-01</p> <p>Airborne Laser Scanning (ALS) is a widely used technology for forestry classification applications. However, single <span class="hlt">tree</span> detection and <span class="hlt">species</span> classification from low density ALS point cloud is limited in a dense forest region. In this study we investigate the division of a forest into homogenous groups at stand level. The study area is located in the Aggtelek karst region (Northeast Hungary) with a complex relief topography. The ALS dataset contained only 4 discrete echoes (at 2-4 pt/m2 density) from the study area during leaf-on season. Ground-truth measurements about canopy closure and proportion of <span class="hlt">tree</span> <span class="hlt">species</span> cover are available for every 70 meter in 500 square meter circular plots. In the first step, ALS data were processed and geometrical and intensity based features were calculated into a 5×5 meter raster based grid. The derived features contained: basic statistics of relative height, canopy RMS, echo ratio, openness, pulse penetration ratio, basic statistics of radiometric feature. In the second step the data were investigated using Combined Cluster and Discriminant Analysis (CCDA, Kovács et al., 2014). The CCDA method first determines a basic grouping for the multiple circle shaped sampling locations using hierarchical clustering and then for the arising grouping possibilities a core cycle is executed comparing the goodness of the investigated groupings with random ones. Out of these comparisons difference values arise, yielding information about the optimal grouping out of the investigated ones. If sub-groups are then further investigated, one might even find homogeneous groups. We found that low density ALS data classification into homogeneous groups are highly dependent on canopy closure, and the proportion of the dominant <span class="hlt">tree</span> <span class="hlt">species</span>. The presented results show high potential using CCDA for determination of homogenous separable groups in LiDAR based <span class="hlt">tree</span> <span class="hlt">species</span> classification. Aggtelek Karst/Slovakian Karst Caves" (HUSK/1101/221/0180, Aggtelek NP</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4206468','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4206468"><span id="translatedtitle">Data Concatenation, Bayesian Concordance and Coalescent-Based Analyses of the <span class="hlt">Species</span> <span class="hlt">Tree</span> for the Rapid Radiation of Triturus Newts</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wielstra, Ben; Arntzen, Jan W.; van der Gaag, Kristiaan J.; Pabijan, Maciej; Babik, Wieslaw</p> <p>2014-01-01</p> <p>The phylogenetic relationships for rapid <span class="hlt">species</span> radiations are difficult to disentangle. Here we study one such case, namely the genus Triturus, which is composed of the marbled and crested newts. We analyze data for 38 genetic markers, positioned in 3-prime untranslated regions of protein-coding genes, obtained with 454 sequencing. Our dataset includes twenty Triturus newts and represents all nine <span class="hlt">species</span>. Bayesian analysis of population structure allocates all individuals to their respective <span class="hlt">species</span>. The branching patterns obtained by data concatenation, Bayesian concordance analysis and coalescent-based estimations of the <span class="hlt">species</span> <span class="hlt">tree</span> differ from one another. The data concatenation based <span class="hlt">species</span> <span class="hlt">tree</span> shows high branch support but branching order is considerably affected by allele choice in the case of heterozygotes in the concatenation process. Bayesian concordance analysis expresses the conflict between individual gene <span class="hlt">trees</span> for part of the Triturus <span class="hlt">species</span> <span class="hlt">tree</span> as low concordance factors. The coalescent-based <span class="hlt">species</span> <span class="hlt">tree</span> is relatively similar to a previously published <span class="hlt">species</span> <span class="hlt">tree</span> based upon morphology and full mtDNA and any conflicting internal branches are not highly supported. Our findings reflect high gene <span class="hlt">tree</span> discordance due to incomplete lineage sorting (possibly aggravated by hybridization) in combination with low information content of the markers employed (as can be expected for relatively recent <span class="hlt">species</span> radiations). This case study highlights the complexity of resolving rapid radiations and we acknowledge that to convincingly resolve the Triturus <span class="hlt">species</span> <span class="hlt">tree</span> even more genes will have to be consulted. PMID:25337997</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://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://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://adsabs.harvard.edu/abs/2009AGUFM.B23A0359M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFM.B23A0359M"><span id="translatedtitle">Leaf gas exchange traits of domestic and exotic <span class="hlt">tree</span> <span class="hlt">species</span> in Cambodia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Miyazawa, Y.; Tateishi, M.; Kumagai, T.; Otsuki, K.</p> <p>2009-12-01</p> <p>In forests under the management by community villagers, exotic <span class="hlt">tree</span> <span class="hlt">species</span> with rapid growth rate are introduced in wide range of Cambodia. To evaluate the influence of the introduction on the forest gas exchange and water budget, we investigated the leaf gas exchange traits of two domestic (Dipterocarpus obtusifolius and Shorea roxburghii) and exotic <span class="hlt">tree</span> <span class="hlt">species</span> (Acasia auriculiformis and Eucalyptus camadilansis). We sampled shoots of each <span class="hlt">species</span> and measured the leaf gas exchange traits (photosynthetic rates under different CO2 concentrations, transpiration rate and stomatal conductance) (6 leaves x 3 <span class="hlt">trees</span> x 4 <span class="hlt">species</span>). We carried out this measurement at 2 months intervals for a year from the beginning of rainy season and compared the obtained traits among <span class="hlt">species</span>. Light saturated rate of net photosynthesis was higher in E. camadilansis but did not differ among other <span class="hlt">species</span> both in rainy and dry seasons. Seasonal patter in photosynthetic traits was not obvious. Each <span class="hlt">species</span> changed stomatal conductance in response to changes in environmental conditions. The response was more sensitive than reported values. In this presentation, we show details about the basic information about the leaf-level gas exchange traits, which are required to run soil- vegetation - atmosphere transfer model.</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://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.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://www.ncbi.nlm.nih.gov/pubmed/25775797','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25775797"><span id="translatedtitle">[Effects of <span class="hlt">tree</span> <span class="hlt">species</span> on polysaccharides content of epiphytic Dendrobium officinale].</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Guo, Ying-Ying; Zhu, Yan; Si, Jin-Ping; Liu, Jing-Jing; Wu, Cheng-Yong; Li, Hui</p> <p>2014-11-01</p> <p>To reveals the effects of <span class="hlt">tree</span> <span class="hlt">species</span> on polysaccharides content of epiphytic Dendrobium officinale. The polysaccharides content of D. officinale attached to living tress in wild or stumps in bionic-facility was determined by phenol-sulfuric acid method. There were extremely significant differences of polysaccharides content of D. officinale attached to different <span class="hlt">tree</span> <span class="hlt">species</span>, but the differences had no relationship with the form and nutrition of barks. The polysaccharides content of D. officinale mainly affected by the light intensity of environment, so reasonable illumination favored the accumulation of polysaccharides. Various polysaccharides content of D. officinal from different attached <span class="hlt">trees</span> is due to the difference of light regulation, but not the form and nutrition of barks. PMID:25775797</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014AGUFM.B51B0028L&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2014AGUFM.B51B0028L&link_type=ABSTRACT"><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.ncbi.nlm.nih.gov/pubmed/11737299','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/11737299"><span id="translatedtitle">Fine-scale spatial genetic structure of eight tropical <span class="hlt">tree</span> <span class="hlt">species</span> as analysed by RAPDs.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Degen, B; Caron, H; Bandou, E; Maggia, L; Chevallier, M H; Leveau, A; Kremer, A</p> <p>2001-10-01</p> <p>The fine-scale spatial genetic structure of eight tropical <span class="hlt">tree</span> <span class="hlt">species</span> (Chrysophyllum sanguinolentum, Carapa procera, Dicorynia guianensis, Eperua grandiflora, Moronobea coccinea, Symphonia globulifera, Virola michelii, Vouacapoua americana) was studied in populations that were part of a silvicultural trial in French Guiana. The <span class="hlt">species</span> analysed have different spatial distribution, sexual system, pollen and seed dispersal agents, flowering phenology and environmental demands. The spatial position of <span class="hlt">trees</span> and a RAPD data set for each <span class="hlt">species</span> were combined using a multivariate genetic distance method to estimate spatial genetic structure. A significant spatial genetic structure was found for four of the eight <span class="hlt">species</span>. In contrast to most observations in temperate forests, where spatial structure is not usually detected at distances greater than 50 m, significant genetic structure was found at distances up to 300 m. The relationships between spatial genetic structure and life history characteristics are discussed. PMID:11737299</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.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=89709','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=89709"><span id="translatedtitle">In Vitro Activities of Ketoconazole, Econazole, Miconazole, and Melaleuca alternifolia (Tea <span class="hlt">Tree</span>) Oil against Malassezia <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>Hammer, K. A.; Carson, C. F.; Riley, T. V.</p> <p>2000-01-01</p> <p>The in vitro activities of ketoconazole, econazole, miconazole, and tea <span class="hlt">tree</span> oil against 54 Malassezia isolates were determined by agar and broth dilution methods. Ketoconazole was more active than both econazole and miconazole, which showed very similar activities. M. furfur was the least susceptible <span class="hlt">species</span>. M. sympodialis, M. slooffiae, M. globosa, and M. obtusa showed similar susceptibilities to the four agents. PMID:10639388</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/19256435','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/19256435"><span id="translatedtitle">[Reproductive phenology of <span class="hlt">tree</span> <span class="hlt">species</span> in the Tenosique tropical forest, Tabasco, Mexico].</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ochoa-Gaona, Susana; Hernández, Isidro Pérez; de Jong, Bernardus H J</p> <p>2008-06-01</p> <p>Between August 2003 and August 2005 we registered the flowering and fruiting of 75 <span class="hlt">tree</span> <span class="hlt">species</span> (341 individual <span class="hlt">trees</span>) in a tropical rain forest at Tenosique, Tabasco, Mexico. Monthly we checked five transects (500 m long; 5 m wide). To test the homogeneity of flowering and fruiting during the year, and between adjacent months, we applied a chi2 test. The flowering was bimodal, with a highest peak in March and April, coinciding with the dry season, and a second lower peak in July when precipitation is relatively low. The highest number of fruiting <span class="hlt">tree</span> <span class="hlt">species</span> occur between May and July, with its peak in May. Each of the most common botanical families showed a particular phenological pattern. Monthly rainfall and the number of <span class="hlt">species</span> flowering or fruiting were not significantly correlated. This means that <span class="hlt">trees</span> are flowering and fruiting all year long, with seasonal increases of both phenological phenomena in the dryer periods. We conclude that phenological patterns vary between individuals and between years and are not seasonally correlated. The data we generated are relevant to program the best periods of seed collections according to individual or groups of <span class="hlt">species</span>, as part of forest management and conservation practices. PMID:19256435</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.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://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://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=541764','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=541764"><span id="translatedtitle">C4 Photosynthesis in <span class="hlt">Tree</span> Form Euphorbia <span class="hlt">Species</span> from Hawaiian Rainforest Sites 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>Pearcy, Robert W.; Troughton, John</p> <p>1975-01-01</p> <p>The 13C 12C isotope ratios and the leaf anatomy of 18 <span class="hlt">species</span> and varieties of Euphorbia native to the Hawaian Islands indicated that all possess C4 photosynthesis. These <span class="hlt">species</span> range from small prostrate coastal strand shrubs to shrubs and <span class="hlt">trees</span> in rainforest and bog habitats. The results show that C4 photosynthesis occurs in plants from a much wider range of habitats and life-forms than has been previously reported. PMID:16659208</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://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://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</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</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27481793','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27481793"><span id="translatedtitle">The Trichoptera barcode initiative: a strategy for generating a <span class="hlt">species</span>-level <span class="hlt">Tree</span> of Life.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhou, Xin; Frandsen, Paul B; Holzenthal, Ralph W; Beet, Clare R; Bennett, Kristi R; Blahnik, Roger J; Bonada, Núria; Cartwright, David; Chuluunbat, Suvdtsetseg; Cocks, Graeme V; Collins, Gemma E; deWaard, Jeremy; Dean, John; Flint, Oliver S; Hausmann, Axel; Hendrich, Lars; Hess, Monika; Hogg, Ian D; Kondratieff, Boris C; Malicky, Hans; Milton, Megan A; Morinière, Jérôme; Morse, John C; Mwangi, François Ngera; Pauls, Steffen U; Gonzalez, María Razo; Rinne, Aki; Robinson, Jason L; Salokannel, Juha; Shackleton, Michael; Smith, Brian; Stamatakis, Alexandros; StClair, Ros; Thomas, Jessica A; Zamora-Muñoz, Carmen; Ziesmann, Tanja; Kjer, Karl M</p> <p>2016-09-01</p> <p>DNA barcoding was intended as a means to provide <span class="hlt">species</span>-level identifications through associating DNA sequences from unknown specimens to those from curated reference specimens. Although barcodes were not designed for phylogenetics, they can be beneficial to the completion of the <span class="hlt">Tree</span> of Life. The barcode database for Trichoptera is relatively comprehensive, with data from every family, approximately two-thirds of the genera, and one-third of the described <span class="hlt">species</span>. Most Trichoptera, as with most of life's <span class="hlt">species</span>, have never been subjected to any formal phylogenetic analysis. Here, we present a phylogeny with over 16 000 unique haplotypes as a working hypothesis that can be updated as our estimates improve. We suggest a strategy of implementing constrained <span class="hlt">tree</span> searches, which allow larger datasets to dictate the backbone phylogeny, while the barcode data fill out the tips of the <span class="hlt">tree</span>. We also discuss how this phylogeny could be used to focus taxonomic attention on ambiguous <span class="hlt">species</span> boundaries and hidden biodiversity. We suggest that systematists continue to differentiate between 'Barcode Index Numbers' (BINs) and '<span class="hlt">species</span>' that have been formally described. Each has utility, but they are not synonyms. We highlight examples of integrative taxonomy, using both barcodes and morphology for <span class="hlt">species</span> description.This article is part of the themed issue 'From DNA barcodes to biomes'. PMID:27481793</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> <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.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://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/25526843','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25526843"><span id="translatedtitle"><span class="hlt">Tree</span> <span class="hlt">species</span> diversity mitigates disturbance impacts on the forest carbon cycle.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pedro, Mariana Silva; Rammer, Werner; Seidl, Rupert</p> <p>2015-03-01</p> <p>Biodiversity fosters the functioning and stability of forest ecosystems and, consequently, the provision of crucial ecosystem services that support human well-being and quality of life. In particular, it has been suggested that <span class="hlt">tree</span> <span class="hlt">species</span> diversity buffers ecosystems against the impacts of disturbances, a relationship known as the "insurance hypothesis". Natural disturbances have increased across Europe in recent decades and climate change is expected to amplify the frequency and severity of disturbance events. In this context, mitigating disturbance impacts and increasing the resilience of forest ecosystems is of growing importance. We have tested how <span class="hlt">tree</span> <span class="hlt">species</span> diversity modulates the impact of disturbance on net primary production and the total carbon stored in living biomass for a temperate forest landscape in Central Europe. Using the simulation model iLand to study the effect of different disturbance regimes on landscapes with varying levels of <span class="hlt">tree</span> <span class="hlt">species</span> richness, we found that increasing diversity generally reduces the disturbance impact on carbon storage and uptake, but that this effect weakens or even reverses with successional development. Our simulations indicate a clear positive relationship between diversity and resilience, with more diverse systems experiencing lower disturbance-induced variability in their trajectories of ecosystem functioning. We found that positive effects of <span class="hlt">tree</span> <span class="hlt">species</span> diversity are mainly driven by an increase in functional diversity and a modulation of traits related to recolonization and resource usage. The results of our study suggest that increasing <span class="hlt">tree</span> <span class="hlt">species</span> diversity could mitigate the effects of intensifying disturbance regimes on ecosystem functioning and improve the robustness of forest carbon storage and the role of forests in climate change mitigation. PMID:25526843</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.