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1

Palatability of wilted and dried multipurpose tree species fed to sheep and goats  

Microsoft Academic Search

Palatability indices of dry and wilted 18 multipurpose tree species (MPTs) were determined using 12 wethers and 12 bucks (mean ± SD liveweight 17.5 ± 1.24 kg and 20.5 ± 1.46 kg, respectively), blocked into two groups on liveweight and age, housed in a roofed and half-walled shed with individual feeding pens. The 18 MPTs were randomly grouped into sets

R. J. Kaitho; N. N. Umunna; I. V. Nsahlai; S. Tamminga; J. van Bruchem; J. Hanson

1997-01-01

2

Reserve carbohydrate levels in the boles and structural roots of five multipurpose tree species in a seasonally dry tropical climate  

Microsoft Academic Search

It is important to know the seasonal cycles of reserve carbohydrates in agroforestry trees because their ability to sprout after cutting may depend on reserve carbohydrate levels. Such information is lacking for tropical agroforestry trees. Reserve carbohydrate trends were examined in uncut, 12-year-old multipurpose trees in the seasonally dry climate of Ibadan, Nigeria. Species included Dactyladenia barteri, Gliricidia sepium, Leucaena

C. R Latt; P. K. R Nair; B. T Kang

2001-01-01

3

Potential of nine multipurpose tree species to reduce saline groundwater tables in the lower Amu Darya River region of Uzbekistan  

Microsoft Academic Search

This paper evaluates the potential of nine multipurpose tree species for afforestation of degraded land in the Khorezm region, Central Asia, particularly their suitability for biodrainage i.e., lowering the elevated groundwater table through the transpirative capacity of plantations. For this purpose water use (WU), water use efficiency (WUE) and tree physiological factors influencing transpiration were assessed during two consecutive years.

Asia Khamzina; John P. A. Lamers; Christopher Martius; Martin Worbes; Paul L. G. Vlek

2006-01-01

4

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

NASA Astrophysics Data System (ADS)

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.

Das, Tapasi; Das, Ashesh Kumar

2013-01-01

5

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

PubMed

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

Das, Tapasi; Das, Ashesh Kumar

2013-01-01

6

In vitro Propagation of Banyan Tree (Ficus benghalensis L.) - A Multipurpose and Keystone Species of Bangladesh  

Microsoft Academic Search

Nodal segments of about 100-year-old banyan tree (Ficus benghalensis L.) was found to be the best for multiple axillary shoot production on MMS1 medium supplemented with 0.5 mg\\/l BA. Subculturing of the nodal segments from regenerated shoots to the same medium profoundly stimulated shoot proliferation and elongation. These shoots were devoid of any root and induced to develop roots by

M. M. Rahman; M. N. Amin; M. F. Hossain

7

Willow (Salix fragilis Linn.): A multipurpose tree species under pest attack in the cold desert of Lahaul valley, northwestern Himalaya, India.  

PubMed

Salix fragilis is the most common willow species grown extensively under the indigenous agroforestry system in the cold desert of Lahaul valley located in the northwestern Himalayas, India. Presently, this tree is under severe pest attack, and other infections have made its survival in the area questionable. This deciduous multipurpose tree species provides vegetation cover to the barren landscape of Lahaul and is a significant contributor of fuel and fodder to the region. This study is a detailed profile of the plant in three villages within this region: Khoksar, Jahlma, and Hinsa. The willow provided 69.5%, 29%, and 42% of the total fuelwood requirements of Jahlma, Khoksar, and Hinsa respectively. A striking observation was that only 30.0 +/- 20.1% trees were healthy: 55.2 +/- 16.1% of the willows have dried up and 14.8 +/- 6.1% were in drying condition due to a combination of pest infestation and infection. To sustain this cultivation of willow under the existing agroforestry system in the region, we recommend that locally available wild species and other established varieties of willow growing in similar regions of the Himalayas be introduced on a trial basis. PMID:16615699

Rawat, Yashwant S; Oinam, Santaram S; Vishvakarma, Subhash C R; Kuniyal, Chandra P; Kuniyal, Jagdish C

2006-02-01

8

Nutritional and anti-nutritional characters and rumen degradability of dry matter and nitrogen for some multipurpose tree species with potential for agroforestry in Zimbabwe  

Microsoft Academic Search

In a preliminary study on the nutritional value of seven multipurpose trees (MPTs), currently showing potential use in agroforestry systems in Zimbabwe, crude protein values ranged from 189 g kg?1 DM in Flemingia macrophylla to 292 g kg?1 DM in Acacia angustissima. Acid detergent fibre (ADF) content was low especially in Sesbania sesban (99 g kg?1 DM), while ADF contents

B. H. Dzowela; L. Hove; J. H. Topps; P. L. Mafongoya

1995-01-01

9

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

PubMed

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 timber and NTFP values. PMID:24061084

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

2013-11-30

10

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

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

2013-01-01

11

Comparative growth performance of some multipurpose trees and shrubs grown at Machakos, Kenya  

Microsoft Academic Search

Growth rates of 29 multipurpose trees grown in an agroforestry arboretum for six years at a sub-humid to semi-arid climatic\\u000a zone are presented. Exotic species such as Grevillea robusta, Sesbania grandiflora, Leucaena leucocephala, Cassia siamea and Sesbania sesban, some of which were outside their traditional climatic zones, had higher diameters, heights and bole volumes\\/tree (upto 130%\\u000a more in certain cases)

Bashir Jama; P. K. R. Nair; P. W. Kurira

1989-01-01

12

Fifth International Poplar Symposium: 'Poplars and willows: from research models to multipurpose trees for a bio-based society'.  

PubMed

Carefully managed tree plantations offer an opportunity for sustainable biomass production. In recent years, the responses of the Salicaceae to environmental constraints have increasingly been investigated at different levels of biological integration, giving rise to a physiological approach to the function of trees in environmental restoration and monitoring. Significant progress has been achieved by the poplar and willow community in understanding targeted characteristics of complex tree stress responses. The Fifth International Poplar Symposium brought together experts in this area, with the main objective being to improve, coordinate and communicate existing national research on the biological and environmental dimension of multifunctional poplar and willow plantations. The secondary objective was to develop a network of research scientists and extension workers to provide scientific support for subjects interested in using fast-growing poplar and willow species for tree-related environmental projects. The ultimate goal was to build up services for the multipurpose tree plantation network on local-level management in order to obtain maximized benefits from tree crops. The purpose was also to maximize the synergy between local knowledge and global-level processes that require information on multipurpose tree crop production. PMID:22158009

Tognetti, Roberto; Massacci, Angelo; Mugnozza, Giuseppe Scarascia

2011-12-01

13

Evaluation and selection of multipurpose tree for improving soil hydro-physical behaviour under hilly eco-system of north east India  

Microsoft Academic Search

Soil hydro-physical behaviour was studied under a 20-year old agroforestry plantation consisting of five multipurpose tree\\u000a species (Pinus kesiya Royle ex-Gordon, Alnus nepalensis D.Don, Parkia roxburghii G.Don, Michelia oblonga Wall. and Gmelina arboria Roxb.) maintained under normal recommended practices at Indian Council of Agricultural Research (ICAR) Complex, Umiam, Meghalaya,\\u000a India. The aim was to select tree species, which could act

R. Saha; J. M. S. Tomar; P. K. Ghosh

2007-01-01

14

The framework tree species approach to conserve medicinal trees in Uganda  

Microsoft Academic Search

Framework species are indigenous tree species planted in a mixed stand to accelerate natural regeneration of forest and encourage\\u000a biodiversity regeneration. In this study we used the framework species method to make multipurpose tree gardens to provide\\u000a traditional healers with woody species used for medicine and other needs like food and firewood. We specifically determined\\u000a the phenology, germination behaviour, survival

Torunn Stangeland; John Tabuti; Kåre A. Lye

2011-01-01

15

Species integrity in trees.  

PubMed

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

Ortiz-Barrientos, Daniel; Baack, Eric J

2014-09-01

16

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 ...

17

Chemical composition and degradation characteristics of foliage of some African multipurpose trees  

Microsoft Academic Search

Samples of foliage from multipurpose leguminous trees (MPT) which had been selected as potential feed supplements for ruminants were examined for their chemical composition and in situ degradation characteristics, and were compared with alfalfa (Medicago sativa) hay and teff (Eragrostis abyssinica) straw. Organic matter (OM), acid detergent fibre (ADF), neutral detergent fibre (NDF), nitrogen, neutral detergent nitrogen, acid detergent lignin

S. M El hassan; A Lahlou Kassi; C. J Newbold; R. J Wallace

2000-01-01

18

In vitro propagation of a multipurpose leguminous tree ( Pterocarpus marsupium Roxb.) using nodal explants  

Microsoft Academic Search

Pterocarpus marsupium (Bijasal) is a valuable multipurpose forest tree. The regeneration rate in natural habitat is low and the tree is overexploited.\\u000a An in vitro propagation protocol has been developed from nodal explants obtained from in vitro raised 18-day-old axenic seedlings.\\u000a The highest shoot regeneration frequency (85%), maximum number of multiple shoots (8.6) as well as length (4.8 cm) were induced

Mohd Kashif Husain; Mohammad Anis; Anwar Shahzad

2008-01-01

19

Acacia albida and other multipurpose trees on the fur farmlands in the Jebel Marra highlands, Western Darfur, Sudan  

Microsoft Academic Search

This paper describes the traditional agroforestry systems based on Acacia albida and other multipurpose trees as practised by the sedentary Fur people on the lower slopes and highlands of the Jebel Marra massif, Sudan. The basic agrosilvopastoral system consists of terraced village fields, where semipermanent rainfed cropping of staple millet and other subsistence crops takes place under stands of multipurpose

S. Miehe

1986-01-01

20

From Gene Trees to Species Trees II: Species Tree Inference by Minimizing Deep  

E-print Network

From Gene Trees to Species Trees II: Species Tree Inference by Minimizing Deep Coalescence Events Louxin Zhang Abstract--When gene copies are sampled from various species, the resulting gene tree might disagree with the containing species tree. The primary causes of gene tree and species tree discord include

Zhang, Louxin

21

Estimating species trees from unrooted gene trees.  

PubMed

In this study, we develop a distance method for inferring unrooted species trees from a collection of unrooted gene trees. The species tree is estimated by the neighbor joining (NJ) tree built from a distance matrix in which the distance between two species is defined as the average number of internodes between two species across gene trees, that is, average gene-tree internode distance. The distance method is named NJ(st) to distinguish it from the original NJ method. Under the coalescent model, we show that if gene trees are known or estimated correctly, the NJ(st) method is statistically consistent in estimating unrooted species trees. The simulation results suggest that NJ(st) and STAR (another coalescence-based method for inferring species trees) perform almost equally well in estimating topologies of species trees, whereas the Bayesian coalescence-based method, BEST, outperforms both NJ(st) and STAR. Unlike BEST and STAR, the NJ(st) method can take unrooted gene trees to infer species trees without using an outgroup. In addition, the NJ(st) method can handle missing data and is thus useful in phylogenomic studies in which data sets often contain missing loci for some individuals. PMID:21447481

Liu, Liang; Yu, Lili

2011-10-01

22

Litter dynamics of six multipurpose trees in a homegarden in Southern Kerala, India  

Microsoft Academic Search

Multipurpose trees, the integral components of homegardens, contribute significantly to the closed nutrient cycling processes\\u000a and sustainability of the ecosystem. Although, the litter production and probable nutrient returns via litter in homegardens\\u000a have been documented, quantification and characterization of the decomposition and bioelement release from the litter have\\u000a received relatively little scientific attention. The objective of the present study is

Sheeba Rebecca Isaac; M. Achuthan Nair

2006-01-01

23

Ziziphus spina-christi (L.) Willd.: a multipurpose fruit tree  

Microsoft Academic Search

Neglected and underutilized species often play a vital role in securing food and livestock feed, income generation and energy\\u000a needs of rural populations. In spite of their great potential little attention has been given to these species. This increases\\u000a the possibility of genetic erosion which would further restrict the survival strategies of people in rural areas. Ziziphus spina-christi is a

Amina Sirag Saied; Jens Gebauer; Karl Hammer; Andreas Buerkert

2008-01-01

24

Discordance of species trees with their most likely gene trees  

E-print Network

Discordance of species trees with their most likely gene trees James H. Degnan & Noah A. Rosenberg sort during speciation, gene trees may differ in topology from each other and from species trees find that for any species tree topology with five or more species, there exist branch lengths for which

Degnan, James

25

Discordance of Species Trees with Their Most Likely Gene Trees  

Microsoft Academic Search

Because of the stochastic way in which lineages sort during speciation, gene trees may differ in topology from each other and from species trees. Surprisingly, assuming that genetic lineages follow a coalescent model of within-species evolution, we find that for any species tree topology with five or more species, there exist branch lengths for which gene tree discordance is so

James H. Degnan; Noah A. Rosenberg

2006-01-01

26

From gene trees to species trees through a supertree approach  

E-print Network

From gene trees to species trees through a supertree approach Celine Scornavacca1,2, , Vincent Abstract. Gene trees are leaf-labeled trees inferred from molecular se- quences. Due to duplication events arising in genome evolution, gene trees usually have multiple copies of some labels, i.e. species

Paris-Sud XI, Université de

27

From Gene Trees to Species Trees through a Supertree Approach  

E-print Network

From Gene Trees to Species Trees through a Supertree Approach Celine Scornavacca1,2, , Vincent Abstract. Gene trees are leaf-labeled trees inferred from molecular se- quences. Due to duplication events arising in genome evolution, gene trees usually have multiple copies of some labels, i.e. species

Paris-Sud XI, Université de

28

Removal of chromium by some multipurpose tree seedlings of Indian thar desert.  

PubMed

An experiment was conducted to study the potential of chromium (Cr) phytoaccumulatory capabilities of four tree species viz., Anogeissus latifolia, Terminalia arjuna, Tecomella undulata, and Salvadora persica Possibility of enhancement of Cr uptake by citric acid and vesicular arbuscular mycorrhizal fungi (VAM) amendments were also tried. Cr is a major pollutant of the environment. Chromium can exist in oxidation states from III to VI, but the most stable and common forms of Cr are trivalent and hexavalent species. Cr(VI) was more toxic to the tree growth in terms of collar diameter (CD) increment in all the tree species than Cr(lll). Roots accumulated more Cr than shoots in all the tree species. There was more than 10 fold increase in root Cr content in comparison with shoot Cr content in all the trees at all the concentration of Cr and all sources of Cr. Citric acid significantly increased the Cr content in the tissues of roots in all the species under both speciation of Cr. The highest increase in Cr content brought by 20 mM citric acid addition was in A. latifolia Results suggest that Anogeissus latifolia is a potential Cr accumulator with citric acid as soil amendment. PMID:21166349

Mathur, Nishi; Singh, Joginder; Bohra, Sachendra; Bohra, Avinash; Vyas, Anil

2010-01-01

29

Multipurpose Dissociation Cell for Enhanced ETD of Intact Protein Species  

NASA Astrophysics Data System (ADS)

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.

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

30

Multipurpose Dissociation Cell for Enhanced ETD of Intact Protein Species  

PubMed Central

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

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

31

Discordance of Species Trees with Their Most Likely Gene Trees  

E-print Network

Discordance of Species Trees with Their Most Likely Gene Trees James H. Degnan1 , Noah A. Rosenberg way in which lineages sort during speciation, gene trees may differ in topology from each other and from species trees. Surprisingly, assuming that genetic lineages follow a coalescent model of within

Rosenberg, Noah

32

The Inference of Gene Trees with Species Trees  

PubMed Central

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

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

2015-01-01

33

The inference of gene trees with species trees.  

PubMed

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

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

2015-01-01

34

Inferring species trees from gene duplication episodes  

Microsoft Academic Search

Gene tree parsimony, which infers a species tree that implies the fewest gene duplications across a collection of gene trees, is a method for inferring phylogenetic trees from paralogous genes. However, it assumes that all duplications are independent, and therefore, it does not account for large-scale gene duplication events like whole genome duplications. We describe two methods to infer species

J. Gordon Burleigh; Mukul S. Bansal; Oliver Eulenstein; Todd J. Vision

2010-01-01

35

Gene tree correction for reconciliation and species tree inference  

PubMed Central

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

2012-01-01

36

Isolation and characterization of microsatellite markers for Acacia senegal (L.) Willd., a multipurpose arid and  

E-print Network

Isolation and characterization of microsatellite markers for Acacia senegal (L.) Willd, France Abstract Acacia senegal is a multipurpose African tree that improves the soil fertility of the markers to detect genetic diversity in this species. Keywords: Acacia senegal, conservation, genetic

Paris-Sud XI, Université de

37

The Probability of Topological Concordance of Gene Trees and Species Trees  

Microsoft Academic Search

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

Noah A. Rosenberg

2002-01-01

38

Exact solutions for species tree inference from discordant gene trees.  

PubMed

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

Chang, Wen-Chieh; Górecki, Pawe?; Eulenstein, Oliver

2013-10-01

39

RESOVING THE GENE TREE AND SPECIES TREE PROBLEM BY PHYLOGENETIC MINING  

E-print Network

RESOVING THE GENE TREE AND SPECIES TREE PROBLEM BY PHYLOGENETIC MINING XIAOXU HAN Department and species tree problem remains a central problem in phylogenomics. To overcome this problem, gene.1. Gene tree and species tree problem The gene tree/species tree problem is still an important problem

Wong, Limsoon

40

Discordance of Species Trees with Their Most Likely Gene Trees: The Case of Five Taxa  

Microsoft Academic Search

Under a coalescent model for within-species evolution, gene trees may differ from species trees to such an extent that the gene tree topology most likely to evolve along the branches of a species tree can disagree with the species tree topology. Gene tree topologies that are more likely to be produced than the topology that matches that of the species

NOAH A. ROSENBERG; RANDA TAO

2008-01-01

41

Isoprene emission from tropical tree species  

Microsoft Academic Search

Foliar emission of isoprene was measured in nine commonly growing tree species of Delhi, India. Dynamic flow enclosure technique was used and gas samples were collected onto Tenax-GC\\/Carboseive cartridges, which were then attached to the sample injection system in the gas chromatograph (GC). Eluting compounds were analysed using a flame ionisation detector (FID). Out of the nine tree species, isoprene

P. K. Padhy; C. K. Varshney

2005-01-01

42

SPECIES DIFFER IN RESPONSES TO TREE SHELTERS  

Microsoft Academic Search

Effects of tree shelters on height, caliper, and di- ameter at breast height of 11 landscape tree species and cul- tivars were investigated in 2 nurseries during a 4-year period; the ratio of height to caliper was calculated as an indicator of trunk sturdiness. Species differed greatly in their responses, ranging in the fourth year from none to 44% and

Henry D. Gerhold

43

From Gene to Organismal Phylogeny: Reconciled Trees and the Gene Tree/Species Tree Problem  

E-print Network

From Gene to Organismal Phylogeny: Reconciled Trees and the Gene Tree/Species Tree Problem Roderic The processes of gene duplication, loss, and lineage sorting can result in incongruence between the phylog- enies of genes and those of species. This incongruence complicates the task of inferring the latter from

Page, Roderic

44

iGLASS: An Improvement to the GLASS Method for Estimating Species Trees from Gene Trees  

E-print Network

iGLASS: An Improvement to the GLASS Method for Estimating Species Trees from Gene Trees ETHAN M. JEWETT and NOAH A. ROSENBERG ABSTRACT Several methods have been designed to infer species trees from gene trees while taking into account gene tree/species tree discordance. Although some of these methods

Rosenberg, Noah

45

Reconciliation of gene and species trees.  

PubMed

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

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

2014-01-01

46

Reconciliation of Gene and Species Trees  

PubMed Central

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

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

2014-01-01

47

Species tree inference by minimizing deep coalescences.  