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.ncbi.nlm.nih.gov/pubmed/16995629','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/16995629"><span id="translatedtitle"><span class="hlt">Tree</span> <span class="hlt">species</span> effects on decomposition and forest floor dynamics in a common garden.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hobbie, Sarah E; Reich, Peter B; Oleksyn, Jacek; Ogdahl, Megan; Zytkowiak, Roma; Hale, Cynthia; Karolewski, Piotr</p> <p>2006-09-01</p> <p>We studied the effects of <span class="hlt">tree</span> <span class="hlt">species</span> on leaf litter decomposition and forest floor dynamics in a common garden experiment of 14 <span class="hlt">tree</span> <span class="hlt">species</span> (Abies alba, Acer platanoides, Acer pseudoplatanus, Betula pendula, Carpinus betulus, Fagus sylvatica, Larix decidua, Picea abies, Pinus nigra, Pinus sylvestris, Pseudotsuga menziesii, Quercus robur, Quercus rubra, and Tilia cordata) in southwestern Poland. We used three simultaneous litter bag experiments to tease apart <span class="hlt">species</span> effects on decomposition via leaf litter chemistry vs. effects on the decomposition environment. Decomposition rates of litter in its plot of origin were negatively correlated with litter lignin and positively correlated with mean annual soil temperature (MAT(soil)) across <span class="hlt">species</span>. Likewise, decomposition of a common litter type across all plots was positively associated with MAT(soil), and decomposition of litter from all plots in a common plot was negatively related to litter lignin but positively related to litter Ca. Taken together, these results indicate that <span class="hlt">tree</span> <span class="hlt">species</span> influenced microbial decomposition primarily via differences in litter lignin (and secondarily, via differences in litter Ca), with high-lignin (and low-Ca) <span class="hlt">species</span> decomposing most slowly, and by affecting MAT(soil), with warmer plots exhibiting more rapid decomposition. In addition to litter bag experiments, we examined forest floor dynamics in each plot by mass balance, since earthworms were a known component of these forest stands and their access to litter in litter bags was limited. Forest floor removal rates estimated from mass balance were positively related to leaf litter Ca (and unrelated to decay rates obtained using litter bags). Litter Ca, in turn, was positively related to the abundance of earthworms, particularly Lumbricus terrestris. Thus, while <span class="hlt">species</span> influence microbially mediated decomposition primarily through differences in litter lignin, differences among <span class="hlt">species</span> in litter Ca are most important in</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 μg CH4-C m-2 h-1) was greater than that of the EU plantation (29.9 ± 0.9 μg CH4-C m-2 h-1). In the AA plantation, the averaged rates of CH4 uptake for the MN (28.6 ± 2.3 μg CH4-C m-2 h-1) and HN treatment (23.8 ± 2.8 μg 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.ncbi.nlm.nih.gov/pubmed/20472645','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/20472645"><span id="translatedtitle">The influence of mixed <span class="hlt">tree</span> plantations on the nutrition of individual <span class="hlt">species</span>: a review.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Richards, Anna E; Forrester, David I; Bauhus, Jürgen; Scherer-Lorenzen, Michael</p> <p>2010-09-01</p> <p>Productivity of <span class="hlt">tree</span> plantations is a function of the supply, capture and efficiency of use of resources, as outlined in the Production Ecology Equation. <span class="hlt">Species</span> interactions in mixed-<span class="hlt">species</span> stands can influence each of these variables. The importance of resource-use efficiency in determining forest productivity has been clearly demonstrated in monocultures; however, substantial knowledge gaps remain for mixtures. This review examines how the physiology and morphology of a given <span class="hlt">species</span> can vary depending on whether it grows in a mixture or monoculture. We outline how physiological and morphological shifts within <span class="hlt">species</span>, resulting from interactions in mixtures, may influence the three variables of the Production Ecology Equation, with an emphasis on nutrient resources [nitrogen (N) and phosphorus (P)]. These include (i) resource availability, including soil nutrient mineralization, N₂ fixation and litter decomposition; (ii) proportion of resources captured, resulting from shifts in spatial, temporal and chemical patterns of root dynamics; (iii) resource-use efficiency. We found that more than 50% of mixed-<span class="hlt">species</span> studies report a shift to greater above-ground nutrient content of <span class="hlt">species</span> grown in mixtures compared to monocultures, indicating an increase in the proportion of resources captured from a site. Secondly, a meta-analysis showed that foliar N concentrations significantly increased for a given <span class="hlt">species</span> in a mixture containing N₂-fixing <span class="hlt">species</span>, compared to a monoculture, suggesting higher rates of photosynthesis and greater resource-use efficiency. Significant shifts in N- and P-use efficiencies of a given <span class="hlt">species</span>, when grown in a mixture compared to a monoculture, occurred in over 65% of studies where resource-use efficiency could be calculated. Such shifts can result from changes in canopy photosynthetic capacities, changes in carbon allocation or changes to foliar nutrient residence times of <span class="hlt">species</span> in a mixture. We recommend that future research</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/21302839','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21302839"><span id="translatedtitle">The trait contribution to wood decomposition rates of 15 Neotropical <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>van Geffen, Koert G; Poorter, Lourens; Sass-Klaassen, Ute; van Logtestijn, Richard S P; Cornelissen, Johannes H C</p> <p>2010-12-01</p> <p>The decomposition of dead wood is a critical uncertainty in models of the global carbon cycle. Despite this, relatively few studies have focused on dead wood decomposition, with a strong bias to higher latitudes. Especially the effect of interspecific variation in <span class="hlt">species</span> traits on differences in wood decomposition rates remains unknown. In order to fill these gaps, we applied a novel method to study long-term wood decomposition of 15 <span class="hlt">tree</span> <span class="hlt">species</span> in a Bolivian semi-evergreen tropical moist forest. We hypothesized that interspecific differences in <span class="hlt">species</span> traits are important drivers of variation in wood decomposition rates. Wood decomposition rates (fractional mass loss) varied between 0.01 and 0.31 yr(-1). We measured 10 different chemical, anatomical, and morphological traits for all <span class="hlt">species</span>. The <span class="hlt">species</span>' average traits were useful predictors of wood decomposition rates, particularly the average diameter (dbh) of the <span class="hlt">tree</span> <span class="hlt">species</span> (R2 = 0.41). Lignin concentration further increased the proportion of explained inter-specific variation in wood decomposition (both negative relations, cumulative R2 = 0.55), although it did not significantly explain variation in wood decomposition rates if considered alone. When dbh values of the actual dead <span class="hlt">trees</span> sampled for decomposition rate determination were used as a predictor variable, the final model (including dead <span class="hlt">tree</span> dbh and lignin concentration) explained even more variation in wood decomposition rates (R2 = 0.71), underlining the importance of dbh in wood decomposition. Other traits, including wood density, wood anatomical traits, macronutrient concentrations, and the amount of phenolic extractives could not significantly explain the variation in wood decomposition rates. The surprising results of this multi-<span class="hlt">species</span> study, in which for the first time a large set of traits is explicitly linked to wood decomposition rates, merits further testing in other forest ecosystems. PMID:21302839</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</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</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</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=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.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4814042','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4814042"><span id="translatedtitle">Mechanism Underlying the Spatial Pattern Formation of Dominant <span class="hlt">Tree</span> <span class="hlt">Species</span> in a Natural Secondary 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>Jia, Guodong; Yu, Xinxiao; Fan, Dengxing; Jia, Jianbo</p> <p>2016-01-01</p> <p>Studying the spatial pattern of plant <span class="hlt">species</span> may provide significant insights into processes and mechanisms that maintain stand stability. To better understand the dynamics of naturally regenerated secondary forests, univariate and bivariate Ripley’s L(r) functions were employed to evaluate intra-/interspecific relationships of four dominant <span class="hlt">tree</span> <span class="hlt">species</span> (Populus davidiana, Betula platyphylla, Larix gmelinii and Acer mono) and to distinguish the underlying mechanism of spatial distribution. The results showed that the distribution of soil, water and nutrients was not fragmented but presented clear gradients. An overall aggregated distribution existed at most distances. No correlation was found between the spatial pattern of soil conditions and that of <span class="hlt">trees</span>. Both positive and negative intra- and interspecific relationships were found between different DBH classes at various distances. Large <span class="hlt">trees</span> did not show systematic inhibition of the saplings. By contrast, the inhibition intensified as the height differences increased between the compared pairs. Except for Larix, universal inhibition of saplings by upper layer <span class="hlt">trees</span> occurred among other <span class="hlt">species</span>, and this reflected the vertical competition for light. Therefore, we believe that competition for light rather than soil nutrients underlies the mechanism driving the formation of stand spatial pattern in the rocky mountainous areas examined. PMID:27028757</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.ncbi.nlm.nih.gov/pubmed/27028757','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27028757"><span id="translatedtitle">Mechanism Underlying the Spatial Pattern Formation of Dominant <span class="hlt">Tree</span> <span class="hlt">Species</span> in a Natural Secondary Forest.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jia, Guodong; Yu, Xinxiao; Fan, Dengxing; Jia, Jianbo</p> <p>2016-01-01</p> <p>Studying the spatial pattern of plant <span class="hlt">species</span> may provide significant insights into processes and mechanisms that maintain stand stability. To better understand the dynamics of naturally regenerated secondary forests, univariate and bivariate Ripley's L(r) functions were employed to evaluate intra-/interspecific relationships of four dominant <span class="hlt">tree</span> <span class="hlt">species</span> (Populus davidiana, Betula platyphylla, Larix gmelinii and Acer mono) and to distinguish the underlying mechanism of spatial distribution. The results showed that the distribution of soil, water and nutrients was not fragmented but presented clear gradients. An overall aggregated distribution existed at most distances. No correlation was found between the spatial pattern of soil conditions and that of <span class="hlt">trees</span>. Both positive and negative intra- and interspecific relationships were found between different DBH classes at various distances. Large <span class="hlt">trees</span> did not show systematic inhibition of the saplings. By contrast, the inhibition intensified as the height differences increased between the compared pairs. Except for Larix, universal inhibition of saplings by upper layer <span class="hlt">trees</span> occurred among other <span class="hlt">species</span>, and this reflected the vertical competition for light. Therefore, we believe that competition for light rather than soil nutrients underlies the mechanism driving the formation of stand spatial pattern in the rocky mountainous areas examined. PMID:27028757</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.ncbi.nlm.nih.gov/pubmed/23360009','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23360009"><span id="translatedtitle">Floristic diversity of regenerated <span class="hlt">tree</span> <span class="hlt">species</span> in Dipterocarp forests in Western Ghats of Karnataka, India.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Prasad, A G Devi; Al-Sagheer, Nageeb A</p> <p>2012-07-01</p> <p>The research was focused on exploring the structure, diversity and form of regeneration process of the Dipterocarp forests in Western Ghats in relation to environmental factors. Eight populations in the distribution range of Dipterocarp forests were selected. In each population 32 plots of 2mx2m were laid down randomly. Atotal of 1243 seedlings < or = 10 cm dbh (diameter at breast height) belonging to 99 <span class="hlt">species</span> and 48 families were recorded. The number of regenerated <span class="hlt">tree</span> <span class="hlt">species</span> was found to be high in the populations of Mudigere (40), Sakleshpura (40) and Makuta (39), which are characterized by favorable locality factors and lower disturbances. The highest similarity index in <span class="hlt">species</span> composition was recorded between the populations of Sampaje in Kodagu district and Gundya in Dakshina Kannada (60%) whereas the lowest similarity index was observed between the population of Sringeri in Chikmagalore and Sampaje (53%) and Gundya and Makuta (35%) in Kodagu district. Dipterocarpus indicus was found to be dominant among the regenerated <span class="hlt">tree</span> <span class="hlt">species</span> in all the sites studied except Gundy and Sampaje. The frequencies of regeneration classes (seedlings, saplings, poles and adult <span class="hlt">trees</span>) were shaped as inverse J curve indicating the normal regeneration pattern under the present disturbance. The average disturbance of litter collection, grazing, fire, weeds and canopy opening were significant among different populations (p < or = 0.05). Negative correlation was observed between disturbance and <span class="hlt">species</span> richness, number of individuals and density. PMID:23360009</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> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4971193','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4971193"><span id="translatedtitle">The Trichoptera barcode initiative: a strategy for generating a <span class="hlt">species</span>-level <span class="hlt">Tree</span> of Life</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Frandsen, Paul B.; Holzenthal, Ralph W.; Beet, Clare R.; Bennett, Kristi R.; Blahnik, Roger J.; Bonada, Núria; Cartwright, David; Chuluunbat, Suvdtsetseg; Cocks, Graeme V.; Collins, Gemma E.; deWaard, Jeremy; Dean, John; Flint, Oliver S.; Hausmann, Axel; Hendrich, Lars; Hess, Monika; Hogg, Ian D.; Kondratieff, Boris C.; Malicky, Hans; Milton, Megan A.; Morinière, Jérôme; Morse, John C.; Mwangi, François Ngera; Pauls, Steffen U.; Gonzalez, María Razo; Rinne, Aki; Robinson, Jason L.; Salokannel, Juha; Shackleton, Michael; Smith, Brian; Stamatakis, Alexandros; StClair, Ros; Thomas, Jessica A.; Zamora-Muñoz, Carmen; Ziesmann, Tanja</p> <p>2016-01-01</p> <p>DNA barcoding was intended as a means to provide <span class="hlt">species</span>-level identifications through associating DNA sequences from unknown specimens to those from curated reference specimens. Although barcodes were not designed for phylogenetics, they can be beneficial to the completion of the <span class="hlt">Tree</span> of Life. The barcode database for Trichoptera is relatively comprehensive, with data from every family, approximately two-thirds of the genera, and one-third of the described <span class="hlt">species</span>. Most Trichoptera, as with most of life's <span class="hlt">species</span>, have never been subjected to any formal phylogenetic analysis. Here, we present a phylogeny with over 16 000 unique haplotypes as a working hypothesis that can be updated as our estimates improve. We suggest a strategy of implementing constrained <span class="hlt">tree</span> searches, which allow larger datasets to dictate the backbone phylogeny, while the barcode data fill out the tips of the <span class="hlt">tree</span>. We also discuss how this phylogeny could be used to focus taxonomic attention on ambiguous <span class="hlt">species</span> boundaries and hidden biodiversity. We suggest that systematists continue to differentiate between ‘Barcode Index Numbers’ (BINs) and ‘species’ that have been formally described. Each has utility, but they are not synonyms. We highlight examples of integrative taxonomy, using both barcodes and morphology for <span class="hlt">species</span> description. This article is part of the themed issue ‘From DNA barcodes to biomes’. PMID:27481793</p> </li> <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://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></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://www.ncbi.nlm.nih.gov/pubmed/24486469','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24486469"><span id="translatedtitle">Converting probabilistic <span class="hlt">tree</span> <span class="hlt">species</span> range shift projections into meaningful classes for management.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hanewinkel, Marc; Cullmann, Dominik A; Michiels, Hans-Gerd; Kändler, Gerald</p> <p>2014-02-15</p> <p>The paper deals with the management problem how to decide on <span class="hlt">tree</span> <span class="hlt">species</span> suitability under changing environmental conditions. It presents an algorithm that classifies the output of a range shift model for major <span class="hlt">tree</span> <span class="hlt">species</span> in Europe into multiple classes that can be linked to qualities characterizing the ecological niche of the <span class="hlt">species</span>. The classes: i) Core distribution area, ii) Extended distribution area, iii) Occasional occurrence area, and iv) No occurrence area are first theoretically developed and then statistically described. The classes are interpreted from an ecological point of view using criteria like population structure, competitive strength, site spectrum and vulnerability to biotic hazards. The functioning of the algorithm is demonstrated using the example of a generalized linear model that was fitted to a pan-European dataset of presence/absence of major <span class="hlt">tree</span> <span class="hlt">species</span> with downscaled climate data from a General Circulation Model (GCM). Applications of the algorithm to <span class="hlt">tree</span> <span class="hlt">species</span> suitability classification on a European and regional level are shown. The thresholds that are used by the algorithm are precision-based and include Cohen's Kappa. A validation of the algorithm using an independent dataset of the German National Forest Inventory shows good accordance of the statistically derived classes with ecological traits for Norway spruce, while the differentiation especially between core and extended distribution for European beech that is in the centre of its natural range in this area is less accurate. We hypothesize that for <span class="hlt">species</span> in the core of their range regional factors like forest history superimpose climatic factors. Problems of uncertainty issued from potentially applying a multitude of modelling approaches and/or climate realizations within the range shift model are discussed and a way to deal with the uncertainty by revealing the underlying attitude towards risk of the decision maker is proposed. PMID:24486469</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27265248','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27265248"><span id="translatedtitle">Taxonomic and ecological relevance of the chlorophyll a fluorescence signature of <span class="hlt">tree</span> <span class="hlt">species</span> in mixed European forests.