PubMed

In a 1997 seminal paper, W. Maddison proposed minimizing deep coalescences, or MDC, as an optimization criterion for inferring the species tree from a set of incongruent gene trees, assuming the incongruence is exclusively due to lineage sorting. In a subsequent paper, Maddison and Knowles provided and implemented a search heuristic for optimizing the MDC criterion, given a set of gene trees. However, the heuristic is not guaranteed to compute optimal solutions, and its hill-climbing search makes it slow in practice. In this paper, we provide two exact solutions to the problem of inferring the species tree from a set of gene trees under the MDC criterion. In other words, our solutions are guaranteed to find the tree that minimizes the total number of deep coalescences from a set of gene trees. One solution is based on a novel integer linear programming (ILP) formulation, and another is based on a simple dynamic programming (DP) approach. Powerful ILP solvers, such as CPLEX, make the first solution appealing, particularly for very large-scale instances of the problem, whereas the DP-based solution eliminates dependence on proprietary tools, and its simplicity makes it easy to integrate with other genomic events that may cause gene tree incongruence. Using the exact solutions, we analyze a data set of 106 loci from eight yeast species, a data set of 268 loci from eight Apicomplexan species, and several simulated data sets. We show that the MDC criterion provides very accurate estimates of the species tree topologies, and that our solutions are very fast, thus allowing for the accurate analysis of genome-scale data sets. Further, the efficiency of the solutions allow for quick exploration of sub-optimal solutions, which is important for a parsimony-based criterion such as MDC, as we show. We show that searching for the species tree in the compatibility graph of the clusters induced by the gene trees may be sufficient in practice, a finding that helps ameliorate the computational requirements of optimization solutions. Further, we study the statistical consistency and convergence rate of the MDC criterion, as well as its optimality in inferring the species tree. Finally, we show how our solutions can be used to identify potential horizontal gene transfer events that may have caused some of the incongruence in the data, thus augmenting Maddison's original framework. We have implemented our solutions in the PhyloNet software package, which is freely available at: http://bioinfo.cs.rice.edu/phylonet. PMID:19749978

Than, Cuong; Nakhleh, Luay

2009-09-01

48

On Reconstructing Species Trees From Gene Trees In Term Of Duplications And Losses  

E-print Network

it. Similarly, in a species tree, an ancient species is defined by the con­ temporary speciesOn Reconstructing Species Trees From Gene Trees In Term Of Duplications And Losses Bin Ma \\Lambda ancestors mapping, the duplication and mutation costs, and the complexity of finding a species tree from

Page, Roderic

49

On Reconstructing Species Trees From Gene Trees In Term Of Duplications And Losses  

E-print Network

it. Similarly, in a species tree, an ancient species is de ned by the con- temporary speciesOn Reconstructing Species Trees From Gene Trees In Term Of Duplications And Losses Bin Ma , Ming ancestors mapping, the duplication and mutation costs, and the complexity of nding a species tree from gene

Page, Roderic

50

Isoprene emission from tropical tree species.  

PubMed

Foliar emission of isoprene was measured in nine commonly growing tree species of Delhi, India. Dynamic flow enclosure technique was used and gas samples were collected onto Tenax-GC/Carboseive cartridges, which were then attached to the sample injection system in the gas chromatograph (GC). Eluting compounds were analysed using a flame ionisation detector (FID). Out of the nine tree species, isoprene emission was found in six species (Eucalyptus sp., Ficus benghalensis, Ficus religiosa, Mangifera indica, Melia azedarach, and Syzygium jambolanum), whereas, in the remaining three tree species (Alstonia scholaris, Azadirachta indica, and Cassia fistula) no isoprene emission was detected or the levels of emission were negligible or below the detection limit (BDL). Among six tree species, the highest hourly emission (10.2 +/- 6.8 microg g(-1) leaf dry weight, average of five seasons) was observed in Ficus religiosa, while minimum emission was from Melia azedarach (2.2 +/- 4.9 microg g(-1) leaf dry weight, average of five seasons). Isoprene emission (average of six species), over five seasons, was found to vary between 3.9 and 8.5 microg g(-1) leaf dry weight during the rainy season. In addition, significant diurnal variation in isoprene emission was observed in each species. The preliminary estimate made in this study on the annual biogenic VOC emission from India may probably be the first of its kind from this part of the world. PMID:15701397

Padhy, P K; Varshney, C K

2005-05-01

51

Pushing the Pace of Tree Species Migration  

PubMed Central

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

Lazarus, Eli D.; McGill, Brian J.

2014-01-01

52

Pushing the pace of tree species migration.  

PubMed

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

Lazarus, Eli D; McGill, Brian J

2014-01-01

53

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

PubMed

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

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

2003-06-01

54

Delimiting species without monophyletic gene trees.  

PubMed

Genetic data are frequently used to delimit species, where species status is determined on the basis of an exclusivity criterium, such as reciprocal monophyly. Not only are there numerous empirical examples of incongruence between the boundaries inferred from such data compared to other sources like morphology -- especially with recently derived species, but population genetic theory also clearly shows that an inevitable bias in species status results because genetic thresholds do not explicitly take into account how the timing of speciation influences patterns of genetic differentiation. This study represents a fundamental shift in how genetic data might be used to delimit species. Rather than equating gene trees with a species tree or basing species status on some genetic threshold, the relationship between the gene trees and the species history is modeled probabilistically. Here we show that the same theory that is used to calculate the probability of reciprocal monophyly can also be used to delimit species despite widespread incomplete lineage sorting. The results from a preliminary simulation study suggest that very recently derived species can be accurately identified long before the requisite time for reciprocal monophyly to be achieved following speciation. The study also indicates the importance of sampling, both with regards to loci and individuals. Withstanding a thorough investigation into the conditions under which the coalescent-based approach will be effective, namely how the timing of divergence relative to the effective population size of species affects accurate species delimitation, the results are nevertheless consistent with other recent studies (aimed at inferring species relationships), showing that despite the lack of monophyletic gene trees, a signal of species divergence persists and can be extracted. Using an explicit model-based approach also avoids two primary problems with species delimitation that result when genetic thresholds are applied with genetic data -- the inherent biases in species detection arising from when and how speciation occurred, and failure to take into account the high stochastic variance of genetic processes. Both the utility and sensitivities of the coalescent-based approach outlined here are discussed; most notably, a model-based approach is essential for determining whether incompletely sorted gene lineages are (or are not) consistent with separate species lineages, and such inferences require accurate model parameterization (i.e., a range of realistic effective population sizes relative to potential times of divergence for the purported species). It is the goal (and motivation of this study) that genetic data might be used effectively as a source of complementation to other sources of data for diagnosing species, as opposed to the exclusion of other evidence for species delimitation, which will require an explicit consideration of the effects of the temporal dynamic of lineage splitting on genetic data. PMID:18027282

Knowles, L Lacey; Carstens, Bryan C

2007-12-01

55

Species Tree Inference by the STAR Method and Its Generalizations  

E-print Network

along gene lineages can be large, and inferred metric gene trees are often far from ultrametric trees from a rooted metric species tree and thus provides a framework for the inference of species trees from sampled gene trees. We prove that the STAR method of Liu et al. (2009) and generalizations of it

Rhodes, John A.

56

Forecast Technical Document Tree Species  

E-print Network

24 RC RC Western red cedar Thuja plicata Cypress 12 24 RC BMF Bornmullers fir Abies bornmuelleriana Botanical name Species group Min. YC Max. YC Model used CAT Atlas cedar Cedrus atlantica Cedar 10 22 NF LCD Cedar of Lebanon Cedrus libani Cedar 10 22 NF XCD other Cedar Cedrus spp. Cedar 10 22 NF LC Lawsons

57

Improvements to a Class of Distance Matrix Methods for Inferring Species Trees from Gene Trees  

E-print Network

Improvements to a Class of Distance Matrix Methods for Inferring Species Trees from Gene Trees available for inferring species trees from gene trees, the GLASS method of Mossel and Roch (2010 branch length estimates. Further, GLASS and STEAC have been shown to be consistent estimators of tree

Rosenberg, Noah

58

Estimating optimal species trees from incomplete gene trees under deep coalescence.  

PubMed

The estimation of species trees typically involves the estimation of trees and alignments on many different genes, so that the species tree can be based on many different parts of the genome. This kind of phylogenomic approach to species tree estimation has the potential to produce more accurate species tree estimates, especially when gene trees can differ from the species tree due to processes such as incomplete lineage sorting (ILS), gene duplication and loss, and horizontal gene transfer. Because ILS (also called "deep coalescence") is a frequent problem in systematics, many methods have been developed to estimate species trees from gene trees or alignments that specifically take ILS into consideration. In this paper we consider the problem of estimating species trees from gene trees and alignments for the general case where the gene trees and alignments can be incomplete, which means that not all the genes contain sequences for all the species. We formalize optimization problems for this context and prove theoretical results for these problems. We also present the results of a simulation study evaluating existing methods for estimating species trees from incomplete gene trees. Our simulation study shows that *BEAST, a statistical method for estimating species trees from gene sequence alignments, produces by far the most accurate species trees. However, *BEAST can only be run on small datasets. The second most accurate method, MRP (a standard supertree method), can analyze very large datasets and produces very good trees, making MRP a potentially acceptable alternative to *BEAST for large datasets. PMID:22697236

Bayzid, Md Shamsuzzoha; Warnow, Tandy

2012-06-01

59

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

E-print Network

Inferring Species Trees Directly from Biallelic Genetic Markers: Bypassing Gene Trees in a Full framework for estimating species trees and species demograph- ics from genetic markers. However, practical trees possible for each genetic marker. Here we describe a polynomial-time algorithm that computes

Rosenberg, Noah

60

FORAGING SUCCESS AND TREE SPECIES USE IN THE LEAST FLYCATCHER  

Microsoft Academic Search

.,BSTRACT.--I examined the effect of tree species morphology on foraging behavior in a hover-gleaning bird species, the Least Flycatcher (Empidonax minimus). Birds in four breeding territories in northern Wisconsin displayed nonsignificant differences in an index of forag- ing success (S) among four tree species of divergent morphology. However, significant vari- ation in S occurred among the three tree species common

CHRISTOPHER M. ROGERS

61

A characterization of the set of species trees that produce anomalous ranked gene trees.  

PubMed

Ranked gene trees, which consider both the gene tree topology and the sequence in which gene lineages separate, can potentially provide a new source of information for use in modeling genealogies and performing inference of species trees. Recently,we have calculated the probability distribution of ranked gene trees under the standard multispecies coalescent model for the evolution of gene lineages along the branches of a fixed species tree, demonstrating the existence of anomalous ranked gene trees (ARGTs), in which a ranked gene tree that does not match the ranked species tree can have greater probability under the model than the matching ranked gene tree. Here, we fully characterize the set of unranked species tree topologies that give rise to ARGTs, showing that this set contains all species tree topologies with five or more taxa, with the exceptions of caterpillars and pseudocaterpillars. The results have implications for the use of ranked gene trees in phylogenetic inference. PMID:22868677

Degnan, James H; Rosenberg, Noah A; Stadler, Tanja

2012-01-01

62

Statistical mapping of tree species over Europe  

Microsoft Academic Search

In order to map the spatial distribution of twenty tree species groups over Europe at 1 km × 1 km resolution, the ICP-Forest\\u000a Level-I plot data were extended with the National Forest Inventory (NFI) plot data of eighteen countries. The NFI grids have\\u000a a much smaller spacing than the ICP grid. In areas with NFI plot data, the proportions of the land

D. J. Brus; G. M. Hengeveld; D. J. J. Walvoort; P. W. Goedhart; A. H. Heidema; G. J. Nabuurs; K. Gunia

2012-01-01

63

Reconciling a Gene Tree to a Species Tree Under the Duplication Paola Bonizzoni  

E-print Network

) for the extant species, the first step constructs a gene tree representing the relationships among the sequencesReconciling a Gene Tree to a Species Tree Under the Duplication Cost Model Paola Bonizzoni Gianluca from evolutionary trees representing the relationships between distinct gene families is of great

Della Vedova, Gianluca

64

Discordance of Species Trees with Their Most Likely Gene Trees: A Unifying Principle  

E-print Network

Letter Discordance of Species Trees with Their Most Likely Gene Trees: A Unifying Principle Noah A@stanford.edu. Associate editor: Barbara Holland Abstract A labeled gene tree topology that disagrees with a labeled species tree topology is said to be anomalous if it is more probable under a coalescent model for gene

Rosenberg, Noah

65

Properties of consensus methods for inferring species trees from gene trees.  

PubMed

Consensus methods provide a useful strategy for summarizing information from a collection of gene trees. An important application of consensus methods is to combine gene trees to estimate a species tree. To investigate the theoretical properties of consensus trees that would be obtained from large numbers of loci evolving according to a basic evolutionary model, we construct consensus trees from rooted gene trees that occur in proportion to gene-tree probabilities derived from coalescent theory. We consider majority-rule, rooted triple (R(*)), and greedy consensus trees obtained from known, rooted gene trees, both in the asymptotic case as numbers of gene trees approach infinity and for finite numbers of genes. Our results show that for some combinations of species-tree branch lengths, increasing the number of independent loci can make the rooted majority-rule consensus tree more likely to be at least partially unresolved. However, the probability that the R(*) consensus tree has the species-tree topology approaches 1 as the number of gene trees approaches infinity. Although the greedy consensus algorithm can be the quickest to converge on the correct species-tree topology when increasing the number of gene trees, it can also be positively misleading. The majority-rule consensus tree is not a misleading estimator of the species-tree topology, and the R(*) consensus tree is a statistically consistent estimator of the species-tree topology. Our results therefore suggest a method for using multiple loci to infer the species-tree topology, even when it is discordant with the most likely gene tree. PMID:20525567

Degnan, James H; DeGiorgio, Michael; Bryant, David; Rosenberg, Noah A

2009-02-01

66

192 No. 95 Zhang Inferring a Species Tree from Gene Trees under the  

E-print Network

) is defined to be the number of "extra" gene branches on species branches [3]. First, we prove a formula192 No. 95 Zhang Inferring a Species Tree from Gene Trees under the Deep Coalescence Cost Louxin of Singapore, 21 Heng Mui Kang Terrace, Singapore 119613 Keywords: gene and species trees, gene duplications

Zhang, Louxin

67

Profiling selected phytochemicals and nutrients in different tissues of the multipurpose tree Moringa oleifera L., grown in Ghana  

Microsoft Academic Search

The purpose of this new study was to determine the types and levels of major phytochemicals (non-nutrients) and nutrients in the different tissues from vegetative and flowering Moringa oleifera L. an important multipurpose crop. Rhamnose and acetyl-rhamnose-substituted glucosinolates were found in all of the M. oleifera tissues with different profiles depending on the tissue. In addition the tissues of M.

Newton K. Amaglo; Richard N. Bennett; Rosario B. Lo Curto; Eduardo A. S. Rosa; Vincenzo Lo Turco; Angela Giuffrida; Alberto Lo Curto; Francesco Crea; Gladys M. Timpo

2010-01-01

68

Progress on Estimating Large Species Trees Tandy Warnow  

E-print Network

Experimental study shows *BEAST much more accurate than tested fast methods, but computationally too expensive Computing, Bioinformatics #12;Species Trees / Gene Trees Discordance Causes: Gene duplication and loss species trees? How do these methods scale (in terms of computational requirements) with the number of taxa

Warnow,Tandy

69

Multipurpose Rooms.  

ERIC Educational Resources Information Center

Presents K-12 and college multipurpose rooms considered outstanding in a competition, which judged the most outstanding learning environments at educational institutions nationwide. Jurors spent two days reviewing projects, highlighting concepts and ideas that made them exceptional. For each citation, the article offers information on the firm,…

American School & University, 2003

2003-01-01

70

Multipurpose Spaces  

ERIC Educational Resources Information Center

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…

Gordon, Douglas

2010-01-01

71

Inferring species trees from incongruent multi-copy gene trees using the Robinson-Foulds distance  

PubMed Central

Background Constructing species trees from multi-copy gene trees remains a challenging problem in phylogenetics. One difficulty is that the underlying genes can be incongruent due to evolutionary processes such as gene duplication and loss, deep coalescence, or lateral gene transfer. Gene tree estimation errors may further exacerbate the difficulties of species tree estimation. Results We present a new approach for inferring species trees from incongruent multi-copy gene trees that is based on a generalization of the Robinson-Foulds (RF) distance measure to multi-labeled trees (mul-trees). We prove that it is NP-hard to compute the RF distance between two mul-trees; however, it is easy to calculate this distance between a mul-tree and a singly-labeled species tree. Motivated by this, we formulate the RF problem for mul-trees (MulRF) as follows: Given a collection of multi-copy gene trees, find a singly-labeled species tree that minimizes the total RF distance from the input mul-trees. We develop and implement a fast SPR-based heuristic algorithm for the NP-hard MulRF problem. We compare the performance of the MulRF method (available at http://genome.cs.iastate.edu/CBL/MulRF/) with several gene tree parsimony approaches using gene tree simulations that incorporate gene tree error, gene duplications and losses, and/or lateral transfer. The MulRF method produces more accurate species trees than gene tree parsimony approaches. We also demonstrate that the MulRF method infers in minutes a credible plant species tree from a collection of nearly 2,000 gene trees. Conclusions Our new phylogenetic inference method, based on a generalized RF distance, makes it possible to quickly estimate species trees from large genomic data sets. Since the MulRF method, unlike gene tree parsimony, is based on a generic tree distance measure, it is appealing for analyses of genomic data sets, in which many processes such as deep coalescence, recombination, gene duplication and losses as well as phylogenetic error may contribute to gene tree discord. In experiments, the MulRF method estimated species trees accurately and quickly, demonstrating MulRF as an efficient alternative approach for phylogenetic inference from large-scale genomic data sets. PMID:24180377

2013-01-01

72

Research Articles Consistency Properties of Species Tree Inference by  

E-print Network

of Human Genetics and the Life Sciences Institute, University of Michigan, Ann Arbor, Michigan. JOURNAL for inconsistency. Under a specific model for the evolution of gene trees along the branches of species trees

Rosenberg, Noah

73

The probability distribution of ranked gene trees on a species tree James H. Degnan a,  

E-print Network

of applications. First, it provides a mathematical basis for studying the properties of gene trees in a standardThe probability distribution of ranked gene trees on a species tree James H. Degnan a, , Noah A Accepted 21 October 2011 Available online 31 October 2011 Keywords: Anomalous gene trees Coalescent

Rosenberg, Noah

74

A Characterization of the Set of Species Trees that Produce Anomalous Ranked Gene Trees  

E-print Network

A Characterization of the Set of Species Trees that Produce Anomalous Ranked Gene Trees James H. Degnan, Noah A. Rosenberg, and Tanja Stadler Abstract--Ranked gene trees, which consider both the gene tree topology and the sequence in which gene lineages separate, can potentially provide a new source

Rosenberg, Noah

75

ASTRAL: genome-scale coalescent-based species tree estimation  

PubMed Central

Motivation: Species trees provide insight into basic biology, including the mechanisms of evolution and how it modifies biomolecular function and structure, biodiversity and co-evolution between genes and species. Yet, gene trees often differ from species trees, creating challenges to species tree estimation. One of the most frequent causes for conflicting topologies between gene trees and species trees is incomplete lineage sorting (ILS), which is modelled by the multi-species coalescent. While many methods have been developed to estimate species trees from multiple genes, some which have statistical guarantees under the multi-species coalescent model, existing methods are too computationally intensive for use with genome-scale analyses or have been shown to have poor accuracy under some realistic conditions. Results: We present ASTRAL, a fast method for estimating species trees from multiple genes. ASTRAL is statistically consistent, can run on datasets with thousands of genes and has outstanding accuracy—improving on MP-EST and the population tree from BUCKy, two statistically consistent leading coalescent-based methods. ASTRAL is often more accurate than concatenation using maximum likelihood, except when ILS levels are low or there are too few gene trees. Availability and implementation: ASTRAL is available in open source form at https://github.com/smirarab/ASTRAL/. Datasets studied in this article are available at http://www.cs.utexas.edu/users/phylo/datasets/astral. Contact: warnow@illinois.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:25161245

Mirarab, S.; Reaz, R.; Bayzid, Md. S.; Zimmermann, T.; Swenson, M. S.; Warnow, T.

2014-01-01

76

TREE SPECIES CLASSIFICATION USING RADIOMETRY, TEXTURE AND SHAPE BASED FEATURES  

E-print Network

signature of species like the red cedar and the fir for in- stance [8]. In [4], a classification basedTREE SPECIES CLASSIFICATION USING RADIOMETRY, TEXTURE AND SHAPE BASED FEATURES Maria S. Kulikova1@ani.stat.fsu.edu ABSTRACT We consider the problem of tree species classification from high resolution aerial images based

Boyer, Edmond

77

Germination ecology of twelve indigenous and eight exotic multipurpose leguminous species from Ethiopia  

Microsoft Academic Search

The germination requirements of seeds of 20 leguminous species were studied in three experiments. In the first experiment, seeds were subjected to mechanical scarification, sulphuric acid and boiling water treatments. In the second experiment, they were treated with dry heat at 60, 80 and 100°C. In the third experiment, seeds were placed at different temperature regimes (10, 15, 20, 25

Demel Teketay

1996-01-01

78

TREE PLANTING SITE EVALUATION FORM "SITE DICTATES SPECIES"  

E-print Network

TREE PLANTING SITE EVALUATION FORM "SITE DICTATES SPECIES" ABOVE GROUND Utilities: Electric issue) Parking proximity: Distance from car doors __________________ Wind: Problem _________ No problem:________________________________________________ Fire hydrant: ________________________________________________ Electric

79

Ecological effects of introduced tree species in Britain  

Microsoft Academic Search

Non-native trees have been introduced to Britain and native trees have been redistributed for over 2000 years, but most species were introduced in the last 400 years, and the ecological consequences have not yet been fully manifested. Introduction has been followed by various forms of adaptation to British conditions: (i) genetic changes in the trees themselves, (ii) assimilation into forest

G. F. Peterken

2001-01-01

80

Identifying a species tree subject to random lateral gene transfer.  