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pollastrini, Martina; Holland, Vera; Brüggemann, Wolfgang; Bruelheide, Helge; Dănilă, Iulian; Jaroszewicz, Bogdan; Valladares, Fernando; Bussotti, Filippo</p> <p>2016-10-01</p> <p>The variability of chlorophyll a fluorescence (ChlF) parameters of forest <span class="hlt">tree</span> <span class="hlt">species</span> was investigated in 209 stands belonging to six European forests, from Mediterranean to boreal regions. The modifying role of environmental factors, forest structure and <span class="hlt">tree</span> diversity (<span class="hlt">species</span> richness and composition) on ChlF signature was analysed. At the European level, conifers showed higher potential performance than broadleaf <span class="hlt">species</span>. Forests in central Europe performed better than those in Mediterranean and boreal regions. At the site level, homogeneous clusters of <span class="hlt">tree</span> <span class="hlt">species</span> were identified by means of a principal component analysis (PCA) of ChlF parameters. The discrimination of the clusters of <span class="hlt">species</span> was influenced by their taxonomic position and ecological characteristics. The <span class="hlt">species</span> richness influenced the <span class="hlt">tree</span> ChlF properties in different ways depending on <span class="hlt">tree</span> <span class="hlt">species</span> and site. <span class="hlt">Tree</span> <span class="hlt">species</span> and site also affected the relationships between ChlF parameters and other plant functional traits (specific leaf area, leaf nitrogen content, light-saturated photosynthesis, wood density, leaf carbon isotope composition). The assessment of the photosynthetic properties of <span class="hlt">tree</span> <span class="hlt">species</span>, by means of ChlF parameters, in relation to their functional traits, is a relevant issue for studies in forest ecology. The connections of data from field surveys with remotely assessed parameters must be carefully explored. PMID:27265248</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://pubs.er.usgs.gov/publication/70123146','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70123146"><span id="translatedtitle">The brown <span class="hlt">tree</span> snake, an introduced pest <span class="hlt">species</span> in the central Pacific Islands</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Fritts, Thomas H.; Rodda, Gordon H.</p> <p>1989-01-01</p> <p>The reproduction of endangered Mariana crows (Corvus kubaryi) is intensively monitored, nests are protected, and (when necessary) eggs or young are moved to the safety of lab conditions until they are less vulnerable to the threats in natural habitats. Barriers on <span class="hlt">tree</span> trunks and judicious pruning of adjacent <span class="hlt">trees</span> are used in attempts to exclude snakes from nest <span class="hlt">trees</span>. Two birds unique to Guam--the Micronesian kingfisher (Halcyon cinnamomina cinnamomina) and Guam rail (Gallirallus owstoni)-- are maintained at captive propagation facilities on Guam and in mainland zoos. Studies of these and other <span class="hlt">species</span>, in captivity and on nearby islands, are underway to bolster our biological understanding of their behavior, reproduction, habitat use, and population biology.</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://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</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/21445684','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21445684"><span id="translatedtitle">Comparative hydraulic architecture of tropical <span class="hlt">tree</span> <span class="hlt">species</span> representing a range of successional stages and wood density.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>McCulloh, Katherine A; Meinzer, Frederick C; Sperry, John S; Lachenbruch, Barbara; Voelker, Steven L; Woodruff, David R; Domec, Jean-Christophe</p> <p>2011-09-01</p> <p>Plant hydraulic architecture (PHA) has been linked to water transport sufficiency, photosynthetic rates, growth form and attendant carbon allocation. Despite its influence on traits central to conferring an overall competitive advantage in a given environment, few studies have examined whether key aspects of PHA are indicative of successional stage, especially within mature individuals. While it is well established that wood density (WD) tends to be lower in early versus late successional <span class="hlt">tree</span> <span class="hlt">species</span>, and that WD can influence other aspects of PHA, the interaction of WD, successional stage and the consequent implications for PHA have not been sufficiently explored. Here, we studied differences in PHA at the scales of wood anatomy to whole-<span class="hlt">tree</span> hydraulic conductance in <span class="hlt">species</span> in early versus late successional Panamanian tropical forests. Although the trunk WD was indistinguishable between the successional groups, the branch WD was lower in the early successional <span class="hlt">species</span>. Across all <span class="hlt">species</span>, WD correlated negatively with vessel diameter and positively with vessel packing density. The ratio of branch:trunk vessel diameter, branch sap flux and whole-<span class="hlt">tree</span> leaf-specific conductance scaled negatively with branch WD across <span class="hlt">species</span>. Pioneer <span class="hlt">species</span> showed greater sap flux in branches than in trunks and a greater leaf-specific hydraulic conductance, suggesting that pioneer <span class="hlt">species</span> can move greater quantities of water at a given tension gradient. In combination with the greater water storage capacitance associated with lower WD, these results suggest these pioneer <span class="hlt">species</span> can save on the carbon expenditure needed to build safer xylem and instead allow more carbon to be allocated to rapid growth. PMID:21445684</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> </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://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</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/16132448','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/16132448"><span id="translatedtitle">Potential <span class="hlt">tree</span> <span class="hlt">species</span> for use in the restoration of unsanitary landfills.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kim, Kee Dae; Lee, Eun Ju</p> <p>2005-07-01</p> <p>Given that they represent the most economical option for disposing of refuse, waste landfills are widespread in urban areas. However, landfills generate air and water pollution and require restoration for landscape development. A number of unsanitary waste landfills have caused severe environmental problems in developing countries. This study aimed to investigate the colonization status of different <span class="hlt">tree</span> <span class="hlt">species</span> on waste landfills to assess their potential for restoring unsanitary landfills in South Korea. Plot surveys were conducted using 10 x 10-m quadrats at seven waste landfill sites: Bunsuri, Dugiri, Hasanundong, Gomaeri, Kyongseodong, Mojeonri, and Shindaedong. We determined the height, diameter at breast height (DBH), and number of <span class="hlt">tree</span> <span class="hlt">species</span> in the plots, and enumerated all saplings < or =1 m high. Because black locust, Robinia pseudoacacia, was the dominant <span class="hlt">tree</span> <span class="hlt">species</span> in the waste landfills, we measured the distance from the presumed mother plant (i.e., the tallest black locust in a patch), height, and DBH of all individuals in black locust patches to determine patch structure. Robinia pseudoacacia, Salix koreensis, and Populus sieboldii formed canopy layers in the waste landfills. The basal area of black locust was 1.51 m(2)/ha, and this <span class="hlt">species</span> had the highest number of saplings among all <span class="hlt">tree</span> <span class="hlt">species</span>. The diameter of the black locust patches ranged from 3.71 to 11.29 m. As the patch diameter increased, the number of regenerated saplings also tended to increase, albeit not significantly. Black locust invaded via bud banks and spread clonally in a concentric pattern across the landfills. This <span class="hlt">species</span> grew well in the dry habitat of the landfills, and its growth rate was very high. Furthermore, black locust has the ability to fix nitrogen symbiotically; it is therefore considered a well-adapted <span class="hlt">species</span> for waste landfills. Eleven woody <span class="hlt">species</span> were selected for screening: Acer palmatum, Albizzia julibrissin, Buxus microphylla var. koreana, Ginkgo</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.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4961160','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4961160"><span id="translatedtitle">The probability of monophyly of a sample of gene lineages on a <span class="hlt">species</span> <span class="hlt">tree</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>Mehta, Rohan S.; Bryant, David; Rosenberg, Noah A.</p> <p>2016-01-01</p> <p>Monophyletic groups—groups that consist of all of the descendants of a most recent common ancestor—arise naturally as a consequence of descent processes that result in meaningful distinctions between organisms. Aspects of monophyly are therefore central to fields that examine and use genealogical descent. In particular, studies in conservation genetics, phylogeography, population genetics, <span class="hlt">species</span> delimitation, and systematics can all make use of mathematical predictions under evolutionary models about features of monophyly. One important calculation, the probability that a set of gene lineages is monophyletic under a two-<span class="hlt">species</span> neutral coalescent model, has been used in many studies. Here, we extend this calculation for a <span class="hlt">species</span> <span class="hlt">tree</span> model that contains arbitrarily many <span class="hlt">species</span>. We study the effects of <span class="hlt">species</span> <span class="hlt">tree</span> topology and branch lengths on the monophyly probability. These analyses reveal new behavior, including the maintenance of nontrivial monophyly probabilities for gene lineage samples that span multiple <span class="hlt">species</span> and even for lineages that do not derive from a monophyletic <span class="hlt">species</span> group. We illustrate the mathematical results using an example application to data from maize and teosinte. PMID:27432988</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2677233','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2677233"><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=pmc">PubMed Central</a></p> <p>Purves, Drew W.</p> <p>2009-01-01</p> <p>Regional species–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: R0 (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.ncbi.nlm.nih.gov/pubmed/27432988','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27432988"><span id="translatedtitle">The probability of monophyly of a sample of gene lineages on a <span class="hlt">species</span> <span class="hlt">tree</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mehta, Rohan S; Bryant, David; Rosenberg, Noah A</p> <p>2016-07-19</p> <p>Monophyletic groups-groups that consist of all of the descendants of a most recent common ancestor-arise naturally as a consequence of descent processes that result in meaningful distinctions between organisms. Aspects of monophyly are therefore central to fields that examine and use genealogical descent. In particular, studies in conservation genetics, phylogeography, population genetics, <span class="hlt">species</span> delimitation, and systematics can all make use of mathematical predictions under evolutionary models about features of monophyly. One important calculation, the probability that a set of gene lineages is monophyletic under a two-<span class="hlt">species</span> neutral coalescent model, has been used in many studies. Here, we extend this calculation for a <span class="hlt">species</span> <span class="hlt">tree</span> model that contains arbitrarily many <span class="hlt">species</span>. We study the effects of <span class="hlt">species</span> <span class="hlt">tree</span> topology and branch lengths on the monophyly probability. These analyses reveal new behavior, including the maintenance of nontrivial monophyly probabilities for gene lineage samples that span multiple <span class="hlt">species</span> and even for lineages that do not derive from a monophyletic <span class="hlt">species</span> group. We illustrate the mathematical results using an example application to data from maize and teosinte. PMID:27432988</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://dx.doi.org/10.1139/X10-199','USGSPUBS'); return false;" href="http://dx.doi.org/10.1139/X10-199"><span id="translatedtitle"><span class="hlt">Tree</span> <span class="hlt">species</span> and soil nutrient profiles in old-growth forests of the Oregon Coast Range</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>Old-growth forests of the Pacific Northwest provide a unique opportunity to examine <span class="hlt">tree</span> <span class="hlt">species</span> – soil relationships in ecosystems that have developed without significant human disturbance. We characterized foliage, forest floor, and mineral soil nutrients associated with four canopy <span class="hlt">tree</span> <span class="hlt">species</span> (Douglas-fir (Pseudotsuga menziesii (Mirbel) Franco), western hemlock (Tsuga heterophylla (Raf.) Sarg.), western redcedar (Thuja plicata Donn ex D. Don), and bigleaf maple (Acer macrophyllum Pursh)) in eight old-growth forests of the Oregon Coast Range. The greatest forest floor accumulations of C, N, P, Ca, Mg, and K occurred under Douglas-fir, primarily due to greater forest floor mass. In mineral soil, western hemlock exhibited significantly lower Ca concentration and sum of cations (Ca + Mg + K) than bigleaf maple, with intermediate values for Douglas-fir and western redcedar. Bigleaf maple explained most <span class="hlt">species</span>-based differences in foliar nutrients, displaying high concentrations of N, P, Ca, Mg, and K. Foliar P and N:P variations largely reflected soil P variation across sites. The four <span class="hlt">tree</span> <span class="hlt">species</span> that we examined exhibited a number of individualistic effects on soil nutrient levels that contribute to biogeochemical heterogeneity in these ecosystems. Where fire suppression and long-term succession favor dominance by highly shade-tolerant western hemlock, our results suggest a potential for declines in both soil Ca availability and soil biogeochemical heterogeneity in old-growth forests.</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://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/18459337','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/18459337"><span id="translatedtitle">Large ontogenetic declines in intra-crown leaf area index in two temperate 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>Nock, C A; Caspersen, J P; Thomas, S C</p> <p>2008-03-01</p> <p>The widespread occurrence of age-related changes in leaf morphology and allocation suggests that the leaf area index of individual <span class="hlt">trees</span> (intra-crown LAI) may decline late in ontogeny. We used direct, within-canopy measurements to quantify the LAI of canopy <span class="hlt">trees</span> with exposed crowns of two temperate deciduous <span class="hlt">species</span>. Intra-crown LAI declined from approximately 7 to 4 in Acer saccharum, and from approximately 9.5 to 6.5 in Betula alleghaniensis, as <span class="hlt">tree</span> size increased (from 15 to 72 cm diameter at breast height [dbh]). For A. saccharum, age (which varied from 30 to 160 years) was a significantly better predictor of LAI decline than dbh. We also modeled the effect of ontogenetic declines in LAI on understory light availability and found that light transmission increases significantly as canopy <span class="hlt">trees</span> grow and mature. Our results thus suggest that gradual declines in LAI with <span class="hlt">tree</span> age may play an important and overlooked role in contributing to the heterogeneity of sub-canopy light regimes in mature forests. PMID:18459337</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, α(v,DBH) [volume (v) and diameter at breast height (DBH)], β(v,h) [v and height (h)], and γ(h,DBH) (h and DBH) were modelled as a function of <span class="hlt">tree</span> age for each <span class="hlt">species</span>. α(v,DBH), and γ(h,DBH) increased with <span class="hlt">tree</span> age and then reached a plateau ranging from 2.45 to 3.12 for α(v,DBH), and 0.874-1.48 for γ(h,DBH). Pine <span class="hlt">species</span> presented a local maximum. No effect of <span class="hlt">tree</span> age on β(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, α(v,DBH), and γ(h,DBH) increased with shade tolerance while β(v,h) was shade-tolerance independent. In the mature stage, β(v,h) increased with shade tolerance, whereas γ(h,DBH) decreased and α(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.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://pubs.er.usgs.gov/publication/70174016','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70174016"><span id="translatedtitle">Do the rich get richer? Varying effects of <span class="hlt">tree</span> <span class="hlt">species</span> identity and diversity on the richness of understory taxa</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Champagne, Juilette; Paine, C. E. Timothy; Schoolmaster, Donald; Stejskal, Robert; Volařík, Daniel; Šebesta, Jan; Trnka, Filip; Koutecký, Tomáš; Švarc, Petr; Svátek, Martin; Hector, Andy; Matula, Radim</p> <p>2016-01-01</p> <p>Understory herbs and soil invertebrates play key roles in soil formation and nutrient cycling in forests. Studies suggest that diversity in the canopy and in the understory are positively associated, but these studies often confound the effects of <span class="hlt">tree</span> <span class="hlt">species</span> diversity with those of <span class="hlt">tree</span> <span class="hlt">species</span> identity and abiotic conditions. We combined extensive field sampling with structural equation modeling to evaluate the simultaneous effects of <span class="hlt">tree</span> diversity on the <span class="hlt">species</span> diversity of understory herbs, beetles, and earthworms. The diversity of earthworms and saproxylic beetles was directly and positively associated with <span class="hlt">tree</span> diversity, presumably because <span class="hlt">species</span> of both these taxa specialize on certain <span class="hlt">species</span> of <span class="hlt">trees</span>. <span class="hlt">Tree</span> identity also strongly affected diversity in the understory, especially for herbs, likely as a result of interspecific differences in canopy light transmittance or litter decomposition rates. Our results suggest that changes in forest management will disproportionately affect certain understory taxa. For instance, changes in canopy diversity will affect the diversity of earthworms and saproxylic beetles more than changes in <span class="hlt">tree</span> <span class="hlt">species</span> composition, whereas the converse would be expected for understory herbs and detritivorous beetles. We conclude that the effects of <span class="hlt">tree</span> diversity on understory taxa can vary from positive to negative and may affect biogeochemical cycling in temperate forests. Thus, maintaining high diversity in temperate forests can promote the diversity of multiple taxa in the understory.