PubMed

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

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

2013-04-01

81

Gene trees, species and species trees in the Ctenosaura palearis clade  

Microsoft Academic Search

The growing use of molecular systematics in conservation has increased the importance of accurate resolution of taxonomic\\u000a units and relationships. DNA data relate most directly to genealogies, which need not have perfect relationships with species\\u000a limits and phylogenies. We used a multilocus gene tree approach to elucidate the relationships between four endangered Central\\u000a American iguanas. We found support for the

Stesha A. PasachnikArthur; Arthur C. Echternacht; Benjamin M. Fitzpatrick

2010-01-01

82

STBase: One Million Species Trees for Comparative Biology  

PubMed Central

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

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

2015-01-01

83

Are Temperate Canopy Spiders Tree-Species Specific?  

PubMed Central

Arboreal spiders in deciduous and coniferous trees were investigated on their distribution and diversity. Insecticidal knock-down was used to comprehensively sample spiders from 175 trees from 2001 to 2003 in the Bia?owie?a forest and three remote forests in Poland. We identified 140 species from 9273 adult spiders. Spider communities were distinguished between deciduous and coniferous trees. The richest fauna was collected from Quercus where beta diversity was also highest. A tree-species-specific pattern was clearly observed for Alnus, Carpinus, Picea and Pinus trees and also for those tree species that were fogged in only four or three replicates, namely Betula and Populus. This hitherto unrecognised association was mainly due to the community composition of common species identified in a Dufrene-Legendre indicator species analysis. It was not caused by spatial or temporal autocorrelation. Explaining tree-species specificity for generalist predators like spiders is difficult and has to involve physical and ecological tree parameters like linkage with the abundance of prey species. However, neither did we find a consistent correlation of prey group abundances with spiders nor could differences in spider guild composition explain the observed pattern. Our results hint towards the importance of deterministic mechanisms structuring communities of generalist canopy spiders although the casual relationship is not yet understood. PMID:24586251

Mupepele, Anne-Christine; Müller, Tobias; Dittrich, Marcus; Floren, Andreas

2014-01-01

84

Early growth and seasonal chemical composition of three indigenous multipurpose tree species (MPTS) in Abeokuta, Nigeria  

Microsoft Academic Search

A study was carried out to evaluate the growth parameters and nutritive qualities of Moringa oleifera, Millettia griffoniana and Pterocarpus santalinoides. The main objective of the study was to assess the potential of the MPTS in supplementing the feed of ruminant animals during\\u000a the dry season when grasses are scarce and their quality generally fall short of animal requirements. Leaf

U. Y. Anele; O. M. Arigbede; J. A. Olanite; I. O. Adekunle; A. O. Jolaosho; O. S. Onifade; A. O. Oni

2008-01-01

85

Axiomatic opportunities and obstacles for inferring a species tree from gene trees.  

PubMed

The reconstruction of a central tendency "species tree" from a large number of conflicting gene trees is a central problem in systematic biology. Moreover, it becomes particularly problematic when taxon coverage is patchy, so that not all taxa are present in every gene tree. Here, we list four apparently desirable properties that a method for estimating a species tree from gene trees could have (the strongest property states that building a species tree from input gene trees and then pruning leaves gives a tree that is the same as, or more resolved than, the tree obtained by first removing the taxa from the input trees and then building the species tree). We show that although it is technically possible to simultaneously satisfy these properties when taxon coverage is complete, they cannot all be satisfied in the more general supertree setting. In part two, we discuss a concordance-based consensus method based on Baum's "plurality clusters", and an extension to concordance supertrees. PMID:24951558

Steel, Mike; Velasco, Joel D

2014-09-01

86

Robustness to divergence time underestimation when inferring species trees from estimated gene trees.  

PubMed

To infer species trees from gene trees estimated from phylogenomic data sets, tractable methods are needed that can handle dozens to hundreds of loci. We examine several computationally efficient approaches-MP-EST, STAR, STEAC, STELLS, and STEM-for inferring species trees from gene trees estimated using maximum likelihood (ML) and Bayesian approaches. Among the methods examined, we found that topology-based methods often performed better using ML gene trees and methods employing coalescent times typically performed better using Bayesian gene trees, with MP-EST, STAR, STEAC, and STELLS outperforming STEM under most conditions. We examine why the STEM tree (also called GLASS or Maximum Tree) is less accurate on estimated gene trees by comparing estimated and true coalescence times, performing species tree inference using simulations, and analyzing a great ape data set keeping track of false positive and false negative rates for inferred clades. We find that although true coalescence times are more ancient than speciation times under the multispecies coalescent model, estimated coalescence times are often more recent than speciation times. This underestimation can lead to increased bias and lack of resolution with increased sampling (either alleles or loci) when gene trees are estimated with ML. The problem appears to be less severe using Bayesian gene-tree estimates. PMID:23988674

DeGiorgio, Michael; Degnan, James H

2014-01-01

87

Estimating Optimal Species Trees from Incomplete Gene Trees under Deep Coalescence  

E-print Network

Bayzid1 and Tandy Warnow1 1Department of Computer Science, University of Texas at Austin, Austin, Texas that *BEAST, a statistical method for estimating species trees from gene sequence alignments, produces by far the most accurate species trees. However, *BEAST can only be run on small datasets. The second most

Ghosh, Joydeep

88

Evidence of Tree Species’ Range Shifts in a Complex Landscape  

PubMed Central

Climate change is expected to change the distribution of species. For long-lived, sessile species such as trees, tracking the warming climate depends on seedling colonization of newly favorable areas. We compare the distribution of seedlings and mature trees for all but the rarest tree species in California, Oregon and Washington, United States of America, a large, environmentally diverse region. Across 46 species, the mean annual temperature of the range of seedlings was 0.120°C colder than that of the range of trees (95% confidence interval from 0.096 to 0.144°C). The extremes of the seedling distributions also shifted towards colder temperature than those of mature trees, but the change was less pronounced. Although the mean elevation and mean latitude of the range of seedlings was higher than and north of those of the range of mature trees, elevational and latitudinal shifts run in opposite directions for the majority of the species, reflecting the lack of a direct biological relationship between species’ distributions and those variables. The broad scale, environmental diversity and variety of disturbance regimes and land uses of the study area, the large number and exhaustive sampling of tree species, and the direct causal relationship between the temperature response and a warming climate, provide strong evidence to attribute the observed shifts to climate change. PMID:25634090

Monleon, Vicente J.; Lintz, Heather E.

2015-01-01

89

Evidence of tree species' range shifts in a complex landscape.  

PubMed

Climate change is expected to change the distribution of species. For long-lived, sessile species such as trees, tracking the warming climate depends on seedling colonization of newly favorable areas. We compare the distribution of seedlings and mature trees for all but the rarest tree species in California, Oregon and Washington, United States of America, a large, environmentally diverse region. Across 46 species, the mean annual temperature of the range of seedlings was 0.120°C colder than that of the range of trees (95% confidence interval from 0.096 to 0.144°C). The extremes of the seedling distributions also shifted towards colder temperature than those of mature trees, but the change was less pronounced. Although the mean elevation and mean latitude of the range of seedlings was higher than and north of those of the range of mature trees, elevational and latitudinal shifts run in opposite directions for the majority of the species, reflecting the lack of a direct biological relationship between species' distributions and those variables. The broad scale, environmental diversity and variety of disturbance regimes and land uses of the study area, the large number and exhaustive sampling of tree species, and the direct causal relationship between the temperature response and a warming climate, provide strong evidence to attribute the observed shifts to climate change. PMID:25634090

Monleon, Vicente J; Lintz, Heather E

2015-01-01

90

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

PubMed

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

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

2012-04-01

91

Exploring the Taxonomy of Oaks and Related Tree Species  

ERIC Educational Resources Information Center

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.

McMaster, Robert T.

2004-01-01

92

ORIGINAL PAPER Potential shift in tree species composition after interaction  

E-print Network

their effects on tree species shifts in the European Central Alps. Tree recruitment after a stand replacing in the Central Alps B. Moser · C. Temperli · G. Schneiter · T. Wohlgemuth Received: 10 August 2009 / Revised: 6 recruitment success after fire disturbance at low altitudes of the Central Alps and may eventually lead

93

Species collapse via hybridization in Darwin's tree finches.  

PubMed

Species hybridization can lead to fitness costs, species collapse, and novel evolutionary trajectories in changing environments. Hybridization is predicted to be more common when environmental conditions change rapidly. Here, we test patterns of hybridization in three sympatric tree finch species (small tree finch Camarhynchus parvulus, medium tree finch Camarhynchus pauper, and large tree finch: Camarhynchus psittacula) that are currently recognized on Floreana Island, Galápagos Archipelago. Genetic analysis of microsatellite data from contemporary samples showed two genetic populations and one hybrid cluster in both 2005 and 2010; hybrid individuals were derived from genetic population 1 (small morph) and genetic population 2 (large morph). Females of the large and rare species were more likely to pair with males of the small common species. Finch populations differed in morphology in 1852-1906 compared with 2005/2010. An unsupervised clustering method showed (a) support for three morphological clusters in the historical tree finch sample (1852-1906), which is consistent with current species recognition; (b) support for two or three morphological clusters in 2005 with some (19%) hybridization; and (c) support for just two morphological clusters in 2010 with frequent (41%) hybridization. We discuss these findings in relation to species demarcations of Camarhynchus tree finches on Floreana Island. PMID:24561597

Kleindorfer, Sonia; O'Connor, Jody A; Dudaniec, Rachael Y; Myers, Steven A; Robertson, Jeremy; Sulloway, Frank J

2014-03-01

94

Computational approaches to species phylogeny inference and gene tree reconciliation.  

PubMed

An intricate relation exists between gene trees and species phylogenies, due to evolutionary processes that act on the genes within and across the branches of the species phylogeny. From an analytical perspective, gene trees serve as character states for inferring accurate species phylogenies, and species phylogenies serve as a backdrop against which gene trees are contrasted for elucidating evolutionary processes and parameters. In a 1997 paper, Maddison discussed this relation, reviewed the signatures left by three major evolutionary processes on the gene trees, and surveyed parsimony and likelihood criteria for utilizing these signatures to elucidate computationally this relation. Here, I review progress that has been made in developing computational methods for analyses under these two criteria, and survey remaining challenges. PMID:24094331

Nakhleh, Luay

2013-12-01

95

Tree Species’ Tolerance to Water Stress, Salinity and Fire  

Microsoft Academic Search

\\u000a According to climate change predictions, water availability might change dramatically in Europe and adjacent regions. This\\u000a change will undoubtedly have an adverse effect on existing tree species and affect their ability to cope with a lack or an\\u000a excess of water, changes in annual precipitation patterns, soil salinity and fire disturbance. The following chapter will\\u000a describe tree species and provenances

Martin Lukac; Margus Pensa; Gabriel Schiller

96

The impact of gene-tree/species-tree discordance on diversification-rate estimation.  

PubMed

Molecular phylogenies are often used to test hypotheses about the tempo and mode of speciation and extinction. One commonly used statistic is Pybus and Harvey's ?, which measures the density of ordered internode distances on an ultrametric tree to infer earlier (negative ?) or later (positive ?) bursts of diversification. However, coalescent theory predicts that ? might be biased toward negative values (inferring early bursts of diversification) when using gene trees rather than species trees. Gene divergences predate species divergences, increasingly so at higher effective population sizes (N(e)), and proportionally more so toward the tips of the tree. Thus, gene trees will have a higher density of older nodes in many cases (particularly at higher N(e)), due to the disproportionate lengthening of terminal branches. This will yield an artifactual signature of early bursts of diversification when estimating ? from gene trees. We simulate gene trees within species trees under both Yule (pure-birth) and birth-death processes, and demonstrate support for these predictions. However, for most realistic estimates of ? in natural populations, gene trees provide relatively good estimates of ?, despite the disproportionate overestimation of younger node ages. This is corroborated with an empirical dataset of North American fence lizards (Sceloporus). PMID:21729043

Burbrink, Frank T; Pyron, R Alexander

2011-07-01

97

Widespread Discordance of Gene Trees with Species Tree in Drosophila: Evidence  

E-print Network

with the opportunity and challenge of understanding the function and history of every base in the model organism Drosophila melanogaster (Dmel). This process will hopefully result in the discovery of new biologicalWidespread Discordance of Gene Trees with Species Tree in Drosophila: Evidence for Incomplete

Pollard, Daniel

98

Can tree species choice influence recruitment of ancient forest species in post-agricultural forest?  

Microsoft Academic Search

Germination and establishment of ancient forest species are bottlenecks in forest habitat restoration. We hypothesised that\\u000a tree species can influence these processes on acidification sensitive soils through their effects on the soil. Seeds of seven\\u000a ancient forest species were sown in soil collected in a post-agricultural forest under four different tree species, notably\\u000a Acer pseudoplatanus, Alnus glutinosa, Fagus sylvatica and

Arno Thomaes; Luc De Keersmaeker; An De Schrijver; Kris Vandekerkhove; Pieter Verschelde; Kris Verheyen

2011-01-01

99

Mapping urban forest tree species using IKONOS imagery: preliminary results  

Microsoft Academic Search

A stepwise masking system with high-resolution IKONOS imagery was developed to identify and map urban forest tree species\\/groups\\u000a 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).

Ruiliang Pu

2011-01-01

100

Geographical range and local abundance of tree species in China.  

PubMed

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 km(2), and >90% of 651 species had ranges >10(5) km(2). 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

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

2013-01-01

101

Geographical Range and Local Abundance of Tree Species in China  

PubMed Central

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

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

2013-01-01

102

ORIGINAL PAPER Impacts of tree species diversity on litter decomposition  

E-print Network

of leaf litter from the same six dominant tree species in the litter layer of three forested ecosystems, two, four, and six species of leaf litter to decompose for 1 year, we found that increasing leaf rates than did litter richness. Effects of leaf litter diversity were non-additive, meaning they were

Cardinale, Bradley J.

103

Lignin characteristics of Abies beshanzuensis , a critically endangered tree species  

Microsoft Academic Search

As one of the major components of plant cell walls, lignin structural features are closely related with taxonomical and genetic\\u000a classification of plants. In this study, the structural features of lignin of Abies beshanzuensis were investigated. Abies firma, which is genetically the closest species to A. beshanzuensis, Cryptomeria japonica, a typical gymnosperm tree species, and Phyllostachys pubescens (bamboo), which includes

Shunliu Shao; Zhenfu Jin; Yu Hui Weng

2008-01-01

104

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

PubMed Central

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 information will be valuable advancements for the field of comparative genomics. PMID:17132051

Pollard, Daniel A; Eisen, Michael B

2006-01-01

105

Two species of endophytic cladosporium in pine trees in Korea.  

PubMed

During our studies on the diverse endophytic fungi resident on conifer needles, many species of Cladosporium previously unreported in Korea were encountered. In this paper, we report on two species of Cladosporium from the needles of pine trees (Pinus spp.). Based on analyses of internal transcribed spacer gene sequence, and cultural and micromorphological characteristics, they were identified as C. oxysporum and C. sphaerospermum. Both species have not been hitherto reported in Korea. PMID:23997628

Paul, Narayan Chandra; Yu, Seung Hun

2008-12-01

106

Oviposition preference of Anoplophora glabripennis emerging from five host tree species under field conditions  

Microsoft Academic Search

The Asian longhorned beetle (ALB), Anoplophora glabripennis (Motschulsky) is a polyphagous woodborer of hardwood trees. In order to well understand the oviposition preference of A. glabripennis emerging from different larval host tree species, we selected five common host tree species in the field and evaluated its\\u000a oviposition preferences. The five host tree species are Acer negundo (AN), Salix matsudana f.

Xiong-fei Yan; Xiao-juan Li; You-qing Luo; Zhi-chun Xu; Gui-fang Tian; Tie-lin Zhang

2008-01-01

107

Predicting Abundance of 80 Tree Species Following Climate Change in the Eastern United States  

Microsoft Academic Search

Projected climate warming will potentially have profound effects on the earth's biota, including a large redistribution of tree species. We developed models to evaluate potential shifts for 80 individual tree species in the eastern United States. First, environmental factors associated with current ranges of tree species were assessed using geographic information systems (GIS) in conjunction with regression tree analysis (RTA).

Louis R. Iverson; Anantha M. Prasad

1998-01-01

108

Coalescent-based species tree inference from gene tree topologies under incomplete lineage sorting by maximum likelihood.  

PubMed

Incomplete lineage sorting can cause incongruence between the phylogenetic history of genes (the gene tree) and that of the species (the species tree), which can complicate the inference of phylogenies. In this article, I present a new coalescent-based algorithm for species tree inference with maximum likelihood. I first describe an improved method for computing the probability of a gene tree topology given a species tree, which is much faster than an existing algorithm by Degnan and Salter (2005). Based on this method, I develop a practical algorithm that takes a set of gene tree topologies and infers species trees with maximum likelihood. This algorithm searches for the best species tree by starting from initial species trees and performing heuristic search to obtain better trees with higher likelihood. This algorithm, called STELLS (which stands for Species Tree InfErence with Likelihood for Lineage Sorting), has been implemented in a program that is downloadable from the author's web page. The simulation results show that the STELLS algorithm is more accurate than an existing maximum likelihood method for many datasets, especially when there is noise in gene trees. I also show that the STELLS algorithm is efficient and can be applied to real biological datasets. PMID:22380439

Wu, Yufeng

2012-03-01

109

Comparative performance of seventeen upperstorey tree species associated with crops in the highlands of Uganda  

Microsoft Academic Search

Trials were established at three sites in Uganda to test the suitability of multipurpose trees (MPTs) as upperstorey in crop lands to provide poles, small timber and fuelwood. The three sites were Kachwekano District Farm Institute (1°16' S, 29°57' E, 2000 m.a.s.l.) in Kabale District, Kabanyolo University Farm (0°28' N, 32°27' E, 1250 m.a.s.l.) in Mpigi District and Bushenyi District

J. Okorio; S. Byenkya; N. Wajja; D. Peden

1994-01-01

110

Support & advice climate change Which tree species to  

E-print Network

Support & advice climate change Which tree species to plant for a changing forestry environment #12 to its likely effects. We must start to implement adaptation strategies today, as England's forests genetic material is a key action to adapt to climate change. The negative impact of pests and diseases

111

TREE SHELTERS ACCELERATE SLOW-GROWING SPECIES IN NURSERIES  

Microsoft Academic Search

Two experiments investigated the effects of tree shelters on height, caliper, and diameter growth of liners of 14 species and cultivars. In the first year at one nursery all nine varieties had greater height growth inside shelters, averaging 325% of controls without shelters, thus adding 1.1 feet (33 cm) to 2.3 feet (70 cm) to their height. After two years

Robert K. Witmer; Henry D. Gerhold; Eric R. Ulrich

112

Regional Assessment of Ozone Sensitive Tree Species Using Bioindicator Plants  

Microsoft Academic Search

Tropospheric ozone occurs at phytotoxic levels in the northeastern and mid-Atlantic regions of the United States. Quantifying possible regional-scale impacts of ambient ozone onforest tree species is difficult and is confounded by other factors, such as moisture and light, which influence the uptake of ozone by plants. Biomonitoring provides an approach to document direct foliar injury irrespective of direct measure

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

2003-01-01

113

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

PubMed

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

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

114

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

PubMed Central

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

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

115

The exotic legume tree species, Acacia mearnsii, alters microbial soil functionalities and the early development of a native tree species,  

E-print Network

The exotic legume tree species, Acacia mearnsii, alters microbial soil functionalities May 2013 Available online 10 June 2013 Keywords: Exotic invasive plant Acacia mearnsii Soil microbial community Ectomycorrhiza a b s t r a c t Acacia mearnsii is one of the most planted Australian Acacia around

Thioulouse, Jean

116

Borers in New Hampshire Apple Trees Several species of insects bore into New Hampshire apple trees, including roundheaded apple tree borer,  

E-print Network

Borers in New Hampshire Apple Trees Several species of insects bore into New Hampshire apple trees of the insects. Roundheaded apple-tree borer (RHATB) Saperda candida Fab. This is the most serious borer in New and mountain ash are all major hosts of this species. They can be sources of the beetles. 2. Paint the lower

New Hampshire, University of

117

Contrasting water-uptake and growth responses to drought in co-occurring riparian tree species  

E-print Network

Contrasting water-uptake and growth responses to drought in co-occurring riparian tree species ABSTRACT Growth responses of riparian trees to changes in water availability are poorly understood, thereby individual tree rings for two co-occurring riparian species, Fraxinus excelsior and Populus nigra. Trees were

Stella, John C.