</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/25084460','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25084460"><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=pubmed">PubMed</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.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://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015ISPAr.XL3..473F&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015ISPAr.XL3..473F&link_type=ABSTRACT"><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/23504733','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23504733"><span id="translatedtitle"><span class="hlt">Tree</span> <span class="hlt">species</span> diversity interacts with elevated CO2 to induce a greater root system response.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Smith, Andrew R; Lukac, Martin; Bambrick, Michael; Miglietta, Franco; Godbold, Douglas L</p> <p>2013-01-01</p> <p>As a consequence of land-use change and the burning of fossil fuels, atmospheric concentrations of CO2 are increasing and altering the dynamics of the carbon cycle in forest ecosystems. In a number of studies using single <span class="hlt">tree</span> <span class="hlt">species</span>, fine root biomass has been shown to be strongly increased by elevated CO2 . However, natural forests are often intimate mixtures of a number of co-occurring <span class="hlt">species</span>. To investigate the interaction between <span class="hlt">tree</span> mixture and elevated CO2 , Alnus glutinosa, Betula pendula and Fagus sylvatica were planted in areas of single <span class="hlt">species</span> and a three <span class="hlt">species</span> polyculture in a free-air CO2 enrichment study (BangorFACE). The <span class="hlt">trees</span> were exposed to ambient or elevated CO2 (580 μmol mol(-1) ) for 4 years. Fine and coarse root biomass, together with fine root turnover and fine root morphological characteristics were measured. Fine root biomass and morphology responded differentially to the elevated CO2 at different soil depths in the three <span class="hlt">species</span> when grown in monocultures. In polyculture, a greater response to elevated CO2 was observed in coarse roots to a depth of 20 cm, and fine root area index to a depth of 30 cm. Total fine root biomass was positively affected by elevated CO2 at the end of the experiment, but not by <span class="hlt">species</span> diversity. Our data suggest that existing biogeochemical cycling models parameterized with data from <span class="hlt">species</span> grown in monoculture may be underestimating the belowground response to global change. PMID:23504733</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.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://www.ncbi.nlm.nih.gov/pubmed/22666497','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22666497"><span id="translatedtitle">Strong neutral spatial effects shape <span class="hlt">tree</span> <span class="hlt">species</span> distributions across life stages at multiple scales.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hu, Yue-Hua; Lan, Guo-Yu; Sha, Li-Qing; Cao, Min; Tang, Yong; Li, Yi-De; Xu, Da-Ping</p> <p>2012-01-01</p> <p>Traditionally, ecologists use lattice (regional summary) count data to simulate <span class="hlt">tree</span> <span class="hlt">species</span> distributions to explore <span class="hlt">species</span> coexistence. However, no previous study has explicitly compared the difference between using lattice count and basal area data and analyzed <span class="hlt">species</span> distributions at both individual <span class="hlt">species</span> and community levels while simultaneously considering the combined scenarios of life stage and scale. In this study, we hypothesized that basal area data are more closely related to environmental variables than are count data because of strong environmental filtering effects. We also address the contribution of niche and the neutral (i.e., solely dependent on distance) factors to <span class="hlt">species</span> distributions. Specifically, we separately modeled count data and basal area data while considering life stage and scale effects at the two levels with simultaneous autoregressive models and variation partitioning. A principal coordinates of neighbor matrix (PCNM) was used to model neutral spatial effects at the community level. The explained variations of <span class="hlt">species</span> distribution data did not differ significantly between the two types of data at either the individual <span class="hlt">species</span> level or the community level, indicating that the two types of data can be used nearly identically to model <span class="hlt">species</span> distributions. Neutral spatial effects represented by spatial autoregressive parameters and the PCNM eigenfunctions drove <span class="hlt">species</span> distributions on multiple scales, different life stages and individual <span class="hlt">species</span> and community levels in this plot. We concluded that strong neutral spatial effects are the principal mechanisms underlying the <span class="hlt">species</span> distributions and thus shape biodiversity spatial patterns. PMID:22666497</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3362550','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3362550"><span id="translatedtitle">Strong Neutral Spatial Effects Shape <span class="hlt">Tree</span> <span class="hlt">Species</span> Distributions across Life Stages at Multiple Scales</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; Lan, Guo-Yu; Sha, Li-Qing; Cao, Min; Tang, Yong; Li, Yi-De; Xu, Da-Ping</p> <p>2012-01-01</p> <p>Traditionally, ecologists use lattice (regional summary) count data to simulate <span class="hlt">tree</span> <span class="hlt">species</span> distributions to explore <span class="hlt">species</span> coexistence. However, no previous study has explicitly compared the difference between using lattice count and basal area data and analyzed <span class="hlt">species</span> distributions at both individual <span class="hlt">species</span> and community levels while simultaneously considering the combined scenarios of life stage and scale. In this study, we hypothesized that basal area data are more closely related to environmental variables than are count data because of strong environmental filtering effects. We also address the contribution of niche and the neutral (i.e., solely dependent on distance) factors to <span class="hlt">species</span> distributions. Specifically, we separately modeled count data and basal area data while considering life stage and scale effects at the two levels with simultaneous autoregressive models and variation partitioning. A principal coordinates of neighbor matrix (PCNM) was used to model neutral spatial effects at the community level. The explained variations of <span class="hlt">species</span> distribution data did not differ significantly between the two types of data at either the individual <span class="hlt">species</span> level or the community level, indicating that the two types of data can be used nearly identically to model <span class="hlt">species</span> distributions. Neutral spatial effects represented by spatial autoregressive parameters and the PCNM eigenfunctions drove <span class="hlt">species</span> distributions on multiple scales, different life stages and individual <span class="hlt">species</span> and community levels in this plot. We concluded that strong neutral spatial effects are the principal mechanisms underlying the <span class="hlt">species</span> distributions and thus shape biodiversity spatial patterns. PMID:22666497</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://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://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.ncbi.nlm.nih.gov/pubmed/23300786','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23300786"><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=pubmed">PubMed</a></p> <p>Cetinkol, 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://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://www.osti.gov/scitech/biblio/1059361','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1059361"><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.osti.gov/scitech">SciTech Connect</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.; Zabotina, Olga A.</p> <p>2012-12-28</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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27323200','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27323200"><span id="translatedtitle">A comparative framework of the Erythrina velutina <span class="hlt">tree</span> <span class="hlt">species</span> in reforested land and native populations.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Souza, E M S; Pereira, G S; Silva-Mann, R; Álvares-Carvalho, S V; Ferreira, R A</p> <p>2016-01-01</p> <p>Erythrina velutina Willd. (Fabaceae: Papillionoideae) is a pioneer <span class="hlt">species</span> found in tropical and subtropical regions of the world that has medicinal properties and that is used in reforestation projects. This <span class="hlt">species</span> is rare in some areas of northeastern Brazil. This study aimed to characterize and compare genetic structures of natural and restored populations of E. velutina, with a focus on the selection of <span class="hlt">tree</span> seeds. A total of 108 individuals from five natural populations and one restored population were analyzed using ISSR markers, resulting in 407 polymorphic fragments. A high rate of polymorphism was observed in the restored population. The highest genetic variability was identified within populations (82%). Genetic bottleneck tests were significant for the Carmópolis/Rosário do Catete and Laranjeiras natural populations along with the Laranjeiras restored population. Genetic distances significantly correlated with spatial distance. Only the restored population retained unique alleles. Similarly, increased genetic distance was observed in individuals of the restored populations compared to the other populations. Observed genetic variation in both natural and restored populations of E. velutina was moderate, thus enabling selection of divergent <span class="hlt">trees</span> from those <span class="hlt">trees</span> supplying seeds. Environmental protection and management of these areas is necessary for the maintenance of these individuals and subsequent reproduction. We recommend suggestions for E. velutina conservation, since the restoration model adopted in this study did not promote the development of the specimens until the reproductive stage in a fashion that aims to augment the soil seed bank supply, as is suggested for pioneer <span class="hlt">species</span>. PMID:27323200</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</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</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</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25836337','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25836337"><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=pubmed">PubMed</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</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 species–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/25424149','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25424149"><span id="translatedtitle">Heterogeneity in soil water and light environments and dispersal limitation: what facilitates <span class="hlt">tree</span> <span class="hlt">species</span> coexistence in a temperate forest?</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Masaki, T; Hata, S; Ide, Y</p> <p>2015-03-01</p> <p>In the present study, we analysed the habitat association of <span class="hlt">tree</span> <span class="hlt">species</span> in an old-growth temperate forest across all life stages to test theories on the coexistence of <span class="hlt">tree</span> <span class="hlt">species</span> in forest communities. An inventory for <span class="hlt">trees</span> was implemented at a 6-ha plot in Ogawa Forest Reserve for adults, juveniles, saplings and seedlings. Volumetric soil water content (SMC) and light levels were measured in 10-m grids. Relationships between the actual number of stems and environmental variables were determined for 35 major <span class="hlt">tree</span> <span class="hlt">species</span>, and the spatial correlations within and among <span class="hlt">species</span> were analysed. The light level had no statistically significant effect on distribution of saplings and seedlings of any <span class="hlt">species</span>. In contrast, most <span class="hlt">species</span> had specific optimal values along the SMC gradient. The optimal values were almost identical in earlier life stages, but were more variable in later life stages among <span class="hlt">species</span>. However, no effective niche partitioning among the <span class="hlt">species</span> was apparent even at the adult stage. Furthermore, results of spatial analyses suggest that dispersal limitation was not sufficient to mitigate competition between <span class="hlt">species</span>. This might result from well-scattered seed distribution via wind and bird dispersal, as well as conspecific density-dependent mortality of seeds and seedlings. Thus, both niche partitioning and dispersal limitation appeared less important for facilitating coexistence of <span class="hlt">species</span> within this forest than expected in tropical forests. The <span class="hlt">tree</span> <span class="hlt">species</span> assembly in this temperate forest might be controlled through a neutral process at the spatial scale tested in this study. PMID:25424149</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2005AGUSMNB22F..03S&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2005AGUSMNB22F..03S&link_type=ABSTRACT"><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</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> </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.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.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.ncbi.nlm.nih.gov/pubmed/27146334','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27146334"><span id="translatedtitle">A test of the hydraulic vulnerability segmentation hypothesis in angiosperm and conifer <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>Johnson, Daniel M; Wortemann, Remi; McCulloh, Katherine A; Jordan-Meille, Lionel; Ward, Eric; Warren, Jeffrey M; Palmroth, Sari; Domec, Jean-Christophe</p> <p>2016-08-01</p> <p>Water transport from soils to the atmosphere is critical for plant growth and survival. However, we have a limited understanding about many portions of the whole-<span class="hlt">tree</span> hydraulic pathway, because the vast majority of published information is on terminal branches. Our understanding of mature <span class="hlt">tree</span> trunk hydraulic physiology, in particular, is limited. The hydraulic vulnerability segmentation hypothesis (HVSH) stipulates that distal portions of the plant (leaves, branches and roots) should be more vulnerable to embolism than trunks, which are nonredundant organs that require a massive carbon investment. In the current study, we compared vulnerability to loss of hydraulic function, leaf and xylem water potentials and the resulting hydraulic safety margins (in relation to the water potential causing 50% loss of hydraulic conductivity) in leaves, branches, trunks and roots of four angiosperms and four conifer <span class="hlt">tree</span> <span class="hlt">species</span>. Across all <span class="hlt">species</span>, our results supported strongly the HVSH as leaves and roots were less resistant to embolism than branches or trunks. However, branches were consistently more resistant to embolism than any other portion of the plant, including trunks. Also, calculated whole-<span class="hlt">tree</span> vulnerability to hydraulic dysfunction was much greater than vulnerability in branches. This was due to hydraulic dysfunction in roots and leaves at less negative water potentials than those causing branch or trunk dysfunction. Leaves and roots had narrow or negative hydraulic safety margins, but trunks and branches maintained positive safety margins. By using branch-based hydraulic information as a proxy for entire plants, much research has potentially overestimated embolism resistance, and possibly drought tolerance, for many <span class="hlt">species</span>. This study highlights the necessity to reconsider past conclusions made about plant resistance to drought based on branch xylem only. This study also highlights the necessity for more research of whole-plant hydraulic physiology to better</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27262582','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27262582"><span id="translatedtitle">Light-exposed shoots of seven coexisting deciduous <span class="hlt">species</span> show common photosynthetic responses to <span class="hlt">tree</span> height.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Miyata, Rie; Kohyama, Takashi S</p> <p>2016-10-01</p> <p>Functional traits of light-exposed leaves have been reported to show <span class="hlt">tree</span> height-dependent change. However, it remains unknown how plastic response of leaf traits to <span class="hlt">tree</span> height is linked with shoot-level carbon gain. To answer this question, we examined the photosynthetic properties of fully lit current-year shoots in crown tops with various heights for seven deciduous broad-leaved <span class="hlt">species</span> dominated in a cool-temperate forest in northern Japan. We measured leaf mass, stomatal conductance, nitrogen content, light-saturated net photosynthetic rate (all per leaf lamina area), foliar stable carbon isotope ratio, and shoot mass allocation to leaf laminae. We employed hierarchical Bayesian models to simultaneously quantify inter-trait relationships for all <span class="hlt">species</span>. We found that leaf and shoot traits were co-varied in association with height, and that there was no quantitative inter-specific difference in leaf- and shoot-level plastic responses to height. Nitrogen content increased and stomatal conductance decreased with height. Reflecting these antagonistic responses to height, photosynthetic rate was almost unchanged with height. Photosynthetic rate divided by stomatal conductance as a proxy of photosynthetic water use efficiency sufficiently explained the variation of foliar carbon isotope ratio. The increase in mass allocation to leaves in a shoot compensated for the height-dependent decline in photosynthetic rate per leaf lamina mass. Consequently, photosynthetic gain at the scale of current-year shoot mass was kept unchanged with <span class="hlt">tree</span> height. We suggest that the convergent responses of shoot functional traits across <span class="hlt">species</span> reflect common requirements for <span class="hlt">trees</span> coexisting in a forest. PMID:27262582</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://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013AIPC.1571..302N&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013AIPC.1571..302N&link_type=ABSTRACT"><span id="translatedtitle">Community structure, diversity and total biomass of <span class="hlt">tree</span> <span class="hlt">species</span> at Kapur dominated forests in Peninsular Malaysia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Norafida, N. A. Nik; Nizam, M. S.; Juliana, W. A. Wan</p> <p>2013-11-01</p> <p>A study was conducted to determine the <span class="hlt">species</span> composition, diversity and biomass of Kapur (Dryobalanops aromatica Gaertn.f.) dominated forests in Peninsular Malaysia. Three forests were selected in different geographical zones, namely Bukit Bauk Virgin Jungle Reserve (BBVJR), Terengganu, Lesong Forest Reserve (LFR), Pahang and Gunung Belumut Recreational Forest (GBRF), Johor. Thirty plots of 0.1 ha (50 m × 20 m) were established with a total sampling area of 1.0 ha at each forest site. All <span class="hlt">trees</span> with ≥5 cm diameter at breast height (dbh) were tagged, measured and voucher specimens were collected. Floristic composition in the study plot at BBVJR recorded 55 families, 147 genera and 336 <span class="hlt">species</span>. In LFR, there were 52 families, 138 genera and 288 <span class="hlt">species</span>, whereas in GBRF there were 52 families, 132 genera and 271 <span class="hlt">species</span>. D. aromatica was the most important <span class="hlt">species</span> in all study plots with the Importance Value Index (IVi) of 17.81%, 23.01% and 16.25% in BBVJR, LFR and GBRF, respectively. Similar trend at family level showed the Dipterocarpaceae was the most important family in each of the areas with the family Importance Value Index (FIVi) of 27.95% (BBVJR), 26.09% (LFR) and 27.16% (GBRF). Shannon diversity index (H'f) and Shannon evenness index (J'f) of <span class="hlt">trees</span> at BBVJR was 5.02 and 0.86; LFR was 4.63 and 0.82; and GBRF was 4.82 and 0.86, respectively. Sorensen's community similarity coefficient (CCs) showed that <span class="hlt">tree</span> communities between BBVJR, LFR and GBRF had low similarities with values of 0.3 to 0.4. The highest total biomass estimated was in LFR with a value of 739.44 t/ha, followed by BBVJR at 701.34 t/ha and GBRF at 606.29 t/ha.</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://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</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</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://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..1816218H&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..1816218H&link_type=ABSTRACT"><span id="translatedtitle">Beech vs. Pine - how different <span class="hlt">tree</span> <span class="hlt">species</span> manage their water demands</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>2016-04-01</p> <p>In north-eastern Germany large parts of the landscape are covered by pine <span class="hlt">trees</span>. Although beech used to be one of the typical <span class="hlt">species</span> for the region, today it makes up only a small fraction of the forested area. In order to reinstate a more natural forest composition an effort is made to decrease the coniferous forest in the next 30 years from 70% to 40% while increasing the deciduous forest from 20% to 40%. This will have consequences for the forest water balance that we would like to understand better. In an attempt to capture the complete <span class="hlt">tree</span> water balance for both <span class="hlt">species</span> we monitored all relevant hydrologic fluxes in four stands of pure beech and pine (both young and old stands) as well as in eight mixed stands (as part of the TERENO observatory). Extensive measurements of throughfall and stemflow were conducted with 35 rain trough systems, 50 stemflow collectors and tipping buckets. Soil moisture was monitored in 70 depth profiles with a total of 450 sensors ranging from 10 cm down to 200 cm. In combination with soil water potential measurements at 5 depths root water uptake from different depths and hydraulic redistribution between depths could be determined. Sapflux sensors recorded <span class="hlt">tree</span> water use for 16 <span class="hlt">trees</span> and groundwater level was monitored at 16 locations. We found that soil moisture conditions under beech were more variable than under pine, especially in the upper 100 cm. This was due to the higher influx of water from stemflow on the one hand and to the more intensive/effective use of soil water by the beech on the other hand. Our sap flux measurements show that beech was able to sustain steady rates of sapflux even under extremely dry soil conditions. While annual average sapflow was twice as high for pines compared to beeches, pine <span class="hlt">trees</span> were less effective in taking up water from the soil and reduced sap flow considerably during dry phases. We still found the upper 100 cm of soil under pine to be generally wetter than under beech and considered</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/Publications.htm?seq_no_115=325437','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/Publications.htm?seq_no_115=325437"><span id="translatedtitle">Sensitation potential of tea <span class="hlt">tree</span> essential oils. Impact of the chemical composition on aging and generation of reactive <span class="hlt">species</span>.</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>Tea <span class="hlt">tree</span> oil (TTO) is a popular skin remedy obtained from the leaves of Melaleuca alternifolia, M. linariifolia or M dissitiflora. Due to the commercial importance ofTTO, substitution or adulteration with other tea <span class="hlt">tree</span> <span class="hlt">species</span> (such as cajeput, niaouli, manuka and kanuka oils) is common and may p...</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://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..1813529B&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..1813529B&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Tree</span> <span class="hlt">species</span> effects on topsoil properties in an old tropical plantation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bauters, Marijn; Boeckx, Pascal; Ampoorter, Evy; Verbeeck, Hans; Döetterl, Sebastian; Baert, Geert; Verheyen, Kris</p> <p>2016-04-01</p> <p>Forest biogeochemistry is strongly linked to the functional strategies of the <span class="hlt">tree</span> community and the topsoil. Research has long documented that <span class="hlt">tree</span> <span class="hlt">species</span> affect soil properties in forests. Our current understanding on this interaction is mainly based on common garden experiments in temperate forest and needs to be extended to other ecosystems if we want to understand this interaction in natural forests worldwide. Using a 77-year-old tropical experimental plantation from central Africa, we examined the relationship between canopy and litter chemical traits and topsoil properties. By the current diversity in this site, the unique setup allowed us to extend the current knowledge from temperate and simplified systems to near-natural tropical forests, and thus bridge the gap between planted monocultures in common gardens, and correlative studies in natural systems. We linked the <span class="hlt">species</span>-specific leaf and litter chemical traits to the topsoil cation composition, acidity, pH and soil organic matter. We found that average canopy trait values were a better predictor for the topsoil than the litter chemistry. Canopy base cation content positively affected topsoil pH and negatively affected acidity. These, in turn strongly determined the soil organic carbon contents of the topsoil, which ranged a <span class="hlt">tree</span>-fold in the experiment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/12683726','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/12683726"><span id="translatedtitle">137Cs distribution among annual rings of different <span class="hlt">tree</span> <span class="hlt">species</span> contaminated after the Chernobyl accident.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Soukhova, N V; Fesenko, S V; Klein, D; Spiridonov, S I; Sanzharova, N I; Badot, P M</p> <p>2003-01-01</p> <p>The distributions of 137Cs among annual rings of Pinus sylvestris and Betula pendula at four experimental sites located in the most contaminated areas in the Russian territory after the Chernobyl accident in 1986 were studied. <span class="hlt">Trees</span> of different ages were sampled from four forest sites with different <span class="hlt">tree</span> compositions and soil properties. The data analysis shows that 137Cs is very mobile in wood and the 1986 rings do not show the highest contamination. The difference between pine and birch in the pattern of radial 137Cs distribution can be satisfactorily explained by the difference in radial ray composition. 137Cs radial distribution in the wood can be described as the sum of two exponential functions for both <span class="hlt">species</span>. The function parameters are height, age and <span class="hlt">species</span> dependent. The distribution of 137Cs in birch wood reveals much more pronounced dependence on site characteristics and/or the age of <span class="hlt">trees</span> than pines. The data obtained can be used to assess 137Cs content in wood. PMID:12683726</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> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/15334971','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/15334971"><span id="translatedtitle">[Characters of greening <span class="hlt">tree</span> <span class="hlt">species</span> in heavy metal pollution protection in Shanghai].</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yang, Xuejun; Tang, Dongqin; Xu, Dongxin; Wang, Xinhua; Pan, Gaohong</p> <p>2004-04-01</p> <p>In this paper, the stream banks nearby Qibao town and the factory area of Shanghai Baoshan Steel Company were selected as the typical areas contaminated by heavy metals. The polluted status was investigated by measuring the heavy metal concentrations of the sampled soils. The results showed that the heavy metal concentrations in the soils of stream banks were a little higher than the control, but obviously higher in the factory area of Shanghai Baoshan Steel Company. The growth status of the greening <span class="hlt">trees</span> was recorded, and their heavy metal concentrations were measured by ICP. According to the research results and historic data, the excellent greening <span class="hlt">tree</span> <span class="hlt">species</span> mainly applied in polluted factory area were Viburnum awabuki, Lagerstroemia indica, Hibiscus mutabilis, Ligustrum lucidum and Sabina chinensis, which could grow well on contaminated soil, and accumulate high concentrations of heavy metal elements. The other <span class="hlt">tree</span> <span class="hlt">species</span> such as Distylium racemosum, Nerium indicum, and Photinia serrulata might be also available in greening for heavy metal pollution protection. PMID:15334971</p> </li> <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> </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/cgi-bin/nph-data_query?bibcode=2000AcO....21...37K&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2000AcO....21...37K&link_type=ABSTRACT"><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</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/20030130','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/20030130"><span id="translatedtitle">[Time lag characteristics of stem sap flow of common <span class="hlt">tree</span> <span class="hlt">species</span> during their growth season in Beijing downtown].</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Hua; Ouyang, Zhi-yun; Zheng, Hua; Wang, Xiao-ke; Ni, Yong-ming; Ren, Yu-fen</p> <p>2009-09-01</p> <p>From April to September in 2008, the stem sap flow velocity (Js) of several common <span class="hlt">tree</span> <span class="hlt">species</span> (Ginkgo biloba, Aesculus chinensis, Magnolia denudata, Robinia pseudoacacia, Pinus tabulaeformis and Cedrus deodara) in Beijing was measured by thermal dissipation method. Crosscorrelation analysis was used to estimate the time lag between the stem sap flow and the driving factors of canopy transpiration among the <span class="hlt">tree</span> <span class="hlt">species</span>. The Js of the six <span class="hlt">tree</span> <span class="hlt">species</span> was significantly correlated with the total radiation (Rs) and vapor pressure deficit (D), and the Js was lagged behind Rs but ahead of D. The maximum correlation coefficient of Js with Rs (0.74-0.93) was often higher than that of Js with D (0.57-0.79), indicating that the diurnal Js was more dependent on Rs than on D. The sampled <span class="hlt">tree</span> <span class="hlt">species</span> except P. tabulaeformis had a shorter time lag of Js with Rs (10-70 min) than with D (47-130 min), and there existed significant differences among R. pseudoacacia, P. tabulaeformis, and C. deodara. The time lag between the Js and the driving factors of canopy transpiration was mainly correlated with the <span class="hlt">tree</span> features (DBH, <span class="hlt">tree</span> height, canopy area, and sapwood area) and the nocturnal water recharge, regardless of <span class="hlt">tree</span> <span class="hlt">species</span>. PMID:20030130</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/18055429','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/18055429"><span id="translatedtitle">Retranslocation of foliar nutrients in evergreen <span class="hlt">tree</span> <span class="hlt">species</span> planted in a Mediterranean environment.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fife, D N; Nambiar, E K S; Saur, E</p> <p>2008-02-01</p> <p>Internal nutrient recycling through retranslocation (resorption) is important for meeting the nutrient demands of new tissue production in <span class="hlt">trees</span>. We conducted a comparative study of nutrient retranslocation from leaves of five <span class="hlt">tree</span> <span class="hlt">species</span> from three genera grown in plantation forests for commercial or environmental purposes in southern Australia--Acacia mearnsii De Wild., Eucalyptus globulus Labill., E. fraxinoides H. Deane & Maiden, E. grandis W. Hill ex Maiden and Pinus radiata D. Don. Significant amounts of nitrogen, phosphorus and potassium were retranslocated during three phases of leaf life. In the first phase, retranslocation occurred from young leaves beginning 6 months after leaf initiation, even when leaves were physiologically most active. In the second phase, retranslocation occurred from mature green leaves during their second year, and in the third phase, retranslocation occurred during senescence before leaf fall. Nutrient retranslocation occurred mainly in response to new shoot production. The pattern of retranslocation was remarkably similar in the leaves of all study <span class="hlt">species</span> (and in the phyllodes of Casuarina glauca Sieber ex Spreng.), despite their diverse genetics, leaf forms and growth rates. There was no net retranslocation of calcium in any of the <span class="hlt">species</span>. The amounts of nutrients at the start of each pre-retranslocation phase had a strong positive relationship with the amounts subsequently retranslocated, and all <span class="hlt">species</span> fitted a common relationship. The percentage reduction in concentration or content (retranslocation efficiency) at a particular growth phase is subject to many variables, even within a <span class="hlt">species</span>, and is therefore not a meaningful measure of interspecific variation. It is proposed that the pattern of retranslocation and its governing factors are similar among <span class="hlt">species</span> in the absence of interspecies competition for growth and crown structure which occurs in mixed <span class="hlt">species</span> stands. PMID:18055429</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016AcO....73...45C&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016AcO....73...45C&link_type=ABSTRACT"><span id="translatedtitle">Interactions between terrestrial mammals and the fruits of two neotropical 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>Camargo-Sanabria, Angela A.; Mendoza, Eduardo</p> <p>2016-05-01</p> <p>Mammalian frugivory is a distinctive biotic interaction of tropical forests; however, most efforts in the Neotropics have focused on cases of animals foraging in the forest canopy, in particular primates and bats. In contrast much less is known about this interaction when it involves fruits deposited on the forest floor and terrestrial mammals. We conducted a camera-trapping survey to analyze the characteristics of the mammalian ensembles visiting fruits of Licania platypus and Pouteria sapota deposited on the forest floor in a well preserved tropical rainforest of Mexico. Both <span class="hlt">tree</span> <span class="hlt">species</span> produce large fruits but contrast in their population densities and fruit chemical composition. In particular, we expected that more <span class="hlt">species</span> of terrestrial mammals would consume P. sapota fruits due to its higher pulp:seed ratio, lower availability and greater carbohydrate content. We monitored fruits at the base of 13 <span class="hlt">trees</span> (P. sapota, n = 4 and L. platypus, n = 9) using camera-traps. We recorded 13 mammal <span class="hlt">species</span> from which we had evidence of 8 consuming or removing fruits. These eight <span class="hlt">species</span> accounted for 70% of the <span class="hlt">species</span> of mammalian frugivores active in the forest floor of our study area. The ensemble of frugivores associated with L. platypus (6 spp.) was a subset of that associated with P. sapota (8 spp). Large body-sized <span class="hlt">species</span> such as Tapirus bairdii, Pecari tajacu and Cuniculus paca were the mammals more frequently interacting with fruits of the focal <span class="hlt">species</span>. Our results further our understanding of the characteristics of the interaction between terrestrial mammalian frugivores and large-sized fruits, helping to gain a more balanced view of its importance across different tropical forests and providing a baseline to compare against defaunated forests.</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/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.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/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://adsabs.harvard.edu/abs/2013AGUFMGC52B..03M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMGC52B..03M"><span id="translatedtitle">Deciduous <span class="hlt">Tree</span> <span class="hlt">Species</span> Alter Nitrogen and Phosphorus Availability in Mid-successional Alaskan Boreal Forest</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.