118

Conservation of tree seeds from tropical dry-lands  

Microsoft Academic Search

The tropical trees, Azadirachta indica (neem), Lannea microcarpa, Sclerocarya birrea and Khaya senegalensis, are important multipurpose species. Unfortunately, difficult seed storage behaviour limits the utilization of these species in reforestation programs and agroforestry systems. This thesis presents the results of investigations aimed at a better understanding of the seed biology, particularly focussed on the improvement of seed survival after drying

Oblé Neya

2006-01-01

119

Climatic extremes improve predictions of spatial patterns of tree species  

USGS Publications Warehouse

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.

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

120

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

SciTech Connect

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

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

2006-08-28

121

A Tree Obscured By Vines: Horizontal Gene Transfer and the Median Tree Method of Estimating Species Phylogeny  

Microsoft Academic Search

A phylogeny is a tree graph representation of genealogical relationships between biological objects. It is of general interest to estimate the phylogeny of whole organisms (species trees) using bio-molecular sequences. When multiple sequences are available for each organism such as with whole genome data, individual phylogenies estimated by each molecule (gene trees) may not be concordant. The lack of concordance

Junhyong Kim; Benjamin A. Salisbury

2001-01-01

122

Seasonal trends in separability of leaf reflectance spectra for Ailanthus altissima and four other tree species  

Microsoft Academic Search

This project investigated the spectral separability of the invasive species Ailanthus altissima, commonly called tree of heaven, and four other native species. Leaves were collected from Ailanthus and four native tree species from May 13 through August 24, 2008, and spectral reflectance factor measurements were gathered for each tree using an ASD (Boulder, Colorado) FieldSpec Pro full-range spectroradiometer. The original

Aaron Burkholder

2010-01-01

123

Letter to the Editor On the article titled ``Estimating species trees using approximate  

E-print Network

Letter to the Editor On the article titled ``Estimating species trees using approximate Bayesian ``Estimating species trees using approxi- mate Bayesian computation'' Fan and Kubatko present an algo- rithm called ST-ABC to sample the posterior distribution of species trees (Molecular Phylogenetics

Rosenberg, Noah

124

Tangled trees: the challenge of inferring species trees from coalescent and noncoalescent genes.  

PubMed

Phylogenies based on different genes can produce conflicting phylogenies; methods that resolve such ambiguities are becoming more popular, and offer a number of advantages for phylogenetic analysis. We review so-called species tree methods and the biological forces that can undermine them by violating important aspects of the underlying models. Such forces include horizontal gene transfer, gene duplication, and natural selection. We review ways of detecting loci influenced by such forces and offer suggestions for identifying or accommodating them. The way forward involves identifying outlier loci, as is done in population genetic analysis of neutral and selected loci, and removing them from further analysis, or developing more complex species tree models that can accommodate such loci. PMID:22399453

Anderson, Christian N K; Liu, Liang; Pearl, Dennis; Edwards, Scott V

2012-01-01

125

Native tree species regulate nitrous oxide fluxes in tropical plantations.  

PubMed

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

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

2014-06-01

126

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

PubMed Central

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

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

2011-01-01

127

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

PubMed

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

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

128

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

PubMed Central

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

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

2014-01-01

129

Pre-epidemic Mortality Rates for Common Phytophthora ramorum Host Tree Species  

E-print Network

371 Pre-epidemic Mortality Rates for Common Phytophthora ramorum Host Tree Species in California1 T pre-epidemic mortality rates for nine common host tree species: bigleaf maple (Acer macrophyllum land. Mortality rates that were developed represent the average annual mortality for trees that were

Standiford, Richard B.

130

Rhizosphere soil microbial index of tree species in a coal mining ecosystem  

Microsoft Academic Search

Microbial characterization of the tree rhizosphere provides important information relating to the screening of tree species for re-vegetation of degraded land. Rhizosphere soil samples collected from a few predominant tree species growing in the coal mining ecosystem of Dhanbad, India, were analyzed for soil organic carbon (SOC), mineralizable N, microbial biomass carbon (MBC), active microbial biomass carbon (AMBC), basal soil

Shipra Sinha; R. E. Masto; L. C. Ram; V. A. Selvi; N. K. Srivastava; R. C. Tripathi; Joshy George

2009-01-01

131

Limits to tree species invasion in pampean grassland and forest plant communities  

Microsoft Academic Search

Factors limiting tree invasion in the Inland Pampas of Argentina were studied by monitoring the establishment of four alien tree species in remnant grassland and cultivated forest stands. We tested whether disturbances facilitated tree seedling recruitment and survival once seeds of invaders were made available by hand sowing. Seed addition to grassland failed to produce seedlings of two study species,

Noemí C. Mazia; Enrique J. Chaneton; Claudio M. Ghersa; Rolando J. C. León

2001-01-01

132

Interannual Variation in Stand Transpiration is Dependent Upon Tree Species  

NASA Astrophysics Data System (ADS)

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.

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

2003-12-01

133

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

PubMed

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

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

2014-08-26

134

Neogene origins and implied warmth tolerance of Amazon tree species  

PubMed Central

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

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

2013-01-01

135

A maximum pseudo-likelihood approach for estimating species trees under the coalescent model  

PubMed Central

Background Several phylogenetic approaches have been developed to estimate species trees from collections of gene trees. However, maximum likelihood approaches for estimating species trees under the coalescent model are limited. Although the likelihood of a species tree under the multispecies coalescent model has already been derived by Rannala and Yang, it can be shown that the maximum likelihood estimate (MLE) of the species tree (topology, branch lengths, and population sizes) from gene trees under this formula does not exist. In this paper, we develop a pseudo-likelihood function of the species tree to obtain maximum pseudo-likelihood estimates (MPE) of species trees, with branch lengths of the species tree in coalescent units. Results We show that the MPE of the species tree is statistically consistent as the number M of genes goes to infinity. In addition, the probability that the MPE of the species tree matches the true species tree converges to 1 at rate O(M -1). The simulation results confirm that the maximum pseudo-likelihood approach is statistically consistent even when the species tree is in the anomaly zone. We applied our method, Maximum Pseudo-likelihood for Estimating Species Trees (MP-EST) to a mammal dataset. The four major clades found in the MP-EST tree are consistent with those in the Bayesian concatenation tree. The bootstrap supports for the species tree estimated by the MP-EST method are more reasonable than the posterior probability supports given by the Bayesian concatenation method in reflecting the level of uncertainty in gene trees and controversies over the relationship of four major groups of placental mammals. Conclusions MP-EST can consistently estimate the topology and branch lengths (in coalescent units) of the species tree. Although the pseudo-likelihood is derived from coalescent theory, and assumes no gene flow or horizontal gene transfer (HGT), the MP-EST method is robust to a small amount of HGT in the dataset. In addition, increasing the number of genes does not increase the computational time substantially. The MP-EST method is fast for analyzing datasets that involve a large number of genes but a moderate number of species. PMID:20937096

2010-01-01

136

Seasonal changes in photosynthesis of eight savanna tree species.  

PubMed

Seasonal variations in carbon assimilation of eight tree species of a north Australian tropical savanna were examined over two wet seasons and one dry season (18 months). Assimilation rates (A) in the two evergreen species, Eucalyptus tetrodonta F. Muell. and E. miniata A. Cunn. ex Schauer, were high throughout the study although there was a 10-20% decline in the dry season compared with the wet season. The three semi-deciduous species (Erythrophleum chlorostachys (F. Muell.) Baillon, Eucalyptus clavigera A. Cunn. ex Schauer, and Xanthostemon paradoxus F. Muell.) showed a 25-75% decline in A in the dry season compared with the wet season, and the deciduous species (Terminalia ferdinandiana Excell, Planchonia careya (F. Muell.) Kunth, and Cochlospermum fraseri Planchon) were leafless for several months in the dry season. Generally, the ratio of intercellular CO(2) concentration to ambient CO(2) concentration (C(i):C(a)) was larger in the wet season than in the dry season, indicating a smaller stomatal limitation of photosynthesis in the wet season compared with the dry season. In all species, the C(i):C(a) ratio and A were essentially independent of leaf-to-air vapor pressure difference (LAVPD) during the wet season, but both parameters generally declined with increasing LAVPD in the dry season. The slope of the positive correlation between A and transpiration rate (E) was less in the wet season than in the dry season. There was no evidence that high E inhibited A. Instantaneous transpiration efficiency was lowest in the wet season and highest during the dry season. Nitrogen-use efficiency (NUE) was higher in the wet season than in the dry season because the decline in A in the dry season was proportionally larger than the decline in foliar nitrogen content. In the wet season, evergreen species exhibited higher NUE than semi-deciduous and deciduous species. In all species, A was linearly correlated with specific leaf area (SLA) and foliar N content. Foliar N content increased with increasing SLA. All species showed a decline in midday leaf water potential as the dry season progressed. Dry season midday water potentials were lowest in semi-deciduous species and highest in the deciduous species, with evergreen species exhibiting intermediate values. PMID:12651322

Eamus, Derek; Myers, Bronwyn; Duff, Gordon; Williams, Dick

1999-08-01

137

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

PubMed

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

Naaz, Afshan; Shahzad, Anwar; Anis, Mohammad

2014-05-01

138

Object-based methods for individual tree identification and tree species classification from high-spatial resolution imagery  

Microsoft Academic Search

Modern forest management poses an increasing need for detailed knowledge of forest information at different spatial scales. At the forest level, the information for tree species assemblage is desired whereas at or below the stand level, individual tree related information is preferred. Remote Sensing provides an effective tool to extract the above information at multiple spatial scales in the continuous

Le Wang

2003-01-01

139

Tree Species Traits Influence Soil Physical, Chemical, and Biological Properties in High Elevation Forests  

Microsoft Academic Search

Background: Previous studies have shown that plants often have species-specific effects on soil properties. In high elevation forests in the Southern Rocky Mountains, North America, areas that are dominated by a single tree species are often adjacent to areas dominated by another tree species. Here, we assessed soil properties beneath adjacent stands of trembling aspen, lodgepole pine, and Engelmann spruce,

Edward Ayres; Heidi Steltzer; Sarah Berg; Matthew D. Wallenstein; Breana L. Simmons; Diana H. Wall

2009-01-01

140

Tree Species Traits Influence Soil Physical, Chemical, and Biological Properties in High Elevation Forests  

Microsoft Academic Search

BackgroundPrevious studies have shown that plants often have species-specific effects on soil properties. In high elevation forests in the Southern Rocky Mountains, North America, areas that are dominated by a single tree species are often adjacent to areas dominated by another tree species. Here, we assessed soil properties beneath adjacent stands of trembling aspen, lodgepole pine, and Engelmann spruce, which

Edward Ayres; Heidi Steltzer; Sarah Berg; Matthew D. Wallenstein; Breana L. Simmons; Diana H. Wall; Thomas Bell

2009-01-01

141

Tree species richness affects litter production and decomposition rates in a tropical biodiversity experiment  

E-print Network

Tree species richness affects litter production and decomposition rates in a tropical biodiversity. We report data on leaf litter production and decomposition from a manipulative biodiversity native tree species, with 1-, 3-, and 6-species mixtures. We estimated litter production during the dry

Bermingham, Eldredge

142

Inferring Species Trees from Gene Trees: A Phylogenetic Analysis of the Elapidae (Serpentes) Based on the Amino Acid Sequences of Venom Proteins  

Microsoft Academic Search

Toward the goal of recovering the phylogenetic relationships among elapid snakes, we separately found the shortest trees from the amino acid sequences for the venom proteins phospholipase A2and the short neurotoxin, collectively representing 32 species in 16 genera. We then applied a method we term gene tree parsimony for inferring species trees from gene trees that works by finding the

Joseph B. Slowinski; Alec Knight; Alejandro P. Rooney

1997-01-01

143

Growthmortality relationships as indicators of life-history strategies: a comparison of nine tree species in unmanaged European forests  

Microsoft Academic Search

Forest succession depends strongly on the life history strategies of individual trees. An important strategic element is the ability to survive unfavourable environmental conditions that result in strongly reduced tree growth. In this study, we investigated whether the relationship between growth and mortality differs among tree species and site conditions. We analysed 10 329 trees of nine tree species (Picea

Harald Bugmann

2008-01-01

144

Effects of tree species, water and nitrogen on mycorrhizal C flux  

NASA Astrophysics Data System (ADS)

Mycorrhiza plays an important role in global carbon cycle, especially, in forest soils, yet the effect of tree species on the amount and timing of C transfer through roots to myccorhiza is largely unknown. We studied the C transport to mycorrhiza under 6 most commonly dominant in boreal forests tree species using the mesh collars installed at the Siberian afforestation experiment. The CO2 flux from mycorrhizal and non-mycorrhizal mesh collars indicated the mycorrhizal C flux. Tree species strongly differed in C flux to mycorrhiza: more C was transferred by deciduous species than by conifers. The mycorrhizal CO2 flux was not linked to soil temperature but rather to trees phenology and to photosynthetic activity. All tree species transfered more carbon to mycorrhiza during the second half of summer and in September, this is because all the carbon photosynthesized earlier is used for building the tree biomass. Seasonal variation in C transfer to mycorrhiza was much larger than hourly variation (within a day). Nitrogen application (50 kg/ha) increased mycorrhizal C flux only under Scots pine, but not under larch, thus the effect of N application is tree species dependent. We found under most tree species that more C was transferred by trees to mycorrhiza in root-free collars, where the soil moisture was higher than in collars with roots. This suggests that trees preferentially support those parts of mycorrhiza, which can gain extra-resources.

Menyailo, O.; Matvienko, A.

2012-12-01

145

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

PubMed Central

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

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

2013-01-01

146

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

NASA Astrophysics Data System (ADS)

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-? lower bound, upper bound uncertainty window): Sugar maple, 0.07 (0.02, 0.11) ?g g-1 h-1; London planetree, 0.15 (0.02, 0.27) ?g g-1 h-1; northern hackberry, 0.33 (0.09, 0.57) ?g g-1 h-1; Japanese zelkova, 0.42 (0.26, 0.58) ?g g-1 h-1; Littleleaf linden, 0.71 (0.33, 1.09) ?g g-1 h-1; Valley Forge elm, 0.96 (0.01, 1.92) ?g g-1 h-1; Turkish hazelnut, 1.30 (0.32, 2.23) ?g g-1 h-1; American basswood, 1.50 (0.40, 2.70) ?g g-1 h-1; and Ohio buckeye, 6.61 (1.76, 11.47) ?g 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) ?g g-1 h-1; Japanese zelkova, 0.11 (0.05, 0.16) ?g g-1 h-1; Littleleaf linden, 0.13 (0.06, 0.21) ?g g-1 h-1; northern hackberry, 0.20 (0.11, 0.30) ?g g-1 h-1; and Ohio buckeye, 0.44 (0.06, 0.83) ?g g-1 h-1. The following trees exhibited emissions of other C10-C15 volatile organic compounds (VOC): Littleleaf linden, 0.15 (0.10, 0.20) ?g g-1 h-1; Ohio buckeye, 0.39 (0.14, 0.65) ?g g-1 h-1; and Turkish hazelnut, 0.72 (0.49, 0.95) ?g g-1 h-1. All tree species studied in this experiment were confirmed to be low isoprene emitters. Compared to many other potential urban tree species, the selected trees can be considered low to moderate BVOC emitters under Colorado growing conditions, with total emission rates one-tenth to one-hundredth the rates of potential high-BVOC emitting trees. The emissions data were used to estimate the impact of this targeted tree planting on the urban BVOC flux and atmospheric VOC burden. Selecting the low-emitting tree species over known high BVOC emitters is equivalent to avoiding VOC emissions from nearly 500,000 cars from the inner city traffic.

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

2014-10-01

147

Landscape variation in tree species richness in northern iran forests.  

PubMed

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

Bourque, Charles P-A; Bayat, Mahmoud

2015-01-01

148

Response of tree growth and species coexistence to density and species evenness in a young forest plantation with two competing species  

PubMed Central

Background and Aims There is considerable evidence for the presence of positive species diversity–productivity relationships in plant populations, but the population parameters determining the type and strength of the relationship are poorly defined. Relationships between species evenness and tree survival or species coexistence are not well established. The objective of this study was to quantify the joint effects of density and species evenness on tree productivity and species coexistence. Methods A 12-year-old experimental tree plantation mixing two species according to a double gradient of density and species proportion was used. A neighbourhood approach was employed and descriptors of local competition were used to model individual tree growth. Fagus sylvatica and Acer pseudoplatanus were used as model species, as they can be considered as ecologically equivalent in their young stages. Key Results Density and tree size were primary factors determining individual growth and stand productivity. Species identity had a significant, but less pronounced, role. Stand productivity was highest when species evenness was close to 1 and slightly lower in uneven mixtures. The reduction in stand productivity when species evenness decreased was of similar magnitude irrespective of which species became dominant, indicating symmetric effects for the two species. When examining individual tree growth in response to species proportion for each species separately, it was observed for both species that individual trees exhibited greater growth in uneven mixtures in which the other species was more frequent. Conclusions The results suggest that mixtures of these two functionally similar species have the highest production at maximum evenness, indicating a complementary effect between them. The presence of a mixture combines both stabilizing mechanisms (individuals from both species show higher growth when surrounded by individuals from the other species) and equalizing mechanisms (the two species have very similar growth curves) that, in turn, determine the species' relative dominance. These processes should act to ensure the long-term coexistence of species. PMID:24323248

Collet, Catherine; Ningre, François; Barbeito, Ignacio; Arnaud, Anthony; Piboule, Alexandre

2014-01-01

149

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

E-print Network

Long range correlations in tree ring chronologies of the USA: Variation within and across species M; accepted 10 December 2012; published 14 February 2013. [1] Tree ring width data are among the best proxies-memory in meteorological and hydrological signals motivates us to investigate such properties in tree ring chronologies

Gao, Jianbo

150

ORIGINAL PAPER Climatic effects on radial growth of major tree species  

E-print Network

disappear from forest communities in those areas. Keywords Climate response . Tree ring . Dendrochronology change on mountainous forests requires a more complete accounting of tree growth­climateORIGINAL PAPER Climatic effects on radial growth of major tree species on Changbai Mountain Dapao

Boyer, Edmond

151

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

PubMed

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

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

2015-03-15

152

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

PubMed Central

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

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

2012-01-01

153

TreeFam v9: a new website, more species and orthology-on-the-fly.  

PubMed

TreeFam (http://www.treefam.org) is a database of phylogenetic trees inferred from animal genomes. For every TreeFam family we provide homology predictions together with the evolutionary history of the genes. Here we describe an update of the TreeFam database. The TreeFam project was resurrected in 2012 and has seen two releases since. The latest release (TreeFam 9) was made available in March 2013. It has orthology predictions and gene trees for 109 species in 15,736 families covering ?2.2 million sequences. With release 9 we made modifications to our production pipeline and redesigned our website with improved gene tree visualizations and Wikipedia integration. Furthermore, we now provide an HMM-based sequence search that places a user-provided protein sequence into a TreeFam gene tree and provides quick orthology prediction. The tool uses Mafft and RAxML for the fast insertion into a reference alignment and tree, respectively. Besides the aforementioned technical improvements, we present a new approach to visualize gene trees and alternative displays that focuses on showing homology information from a species tree point of view. From release 9 onwards, TreeFam is now hosted at the EBI. PMID:24194607

Schreiber, Fabian; Patricio, Mateus; Muffato, Matthieu; Pignatelli, Miguel; Bateman, Alex

2014-01-01

154

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

PubMed Central

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

Sandor, Manette E.; Chazdon, Robin L.

2014-01-01

155

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

PubMed

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

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

2014-10-01

156

Privatized multipurpose reactor initiative  

Microsoft Academic Search

ABB Combustion Engineering (ABB CE) and seven other companies have submitted a plan to the DOE for deploying a multipurpose reactor at the Savannah River Plant. The facility would consume excess plutonium as fuel, irradiate tritium producing targets, and generate electricity. The plan proposes to establish a consortium that would privately finance and own two System 80+ nuclear units and

1995-01-01

157

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

E-print Network

Seven new species of the Botryosphaeriaceae from baobab and other native trees in Western Australia Sciences and Biotechnology, Murdoch University, Perth, 6150, Australia Bernard Slippers Forestry University, Perth, 6150, Australia Abstract: In this study seven new species of the Botryosphaeriaceae

158

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, ...

159

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

PubMed Central

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

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

2014-01-01

160

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

NASA Astrophysics Data System (ADS)

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

Kim, Sooyoung

161

Ambient levels of ozone reduce net photosynthesis in tree and crop species  

Microsoft Academic Search

Experiments were conducted to measure the photosynthetic response of three crop and four tree species to realistic concentrations of ozone and (for tree species only) simulated acidic rain. The ozone concentrations were representative of those found in clean ambient air, in mildly to moderately polluted air such as occurs in much of the US during the summer, and in more

P. B. Reich; R. G. Amundson

1985-01-01

162

TREE SPECIES EFFECTS ON DECOMPOSITION AND FOREST FLOOR DYNAMICS IN A COMMON GARDEN  

Microsoft Academic Search

We studied the effects of tree species on leaf litter decomposition and forest floor dynamics in a common garden experiment of 14 tree species (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

Sarah E. Hobbie; Peter B. Reich; Jacek Oleksyn; Megan Ogdahl; Roma Zytkowiak; Cynthia Hale; Piotr Karolewski

2006-01-01

163

Singletree biomass and stem volume functions for eleven tree species used in Icelandic forestry  

Microsoft Academic Search

In this study we made destructive measurements on sample trees of eleven tree species from plantations spread around the main island of Iceland. These species are downy birch (Betula pubescens), rowan (Sorbus aucuparia), feltleaf willow (Salix alaxensis), dark-leafed willow (Salix myrsinifolia), black cottonwood (Populus trichocarpa), Sitka spruce (Picea sitchensis), Engelmann spruce (Picea engelmannii), white spruce (Picea glauca), Norway spruce (Picea

ARNÓR SNORRASON

2006-01-01

164

Issues in species classification of trees in old growth conifer stands  

Microsoft Academic Search

Old growth temperate conifer forest canopies are composed of assemblages of tree crowns that vary by species, height, size, and intercrown distance. The challenge this complexity presents to species classification is formidable. In this paper we describe the exploration of spectral properties of old growth tree crowns as captured on two independent acquisitions of 0.7 m ground resolution compact airborne

Donald G. Leckie; Sally Tinis; Trisalyn Nelson; Charles Burnett; François A. Gougeon; Ed Cloney; Dennis Paradine

2005-01-01

165

Tree Competition and Species Coexistence in a Sub-boreal Forest, Northern Japan  

Microsoft Academic Search

The growth and mortality patterns and the mode of competition of six tree species forming a sub-boreal climax forest in Hokkaido, northern Japan, were investigated based on the diffusion model at the level of the individual tree ? 2 m height in a 2·3-ha study site. Picea jezoensis, Picea glehnii, Betula ermanii and Abies sachalinensis were dominant species, occupying approx.

Yasuhiro Kubota; Toshihiko Hara

1995-01-01

166

Tree species preferences of foraging insectivorous birds in a northern hardwoods forest  

Microsoft Academic Search

Birds searching for insects in the canopy of a northern hardwoods forest depart significantly from random in their use of tree species, even when these trees are generally similar in life form. All 10 foliage-dwelling bird species in the Hubbard Brook forest showed preferences for Yellow Birch, most had an aversion to Beech and Sugar Maple, and a few had

Richard T. Holmes; Scott K. Robinson

1981-01-01

167

Impact of several common tree species of European temperate forests on soil fertility  

Microsoft Academic Search

Abstract ? The aim of the present work was to provide a synopsis of the scientific literature concerning the effects of different tree spe- cies on soil and to quantify the effect of common,European temperate forest species on soil fertility. The scientific literature dealing with the tree species effect on soil has been reviewed. The composition of forest overstory has

Laurent Augusto; Jacques Ranger; Dan Binkley; Andreas Rothe

2002-01-01

168

CONSEQUENCES OF GLOBAL CLIMATE CHANGE FOR GEOGRAPHIC DISTRIBUTIONS OF CERRADO TREE SPECIES  

Microsoft Academic Search

The present study applies a series of new techniques to understand the conservation of Cerrado tree species in the face of climate change. We applied techniques from the emerging field of ecological niche modeling to develop a first-pass assessment of likely effects of climate change on tree species' distributions in the Cerrado biome by relating known occurrence points to electronic

Marinez Ferreira de Siqueira; Andrew Townsend Peterson

2003-01-01

169

POTENTIAL EFFECTS OF CLIMATE CHANGE ON ECOSYSTEM AND TREE SPECIES DISTRIBUTION IN BRITISH COLUMBIA  

Microsoft Academic Search

A new ecosystem-based climate envelope modeling approach was applied to assess potential climate change impacts on forest communities and tree species. Four orthogonal canonical discriminant functions were used to describe the realized climate space for British Columbia's ecosystems and to model portions of the realized niche space for tree species under current and predicted future climates. This conceptually simple model

Andreas Hamann; Tongli Wang

2006-01-01

170

Accuracy of Tree Grade Projections for Five Appalachian Hardwood Species  

Microsoft Academic Search

The potential value increase of individual trees is an important factor in planning effective forest management strategies. Similar to other investments, trees with high potential value increase are retained and allowed to grow, and those with relatively low potential value increase are harvested so that the proceeds may earn a higher rate of return elsewhere. Tree grade is used to

Gary W. Miller; Aaron T. Graves; Kurt W. Gottschalk; John E. Baumgras

171

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

PubMed

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

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

2015-01-01

172

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

PubMed Central

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

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

2015-01-01

173

Landscape Variation in Tree Species Richness in Northern Iran Forests  

PubMed Central

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

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

2015-01-01

174

Investigating multiple data sources for tree species classification in temperate forest and use for single tree delineation  

NASA Astrophysics Data System (ADS)

Despite numerous studies existing for tree species classification the difficult situation in dense and mixed temperate forest is still a challenging task. This study attempts to extend the existing limitations by investigating comprehensive sets of different types of features derived from multiple data sources. These sets include features from full-waveform LiDAR, LiDAR height metrics, texture, hyperspectral data and colour infrared (CIR) images. Support vector machines (SVM) are used as an appropriate classifier to handle the high dimensional feature space and an internal ranking method allows the determination of the most important parameters. In addition, for species discrimination, focus is put on single tree applicable scale. While most experiences within these scales derive from boreal forests and are often restricted to two or three species, we concentrate on more complex temperate forests. The four main species pine (Pinus sylvestris), spruce (Picea abies), oak (Quercus petraea) and beech (Fagus sylvatica) are classified with an accuracy of 89.7%, 88.7%, 83.1% and 90.7%, respectively. Instead of directly classifying delineated single trees a raster cell based classification is conducted. This overcomes problems with erroneous polygons of merged tree crowns, which occur frequently within dense deciduous or mixed canopies. Lastly, we further test the possibility to correct these failures by combining species classification with single tree delineation.

Heinzel, Johannes; Koch, Barbara

2012-08-01

175

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

PubMed

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 deep coalescence. PMID:20525608

Leaché, Adam D

2009-12-01

176

Fast and Consistent Estimation of Species Trees Using Supermatrix Rooted Triples  

PubMed Central

Concatenated sequence alignments are often used to infer species-level relationships. Previous studies have shown that analysis of concatenated data using maximum likelihood (ML) can produce misleading results when loci have differing gene tree topologies due to incomplete lineage sorting. Here, we develop a polynomial time method that utilizes the modified mincut supertree algorithm to construct an estimated species tree from inferred rooted triples of concatenated alignments. We term this method SuperMatrix Rooted Triple (SMRT) and use the notation SMRT-ML when rooted triples are inferred by ML. We use simulations to investigate the performance of SMRT-ML under Jukes–Cantor and general time-reversible substitution models for four- and five-taxon species trees and also apply the method to an empirical data set of yeast genes. We find that SMRT-ML converges to the correct species tree in many cases in which ML on the full concatenated data set fails to do so. SMRT-ML can be conservative in that its output tree is often partially unresolved for problematic clades. We show analytically that when the species tree is clocklike and mutations occur under the Cavender–Farris–Neyman substitution model, as the number of genes increases, SMRT-ML is increasingly likely to infer the correct species tree even when the most likely gene tree does not match the species tree. SMRT-ML is therefore a computationally efficient and statistically consistent estimator of the species tree when gene trees are distributed according to the multispecies coalescent model. PMID:19833741

DeGiorgio, Michael; Degnan, James H.

2010-01-01

177

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

PubMed

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

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

2015-03-01

178

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

NASA Astrophysics Data System (ADS)

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

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

2011-04-01

179

Photosynthesis rates of selected tree species in lowland dipterocarp rainforest of Sabah, Malaysia  

Microsoft Academic Search

Diurnal courses of net photosynthesis, transpiration and water potential of leaves of ten woody species from the natural\\u000a lowland dipterocarp forests in Sabah (North Borneo, Malaysia) and one exotic tree species were studied in the field. The indigenous\\u000a species represent different ecological niches and successional stages in the various layers of the dipterocarp forest, such\\u000a as pioneers, trees of the

C. Eschenbach; R. Glauner; M. Kleine; L. Kappen

1998-01-01

180

Regeneration microsites and tree species coexistence in temperate rain forests of Chiloe Island, Chile  

Microsoft Academic Search

Summary 1 We studied the importance of fallen logs as recruitment sites for tree species, their role in species coexistence, and also the influence of canopy openness and litter depth on tree species establishment in mid-successional and old-growth temperate rain forests of Chiloé Island, southern Chile. 2 Old-growth (OG) stands showed significantly more fallen logs than mid-successional (MS) stands. Concomitantly,

Duncan A. Christie; Juan J. Armesto

2003-01-01

181

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

USGS Publications Warehouse

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.

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

2008-01-01

182

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

PubMed Central

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

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

2014-01-01

183

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

PubMed

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

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

2014-01-01

184

Water-use Comparison of the Invasive Tree Species, Melaleuca Quinquenervia, and two Native Tree Species,Taxodium Distichum and Pinus Elliottii, in Southwest Florida  

NASA Astrophysics Data System (ADS)

Melaleuca (Melaleuca quinquenervia), an invasive tree species in southern Florida, is generally thought to have higher transpiration rates than the native vegetation, however little empirical data is available to support this claim. In this study, thermal dissipation probes were used to measure transpiration rates of the three species growing in a hydric ecotone in southwest Florida. Transpiration rates of melaleuca, slash pine (Pinus elliottii), and bald cypress (Taxodium distichum) were compared to assess seasonal variability between the wet and dry seasons. Individually trees of both bald cypress and slash pine showed significantly higher water fluxes than melaleuca (p<0.05). However, when individual tree fluxes were scaled to the ecosystem-level, melaleuca contributed 21% of the water flux and bald cypress contributed 72% during the wet season. Melaleuca's increased contribution at the landscape-level results from higher tree densities at our study site. Following leaf senescence in the early dry season, bald cypress continues to be a significant water user at the landscape level. With higher atmospheric demands for water, bald cypress was the least conservative of the three species with respect to water use, whereas on days with low atmospheric demands for water the three species function similarly. These results do not support the hypothesis that melaleuca uses more water than the native Florida tree species, however, they suggest the density of melaleuca at the landscape-scale is important in our understanding of its role in the hydrologic cycle.

Knight, T. M.; Leisure, R. M.; Everham, E. M.; Bovard, B. D.

2008-12-01

185

Conspecific Plant-Soil Feedbacks of Temperate Tree Species in the Southern Appalachians, USA  

PubMed Central

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

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

2012-01-01

186

Spatial Patterns in the Distribution of Tropical Tree Species  

Microsoft Academic Search

Fully mapped tree census plots of large area, 25 to 52 hectares, have now been completed at six different sites in tropical forests, including dry deciduous to wet evergreen forest on two continents. One of the main goals of these plots has been to evaluate spatial patterns in tropical tree populations. Here the degree of aggregation in the distribution of

Richard Condit; Peter S. Ashton; Patrick Baker; Sarayudh Bunyavejchewin; Savithri Gunatilleke; Nimal Gunatilleke; Stephen P. Hubbell; Robin B. Foster; Akira Itoh; James V. LaFrankie; Hua Seng Lee; Elizabeth Losos; N. Manokaran; R. Sukumar; Takuo Yamakura

2000-01-01

187

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

PubMed

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

Smith, Duncan D; Sperry, John S

2014-12-01

188

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

PubMed Central

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.

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

2015-01-01

189

Patterns in tree species richness as a test of the glacial extinction hypothesis  

Microsoft Academic Search

IT is well established that Europe has far fewer tree species and genera than either eastern North America or eastern Asia1-3. Fossil evidence shows that west-central Europe had a much richer tree flora during the Upper Tertiary (25-2 Myr BP), with many genera which now survive only in temperate regions of North America and Asia3. These trees seem to have

J. M. Adams; F. I. Woodward

1989-01-01

190

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

ERIC Educational Resources Information Center

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…

Lückmann, Katrin; Menzel, Susanne

2014-01-01

191

Segmented canonical discriminant analysis of in situ hyperspectral data for identifying 13 urban tree species  

Microsoft Academic Search

A total of 458 in situ hyperspectral data were collected from 13 urban tree species in the City of Tampa, FL, USA using a spectrometer. The 13 species include 11 broadleaf and two conifer species. Three different techniques, segmented canonical discriminant analysis (CDA), segmented principal component analysis (PCA) and segmented stepwise discriminate analysis (SDA), were applied and compared for dimension

Ruiliang Pu; Desheng Liu

2011-01-01

192

Species Divergence and Phylogenetic Variation of Ecophysiological Traits in Lianas and Trees  

PubMed Central

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

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

2014-01-01

193

A "new" tree fern species from southeastern Brazil: Cyathea myriotricha (Cyatheaceae)  

E-print Network

A "new" tree fern species from southeastern Brazil: Cyathea myriotricha (Cyatheaceae) ROBBIN C-mail: ejs7@duke.edu Abstract. Morphological and plastid rbcL and trnG-R sequence data suggest that the fern currently recognized as Megalastrum lasiernos (Dryopteridaceae) is in fact a tree fern (Cyatheaceae

Schuettpelz, Eric

194

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...

195

Hydraulic redistribution study in two native tree species of agroforestry parklands of West African dry savanna  

Microsoft Academic Search

Hydraulic redistribution (HR) in karité (Vitellaria paradoxa) and néré (Parkia biglobosa) tree species was studied by monitoring the soil water potential (?s) using thermocouple psychrometers at four compass directions, various distances from trees and at different soil depths (max depth 80cm) during the dry seasons of 2004 and 2005. A modified WaNuLCAS model was then used to infer the amount

Jules Bayala; Lee Kheng Heng; Meine van Noordwijk; Sibiri Jean Ouedraogo

2008-01-01

196

Fine root architecture, morphology, and biomass of different branch orders of two Chinese temperate tree species  

Microsoft Academic Search

We have limited understanding of architecture and morphology of fine root systems in large woody trees. This study investigated architecture, morphology, and biomass of different fine root branch orders of two temperate tree species from Northeastern China—Larix gmelinii Rupr and Fraxinus mandshurica Rupr —by sampling up to five fine root branch orders three times during the 2003 growing season from

Zhengquan Wang; Dali Guo; Xiangrong Wang; Jiacun Gu; Li Mei

2006-01-01

197

Multilocus species tree analyses resolve the ancient radiation of the subtribe Zizaniinae (Poaceae).  

PubMed

The phylogeny of the subtribe Zizaniinae of rice tribe (Oryzeae) has not been well resolved, particularly for the monotypic Hygroryza whose systematic position was inconsistent in previous studies. Here, we used the concatenation approach and coalescent-based species tree methods to reconstruct the phylogeny of Zizaniinae based on sequences of 14 nuclear single-copy loci and concatenated chloroplast fragments. Despite the low resolution of the tree from concatenated data and substantial topological incongruence of individual gene trees, the species trees inferred from three coalescent-based methods were fully concordant and highly supported. Importantly, the genus Hygroryza was consistently recovered with strong support by all coalescent-based methods. Further various phylogenetic analyses indicated that incomplete lineage sorting was the most likely process that generated pervasive discordance among individual gene trees, although hybridization and introgression cannot be excluded completely. Our species tree inferences based on multilocus data successfully resolved the phylogenetic relationships of the Zizaniinae lineages and confirmed that ancient rapid radiation has taken place in the diversification history of Zizaniinae. This study demonstrates that coalescent-based species tree approaches outperformed the concatenation method and could effectively decipher ancient rapid radiations as long as well resolved individual gene trees were sufficiently sampled. PMID:25655566

Tang, Liang; Zou, Xin-Hui; Zhang, Lin-Bin; Ge, Song

2015-03-01

198

Functional traits shape ontogenetic growth trajectories of rain forest tree species  

E-print Network

rates. Here, we use a size-dependent model of tree growth to test the extent to which of 17 functional-depen- dent diameter growth models using 16 years of census data from 5524 individuals of 50 rain forest tree of ontogenetic changes in growth rate varied widely among species. 4. The Trait-Model provided the best

199

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

PubMed

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

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

2014-05-01

200

Multipurpose Cargo Transfer Bag  

NASA Technical Reports Server (NTRS)

The Logistics Reduction (LR) project within the Advanced Exploration Systems (AES) program is tasked with reducing logistical mass and repurposing logistical items. Multipurpose 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.

Broyan, James; Baccus, Shelley

2014-01-01

201

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

NASA Astrophysics Data System (ADS)

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

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

2011-12-01

202

Hyperspectral discrimination of tropical rain forest tree species at leaf to crown scales  

Microsoft Academic Search

We investigated the utility of high spectral and spatial resolution imagery for the automated species-level classification of individual tree crowns (ITCs) in a tropical rain forest (TRF). Laboratory spectrometer and airborne reflectance spectra (161 bands, 437–2434 nm) were acquired from seven species of emergent trees. Analyses focused on leaf-, pixel- and crown-scale spectra. We first described the spectral regions and

Matthew L. Clark; Dar A. Roberts; David B. Clark

2005-01-01

203

Climate Change and Shifts in Potential Tree Species Range Limits in the Great Lakes Region  

Microsoft Academic Search

The model STASH (STAtic SHell) was used to generate current and future potential geographic ranges of ten important forest tree species within the Great Lakes region. This model uses bioclimatic variables to predict the suitable climate-space for tree species. Current climate values were derived from weather records, and two general circulation models (CGCM1 and HadCM2) predicted future climate scenarios. Shifts

Karen V. Walker; Margaret B. Davis; Shinya Sugita

2002-01-01

204

Conservation prospects for threatened Vietnamese tree species: results from a demographic study  

Microsoft Academic Search

Given that changes in population size are slow, information on future prospects of long-lived tree species is necessarily\\u000a obtained from demographic models. We studied six threatened tree species in four Vietnamese protected areas: the broad-leaved\\u000a Annamocarya sinensis, Manglietia fordiana and Parashorea chinensis, and the coniferous Calocedrus macrolepis, Dacrydium elatum and Pinus kwangtungensis. With data from a 2-year field study on

Pham Duc Chien; Pieter A. Zuidema; Nguyen Hoang Nghia

2008-01-01

205

Gas Exchange and Water Use Efficiency of Three Native Tree Species in Hunshandak Sandland of China  

Microsoft Academic Search

Only three tree species, i.e. Ulmus pumila, Malus baccata, and Prunus padus, are distributed in Hunshandak Sandland (HS) in Inner Mongolia, China. Field studies of gas exchange and chlorophyll (Chl)\\u000a fluorescence of these three tree species were conducted in three arid periods of growth season 2002. Net photosynthetic rate\\u000a (P\\u000a N), transpiration rate (E), stomatal conductance (g\\u000a s), and Fv\\/Fm

Y. G. Li; G. M. Jiang; S. L. Niu; M. Z. Liu; Y. Peng; S. L. Yu; L. M. Gao

2003-01-01

206

Growth Strategies of Tropical Tree Species: Disentangling Light and Size Effects  

PubMed Central

An understanding of the drivers of tree growth at the species level is required to predict likely changes of carbon stocks and biodiversity when environmental conditions change. Especially in species-rich tropical forests, it is largely unknown how species 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 tree diameter on growth of 274 woody species in a 50-ha long-term forest census plot in Barro Colorado Island, Panama. Light reaching each individual tree 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 species correctly weighted by their abundance. All species 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 species 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 species. As a consequence, growth rankings of the species at low (2%) and high light (20%) were highly correlated. Rare species tended to grow faster and showed a greater sensitivity to light than abundant species. Overall, tree size was less important for growth than light and about half the species were predicted to grow faster in diameter when bigger or smaller, respectively. Together light availability and tree 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 tree growth in the tropics. PMID:21966498

Rüger, Nadja; Berger, Uta; Hubbell, Stephen P.; Vieilledent, Ghislain; Condit, Richard

2011-01-01

207

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

NASA Astrophysics Data System (ADS)