</p> <p>2013-12-01</p> <p>In Alaskan boreal forest, increased fire severity associated with climate change is altering successional processes and ecosystem nutrient dynamics. Fire is a common disturbance in Interior Alaska and typically burns forests dominated by black spruce (Picea mariana), a <span class="hlt">tree</span> <span class="hlt">species</span> associated with slow nutrient turnover and high soil organic matter accumulation rates. Historically, low severity fires have driven black spruce regeneration post-fire, thereby maintaining slow nutrient cycling rates and large soil organic matter stocks. In contrast, high severity fires consume the organic layer and can lead to the establishment of deciduous <span class="hlt">tree</span> <span class="hlt">species</span> on exposed mineral soil, which produce less recalcitrant leaf litter and exhibit faster nutrient cycling rates. To improve our understanding of the long-term impacts of <span class="hlt">tree</span> <span class="hlt">species</span> composition on nutrient cycling in boreal forest, we quantified nitrogen (N) cycling rates and estimated soil N, phosphorus (P), and base cation pools in adjacent, mid-successional stands of black spruce and Alaska paper birch (Betula neoalaskana) that established following a 1960 fire near Fairbanks, Alaska. Results indicate significantly higher net N mineralization in paper birch soils relative to black spruce for both the fibric organic layer and top 10 cm of mineral soil during 30-day and 90-day lab incubation studies. Net nitrification was significantly higher in the paper birch fibric layer after 90 days. Total soil N concentrations did not differ between paper birch and black spruce stands, however the black spruce organic layer was significantly larger than that of birch, resulting in larger organic layer N stocks (130 vs. 87 g N m2). In contrast, total P concentrations were significantly higher in the organic layer in birch forest, but the total P stocks did not differ significantly between <span class="hlt">species</span> because of the larger mass of soil organic matter in the black spruce. These findings suggest that a shift towards greater deciduous</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25938417','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25938417"><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=pubmed">PubMed</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.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/15278429','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/15278429"><span id="translatedtitle">El Niño droughts and their effects on <span class="hlt">tree</span> <span class="hlt">species</span> composition and diversity in tropical rain forests.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Slik, J W F</p> <p>2004-09-01</p> <p>In this study I investigated the effects of the extreme, 1997/98 El Niño related drought on <span class="hlt">tree</span> mortality and understorey light conditions of logged and unlogged tropical rain forest in the Indonesian province of East Kalimantan (Borneo). My objectives were to test (1) whether drought had a significant effect on <span class="hlt">tree</span> mortality and understorey light conditions, (2) whether this effect was greater in logged than in undisturbed forest, (3) if the expected change in <span class="hlt">tree</span> mortality and light conditions had an effect on Macaranga pioneer seedling and sapling densities, and (4) which (a)biotic factors influenced <span class="hlt">tree</span> mortality during the drought. The 1997/1998 drought led to an additional <span class="hlt">tree</span> mortality of 11.2, 18.1, and 22.7% in undisturbed, old logged and recently logged forest, respectively. Mortality was highest in logged forests, due to extremely high mortality of pioneer Macaranga <span class="hlt">trees</span> (65.4%). Canopy openness was significantly higher during the drought than during the non-drought year (6.0, 8.6 and 10.4 vs 3.7, 3.8 and 3.7 in undisturbed, old logged and recently logged forest, respectively) and was positively correlated with the number of dead standing <span class="hlt">trees</span>. The increase in light in the understorey was accompanied by a 30 to 300-fold increase in pioneer Macaranga seedling densities. Factors affecting <span class="hlt">tree</span> mortality during drought were (1) <span class="hlt">tree</span> <span class="hlt">species</span> successional status, (2) <span class="hlt">tree</span> size, and (3) <span class="hlt">tree</span> location with respect to soil moisture. <span class="hlt">Tree</span> density and basal area per surface unit had no influence on <span class="hlt">tree</span> mortality during drought. The results of this study show that extreme droughts, such as those associated with El Niño events, can affect the <span class="hlt">tree</span> <span class="hlt">species</span> composition and diversity of tropical forests in two ways: (1) by disproportionate mortality of certain <span class="hlt">tree</span> <span class="hlt">species</span> groups and <span class="hlt">tree</span> size classes, and (2) by changing the light environment in the forest understorey, thereby affecting the recruitment and growth conditions of small and immature <span class="hlt">trees</span>. PMID</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..1816036G&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..1816036G&link_type=ABSTRACT"><span id="translatedtitle">Response of soil microbial community composition to afforestation with pure and mixed <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>Gunina, Anna; Smith, Andrew; Godbold, Douglas; Kuzyakov, Yakov; Jones, Davey</p> <p>2016-04-01</p> <p>Afforestation of agricultural land affects soil ecosystem functions by inducing carbon (C) and nitrogen (N) sequestration and promoting shifts in microbial community structure. Soil C and N stocks undergo progressive changes over several decades after forest establishment, particularly in successional forests. In contrast, microbial community structure can be shifted already in the first decade and thus, direct effect of <span class="hlt">tree</span> <span class="hlt">species</span> can be revealed. Thus, the aim of this study was to determine how soil microbial community composition is altered by afforestation with either one, two or three <span class="hlt">species</span> mixtures of <span class="hlt">trees</span>, which possess strongly contrasting functional traits. The study was conducted at the BangorDIVERSE temperate forest experiment established in 2004 on a former arable soil. Soil samples were collected under single, two and three <span class="hlt">species</span> mixtures of alder, birch, beech and oak, while contiguous field was chosen as a control. Soil samples were analysed for key quality indicators (total C and N, pH, nitrate and ammonium), and microbial community structure was determined by phospholipid fatty acids (PLFAs) analysis. Ten years after afforestation, total soil C, N and C/N ratios were not strongly affected, with the highest positive changes (up to 20%) for the birch, alder+oak and birch+beech plots. Decrease of C and N contents were observed for the pure beech plot. pH decreased by 1-1.2 units for all forest plots compare to the control soil. Total PLFAs content (370-630 nmol g‑1 soil) increased in comparison to the control (315 nmol g‑1 soil), resulting in the changes in total PLFAs content from 20 to 100%. Thus, changes of chemical properties (C, N) occur slower than changes of microbial biomarkers at the early stage of afforestation. Bacterial PLFA content was shifted by 20-120%, whereas fungal PLFAs were changed by 50-300%, reflecting stronger impact of afforestation on the recovery of fungal communities than on bacterial. Principal component analysis</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2008Geomo.100..401D&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2008Geomo.100..401D&link_type=ABSTRACT"><span id="translatedtitle">Quantifying root-reinforcement of river bank soils by four Australian <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>Docker, B. B.; Hubble, T. C. T.</p> <p>2008-08-01</p> <p>The increased shear resistance of soil due to root-reinforcement by four common Australian riparian <span class="hlt">trees</span>, Casuarina glauca, Eucalyptus amplifolia, Eucalyptus elata and Acacia floribunda, was determined in-situ with a field shear-box. Root pull-out strengths and root tensile-strengths were also measured and used to evaluate the utility of the root-reinforcement estimation models that assume simultaneous failure of all roots at the shear plane. Field shear-box results indicate that <span class="hlt">tree</span> roots fail progressively rather than simultaneously. Shear-strengths calculated for root-reinforced soil assuming simultaneous root failure, yielded values between 50% and 215% higher than directly measured shear-strengths. The magnitude of the overestimate varies among <span class="hlt">species</span> and probably results from differences in both the geometry of the root-system and tensile strengths of the root material. Soil blocks under A. floribunda which presents many, well-spread, highly-branched fine roots with relatively higher tensile strength, conformed most closely with root model estimates; whereas E. amplifolia, which presents a few, large, unbranched vertical roots, concentrated directly beneath the <span class="hlt">tree</span> stem and of relatively low tensile strength, deviated furthest from model-estimated shear-strengths. These results suggest that considerable caution be exercised when applying estimates of increased shear-strength due to root-reinforcement in riverbank stability modelling. Nevertheless, increased soil shear strength provided by <span class="hlt">tree</span> roots can be calculated by knowledge of the Root Area Ratio ( RAR) at the shear plane. At equivalent RAR values, A. floribunda demonstrated the greatest earth reinforcement potential of the four <span class="hlt">species</span> studied.</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</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1991usra.proc..227.','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1991usra.proc..227."><span id="translatedtitle"><span class="hlt">Multipurpose</span> satellite bus (MPS)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p></p> <p></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/2060/19930020554','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.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://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> </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.osti.gov/scitech/biblio/250422','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/250422"><span id="translatedtitle">Stem cubic-foot volume tables for <span class="hlt">tree</span> <span class="hlt">species</span> in the piedmont. Forest Service research paper</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Clark, A.; Souter, R.A.</p> <p>1996-03-01</p> <p>Steamwood cubic-foot volume inside bark tables are presented for 16 <span class="hlt">species</span> and 8 <span class="hlt">species</span> groups based on equations used to estimate timber sale volumes on national forests in the Piedmont. Tables are based on form class measurement data for 2,753 <span class="hlt">trees</span> sampled in the Piedmont and taper data collected across the South. A series of tables is presented for each <span class="hlt">species</span> based on diameter at breast height (d.b.h.) in combination with total height and height to a 4-inch diameter outside bark (d.o.b.) top. Volume tables are also presented based on d.b.h. in combination with height to a 7-inch d.o.b. top for softwoods and height to a 9-inch d.o.b. top for hardwoods.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24805976','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24805976"><span id="translatedtitle">Temporal variability of forest communities: empirical estimates of population change in 4000 <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>Chisholm, Ryan A; Condit, Richard; Rahman, K Abd; Baker, Patrick J; Bunyavejchewin, Sarayudh; Chen, Yu-Yun; Chuyong, George; Dattaraja, H S; Davies, Stuart; Ewango, Corneille E N; Gunatilleke, C V S; Nimal Gunatilleke, I A U; Hubbell, Stephen; Kenfack, David; Kiratiprayoon, Somboon; Lin, Yiching; Makana, Jean-Remy; Pongpattananurak, Nantachai; Pulla, Sandeep; Punchi-Manage, Ruwan; Sukumar, Raman; Su, Sheng-Hsin; Sun, I-Fang; Suresh, H S; Tan, Sylvester; Thomas, Duncan; Yap, Sandra</p> <p>2014-07-01</p> <p>Long-term surveys of entire communities of <span class="hlt">species</span> are needed to measure fluctuations in natural populations and elucidate the mechanisms driving population dynamics and community assembly. We analysed changes in abundance of over 4000 <span class="hlt">tree</span> <span class="hlt">species</span> in 12 forests across the world over periods of 6-28 years. Abundance fluctuations in all forests are large and consistent with population dynamics models in which temporal environmental variance plays a central role. At some sites we identify clear environmental drivers, such as fire and drought, that could underlie these patterns, but at other sites there is a need for further research to identify drivers. In addition, cross-site comparisons showed that abundance fluctuations were smaller at <span class="hlt">species</span>-rich sites, consistent with the idea that stable environmental conditions promote higher diversity. Much community ecology theory emphasises demographic variance and niche stabilisation; we encourage the development of theory in which temporal environmental variance plays a central role. PMID:24805976</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; Španjol, 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.ncbi.nlm.nih.gov/pubmed/22969411','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22969411"><span id="translatedtitle">Clade age and <span class="hlt">species</span> richness are decoupled across the eukaryotic <span class="hlt">tree</span> of life.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rabosky, Daniel L; Slater, Graham J; Alfaro, Michael E</p> <p>2012-08-01</p> <p>Explaining the dramatic variation in <span class="hlt">species</span> richness across the <span class="hlt">tree</span> of life remains a key challenge in evolutionary biology. At the largest phylogenetic scales, the extreme heterogeneity in <span class="hlt">species</span> richness observed among different groups of organisms is almost certainly a function of many complex and interdependent factors. However, the most fundamental expectation in macroevolutionary studies is simply that <span class="hlt">species</span> richness in extant clades should be correlated with clade age: all things being equal, older clades will have had more time for diversity to accumulate than younger clades. Here, we test the relationship between stem clade age and <span class="hlt">species</span> richness across 1,397 major clades of multicellular eukaryotes that collectively account for more than 1.2 million described <span class="hlt">species</span>. We find no evidence that clade age predicts <span class="hlt">species</span> richness at this scale. We demonstrate that this decoupling of age and richness is unlikely to result from variation in net diversification rates among clades. At the largest phylogenetic scales, contemporary patterns of <span class="hlt">species</span> richness are inconsistent with unbounded diversity increase through time. These results imply that a fundamentally different interpretative paradigm may be needed in the study of phylogenetic diversity patterns in many groups of organisms. PMID:22969411</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3433737','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3433737"><span id="translatedtitle">Clade Age and <span class="hlt">Species</span> Richness Are Decoupled Across the Eukaryotic <span class="hlt">Tree</span> of Life</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>2012-01-01</p> <p>Explaining the dramatic variation in <span class="hlt">species</span> richness across the <span class="hlt">tree</span> of life remains a key challenge in evolutionary biology. At the largest phylogenetic scales, the extreme heterogeneity in <span class="hlt">species</span> richness observed among different groups of organisms is almost certainly a function of many complex and interdependent factors. However, the most fundamental expectation in macroevolutionary studies is simply that <span class="hlt">species</span> richness in extant clades should be correlated with clade age: all things being equal, older clades will have had more time for diversity to accumulate than younger clades. Here, we test the relationship between stem clade age and <span class="hlt">species</span> richness across 1,397 major clades of multicellular eukaryotes that collectively account for more than 1.2 million described <span class="hlt">species</span>. We find no evidence that clade age predicts <span class="hlt">species</span> richness at this scale. We demonstrate that this decoupling of age and richness is unlikely to result from variation in net diversification rates among clades. At the largest phylogenetic scales, contemporary patterns of <span class="hlt">species</span> richness are inconsistent with unbounded diversity increase through time. These results imply that a fundamentally different interpretative paradigm may be needed in the study of phylogenetic diversity patterns in many groups of organisms. PMID:22969411</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://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=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.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.