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> <div class="credits"> <p class="dwt_author">Bowers, M. C.; Gao, J. B.; Tung, W. W.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-02-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">208</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Background Previous studies have shown that plants often have <span class="hlt">species</span>-specific effects on soil properties. In high elevation forests in the Southern Rocky Mountains, North America, areas that are dominated by a single <span class="hlt">tree</span> <span class="hlt">species</span> are often adjacent to areas dominated by another <span class="hlt">tree</span> <span class="hlt">species</span>. Here, we assessed soil properties beneath adjacent stands of trembling aspen, lodgepole pine, and Engelmann spruce, which are dominant <span class="hlt">tree</span> <span class="hlt">species</span> in this region and are distributed widely in North America. We hypothesized that soil properties would differ among stands dominated by different <span class="hlt">tree</span> <span class="hlt">species</span> and expected that aspen stands would have higher soil temperatures due to their open structure, which, combined with higher quality litter, would result in increased soil respiration rates, nitrogen availability, and microbial biomass, and differences in soil faunal community composition. Methodology/Principal Findings We assessed soil physical, chemical, and biological properties at four sites where stands of aspen, pine, and spruce occurred in close proximity to one-another in the San Juan Mountains, Colorado. Leaf litter quality differed among the <span class="hlt">tree</span> <span class="hlt">species</span>, with the highest nitrogen (N) concentration and lowest lignin?N in aspen litter. Nitrogen concentration was similar in pine and spruce litter, but lignin?N was highest in pine litter. Soil temperature and moisture were highest in aspen stands, which, in combination with higher litter quality, probably contributed to faster soil respiration rates from stands of aspen. Soil carbon and N content, ammonium concentration, and microbial biomass did not differ among <span class="hlt">tree</span> <span class="hlt">species</span>, but nitrate concentration was highest in aspen soil and lowest in spruce soil. In addition, soil fungal, bacterial, and nematode community composition and rotifer, collembolan, and mesostigmatid mite abundance differed among the <span class="hlt">tree</span> <span class="hlt">species</span>, while the total abundance of nematodes, tardigrades, oribatid mites, and prostigmatid mites did not. Conclusions/Significance Although some soil characteristics were unaffected by <span class="hlt">tree</span> <span class="hlt">species</span> identity, our results clearly demonstrate that these dominant <span class="hlt">tree</span> <span class="hlt">species</span> are associated with soils that differ in several physical, chemical, and biotic properties. Ongoing environmental changes in this region, e.g. changes in fire regime, frequency of insect outbreaks, changes in precipitation patterns and snowpack, and land-use change, may alter the relative abundance of these <span class="hlt">tree</span> <span class="hlt">species</span> over coming decades, which in turn will likely alter the soils. PMID:19536334</p> <div class="credits"> <p class="dwt_author">Ayres, Edward; Steltzer, Heidi; Berg, Sarah; Wallenstein, Matthew D.; Simmons, Breana L.; Wall, Diana H.</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">209</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://extension.unh.edu/resources/files/Resource000980_Rep1106.pdf"> <span id="translatedtitle">List of New Hampshire Native <span class="hlt">Trees</span> There are something like 70 natives <span class="hlt">tree</span> <span class="hlt">species</span> found in the wild in New Hampshire. The exact number is</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p class="result-summary">Picea mariana red spruce Picea rubens white spruce Picea glauca White Cedar Chamaecyparis (Cupressaceae) Atlantic white-cedar Chamaecyparis thyoides List of New Hampshire Native <span class="hlt">Trees</span> Page 1 of 4 #12;List of NewList of New Hampshire Native <span class="hlt">Trees</span> There are something like 70 natives <span class="hlt">tree</span> <span class="hlt">species</span> found</p> <div class="credits"> <p class="dwt_author">New Hampshire, University of</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">210</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/25540456"> <span id="translatedtitle">Assessing approaches for inferring <span class="hlt">species</span> <span class="hlt">trees</span> from multi-copy genes.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">With the availability of genomic sequence data, there is increasing interest in using genes with a possible history of duplication and loss for <span class="hlt">species</span> <span class="hlt">tree</span> inference. Here we assess the performance of both nonprobabilistic and probabilistic <span class="hlt">species</span> <span class="hlt">tree</span> inference approaches using gene duplication and loss and coalescence simulations. We evaluated the performance of gene <span class="hlt">tree</span> parsimony (GTP) based on duplication (Only-dup), duplication and loss (Dup-loss), and deep coalescence (Deep-c) costs, the NJst distance method, the MulRF supertree method, and PHYLDOG, which jointly estimates gene <span class="hlt">trees</span> and <span class="hlt">species</span> <span class="hlt">tree</span> using a hierarchical probabilistic model. We examined the effects of gene <span class="hlt">tree</span> and <span class="hlt">species</span> sampling, gene <span class="hlt">tree</span> error, and duplication and loss rates on the accuracy of phylogenetic estimates. In the 10-taxon duplication and loss simulation experiments, MulRF is more accurate than the other methods when the duplication and loss rates are low, and Dup-loss is generally the most accurate when the duplication and loss rates are high. PHYLDOG performs well in 10-taxon duplication and loss simulations, but its run time is prohibitively long on larger data sets. In the larger duplication and loss simulation experiments, MulRF outperforms all other methods in experiments with at most 100 taxa; however, in the larger simulation, Dup-loss generally performs best. In all duplication and loss simulation experiments with more than 10 taxa, all methods perform better with more gene <span class="hlt">trees</span> and fewer missing sequences, and they are all affected by gene <span class="hlt">tree</span> error. Our results also highlight high levels of error in estimates of duplications and losses from GTP methods and demonstrate the usefulness of methods based on generic <span class="hlt">tree</span> distances for large analyses. PMID:25540456</p> <div class="credits"> <p class="dwt_author">Chaudhary, Ruchi; Boussau, Bastien; Burleigh, J Gordon; Fernández-Baca, David</p> <p class="dwt_publisher"></p> <p class="publishDate">2015-03-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">211</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Roberts, David R; Hamann, Andreas</p> <p class="dwt_publisher"></p> <p class="publishDate">2015-04-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">212</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://forestecology.cfans.umn.edu/HobbielEcosyst2007.pdf"> <span id="translatedtitle"><span class="hlt">Tree</span> <span class="hlt">Species</span> Effects on Soil Organic Matter Dynamics: The Role of Soil Cation Composition</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">We studied the influence of <span class="hlt">tree</span> <span class="hlt">species</span> on soil carbon and nitrogen (N) dynamics in a common garden of replicated monocultures\\u000a of fourteen angiosperm and gymnosperm, broadleaf and needleleaf <span class="hlt">species</span> in southwestern Poland. We hypothesized that <span class="hlt">species</span>\\u000a would influence soil organic matter (SOM) decomposition primarily via effects on biogeochemical recalcitrance, with <span class="hlt">species</span>\\u000a having tissues with high lignin concentrations retarding rates</p> <div class="credits"> <p class="dwt_author">Sarah E. Hobbie; Megan Ogdahl; Jon Chorover; Oliver A. Chadwick; Jacek Oleksyn; Roma Zytkowiak; Peter B. Reich</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">213</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.for.gov.bc.ca/hfd/library/FIA/2008/FSP_Y081116b.pdf"> <span id="translatedtitle">BCFSP Project Y081116 Growth of 10 <span class="hlt">tree</span> <span class="hlt">species</span> in relation to location and microclimatic gradients in a strip shelterwood</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Preliminary results indicate that patterns of <span class="hlt">tree</span> growth are related to microclimatic gradients in these openings. Height growth of the various <span class="hlt">tree</span> <span class="hlt">species</span> reflects their tolerance to drought and shade in openings. Among the <span class="hlt">tree</span> <span class="hlt">species</span> evaluated, Western hemlock and Engelmann spruce were best suited at the south edge and in the intact forest, but Douglas fir performed best at</p> <div class="credits"> <p class="dwt_author">K. L. Hossain; P. G. Comeau</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">214</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/59111197"> <span id="translatedtitle">Estimating <span class="hlt">Species</span> Interactions in a Woodpecker <span class="hlt">Tree</span>-Hole Community at the Individual, Population, and Community Levels</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The endangered red-cockaded woodpecker (Picoides borealis) is a keystone <span class="hlt">species</span> in the southeastern United States where it excavates <span class="hlt">tree</span> holes in living pines <span class="hlt">trees</span>. An understanding of the interactions among the <span class="hlt">species</span> using the <span class="hlt">tree</span> holes may indicate whether they affect red-cockaded woodpeckers negatively. In the Apalachicola National Forest of northern Florida, I conducted a series of experiments at the</p> <div class="credits"> <p class="dwt_author">Eric L. Walters</p> <p class="dwt_publisher"></p> <p class="publishDate">2004-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">215</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Woodward, Andrea</p> <p class="dwt_publisher"></p> <p class="publishDate">1998-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">216</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://oaspub.epa.gov/eims/eimsapi.dispdetail?deid=64306"> <span id="translatedtitle">ISOPRENE EMISSION CAPACITY FOR U.S. <span class="hlt">TREE</span> <span class="hlt">SPECIES</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p class="result-summary">Isoprene emission capacity measurements are presented from 18 North American oak (Quercus) <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> <div class="credits"> <p class="dwt_author"></p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">217</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.springerlink.com/index/vp851221176505l4.pdf"> <span id="translatedtitle">Photosynthesis-nitrogen relations in Amazonian <span class="hlt">tree</span> <span class="hlt">species</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Among <span class="hlt">species</span>, photosynthetic capacity (Amax) is usually related to leaf nitrogen content (N), but variation in the <span class="hlt">species</span>-specific relationship is not well understood. To address this issue, we studied Amax-N relationships in 23 <span class="hlt">species</span> in adjacent Amazonian communities differentially limited by nitrogen (N), phosphorus (P), and\\/or other mineral nutrients. Five <span class="hlt">species</span> were studied in each of three late successional forest</p> <div class="credits"> <p class="dwt_author">P. B. Reich; M. B. Walters; D. S. Ellsworth; C. Uhl</p> <p class="dwt_publisher"></p> <p class="publishDate">1994-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">218</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/12566259"> <span id="translatedtitle">Reliance on stored water increases with <span class="hlt">tree</span> size in three <span class="hlt">species</span> in the Pacific Northwest.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">In tall old forests, limitations to water transport may limit maximum <span class="hlt">tree</span> height and reduce photosynthesis and carbon sequestration. We evaluated the degree to which tall <span class="hlt">trees</span> could potentially compensate for hydraulic limitations to water transport by increased use of water stored in xylem. Using sap flux measurements in three <span class="hlt">tree</span> <span class="hlt">species</span> of the Pacific Northwest, we showed that reliance on stored water increases with <span class="hlt">tree</span> size and estimated that use of stored water increases photosynthesis. For Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), water stored in xylem accounted for 20 to 25% of total daily water use in 60-m <span class="hlt">trees</span>, whereas stored water comprised 7% of daily water use in 15-m <span class="hlt">trees</span>. For Oregon white oak (Quercus garryana Dougl. ex Hook.), water stored in xylem accounted for 10 to 23% of total daily water use in 25-m <span class="hlt">trees</span>, whereas stored water comprised 9 to 13% of daily water use in 10-m <span class="hlt">trees</span>. For ponderosa pine (Pinus ponderosa Dougl. ex Laws.), water stored in xylem accounted for 4 to 20% of total daily water use in 36-m <span class="hlt">trees</span>, whereas stored water comprised 2 to 4% of daily water use in 12-m <span class="hlt">trees</span>. In 60-m Douglas-fir <span class="hlt">trees</span>, we estimated that use of stored water supported 18% more photosynthesis on a daily basis than would occur if no stored water were used, whereas 15-m Douglas-fir <span class="hlt">trees</span> gained 10% greater daily photosynthesis from use of stored water. We conclude that water storage plays a significant role in the water and carbon economy of tall <span class="hlt">trees</span> and old forests. PMID:12566259</p> <div class="credits"> <p class="dwt_author">Phillips, N G; Ryan, M G; Bond, B J; McDowell, N G; Hinckley, T M; Cermák, J</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-03-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">219</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/19895558"> <span id="translatedtitle">The interface between phylogenetics and population genetics: investigating gene <span class="hlt">trees</span>, <span class="hlt">species</span> <span class="hlt">trees</span>, and population dynamics in the Phyllophaga fraterna <span class="hlt">species</span> group.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">This study uses traditional and contemporary phylogenetic and population genetic analyses to assess the causes of discordance (i.e., lineage sorting and introgression) among mitochondrial and nuclear gene <span class="hlt">trees</span> for a clade of eastern North American scarab beetles (fraterna <span class="hlt">species</span> group, genus Phyllophaga). I estimated gene <span class="hlt">trees</span> using individual and combined analysis of one mitochondrial and two nuclear loci in MrBayes, and inferred a <span class="hlt">species</span> <span class="hlt">tree</span> using a hierarchical coalescent approach based on all loci in the program Best. Because hybridization violates the assumptions of BEST, I tested for introgression by comparing <span class="hlt">species</span> monophyly between the mitochondrial and nuclear gene <span class="hlt">trees</span> based on the prediction that cytoplasmic genomes introgress more readily than nuclear genomes. Haplotype exclusivity was identified using Bayesian tests of monophyly and the genealogical sorting index. I used the results of the phylogenetic analyses and monophyly tests to develop an explicit hypothesis of introgression that could be tested in the program IMa. Results from these analyses provided evidence for introgression across clades within the fraterna group. The tiered analytical approach used in this study demonstrated how the use of multiple methods can identify when assumptions are violated and methods are prone to yield misleading results. PMID:19895558</p> <div class="credits"> <p class="dwt_author">Polihronakis, Maxi</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-04-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">220</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/23769751"> <span id="translatedtitle">Effects of missing data on <span class="hlt">species</span> <span class="hlt">tree</span> estimation under the coalescent.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">With recent advances in genomic sequencing, the importance of taking the effects of the processes that can cause discord between the speciation history and the individual gene histories into account has become evident. For multilocus datasets, it is difficult to achieve complete coverage of all sampled loci across all sample specimens, a problem that also arises when combining incompletely overlapping datasets. Here we examine how missing data affects the accuracy of <span class="hlt">species</span> <span class="hlt">tree</span> reconstruction. In our study, 10- and 100-locus sequence datasets were simulated under the coalescent model from shallow and deep speciation histories, and <span class="hlt">species</span> <span class="hlt">trees</span> were estimated using the maximum likelihood and Bayesian frameworks (with STEM and (*)BEAST, respectively). The accuracy of the estimated <span class="hlt">species</span> <span class="hlt">trees</span> was evaluated using the symmetric difference and the SPR distance. We examine the effects of sampling more than one individual per <span class="hlt">species</span>, as well as the effects of different patterns of missing data (i.e., different amounts of missing data, which is represented among random taxa as opposed to being concentrated in specific taxa, as is often the case for empirical studies). Our general conclusion is that the <span class="hlt">species</span> <span class="hlt">tree</span> estimates are remarkably resilient to the effects of missing data. We find that for datasets with more limited numbers of loci, sampling more than one individual per <span class="hlt">species</span> has the strongest effect on improving <span class="hlt">species</span> <span class="hlt">tree</span> accuracy when there is missing data, especially at higher degrees of missing data. For larger multilocus datasets (e.g., 25-100 loci), the amount of missing data has a negligible effect on <span class="hlt">species</span> <span class="hlt">tree</span> reconstruction, even at 50% missing data and a single sampled individual per <span class="hlt">species</span>. PMID:23769751</p> <div class="credits"> <p class="dwt_author">Hovmöller, Rasmus; Knowles, L Lacey; Kubatko, Laura S</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-12-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_10");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' 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id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_11");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a onClick='return showDiv("page_4");' href="#">4</a> <a onClick='return showDiv("page_5");' href="#">5</a> <a onClick='return showDiv("page_6");' href="#">6</a> <a onClick='return showDiv("page_7");' href="#">7</a> <a onClick='return showDiv("page_8");' href="#">8</a> <a onClick='return showDiv("page_9");' href="#">9</a> <a onClick='return showDiv("page_10");' href="#">10</a> <a onClick='return showDiv("page_11");' href="#">11</a> <a style="font-weight: bold;">12</a> <a onClick='return showDiv("page_13");' href="#">13</a> <a onClick='return showDiv("page_14");' href="#">14</a> <a onClick='return showDiv("page_15");' href="#">15</a> <a onClick='return showDiv("page_16");' href="#">16</a> <a onClick='return showDiv("page_17");' href="#">17</a> <a onClick='return showDiv("page_18");' href="#">18</a> <a onClick='return showDiv("page_19");' href="#">19</a> <a onClick='return showDiv("page_20");' href="#">20</a> <a onClick='return showDiv("page_21");' href="#">21</a> <a onClick='return showDiv("page_22");' href="#">22</a> <a onClick='return showDiv("page_23");' href="#">23</a> <a onClick='return showDiv("page_24");' href="#">24</a> <a onClick='return showDiv("page_25");' href="#">25</a> </span> </span> <a id="NextPageLink" onclick='return showDiv("page_13");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">221</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Cherubini, Paolo; Gartner, Barbara L; Tognetti, Roberto; Bräker, Otto U; Schoch, Werner; Innes, John L</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-02-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">222</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1991usra.proc..227."> <span id="translatedtitle"><span class="hlt">Multipurpose</span> satellite bus (MPS)</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author"></p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">223</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19910009823&hterms=Radiation+Hardened+Design&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DRadiation%2BHardened%2BDesign"> <span id="translatedtitle"><span class="hlt">Multipurpose</span> hardened spacecraft insulation</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Steimer, Carlos H.</p> <p class="dwt_publisher"></p> <p class="publishDate">1990-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">224</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/21322961"> <span id="translatedtitle"><span class="hlt">Multipurpose</span> Compact Spectrometric Unit</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Bocarov, Viktor; Cermak, Pavel; Mamedov, Fadahat; Stekl, Ivan [Institute of Experimental and Applied Physics, Czech Technical University in Prague, Horska 3a/22, CZ-12800 Prague 2 (Czech Republic)</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-11-09</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">225</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19930020554&hterms=crisis+communication&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dcrisis%2Bcommunication"> <span id="translatedtitle"><span class="hlt">Multipurpose</span> satellite bus (MPS)</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author"></p> <p class="dwt_publisher"></p> <p class="publishDate">1991-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">226</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/23360013"> <span id="translatedtitle">Determination of incoming solar radiation in major <span class="hlt">tree</span> <span class="hlt">species</span> in Turkey.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Light requirements and spatial distribution of major forest <span class="hlt">tree</span> <span class="hlt">species</span> in Turkey hasn't been analyzed yet. Continuous surface solar radiation data, especially at mountainous-forested areas, are needed to put forward this relationship between forest <span class="hlt">tree</span> <span class="hlt">species</span> and solar radiation. To achieve this, GIS-based modeling of solar radiation is one of the methods used in rangelands to estimate continuous surface solar radiation. Therefore, mean monthly and annual total global solar radiation maps of whole Turkey were computed spatially using GRASS GIS software "r.sun" model under clear-sky (cloudless) conditions. 147498 pure forest stand point-based data were used in the study for calculating mean global solar radiation values of all the major forest <span class="hlt">tree</span> <span class="hlt">species</span> of Turkey. Beech had the lowest annual mean total global solar radiation value of 1654.87 kWh m(-2), whereas juniper had the highest value of 1928.89 kWh m(-2). The rank order of <span class="hlt">tree</span> <span class="hlt">species</span> according to the mean monthly and annual total global solar radiation values, using a confidence level of p < 0.05, was as follows: Beech < Spruce < Fir <span class="hlt">species</span> < Oak <span class="hlt">species</span> < Scotch pine < Red pine < Cedar < Juniper. The monthly and annual solar radiation values of sites and light requirements of forest <span class="hlt">trees</span> ranked similarly. PMID:23360013</p> <div class="credits"> <p class="dwt_author">Yilmaz, Osman Yalcin; Sevgi, Orhan; Koc, Ayhan</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-07-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">227</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3799400"> <span id="translatedtitle">Flowering and Fruiting Phenology of <span class="hlt">Tree</span> <span class="hlt">Species</span> in Mount Papandayan Nature Reserve, West Java, Indonesia</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Mount Papandayan Nature Reserve (MPNR) is an area highly rich in biodiversity, however deforestation has left a vast area urgently in need of reforestation. When reforestation is designed to restore some level of biodiversity, it is imperative that native <span class="hlt">tree</span> <span class="hlt">species</span> are used for planting. This research aimed to provide information on the flowering and fruiting phenology of native <span class="hlt">trees</span>. Such information can be useful to plan seed collection and mass seedling production in the nursery. The observations were conducted each month during August 2009–July 2010 by recording flowering and fruiting <span class="hlt">trees</span> along two survey track passing through the middle of the mixed forest of MPNR. Data gathered were used to construct a simple phenology calendar. During the study, there were 155 <span class="hlt">trees</span> of 43 <span class="hlt">species</span> found flowering or fruiting along the survey track. The peak time of flowering and fruiting was in July (13 <span class="hlt">species</span> flowering and 19 <span class="hlt">species</span> fruiting), while the lowest level was in October (1 <span class="hlt">species</span> flowering and 3 <span class="hlt">species</span> fruiting). According to the phenology calendar constructed, March to July were considered to be the appropriate time to collect seeds of native <span class="hlt">trees</span> in Mount Papandayan. PMID:24575236</p> <div class="credits"> <p class="dwt_author">Sulistyawati, Endah; Mashita, Nusa; Setiawan, Nuri Nurlaila; Choesin, Devi N; Suryana, Pipin</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">228</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.genomics.arizona.edu/553/Readings/Pollard_et_al_2006.pdf"> <span id="translatedtitle">Widespread Discordance of Gene <span class="hlt">Trees</span> with <span class="hlt">Species</span> <span class="hlt">Tree</span> in Drosophila: Evidence for Incomplete Lineage Sorting</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The phylogenetic relationship of the now fully sequenced <span class="hlt">species</span> Drosophila erecta and D. yakuba with respect to the D. melanogaster <span class="hlt">species</span> complex has been a subject of controversy. All three possible groupings of the <span class="hlt">species</span> have been reported in the past, though recent multi-gene studies suggest that D. erecta and D. yakuba are sister <span class="hlt">species</span>. Using the whole genomes of</p> <div class="credits"> <p class="dwt_author">Daniel A. Pollard; Venky N. Iyer; Alan M. Moses; Michael B. Eisen</p> <p class="dwt_publisher"></p> <p class="publishDate">2006-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">229</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://kuscholarworks.ku.edu/handle/1808/6553"> <span id="translatedtitle">Ecological niche modeling and local knowledge predict new populations of *Gymnocladus assamicus* a critically endangered <span class="hlt">tree</span> <span class="hlt">species</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p class="result-summary">Gymnocladus assamicus is a critically endangered <span class="hlt">tree</span> <span class="hlt">species</span> endemic to northeastern India. Local inhabitants traditionally used this <span class="hlt">species</span> for a variety of purposes. However, rapid population declines led to the <span class="hlt">species</span> being considered extinct...