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-tree’ 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://www.ncbi.nlm.nih.gov/pubmed/27066053','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27066053"><span id="translatedtitle">Limited Growth Recovery after Drought-Induced Forest Dieback in Very Defoliated <span class="hlt">Trees</span> of Two Pine <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>Guada, Guillermo; Camarero, J Julio; Sánchez-Salguero, Raúl; Cerrillo, Rafael M Navarro</p> <p>2016-01-01</p> <p>Mediterranean pine forests display high resilience after extreme climatic events such as severe droughts. However, recent dry spells causing growth decline and triggering forest dieback challenge the capacity of some forests to recover following major disturbances. To describe how resilient the responses of forests to drought can be, we quantified growth dynamics in plantations of two pine <span class="hlt">species</span> (Scots pine, black pine) located in south-eastern Spain and showing drought-triggered dieback. Radial growth was characterized at inter- (<span class="hlt">tree</span>-ring width) and intra-annual (xylogenesis) scales in three defoliation levels. It was assumed that the higher defoliation the more negative the impact of drought on <span class="hlt">tree</span> growth. <span class="hlt">Tree</span>-ring width chronologies were built and xylogenesis was characterized 3 years after the last severe drought occurred. Annual growth data and the number of tracheids produced in different stages of xylem formation were related to climate data at several time scales. Drought negatively impacted growth of the most defoliated <span class="hlt">trees</span> in both pine <span class="hlt">species</span>. In Scots pine, xylem formation started earlier in the non-defoliated than in the most defoliated <span class="hlt">trees</span>. Defoliated <span class="hlt">trees</span> presented the shortest duration of the radial-enlargement phase in both <span class="hlt">species</span>. On average the most defoliated <span class="hlt">trees</span> formed 60% of the number of mature tracheids formed by the non-defoliated <span class="hlt">trees</span> in both <span class="hlt">species</span>. Since radial enlargement is the xylogenesis phase most tightly related to final growth, this explains why the most defoliated <span class="hlt">trees</span> grew the least due to their altered xylogenesis phases. Our findings indicate a very limited resilience capacity of drought-defoliated Scots and black pines. Moreover, droughts produce legacy effects on xylogenesis of highly defoliated <span class="hlt">trees</span> which could not recover previous growth rates and are thus more prone to die. PMID:27066053</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4817349','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4817349"><span id="translatedtitle">Limited Growth Recovery after Drought-Induced Forest Dieback in Very Defoliated <span class="hlt">Trees</span> of Two Pine <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>Guada, Guillermo; Camarero, J. Julio; Sánchez-Salguero, Raúl; Cerrillo, Rafael M. Navarro</p> <p>2016-01-01</p> <p>Mediterranean pine forests display high resilience after extreme climatic events such as severe droughts. However, recent dry spells causing growth decline and triggering forest dieback challenge the capacity of some forests to recover following major disturbances. To describe how resilient the responses of forests to drought can be, we quantified growth dynamics in plantations of two pine <span class="hlt">species</span> (Scots pine, black pine) located in south-eastern Spain and showing drought-triggered dieback. Radial growth was characterized at inter- (<span class="hlt">tree</span>-ring width) and intra-annual (xylogenesis) scales in three defoliation levels. It was assumed that the higher defoliation the more negative the impact of drought on <span class="hlt">tree</span> growth. <span class="hlt">Tree</span>-ring width chronologies were built and xylogenesis was characterized 3 years after the last severe drought occurred. Annual growth data and the number of tracheids produced in different stages of xylem formation were related to climate data at several time scales. Drought negatively impacted growth of the most defoliated <span class="hlt">trees</span> in both pine <span class="hlt">species</span>. In Scots pine, xylem formation started earlier in the non-defoliated than in the most defoliated <span class="hlt">trees</span>. Defoliated <span class="hlt">trees</span> presented the shortest duration of the radial-enlargement phase in both <span class="hlt">species</span>. On average the most defoliated <span class="hlt">trees</span> formed 60% of the number of mature tracheids formed by the non-defoliated <span class="hlt">trees</span> in both <span class="hlt">species</span>. Since radial enlargement is the xylogenesis phase most tightly related to final growth, this explains why the most defoliated <span class="hlt">trees</span> grew the least due to their altered xylogenesis phases. Our findings indicate a very limited resilience capacity of drought-defoliated Scots and black pines. Moreover, droughts produce legacy effects on xylogenesis of highly defoliated <span class="hlt">trees</span> which could not recover previous growth rates and are thus more prone to die. PMID:27066053</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</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</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..18.4813K&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016EGUGA..18.4813K&link_type=ABSTRACT"><span id="translatedtitle">Metaproteogenomics reveals the soil microbial communities active in nutrient cycling processes under different <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>Keiblinger, Katharina Maria; Masse, Jacynthe; Zühlke, Daniela; Riedel, Katharina; Zechmeister-Boltenstern, Sophie; Prescott, Cindy E.; Grayston, Sue</p> <p>2016-04-01</p> <p><span class="hlt">Tree</span> <span class="hlt">species</span> exert strong effects on microbial communities in litter and soil and may alter rates of soil processes fundamental to nutrient cycling and carbon fluxes (Prescott and Grayston 2013). However, the influence of <span class="hlt">tree</span> <span class="hlt">species</span> on decomposition processes are still contradictory and poorly understood. An understanding of the mechanisms underlying plant influences on soil processes is important for our ability to predict ecosystem response to altered global/environmental conditions. In order to link microbial community structure and function to forest-floor nutrient cycling processes, we sampled forest floors under western redcedar (Thuja plicata), Douglas-fir (Pseudotsuga menziesii) and Sitka spruce (Picea sitchensis) grown in nutrient-poor sites in common garden experiments on Vancouver island (Canada). We measured forest-floor total N, total C, initial NH4+ and NO3‑ concentrations, DOC, Cmic and Nmic. Gross rates of ammonification and NH4+ consumption were measured using the 15N pool-dilution method. Organic carbon quality was assessed through FTIR analyses. Microbial community structure was analysed by a metaproteogenomic approach using 16S and ITS amplification and sequencing with MiSeq platform. Proteins were extracted and peptides characterized via LC-MS/MS on a Velos Orbitrap to assess the active microbial community. Different microbial communities were active under the three <span class="hlt">tree</span> <span class="hlt">species</span> and variation in process rates were observed and will be discussed. This research provides new insights on microbial processes during organic matter decomposition. The metaproteogenomic approach enables us to investigate these changes with respect to possible effects on soil C-storage at even finer taxonomic resolution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/15046839','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/15046839"><span id="translatedtitle">Chemical and morphological characteristics of key <span class="hlt">tree</span> <span class="hlt">species</span> of the Carpathian Mountains.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mankovská, Blanka; Godzik, Barbara; Badea, Ovidiu; Shparyk, Yuri; Moravcík, Pavel</p> <p>2004-07-01</p> <p>Concentrations of Al, B, Ca, Cu, Fe, K, Mg, Mn, N, Na, P, S and Zn in the foliage of white fir (Abies alba), Norway spruce (Picea abies) and common beech (Fagus sylvatica) from 25 sites of the Carpathian Mts. forests (Czech Republic, Poland, Romania, Slovakia and Ukraine) are discussed in a context of their limit values. S/N ratio was different from optimum in 90% of localities when compared with the European limit values. Likewise we found increase of Fe and Cu concentrations compared with their background levels in 100% of locations. Mn concentrations were increased in 76% of localities. Mn mobilization values indicate the disturbance of physiological balance leading to the change of the ratio with Fe. SEM-investigation of foliage waxes from 25 sites in the Carpathian Mts. showed, that there is a statistically significant difference in mean wax quality. Epistomatal waxes were damaged as indicated by increased development of net and amorphous waxes. The most damaged stomata in spruce needles were from Yablunitsa, Synevir and Brenna; in fir needles from Stoliky, and in beech leaves from Malá Fatra, Morské Oko and Beregomet. Spruce needles in the Carpathian Mts. had more damaged stomata than fir needles and beech leaves. Spruce seems to be the most sensitive <span class="hlt">tree</span> <span class="hlt">species</span> to environmental stresses including air pollution in forests of the Carpathian Mountains. Foliage surfaces of three forest <span class="hlt">tree</span> <span class="hlt">species</span> contained Al, Si, Ca, Fe, Mg, K, Cl, Mn, Na, Ni and Ti in all studied localities. Presence of nutrition elements (Ca, Fe, Mg, K and Mn) on foliage surface hinders opening and closing stomata and it is not physiologically usable for <span class="hlt">tree</span> <span class="hlt">species</span>. PMID:15046839</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013AGUFM.B52D..03B&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013AGUFM.B52D..03B&link_type=ABSTRACT"><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.ncbi.nlm.nih.gov/pubmed/23229391','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23229391"><span id="translatedtitle">Consumer preference for seeds and seedlings of rare <span class="hlt">species</span> impacts <span class="hlt">tree</span> diversity at multiple scales.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Young, Hillary S; McCauley, Douglas J; Guevara, Roger; Dirzo, Rodolfo</p> <p>2013-07-01</p> <p>Positive density-dependent seed and seedling predation, where herbivores selectively eat seeds or seedlings of common <span class="hlt">species</span>, is thought to play a major role in creating and maintaining plant community diversity. However, many herbivores and seed predators are known to exhibit preferences for rare foods, which could lead to negative density-dependent predation. In this study, we first demonstrate the occurrence of increased predation of locally rare <span class="hlt">tree</span> <span class="hlt">species</span> by a widespread group of insular seed and seedling predators, land crabs. We then build computer simulations based on these empirical data to examine the effects of such predation on diversity patterns. Simulations show that herbivore preferences for locally rare <span class="hlt">species</span> are likely to drive scale-dependent effects on plant community diversity: at small scales these foraging patterns decrease plant community diversity via the selective consumption of rare plant <span class="hlt">species</span>, while at the landscape level they should increase diversity, at least for short periods, by promoting clustered local dominance of a variety of <span class="hlt">species</span>. Finally, we compared observed patterns of plant diversity at the site to those obtained via computer simulations, and found that diversity patterns generated under simulations were highly consistent with observed diversity patterns. We posit that preference for rare <span class="hlt">species</span> by herbivores may be prevalent in low- or moderate-diversity systems, and that these effects may help explain diversity patterns across different spatial scales in such ecosystems. PMID:23229391</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> </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/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=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/17205910','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/17205910"><span id="translatedtitle">Regional and phylogenetic variation of wood density across 2456 Neotropical <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>Chave, Jérôme; Muller-Landau, Helene C; Baker, Timothy R; Easdale, Tomás A; ter Steege, Hans; Webb, Campbell O</p> <p>2006-12-01</p> <p>Wood density is a crucial variable in carbon accounting programs of both secondary and old-growth tropical forests. It also is the best single descriptor of wood: it correlates with numerous morphological, mechanical, physiological, and ecological properties. To explore the extent to which wood density could be estimated for rare or poorly censused taxa, and possible sources of variation in this trait, we analyzed regional, taxonomic, and phylogenetic variation in wood density among 2456 <span class="hlt">tree</span> <span class="hlt">species</span> from Central and South America. Wood density varied over more than one order of magnitude across <span class="hlt">species</span>, with an overall mean of 0.645 g/cm3. Our geographical analysis showed significant decreases in wood density with increasing altitude and significant differences among low-altitude geographical regions: wet forests of Central America and western Amazonia have significantly lower mean wood density than dry forests of Central and South America, eastern and central Amazonian forests, and the Atlantic forests of Brazil; and eastern Amazonian forests have lower wood densities than the dry forests and the Atlantic forest. A nested analysis of variance showed that 74% of the <span class="hlt">species</span>-level wood density variation was explained at the genus level, 34% at the Angiosperm Phylogeny Group (APG) family level, and 19% at the APG order level. This indicates that genus-level means give reliable approximations of values of <span class="hlt">species</span>, except in a few hypervariable genera. We also studied which evolutionary shifts in wood density occurred in the phylogeny of seed plants using a composite phylogenetic <span class="hlt">tree</span>. Major changes were observed at deep nodes (Eurosid 1), and also in more recent divergences (for instance in the Rhamnoids, Simaroubaceae, and Anacardiaceae). Our unprecedented wood density data set yields consistent guidelines for estimating wood densities when <span class="hlt">species</span>-level information is lacking and should significantly reduce error in Central and South American carbon accounting</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</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5000521','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5000521"><span id="translatedtitle">Fine Root Productivity and Turnover of Ectomycorrhizal and Arbuscular Mycorrhizal <span class="hlt">Tree</span> <span class="hlt">Species</span> in a Temperate Broad-Leaved Mixed 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>Kubisch, Petra; Hertel, Dietrich; Leuschner, Christoph</p> <p>2016-01-01</p> <p>Advancing our understanding of <span class="hlt">tree</span> fine root dynamics is of high importance for <span class="hlt">tree</span> physiology and forest biogeochemistry. In temperate broad-leaved forests, ectomycorrhizal (EM) and arbuscular mycorrhizal (AM) <span class="hlt">tree</span> <span class="hlt">species</span> often are coexisting. It is not known whether EM and AM <span class="hlt">trees</span> differ systematically in fine root dynamics and belowground resource foraging strategies. We measured fine root productivity (FRP) and fine root turnover (and its inverse, root longevity) of three EM and three AM broad-leaved <span class="hlt">tree</span> <span class="hlt">species</span> in a natural cool-temperate mixed forest using ingrowth cores and combined the productivity data with data on root biomass per root orders. FRP and root turnover were related to root morphological traits and aboveground productivity. FRP differed up to twofold among the six coexisting <span class="hlt">species</span> with larger <span class="hlt">species</span> differences in lower horizons than in the topsoil. Root turnover varied up to fivefold among the <span class="hlt">species</span> with lowest values in Acer pseudoplatanus and highest in its congener Acer platanoides. Variation in root turnover was larger within the two groups than between EM and AM <span class="hlt">species</span>. We conclude that the main determinant of FRP and turnover in this mixed forest is <span class="hlt">species</span> identity, while the influence of mycorrhiza type seems to be less important. PMID:27617016</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27617016','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27617016"><span id="translatedtitle">Fine Root Productivity and Turnover of Ectomycorrhizal and Arbuscular Mycorrhizal <span class="hlt">Tree</span> <span class="hlt">Species</span> in a Temperate Broad-Leaved Mixed Forest.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kubisch, Petra; Hertel, Dietrich; Leuschner, Christoph</p> <p>2016-01-01</p> <p>Advancing our understanding of <span class="hlt">tree</span> fine root dynamics is of high importance for <span class="hlt">tree</span> physiology and forest biogeochemistry. In temperate broad-leaved forests, ectomycorrhizal (EM) and arbuscular mycorrhizal (AM) <span class="hlt">tree</span> <span class="hlt">species</span> often are coexisting. It is not known whether EM and AM <span class="hlt">trees</span> differ systematically in fine root dynamics and belowground resource foraging strategies. We measured fine root productivity (FRP) and fine root turnover (and its inverse, root longevity) of three EM and three AM broad-leaved <span class="hlt">tree</span> <span class="hlt">species</span> in a natural cool-temperate mixed forest using ingrowth cores and combined the productivity data with data on root biomass per root orders. FRP and root turnover were related to root morphological traits and aboveground productivity. FRP differed up to twofold among the six coexisting <span class="hlt">species</span> with larger <span class="hlt">species</span> differences in lower horizons than in the topsoil. Root turnover varied up to fivefold among the <span class="hlt">species</span> with lowest values in Acer pseudoplatanus and highest in its congener Acer platanoides. Variation in root turnover was larger within the two groups than between EM and AM <span class="hlt">species</span>. We conclude that the main determinant of FRP and turnover in this mixed forest is <span class="hlt">species</span> identity, while the influence of mycorrhiza type seems to be less important. PMID:27617016</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016ISPAr41B8..593H&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2016ISPAr41B8..593H&link_type=ABSTRACT"><span id="translatedtitle">Forest <span class="hlt">Tree</span> <span class="hlt">Species</span> Distribution Mapping Using Landsat Satellite Imagery and Topographic Variables with the Maximum Entropy Method in Mongolia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hao Chiang, Shou; Valdez, Miguel; Chen, Chi-Farn</p> <p>2016-06-01</p> <p>Forest is a very important ecosystem and natural resource for living things. Based on forest inventories, government is able to make decisions to converse, improve and manage forests in a sustainable way. Field work for forestry investigation is difficult and time consuming, because it needs intensive physical labor and the costs are high, especially surveying in remote mountainous regions. A reliable forest inventory can give us a more accurate and timely information to develop new and efficient approaches of forest management. The remote sensing technology has been recently used for forest investigation at a large scale. To produce an informative forest inventory, forest attributes, including <span class="hlt">tree</span> <span class="hlt">species</span> are unavoidably required to be considered. In this study the aim is to classify forest <span class="hlt">tree</span> <span class="hlt">species</span> in Erdenebulgan County, Huwsgul province in Mongolia, using Maximum Entropy method. The study area is covered by a dense forest which is almost 70% of total territorial extension of Erdenebulgan County and is located in a high mountain region in northern Mongolia. For this study, Landsat satellite imagery and a Digital Elevation Model (DEM) were acquired to perform <span class="hlt">tree</span> <span class="hlt">species</span> mapping. The forest <span class="hlt">tree</span> <span class="hlt">species</span> inventory map was collected from the Forest Division of the Mongolian Ministry of Nature and Environment as training data and also used as ground truth to perform the accuracy assessment of the <span class="hlt">tree</span> <span class="hlt">species</span> classification. Landsat images and DEM were processed for maximum entropy modeling, and this study applied the model with two experiments. The first one is to use Landsat surface reflectance for <span class="hlt">tree</span> <span class="hlt">species</span> classification; and the second experiment incorporates terrain variables in addition to the Landsat surface reflectance to perform the <span class="hlt">tree</span> <span class="hlt">species</span> classification. All experimental results were compared with the <span class="hlt">tree</span> <span class="hlt">species</span> inventory to assess the classification accuracy. Results show that the second one which uses Landsat surface reflectance coupled</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> <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</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</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://adsabs.harvard.edu/abs/2010AGUFM.A53C0262A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.A53C0262A"><span id="translatedtitle">Soil Terpene Emissions in a Subalpine Coniferous Forest: <span class="hlt">Tree</span> <span class="hlt">Species</span>, Soil Temperature and Moisture Effects</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Asensio, D.; Duhl, T.; Greenberg, J.; Guenther, A. B.; Monson, R. K.</p> <p>2010-12-01</p> <p>Some studies have shown soils can contribute significantly to the canopy level fluxes of volatile organic compounds (VOCs) in some ecosystem types during some seasons. Yet patterns of soil VOCs fluxes as well as controls are poorly known and so the potential importance of soil VOCs emissions on the total global BVOCs emissions from terrestrial sources remains unclear. We measured soil terpene emission at a high-elevation, mixed conifer, subalpine forest site at the Niwot Ridge Ameriflux Site in Colorado. Given the important role of terpenes on the formation of secondary organic aerosols and given that high amounts of terpenes are produced and stored in coniferous tissues (e. g. roots and litter) we focused only on these compounds in this study. The objectives were to quantify soil terpene flux and its contribution to the canopy level flux and to identify environmental variables controlling soil terpene emissions in this forest, such as <span class="hlt">tree</span> <span class="hlt">species</span>, <span class="hlt">tree</span> <span class="hlt">species</span> density, total soil organic matter content, soil temperature and soil moisture . During the summer 2009 (August), soil terpene emission rates were measured in soil chambers regularly distributed in a 200 x 200 m area around the flux tower. To test the effect of the <span class="hlt">tree</span> <span class="hlt">species</span> on soil emissions, additional chambers were placed on relative pure stands of each one of the representative <span class="hlt">species</span>. The average total monoterterpene emission rate during August 2009 was 21 μg C m-2 h-1. These emissions represent 9% of the total terpene canopy fluxes reported in this forest during the same period on previous summers (August 2007, 238 μg C m-2 h-1). The range of monoterpene emission was found to be high; emissions went up to 368 μg C m-2 h-1 under specific conditions. Total sesquiterpene emissions were much lower than monoterpenes (0.04 ± 0.01 μg C m-2 h-1). Due to the high variability found, no clear effect of the space distribution was identified. However, soil terpene emissions were significantly affected by</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</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.ncbi.nlm.nih.gov/pubmed/27489479','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27489479"><span id="translatedtitle">A new <span class="hlt">species</span> in the <span class="hlt">tree</span> genus Polyceratocarpus (Annonaceae) from the Udzungwa Mountains of Tanzania.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Marshall, Andrew R; Couvreur, Thomas L P; Summers, Abigail L; Deere, Nicolas J; Luke, W R Quentin; Ndangalasi, Henry J; Sparrow, Sue; Johnson, David M</p> <p>2016-01-01</p> <p>Polyceratocarpus askhambryan-iringae, an endemic <span class="hlt">tree</span> <span class="hlt">species</span> of Annonaceae from the Udzungwa Mountains of Tanzania, is described and illustrated. The new <span class="hlt">species</span> is identified as a member of the genus Polyceratocarpus by the combination of staminate and bisexual flowers, axillary inflorescences, subequal outer and inner petals, and multi-seeded monocarps with pitted seeds. From Polyceratocarpus scheffleri, with which it has previously been confused, it differs in the longer pedicels, smaller and thinner petals, shorter bracts, and by generally smaller, less curved monocarps that have a clear stipe and usually have fewer seeds. Because Polyceratocarpus askhambryan-iringae has a restricted extent of occurrence, area of occupancy, and ongoing degradation of its forest habitat, we recommend classification of it as Endangered (EN) on the IUCN Red List. PMID:27489479</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/22864697','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22864697"><span id="translatedtitle">Controls on coarse wood decay in temperate <span class="hlt">tree</span> <span class="hlt">species</span>: birth of the LOGLIFE experiment.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cornelissen, Johannes H C; Sass-Klaassen, Ute; Poorter, Lourens; van Geffen, Koert; van Logtestijn, Richard S P; van Hal, Jurgen; Goudzwaard, Leo; Sterck, Frank J; Klaassen, René K W M; Freschet, Grégoire T; van der Wal, Annemieke; Eshuis, Henk; Zuo, Juan; de Boer, Wietse; Lamers, Teun; Weemstra, Monique; Cretin, Vincent; Martin, Rozan; Ouden, Jan den; Berg, Matty P; Aerts, Rien; Mohren, Godefridus M J; Hefting, Mariet M</p> <p>2012-01-01</p> <p>Dead wood provides a huge terrestrial carbon stock and a habitat to wide-ranging organisms during its decay. Our brief review highlights that, in order to understand environmental change impacts on these functions, we need to quantify the contributions of different interacting biotic and abiotic drivers to wood decomposition. LOGLIFE is a new long-term 'common-garden' experiment to disentangle the effects of <span class="hlt">species</span>' wood traits and site-related environmental drivers on wood decomposition dynamics and its associated diversity of microbial and invertebrate communities. This experiment is firmly rooted in pioneering experiments under the directorship of Terry Callaghan at Abisko Research Station, Sweden. LOGLIFE features two contrasting forest sites in the Netherlands, each hosting a similar set of coarse logs and branches of 10 <span class="hlt">tree</span> <span class="hlt">species</span>. LOGLIFE welcomes other researchers to test further questions concerning coarse wood decay that will also help to optimise forest management in view of carbon sequestration and biodiversity conservation. PMID:22864697</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4956929','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4956929"><span id="translatedtitle">A new <span class="hlt">species</span> in the <span class="hlt">tree</span> genus Polyceratocarpus (Annonaceae) from the Udzungwa Mountains of Tanzania</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Marshall, Andrew R.; Couvreur, Thomas L.P.; Summers, Abigail L.; Deere, Nicolas J.; Luke, W.R. Quentin; Ndangalasi, Henry J.; Sparrow, Sue; Johnson, David M.</p> <p>2016-01-01</p> <p>Abstract Polyceratocarpus askhambryan-iringae, an endemic <span class="hlt">tree</span> <span class="hlt">species</span> of Annonaceae from the Udzungwa Mountains of Tanzania, is described and illustrated. The new <span class="hlt">species</span> is identified as a member of the genus Polyceratocarpus by the combination of staminate and bisexual flowers, axillary inflorescences, subequal outer and inner petals, and multi-seeded monocarps with pitted seeds. From Polyceratocarpus scheffleri, with which it has previously been confused, it differs in the longer pedicels, smaller and thinner petals, shorter bracts, and by generally smaller, less curved monocarps that have a clear stipe and usually have fewer seeds. Because Polyceratocarpus askhambryan-iringae has a restricted extent of occurrence, area of occupancy, and ongoing degradation of its forest habitat, we recommend classification of it as Endangered (EN) on the IUCN Red List. PMID:27489479</p> </li> <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</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</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=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://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013AGUFM.B43C0515G&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013AGUFM.B43C0515G&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Tree</span> <span class="hlt">species</span> classification in the Southern Sierra Nevada Mountains based on MASTER and LIDAR imagery</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gibbons, S.; Grigsby, S.; Ustin, S.</p> <p>2013-12-01</p> <p>NASA recently collected MASTER (MODIS/ASTER) imagery over the Southern Sierra Nevada Mountains as part of the HyspIRI (Hyperspectral Infrared Imager) preparatory campaign, a location that was chosen for its distinct changes in vegetative <span class="hlt">species</span> with elevation. Differentiation between functional types based on spectral data has been successful, however, classification between individual <span class="hlt">species</span> is more difficult to accomplish with only the visible and near infrared portions of the spectrum. I used MASTER imagery in combination with Critical Zone Observatory LIDAR data to map <span class="hlt">species</span> across both a low and high elevation site in the San Joaquin Experimental Range. While the visible and thermal bands of MASTER images provided an improved classification over shortwave bands, the physical characteristics from the LIDAR data showed the most contrast between the land covers, including <span class="hlt">tree</span> <span class="hlt">species</span>. The National Ecological Observation Network (NEON) plans to use LIDAR and spectral data to monitor 20 domains, including the San Joaquin Experimental Range, for the next thirty years. Understanding the current <span class="hlt">species</span> distributions not only provides insight on the available resources of the area but will also act as a baseline to determine the effects of environmental changes on vegetation using future NEON data.</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/22886165','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22886165"><span id="translatedtitle">Restinga forests of the Brazilian coast: richness and abundance of <span class="hlt">tree</span> <span class="hlt">species</span> on different soils.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Magnago, Luiz F S; Martins, Sebastião V; Schaefer, Carlos E G R; Neri, Andreza V</p> <p>2012-09-01</p> <p>The aim of this study was to determine changes in composition, abundance and richness of <span class="hlt">species</span> along a forest gradient with varying soils and flood regimes. The forests are located on the left bank of the lower Jucu River, in Jacarenema Natural Municipal Park, Espírito Santo. A survey of shrub/<span class="hlt">tree</span> <span class="hlt">species</span> was done in 80 plots, 5x25 m, equally distributed among the forests studied. We included in the sampling all individuals with >3.2 cm diameter at breast height (1.30 m). Soil samples were collected from the surface layer (0-10 cm) in each plot for chemical and physical analysis. The results indicate that a significant pedological gradient occurs, which is influenced by varying seasonal groundwater levels. Restinga forest formations showed significant differences in <span class="hlt">species</span> richness, except for Non-flooded Forest and Non-flooded Forest Transition. The Canonical Correlation Analysis (CCA) showed that some <span class="hlt">species</span> are distributed along the gradient under the combined influence of drainage, nutrient concentration and physical characteristics of the soil. Regarding the variables tested, flooding seems to be a more limiting factor for the establishment of plant <span class="hlt">species</span> in Restinga forests than basic soil fertility attributes. PMID:22886165</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/24740283','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24740283"><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=pubmed">PubMed</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.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/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.ncbi.nlm.nih.gov/pubmed/27255837','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27255837"><span id="translatedtitle">The rubber <span class="hlt">tree</span> genome reveals new insights into rubber production and <span class="hlt">species</span> adaptation.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tang, Chaorong; Yang, Meng; Fang, Yongjun; Luo, Yingfeng; Gao, Shenghan; Xiao, Xiaohu; An, Zewei; Zhou, Binhui; Zhang, Bing; Tan, Xinyu; Yeang, Hoong-Yeet; Qin, Yunxia; Yang, Jianghua; Lin, Qiang; Mei, Hailiang; Montoro, Pascal; Long, Xiangyu; Qi, Jiyan; Hua, Yuwei; He, Zilong; Sun, Min; Li, Wenjie; Zeng, Xia; Cheng, Han; Liu, Ying; Yang, Jin; Tian, Weimin; Zhuang, Nansheng; Zeng, Rizhong; Li, Dejun; He, Peng; Li, Zhe; Zou, Zhi; Li, Shuangli; Li, Chenji; Wang, Jixiang; Wei, Dong; Lai, Chao-Qiang; Luo, Wei; Yu, Jun; Hu, Songnian; Huang, Huasun</p> <p>2016-01-01</p> <p>The Para rubber <span class="hlt">tree</span> (Hevea brasiliensis) is an economically important tropical <span class="hlt">tree</span> <span class="hlt">species</span> that produces natural rubber, an essential industrial raw material. Here we present a high-quality genome assembly of this <span class="hlt">species</span> (1.37 Gb, scaffold N50 = 1.28 Mb) that covers 93.8% of the genome (1.47 Gb) and harbours 43,792 predicted protein-coding genes. A striking expansion of the REF/SRPP (rubber elongation factor/small rubber particle protein) gene family and its divergence into several laticifer-specific isoforms seem crucial for rubber biosynthesis. The REF/SRPP family has isoforms with sizes similar to or larger than SRPP1 (204 amino acids) in 17 other plants examined, but no isoforms with similar sizes to REF1 (138 amino acids), the predominant molecular variant. A pivotal point in Hevea evolution was the emergence of REF1, which is located on the surface of large rubber particles that account for 93% of rubber in the latex (despite constituting only 6% of total rubber particles, large and small). The stringent control of ethylene synthesis under active ethylene signalling and response in laticifers resolves a longstanding mystery of ethylene stimulation in rubber production. Our study, which includes the re-sequencing of five other Hevea cultivars and extensive RNA-seq data, provides a valuable resource for functional genomics and tools for breeding elite Hevea cultivars. PMID:27255837</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SPIE.9245E..0ZR','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SPIE.9245E..0ZR"><span id="translatedtitle">Mapping <span class="hlt">tree</span> <span class="hlt">species</span> in a boreal forest area using RapidEye and Lidar data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rochdi, N.; Yang, X.; Staenz, K.; Patterson, Shane; Purdy, Brett</p> <p>2014-10-01</p> <p><span class="hlt">Tree</span> <span class="hlt">species</span> composition is one of the criteria required for assessing forest reclamation in the province of Alberta in Canada. This information is also very important for forest management and conservation purposes. In this paper the performances of RapidEye data alone and in combination with the Light Detection And Ranging data is assessed for mapping <span class="hlt">tree</span> <span class="hlt">species</span> in a boreal forest area in Alberta. Both the random forest and support vector machine classification techniques were evaluated. A significant improvement in the classification outputs was observed when using both data types. Random forest outperformed the support vector machine classifier. Overall, the difference in acquisition time between the RapidEye and Light Detection And Ranging data did not seem to affect significantly the classification results. Using random forest, six input variables were identified as the most important for the classification process including digital elevation model, terrain slope, canopy height, the red-edge normalized difference vegetation index, and the red-edge and near-infrared bands.</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>Enβle, 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=3387126','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3387126"><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=pmc">PubMed Central</a></p> <p>Russell, Ann E.; Raich, James W.</p> <p>2012-01-01</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 CO2 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, δ13C 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/20960206','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/20960206"><span id="translatedtitle">Development, characterization, and cross-<span class="hlt">species</span>/genera transferability of SSR markers for rubber <span class="hlt">tree</span> (Hevea brasiliensis).</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yu, Fei; Wang, Bao-Hua; Feng, Su-Ping; Wang, Jing-Yi; Li, Wei-Guo; Wu, Yao-Ting</p> <p>2011-03-01</p> <p>Genomic simple sequence repeat (SSR) markers are particularly valuable in studies of genetic diversity, evolution, genetic linkage map construction, quantitative trait loci tagging, and marker-assisted selection because of their multi-allelic nature, reproducibility, co-dominant inheritance, high abundance, and extensive genome coverage. The traditional methods of SSR marker development, such as genomic-SSR hybrid screening and microsatellite enrichment, have the disadvantages of high cost and complex operation. The selectively amplified microsatellite method is less costly and highly efficient as well as being simple and convenient. In this study, 252 sequences with SSRs were cloned from the rubber <span class="hlt">tree</span> (Hevea brasiliensis) genome from which 258 SSR loci were obtained. The average repeat number was six. There were only 10 (3.9%) mononucleotide, trinucleotide, and pentanucleotide repeats, whereas the remaining 248 (96.1%) were dinucleotide repeats, including 128 (49.6%) GT/CA repeats, 118 (45.7%) GA/CT repeats, and 2 (0.8%) AT/TA repeats. A total of 126 primer pairs (see ESM) were successfully designed of which 36 primer pairs generated polymorphic products from 12 accessions of the cultivated <span class="hlt">species</span>, 4 related <span class="hlt">species</span>, and 3 <span class="hlt">species</span> of the family Euphorbiaceae. In addition, investigations based on four genomic SSRs (GAR4, ACR22, CTR25, and GTR28) by cloning and sequencing provided evidence for cross-<span class="hlt">species</span>/genera applicability, and homologous sequences were obtained from the rubber <span class="hlt">tree</span> and Euphorbiaceae. Further analysis about the variation of the flanking regions of the four markers was carried out. PMID:20960206</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/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=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</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013JARS....7.3480A&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2013JARS....7.3480A&link_type=ABSTRACT"><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.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> </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_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><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" 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_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</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="401"> <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://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=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 representat