</p> <div class="credits"> <p class="dwt_author">Menon, Shaily; Choudhury, Bahrul I.; Khan, M. Latif; Peterson, A. Townsend</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-04-16</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">230</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://forestecology.cfans.umn.edu/prod/groups/cfans/@pub/@cfans/@forestecology/documents/asset/cfans_asset_412313.pdf"> <span id="translatedtitle"><span class="hlt">Tree</span> <span class="hlt">Species</span> Effects on Soil Organic Matter Dynamics: The Role of Soil</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p class="result-summary">Barbara, CA 93106, USA; 4 Polish Academy of Sciences, Institute of Dendrology, Kornik, 62-035, Poland; 5 the influence of <span class="hlt">tree</span> <span class="hlt">species</span> on soil carbon and nitrogen (N) dynamics in a common garden of replicated monocultures of fourteen angiosperm and gymnosperm, broadleaf and nee- dleleaf <span class="hlt">species</span> in southwestern Poland</p> <div class="credits"> <p class="dwt_author">Minnesota, University of</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">231</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.fs.fed.us/ne/newtown_square/publications/other_publishers/OCR/ne_2003_keena001.pdf"> <span id="translatedtitle">Survival and Development of Lymantria monacha (Lepidoptera: Lymantriidae) on North American and Introduced Eurasian <span class="hlt">Tree</span> <span class="hlt">Species</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Lymantria monacha (L.) (Lepidoptera: Lymantriidae), the nun moth, is a Eurasian pest of conifers that has potential for accidental introduction into North America. To project the potential host range of this insect if introd ucedinto North America, survival andd evelopment of L. monacha on 26 North American andeight introd ucedEurasian <span class="hlt">tree</span> <span class="hlt">species</span> were examined . Seven conifer <span class="hlt">species</span> (Abies concolor,</p> <div class="credits"> <p class="dwt_author">M. A. Keena</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">232</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ese.u-psud.fr/epc/conservation/PDFs/ECOE/leathwick.pdf"> <span id="translatedtitle">Soil and atmospheric water deficits and the distribution of New Zealand's indigenous <span class="hlt">tree</span> <span class="hlt">species</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Summary 1. An extensive data set describing the composition of New Zealand's remaining indig- enous forests was used to estimate the degree of correlation between measures of both soil and atmospheric water deficit and the distribution of common <span class="hlt">tree</span> <span class="hlt">species</span>. 2. For most <span class="hlt">species</span>, regression models incorporating measures of air saturation deficit in early autumn, as well as an annual</p> <div class="credits"> <p class="dwt_author">D. Whitehead</p> <p class="dwt_publisher"></p> <p class="publishDate">2001-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">233</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/10466294"> <span id="translatedtitle">Climate signal in <span class="hlt">tree</span>-ring chronologies in a temperate climate: A multi-<span class="hlt">species</span> approach</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary"><span class="hlt">Tree</span>-rings can provide continuous yearly paleoclimatic records for regions or periods of time with no instrumental climate data. However, different <span class="hlt">species</span> respond to different climate parameters with, for example, some sensitive to moisture and others to temperature. Here, we describe four common <span class="hlt">species</span> growing in Northern Ireland and their suitability for climate reconstruction.Our results suggest that beech and ash are</p> <div class="credits"> <p class="dwt_author">A. M. García-Suárez; C. J. Butler; M. G. L. Baillie</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">234</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ijs.sgmjournals.org/cgi/reprint/29/1/60.pdf"> <span id="translatedtitle">HansenuZa ahi, a New Heterothallic <span class="hlt">Species</span> of Yeast from Exudates of Alder <span class="hlt">Trees</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">A novel member of the yeast genus Hansenula was recovered three times in 1968 from slime exudates of Alnus rubra in the state of Washington and in the province of British Columbia. The new <span class="hlt">species</span> is named Hansenula alni because of its specific habitat in exudates of alder <span class="hlt">trees</span>. This <span class="hlt">species</span> occurs naturally in the haploid condition. Upon mixing of</p> <div class="credits"> <p class="dwt_author">H. J. PHAFF; M. W. MILLER; MARY MIRANDA</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">235</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ars.usda.gov/services/TekTran.htm">Technology Transfer Automated Retrieval System (TEKTRAN)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author"></p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">236</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.stanford.edu/group/rosenberglab/papers/DeGiorgioDegnan2010-MolBiolEvol.pdf"> <span id="translatedtitle">Fast and Consistent Estimation of <span class="hlt">Species</span> <span class="hlt">Trees</span> Using Supermatrix Rooted Triples</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p class="result-summary">of Michigan 2 Department of Mathematics and Statistics, University of Canterbury, Christchurch, New Zealand Holland Abstract Concatenated sequence alignments are often used to infer <span class="hlt">species</span>-level relationships the <span class="hlt">species</span> <span class="hlt">tree</span>. SMRT-ML is therefore a computationally efficient and statistically consistent estimator</p> <div class="credits"> <p class="dwt_author">Rosenberg, Noah</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">237</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.zfmk.de/BZB/BzB_54_4_12_Vig_Marko.pdf"> <span id="translatedtitle"><span class="hlt">Species</span> Composition of Leaf Beetle Assemblages in Deciduous <span class="hlt">Tree</span> Canopies in Hungary (Coleoptera: Chrysomelidae)1</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The <span class="hlt">species</span> richness and <span class="hlt">species</span> composition of Coleoptera assemblages were investigated in deciduous <span class="hlt">tree</span> canopies in Hungary. Apple and pear orchards were investigated in Nagykovácsi, Kecskemét and Sárospatak in 1990- 94, and limes and maples in Keszthely in 1999-2002. This study presents in detail the findings on leaf beetles. Earlier investigations in Hungary revealed surprisingly high diversity of Coleoptera assemblages</p> <div class="credits"> <p class="dwt_author">Károly VIG; Viktor MARKÓ</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">238</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ecostudies.org/reprints/Finzi_et_al_1998_Ecol_Appl_8_447-454.pdf"> <span id="translatedtitle">Canopy <span class="hlt">tree</span>-soil interactions within temperate forest: <span class="hlt">species</span> effects on pH and cations</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">We quantified soil acidity and exchangeable cations in the forest floor and upper 7.5 cm of mineral soil beneath the canopies of individual <span class="hlt">trees</span> of six different <span class="hlt">species</span> in a mixed-<span class="hlt">species</span> forest in northwestern Connecticut. Soil pH decreased in a sequence starting with sugar maple (Acer saccharum) . white ash (Fraxinus americana) . red maple (Acer rubrum) . beech (Fagus</p> <div class="credits"> <p class="dwt_author">Adrien C. Finzi; Charles D. Canham; Nico van Breemen</p> <p class="dwt_publisher"></p> <p class="publishDate">1998-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">239</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/18959161"> <span id="translatedtitle">Ocurrence of ectomycorrhizal, hypogeous fungi in plantations of exotic <span class="hlt">tree</span> <span class="hlt">species</span> in central Argentina.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Eleven hypogeous, ectomycorrhizal <span class="hlt">species</span> of Basidiomycota, including two new <span class="hlt">species</span>, and one of the Zygomycota were collected in exotic <span class="hlt">tree</span> plantations in C6rdoba Province, Argentina. Descomyces fusisporus sp. nov., D. varians sp. nov., Hydnangium archeri (Berk.) Rodway, H. carneum Wallr., Hysterangium gardneri E. Fisch. and Setchelliogaster tenuipes (Setch.) Pouzar were associated with Eucalyptus spp. Endogone lactiflua Berk., Hymenogaster lycoperdineus Vittad., H. griseus Vittad., H. rehsteineri Bucholtz, Rhizopogon couchii A.H. Sm. and R. roseolus (Corda) Th. Fr., were associated with various northern hemisphere <span class="hlt">tree</span> <span class="hlt">species</span>. Descriptions are provided to aid identification of the hypogeous fungi in exotic plantations of Argentina. PMID:18959161</p> <div class="credits"> <p class="dwt_author">Nouhra, Eduardo R; Dominguez, Laura S; Daniele, Graciela G; Longo, Silvana; Trappe, James M; Claridge, Andrew W</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">240</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/21586031"> <span id="translatedtitle">Microsatellite loci for two East African <span class="hlt">tree</span> <span class="hlt">species</span>, Leptonychia usambarensis (Sterculiaceae) and Sorindeia madagascariensis (Anacardiaceae).</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">We isolated 20 trinucleotide microsatellites from two African <span class="hlt">tree</span> <span class="hlt">species</span>: Sorindeia madagascariensis (nine microsatellites) and Leptonychia usambarensis (11 microsatellites). Number of alleles ranged from three to seven in Sorindeia and two to 10 in Leptonychia. Observed heterozygosity ranged from 0.025 to 0.829 for Sorindeia and from 0.226 to 0.933 for Leptonychia. Two loci from each <span class="hlt">species</span> departed from Hardy-Weinberg equilibrium. These microsatellite markers will be used to study how forest fragmentation affects pollination and seed dispersal processes of these <span class="hlt">tree</span> <span class="hlt">species</span>. PMID:21586031</p> <div class="credits"> <p class="dwt_author">Cordeiro, N J; Feldheim, K A; Ikejimba, E; Ndangalasi, H J</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-11-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_11");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' 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src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">241</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/16539132"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">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. PMID:16539132</p> <div class="credits"> <p class="dwt_author">Coyle, D R; Booth, D C; Wallace, M S</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">242</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">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 Ã?Â?Ã?Â?rst 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> <div class="credits"> <p class="dwt_author">D.R. Coyle; D.C. Booth: M.S. Wallace</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">243</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Wind disturbance has been a frequently overlooked abiotic cause of mass <span class="hlt">tree</span> mortality in the Amazon basin. In the Peruvian Amazon these wind disturbances are produced by meteorological events such as convective systems. Downbursts for example produce short term descendent wind speeds that can be in excess of 30 m s-1. These are capable of producing <span class="hlt">tree</span> blowdowns which have been reported to be as large as 33 km2 in the Amazon basin. We used the chronosequence of Landsat Satellite imagery to find and locate where these blowdowns have occurred in the Loreto region of the Peruvian Amazon. Spectral Mixture Analysis was used to estimate the proportion landcover of green vegetation, non-photosynthetic vegetation (NPV), soil and shade in each pixel. The change in NPV was calculated by subtracting the NPV signal in the Landsat image prior to the blowdown occurrence, from the image following the disturbance. Our prior research has established a linear relationship between <span class="hlt">tree</span> mortality and change in NPV. It is hypothesized that these mass <span class="hlt">tree</span> mortality events result in changes in the <span class="hlt">tree</span> <span class="hlt">species</span> assemblage of affected forests. Here we present preliminary <span class="hlt">tree</span> <span class="hlt">species</span> assemblage data from two sites in the Peruvian Amazon near Iquitos, Peru. The site (ALP) at the Allpahuayo Mishana reserve (3.945 S, 73.455 W) is 30 km south of Iquitos, Peru, and hosts the remnants of a 50 ha blowdown that occurred in either 1992 or 1993. Another site (NAPO) on the Napo river about 60 km north of Iquitos, is the location of an approximately 300 ha blowdown that occurred in 1998. At each site, a 3000 m x 10 m transect encompassing non disturbed and disturbed areas was installed, and <span class="hlt">trees</span> greater than 10 cm diameter at breast height were measured for diameter, height and were identified to the <span class="hlt">species</span>. Stem density of <span class="hlt">trees</span> with diameter at breast height > 10 cm, and <span class="hlt">tree</span> height appear to be similar both inside and outside the blowdown affected areas of the forests at both sites. At the ALP and NAPO sites the most dramatic change in the <span class="hlt">tree</span> <span class="hlt">species</span> assemblage has been a three and an eleven fold increase in the pioneer <span class="hlt">tree</span> family, Cecropiaceae, respectively. This preliminary data suggests that wind disturbance is capable of producing large shifts in the <span class="hlt">tree</span> <span class="hlt">species</span> assemblage of affected Amazon forests.</p> <div class="credits"> <p class="dwt_author">Rifai, S. W.; Chambers, J. Q.; Negron Juarez, R. I.; Ramirez, F.; Tello, R.; Alegria Muñoz, W.</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">244</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/12650343"> <span id="translatedtitle">Survival and development of Lymantria monacha (Lepidoptera: Lymantriidae) on North American and introduced Eurasian <span class="hlt">tree</span> <span class="hlt">species</span>.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Lymantria monacha (L.) (Lepidoptera: Lymantriidae), the nun moth, is a Eurasian pest of conifers that has potential for accidental introduction into North America. To project the potential host range of this insect if introduced into North America, survival and development of L. monacha on 26 North American and eight introduced Eurasian <span class="hlt">tree</span> <span class="hlt">species</span> were examined. Seven conifer <span class="hlt">species</span> (Abies concolor, Picea abies, P. glauca, P. pungens, Pinus sylvestris with male cones, P. menziesii variety glance, and Tsuga canadensis) and six broadleaf <span class="hlt">species</span> (Betula populifolia, Malus x domestica, Prunus serotiaa, Quercus lobata, Q. rubra, and Q. velutina) were suitable for L. monacha survival and development. Eleven of the host <span class="hlt">species</span> tested were rated as intermediate in suitability, four conifer <span class="hlt">species</span> (Larix occidentalis, P. nigra, P. ponderosa, P. strobus, and Pseudotsuga menziesii variety menziesii) and six broadleaf <span class="hlt">species</span> (Carpinus caroliniana, Carya ovata, Fagus grandifolia, Populus grandidentata, Q. alba, and Tilia cordata) and the remaining 10 <span class="hlt">species</span> tested were rated as poor (Acer rubrum, A. platanoidies, A. saccharum, F. americana, Juniperus virginiana, Larix kaempferi, Liriodendron tulipfera, Morus alba, P. taeda, and P. deltoides). The phenological state of the <span class="hlt">trees</span> had a major impact on establishment, survival, and development of L. monacha on many of the <span class="hlt">tree</span> <span class="hlt">species</span> tested. Several of the deciduous <span class="hlt">tree</span> <span class="hlt">species</span> that are suitable for L. monacha also are suitable for L. dispar (L.) and L. mathura Moore. Establishment of L. monacha in North America would be catastrophic because of the large number of economically important <span class="hlt">tree</span> <span class="hlt">species</span> on which it can survive and develop, and the ability of mated females to fly and colonize new areas. PMID:12650343</p> <div class="credits"> <p class="dwt_author">Keena, M A</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-02-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">245</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Ratiarison, Sandra; Forget, Pierre-Michel</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-09-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">246</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3630193"> <span id="translatedtitle"><span class="hlt">Tree</span> <span class="hlt">Species</span> Composition Influences Enzyme Activities and Microbial Biomass in the Rhizosphere: A Rhizobox Approach</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Monoculture causes nutrient losses and leads to declines in soil fertility and biomass production over successive cultivation. The rhizosphere, a zone of usually high microbial activities and clearly distinct from bulk soil, is defined as the volume of soil around living roots and influenced by root activities. Here we investigated enzyme activities and microbial biomass in the rhizosphere under different <span class="hlt">tree</span> compositions. Six treatments with poplar, willow, and alder mono- or mixed seedlings were grown in rhizoboxes. Enzyme activities associated with nitrogen cycling and microbial biomass were measured in all rhizosphere and bulk soils. Both enzyme activities and microbial biomass in the rhizosphere differed significantly <span class="hlt">tree</span> compositions. Microbial biomass contents were more sensitive to the changes of the rhizosphere environment than enzyme activities. <span class="hlt">Tree</span> <span class="hlt">species</span> coexistence did not consistently increase tested enzyme activities and microbial biomass, but varied depending on the complementarities of <span class="hlt">species</span> traits. In general, impacts of <span class="hlt">tree</span> <span class="hlt">species</span> and coexistence were more pronounced on microbial composition than total biomass, evidenced by differences in microbial biomass C/N ratios stratified across the rhizosphere soils. Compared to poplar clone monoculture, other <span class="hlt">tree</span> <span class="hlt">species</span> addition obviously increased rhizosphere urease activity, but greatly reduced rhizosphere L-asparaginase activity. Poplar growth was enhanced only when coexisted with alder. Our results suggested that a highly productive or keystone plant <span class="hlt">species</span> in a community had greater influence over soil functions than the contribution of diversity. PMID:23637838</p> <div class="credits"> <p class="dwt_author">Fang, Shengzuo; Liu, Dong; Tian, Ye; Deng, Shiping; Shang, Xulan</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">247</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">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 class="dwt_publisher"></p> <p class="publishDate">2014-12-22</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">248</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4240985"> <span id="translatedtitle">Multiple <span class="hlt">species</span> of wild <span class="hlt">tree</span> peonies gave rise to the ‘king of flowers’, Paeonia suffruticosa Andrews</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">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 class="dwt_publisher"></p> <p class="publishDate">2014-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">249</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19690000403&hterms=titration&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dtitration"> <span id="translatedtitle">Novel <span class="hlt">multipurpose</span> timer for laboratories</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary"><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> <div class="credits"> <p class="dwt_author">Eisler, W. J.; Klein, P. D.</p> <p class="dwt_publisher"></p> <p class="publishDate">1969-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">250</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ualberta.ca/~fhe/He-publications/Volkov.Nature05.pdf"> <span id="translatedtitle">2005 Nature Publishing Group Density dependence explains <span class="hlt">tree</span> <span class="hlt">species</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p class="result-summary">of the current neutral theory in ecology3­10 can easily be generalized to incorporate symmetric density is that seeds that disperse farther away from the maternal parent are more likely to escape mortality from host-dependent deaths are then exploited by less-common <span class="hlt">species</span>. Therefore, among-<span class="hlt">species</span> frequency dependence</p> <div class="credits"> <p class="dwt_author">He, Fangliang</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">251</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/40153400"> <span id="translatedtitle">Different photosynthesis-nitrogen relations in deciduous hardwood and evergreen coniferous <span class="hlt">tree</span> <span class="hlt">species</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The relationship between photosynthetic capacity (Amax) and leaf nitrogen concentration (N) among all C3 <span class="hlt">species</span> can be described roughly with one general equation, yet within that overall pattern <span class="hlt">species</span> groups or individual <span class="hlt">species</span> may have markedly different Amax-N relationships. To determine whether one or several predictive, fundamental Amax-N relationships exist for temperate <span class="hlt">trees</span> we measured Amax, specific leaf area (SLA)</p> <div class="credits"> <p class="dwt_author">P. B. Reich; M. B. Walters; B. D. Kloeppel; D. S. Ellsworth</p> <p class="dwt_publisher"></p> <p class="publishDate">1995-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">252</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.springerlink.com/index/p6k368415j220172.pdf"> <span id="translatedtitle">Shade does not ameliorate drought effects on the <span class="hlt">tree</span> fern <span class="hlt">species</span> Dicksonia antarctica and Cyathea australis</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">We examined the responses of two <span class="hlt">tree</span> fern <span class="hlt">species</span> (Dicksonia antarctica and Cyathea australis) growing under moderate and high light regimes to short-term water deficit followed by rewatering. Under adequate water supply,\\u000a morphological and photosynthetic characteristics differed between <span class="hlt">species</span>. D. antarctica, although putatively the more shade and less drought adapted <span class="hlt">species</span>, had greater chlorophyll a\\/b ratio, and greater water use</p> <div class="credits"> <p class="dwt_author">Liubov VolkovaLauren; Lauren T. Bennett; Andrew Merchant; Michael Tausz</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">253</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.fs.fed.us/nrs/atlas/"> <span id="translatedtitle">A Climate Change Atlas For 80 Forest <span class="hlt">Tree</span> <span class="hlt">Species</span> Of The Eastern United States</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://nsdl.org/nsdl_dds/services/ddsws1-1/service_explorer.jsp">NSDL National Science Digital Library</a></p> <p class="result-summary">This is a <span class="hlt">tree</span> <span class="hlt">species</span> distribution atlas. It contains information for 80 <span class="hlt">species</span> in the eastern half of the United States (east of the 100th meridian). The site contains distribution maps and tables for different climate change scenarios, life-history and disturbance attributes, ecological attributes, forest type maps, sorted lists of <span class="hlt">species</span> importance values (by state and county) for different climate change scenarios, and more.</p> <div class="credits"> <p class="dwt_author">Iverson, Louis</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">254</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.personal.psu.edu/faculty/a/g/agl/Black_et_al_2009_AFS.pdf"> <span id="translatedtitle">Properties of boundary-line release criteria in North American <span class="hlt">tree</span> <span class="hlt">species</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">– \\u000a \\u000a • Boundary line release criteria are increasingly applied to evaluate forest disturbance histories from <span class="hlt">tree</span>-ring data. However,\\u000a a number of important properties central to the technique have not been evaluated, including: (i) the ability of boundary\\u000a line release criteria to standardize releases across various sites, <span class="hlt">species</span>, and <span class="hlt">tree</span> life stages (ii) the minimum sample\\u000a sizes necessary for developing boundary</p> <div class="credits"> <p class="dwt_author">Bryan A. Black; Marc D. Abrams; James S. Rentch; Peter J. Gould</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">255</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://pubs.er.usgs.gov/publication/5211165"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Twedt, D.J.; Wilson, R.R.</p> <p class="dwt_publisher"></p> <p class="publishDate">2002-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">256</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013JARS....7.3502F"> <span id="translatedtitle">Analyzing the spectral variability of tropical <span class="hlt">tree</span> <span class="hlt">species</span> using hyperspectral feature selection and leaf optical modeling</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Hyperspectral remote sensing can provide information about <span class="hlt">species</span> richness over large areas and may be useful for <span class="hlt">species</span> discrimination in tropical environments. Here, we analyze the main sources of variability in leaf spectral signatures of tropical <span class="hlt">trees</span> and examine the potential of spectroscopic reflectance measurements (450 to 2450 nm) for <span class="hlt">tree</span> <span class="hlt">species</span> discrimination. We assess within- and among-<span class="hlt">species</span> spectral variability and perform a feature selection procedure to identify wavebands in which the <span class="hlt">species</span> most differ from each other. We assess the discriminative power of these wavebands by calculating a separability index and then classifying the <span class="hlt">species</span>. Finally, leaf chemical and structural parameters of each <span class="hlt">species</span> are retrieved by inversion of the leaf optical model PROSPECT-5. Among-<span class="hlt">species</span> spectral variability is almost five times greater than within-<span class="hlt">species</span> spectral variability. The feature selection procedure reveals that wavebands, where <span class="hlt">species</span> most differ, are located at the visible, red edge, and shortwave infrared regions. Classification of the <span class="hlt">species</span> using these wavebands reaches 96% overall accuracy. Leaf chemical and structural properties retrieve by model inversion show that differences in leaf pigment concentrations and leaf internal structure are the most important parameters controlling the spectral variability of <span class="hlt">species</span>. These parameters also contribute to the variation in red edge position among <span class="hlt">species</span>.</p> <div class="credits"> <p class="dwt_author">Ferreira, Matheus Pinheiro; Grondona, Atilio Efrain Bica; Rolim, Silvia Beatriz Alves; Shimabukuro, Yosio Edemir</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">257</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/18959329"> <span id="translatedtitle"><span class="hlt">Tree</span> <span class="hlt">species</span> control rates of free-living nitrogen fixation in a tropical rain forest.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Tropical rain forests represent some of the most diverse ecosystems on earth, yet mechanistic links between <span class="hlt">tree</span> <span class="hlt">species</span> identity and ecosystem function in these forests remains poorly understood. Here, using free-living nitrogen (N) fixation as a model, we explore the idea that interspecies variation in canopy nutrient concentrations may drive significant local-scale variation in biogeochemical processes. Biological N fixation is the largest "natural" source of newly available N to terrestrial ecosystems, and estimates suggest the highest such inputs occur in tropical ecosystems. While patterns of and controls over N fixation in these systems remain poorly known, the data we do have suggest that chemical differences among <span class="hlt">tree</span> <span class="hlt">species</span> canopies could affect free-living N fixation rates. In a diverse lowland rain forest in Costa Rica, we established a series of vertical, canopy-to-soil profiles for six common canopy <span class="hlt">tree</span> <span class="hlt">species</span>, and we measured free-living N fixation rates and multiple aspects of chemistry of live canopy leaves, senesced canopy leaves, bulk leaf litter, and soil for eight individuals of each <span class="hlt">tree</span> <span class="hlt">species</span>. Free-living N fixation rates varied significantly among <span class="hlt">tree</span> <span class="hlt">species</span> for all four components, and independent of <span class="hlt">species</span> identity, rates of N fixation ranged by orders of magnitude along the vertical profile. Our data suggest that variations in phosphorus (P) concentration drove a significant fraction of the observed <span class="hlt">species</span>-specific variation in free-living N fixation rates within each layer of the vertical profile. Furthermore, our data suggest significant links between canopy and forest floor nutrient concentrations; canopy P was correlated with bulk leaf litter P below individual <span class="hlt">tree</span> crowns. Thus, canopy chemistry may affect a suite of ecosystem processes not only within the canopy itself, but at and beneath the forest floor as well. PMID:18959329</p> <div class="credits"> <p class="dwt_author">Reed, Sasha C; Cleveland, Cory C; Townsend, Alan R</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-10-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">258</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/23632032"> <span id="translatedtitle"><span class="hlt">Species</span> <span class="hlt">tree</span> reconstruction of a poorly resolved clade of salamanders (Ambystomatidae) using multiple nuclear loci.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">The analysis of diverse data sets can yield different phylogenetic estimates that challenge systematists to explain the source of discordance. The mole salamanders (family Ambystomatidae) are a classic example of this phylogenetic conflict. Previous attempts to resolve the ambystomatid <span class="hlt">species</span> <span class="hlt">tree</span> using allozymic, morphological, and mitochondrial sequence data have yielded different estimates, making it unclear which data source best approximates ambystomatid phylogeny and which ones yield phylogenetically inaccurate reconstructions. To shed light on this conflict, we present the first multi-locus DNA sequence-based phylogenetic study of the Ambystomatidae. We utilized a range of analyses, including coalescent-based methods of <span class="hlt">species-tree</span> estimation that account for incomplete lineage sorting within a locus and concordance-based methods that estimate the number of sampled loci that support a particular clade. We repeated these analyses with the removal of individual loci to determine if any locus has a disproportionate effect on our phylogenetic results. Collectively, these results robustly resolved many deep and relatively shallow clades within Ambystoma, including the placement of A. gracile and A. talpoideum as the sister clade to a clade containing all remaining ambystomatids, and the placement of A. maculatum as the sister lineage to all remaining ambystomatids excluding A. gracile and A. talpoideum. Both Bayesian coalescent and concordance methods produced similar results, highlighting strongly supported branches in the <span class="hlt">species</span> <span class="hlt">tree</span>. Furthermore, coalescent-based analyses that excluded loci produced overlapping <span class="hlt">species-tree</span> posterior distributions, suggesting that no particular locus--including mtDNA--disproportionately contributed to our <span class="hlt">species-tree</span> estimates. Overall, our phylogenetic estimates have greater similarity with previous allozyme and mitochondrial sequence-based phylogenetic estimates. However, intermediate depths of divergence in the ambystomatid <span class="hlt">species</span> <span class="hlt">tree</span> remain unresolved, potentially highlighting a region of rapid <span class="hlt">species</span> radiation or a hard polytomy, which limits our ability to comment on previous morphologically-based taxonomic groups. PMID:23632032</p> <div class="credits"> <p class="dwt_author">Williams, Joshua S; Niedzwiecki, John H; Weisrock, David W</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-09-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">259</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.uncg.edu/~eplacey/Moore&Lacey.pdf"> <span id="translatedtitle">A Comparison of Germination and Early Growth of Four Early Successional <span class="hlt">Tree</span> <span class="hlt">Species</span> of the Southeastern United States in</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p class="result-summary">A Comparison of Germination and Early Growth of Four Early Successional <span class="hlt">Tree</span> <span class="hlt">Species</span> experiment comparing the germination and early seedling growth of four early successional <span class="hlt">tree</span> <span class="hlt">species</span> found for the experiment. Liquidambar and Platanus, the native <span class="hlt">species</span>, germinated significantly more quickly and were more</p> <div class="credits"> <p class="dwt_author">Lacey, Elizabeth P.</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">260</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2011LNCS.6398...93D"> <span id="translatedtitle">An Efficient Algorithm for Gene/<span class="hlt">Species</span> <span class="hlt">Trees</span> Parsimonious Reconciliation with Losses, Duplications and Transfers</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary"><span class="hlt">Tree</span> reconciliation methods aim at estimating the evolutionary events that cause discrepancy between gene <span class="hlt">trees</span> and <span class="hlt">species</span> <span class="hlt">trees</span>. We provide a discrete computational model that considers duplications, transfers and losses of genes. The model yields a fast and exact algorithm to infer time consistent and most parsimonious reconciliations. Then we study the conditions under which parsimony is able to accurately infer such events. Overall, it performs well even under realistic rates, transfers being in general less accurately recovered than duplications. An implementation is freely available at http://www.atgc-montpellier.fr/MPR.</p> <div class="credits"> <p class="dwt_author">Doyon, Jean-Philippe; Scornavacca, Celine; Gorbunov, K. Yu.; Szöll?si, Gergely J.; Ranwez, Vincent; Berry, Vincent</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_12");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a 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href="#">11</a> <a onClick='return showDiv("page_12");' href="#">12</a> <a onClick='return showDiv("page_13");' href="#">13</a> <a style="font-weight: bold;">14</a> <a onClick='return showDiv("page_15");' href="#">15</a> <a onClick='return showDiv("page_16");' href="#">16</a> <a onClick='return showDiv("page_17");' href="#">17</a> <a onClick='return showDiv("page_18");' href="#">18</a> <a onClick='return showDiv("page_19");' href="#">19</a> <a onClick='return showDiv("page_20");' href="#">20</a> <a onClick='return showDiv("page_21");' href="#">21</a> <a onClick='return showDiv("page_22");' href="#">22</a> <a onClick='return showDiv("page_23");' href="#">23</a> <a onClick='return showDiv("page_24");' href="#">24</a> <a onClick='return showDiv("page_25");' href="#">25</a> </span> </span> <a id="NextPageLink" onclick='return showDiv("page_15");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">261</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20010004212&hterms=Trees&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DTrees"> <span id="translatedtitle">BOREAS TE-4 Branch Bag Data From Boreal <span class="hlt">Tree</span> <span class="hlt">Species</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Hall, Forrest G. (Editor); Papagno, Andrea (Editor); Berry, Joseph A.; Fu, Wei; Fredeen, Art; Gamon, John</p> <p class="dwt_publisher"></p> <p class="publishDate">2000-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">262</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2954149"> <span id="translatedtitle">Influences of Forest Structure, Climate and <span class="hlt">Species</span> Composition on <span class="hlt">Tree</span> Mortality across the Eastern US</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Few studies have quantified regional variation in <span class="hlt">tree</span> mortality, or explored whether <span class="hlt">species</span> compositional changes or within-<span class="hlt">species</span> variation are responsible for regional patterns, despite the fact that mortality has direct effects on the dynamics of woody biomass, <span class="hlt">species</span> composition, stand structure, wood production and forest response to climate change. Using Bayesian analysis of over 430,000 <span class="hlt">tree</span> records from a large eastern US forest database we characterised <span class="hlt">tree</span> mortality as a function of climate, soils, <span class="hlt">species</span> and size (stem diameter). We found (1) mortality is U-shaped vs. stem diameter for all 21 <span class="hlt">species</span> examined; (2) mortality is hump-shaped vs. plot basal area for most <span class="hlt">species</span>; (3) geographical variation in mortality is substantial, and correlated with several environmental factors; and (4) individual <span class="hlt">species</span> vary substantially from the combined average in the nature and magnitude of their mortality responses to environmental variation. Regional variation in mortality is therefore the product of variation in <span class="hlt">species</span> composition combined with highly varied mortality-environment correlations within <span class="hlt">species</span>. The results imply that variation in mortality is a crucial part of variation in the forest carbon cycle, such that including this variation in models of the global carbon cycle could significantly narrow uncertainty in climate change predictions. PMID:20967250</p> <div class="credits"> <p class="dwt_author">Lines, Emily R.; Coomes, David A.; Purves, Drew W.</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">263</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Liu, Guifeng; Yang, Chuanping; Zhao, Guangyi</p> <p class="dwt_publisher"></p> <p class="publishDate">2002-11-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">264</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014IJAEO..28..140G"> <span id="translatedtitle">Forest <span class="hlt">tree</span> <span class="hlt">species</span> discrimination in western Himalaya using EO-1 Hyperion</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The information acquired in the narrow bands of hyperspectral remote sensing data has potential to capture plant <span class="hlt">species</span> spectral variability, thereby improving forest <span class="hlt">tree</span> <span class="hlt">species</span> mapping. This study assessed the utility of spaceborne EO-1 Hyperion data in discrimination and classification of broadleaved evergreen and conifer forest <span class="hlt">tree</span> <span class="hlt">species</span> in western Himalaya. The pre-processing of 242 bands of Hyperion data resulted into 160 noise-free and vertical stripe corrected reflectance bands. Of these, 29 bands were selected through step-wise exclusion of bands (Wilk's Lambda). Spectral Angle Mapper (SAM) and Support Vector Machine (SVM) algorithms were applied to the selected bands to assess their effectiveness in classification. SVM was also applied to broadband data (Landsat TM) to compare the variation in classification accuracy. All commonly occurring six gregarious <span class="hlt">tree</span> <span class="hlt">species</span>, viz., white oak, brown oak, chir pine, blue pine, cedar and fir in western Himalaya could be effectively discriminated. SVM produced a better <span class="hlt">species</span> classification (overall accuracy 82.27%, kappa statistic 0.79) than SAM (overall accuracy 74.68%, kappa statistic 0.70). It was noticed that classification accuracy achieved with Hyperion bands was significantly higher than Landsat TM bands (overall accuracy 69.62%, kappa statistic 0.65). Study demonstrated the potential utility of narrow spectral bands of Hyperion data in discriminating <span class="hlt">tree</span> <span class="hlt">species</span> in a hilly terrain.</p> <div class="credits"> <p class="dwt_author">George, Rajee; Padalia, Hitendra; Kushwaha, S. P. S.</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-05-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">265</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4110017"> <span id="translatedtitle">Negative Density Dependence Regulates Two <span class="hlt">Tree</span> <span class="hlt">Species</span> at Later Life Stage in a Temperate Forest</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Piao, Tiefeng; Chun, Jung Hwa; Yang, Hee Moon; Cheon, Kwangil</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">266</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Devi, N Linthoingambi; Das, Ashesh Kumar</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-03-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">267</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/24588709"> <span id="translatedtitle">Interpreting <span class="hlt">species</span>-specific variation in <span class="hlt">tree</span>-ring oxygen isotope ratios among three temperate forest <span class="hlt">trees</span>.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Although considerable variation has been documented in <span class="hlt">tree</span>-ring cellulose oxygen isotope ratios (?(18)O(cell)) among co-occurring <span class="hlt">species</span>, the underlying causes are unknown. Here, we used a combination of field measurements and modelling to investigate the mechanisms behind variations in late-wood ?(18) O(cell) (?(18)O(lc)) among three co-occurring <span class="hlt">species</span> (chestnut oak, black oak and pitch pine) in a temperate forest. For two growing seasons, we quantified among-<span class="hlt">species</span> variation in ?(18)O(lc), as well as several variables that could potentially cause the ?(18)O(lc) variation. Data analysis based on the ?(18) O(cell) model rules out leaf water enrichment (?(18)O(lw)) and <span class="hlt">tree</span>-ring formation period (?t), but highlights source water ?(18) O (?(18) O(sw)) as an important driver for the measured difference in ?(18)O(lc) between black and chestnut oak. However, the enriched ?(18)O(lc) in pitch pine relative to the oaks could not be sufficiently explained by consideration of the above three variables only, but rather, we show that differences in the proportion of oxygen exchange during cellulose synthesis (p(ex)) is most likely a key mechanism. Our demonstration of the relevance of some <span class="hlt">species</span>-specific features (or lack thereof) to ?(18)O(cell) has important implications for isotope based ecophysiological/paleoclimate studies. PMID:24588709</p> <div class="credits"> <p class="dwt_author">Song, Xin; Clark, Kenneth S; Helliker, Brent R</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-09-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">268</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3641141"> <span id="translatedtitle">A Phylogenetic Perspective on the Individual <span class="hlt">Species</span>-Area Relationship in Temperate and Tropical <span class="hlt">Tree</span> Communities</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Ecologists have historically used <span class="hlt">species</span>-area relationships (SARs) as a tool to understand the spatial distribution of <span class="hlt">species</span>. Recent work has extended SARs to focus on individual-level distributions to generate individual <span class="hlt">species</span> area relationships (ISARs). The ISAR approach quantifies whether individuals of a <span class="hlt">species</span> tend have more or less <span class="hlt">species</span> richness surrounding them than expected by chance. By identifying richness ‘accumulators’ and ‘repellers’, respectively, the ISAR approach has been used to infer the relative importance of abiotic and biotic interactions and neutrality. A clear limitation of the SAR and ISAR approaches is that all <span class="hlt">species</span> are treated as evolutionarily independent and that a large amount of work has now shown that local <span class="hlt">tree</span> neighborhoods exhibit non-random phylogenetic structure given the <span class="hlt">species</span> richness. Here, we use nine tropical and temperate forest dynamics plots to ask: (i) do ISARs change predictably across latitude?; (ii) is the phylogenetic diversity in the neighborhood of <span class="hlt">species</span> accumulators and repellers higher or lower than that expected given the observed <span class="hlt">species</span> richness?; and (iii) do <span class="hlt">species</span> accumulators, repellers distributed non-randomly on the community phylogenetic <span class="hlt">tree</span>? The results indicate no clear trend in ISARs from the temperate zone to the tropics and that the phylogenetic diversity surrounding the individuals of <span class="hlt">species</span> is generally only non-random on very local scales. Interestingly the distribution of <span class="hlt">species</span> accumulators and repellers was non-random on the community phylogenies suggesting the presence of phylogenetic signal in the ISAR across latitude. PMID:23650553</p> <div class="credits"> <p class="dwt_author">Yang, Jie; Swenson, Nathan G.; Cao, Min; Chuyong, George B.; Ewango, Corneille E. N.; Howe, Robert; Kenfack, David; Thomas, Duncan; Wolf, Amy; Lin, Luxiang</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">269</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://pubs.er.usgs.gov/publication/70004657"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p class="result-summary">Ecosystem level studies identify plant soil feed backs as important controls on soil nutrient availability,particularly for nitrogen and phosphorus. Although site and <span class="hlt">species</span> specific studies of <span class="hlt">tree</span> <span class="hlt">species</span> soil relationships are relatively common,comparatively fewer studies consider multiple coexisting speciesin old-growth forests across a range of sites that vary underlying soil fertility. We characterized patterns in forest floor and mineral soil nutrients associated with four common <span class="hlt">tree</span> <span class="hlt">species</span> across eight undisturbed old-growth forests in Oregon, USA, and used two complementary conceptual models to assess <span class="hlt">tree</span> <span class="hlt">species</span> soil relationships. Plant soil feedbacks that could reinforce sitelevel differences in nutrient availability were assessed using the context dependent relationships model, where by relative <span class="hlt">species</span> based differences in each soil nutrient divergedorconvergedas nutrient status changed across sites. <span class="hlt">Tree</span> <span class="hlt">species</span> soil relationships that did not reflect strong feedbacks were evaluated using a site independent relationships model, where by forest floor and surface mineral soil nutrient tools differed consistently by <span class="hlt">tree</span> <span class="hlt">species</span> across sites,without variation in deeper mineral soils. We found that theorganically cycled elements carbon, nitrogen, and phosphorus exhibited context-dependent differences among <span class="hlt">species</span> in both forest floor and mineral soil, and most of ten followed adivergence model,where by <span class="hlt">species</span> differences were greatest at high-nutrient sites. These patterns are consistent with the oryemphasizing biotic control of these elements through plant soil feedback mechanisms. Site independent <span class="hlt">species</span> differences were strongest for pool so if the weather able cations calcium, magnesium, potassium,as well as phosphorus, in mineral soils. Site independent <span class="hlt">species</span> differences in forest floor nutrients we reattributable too nespecies that displayed significant greater forest floor mass accumulation. Our finding confirmed that site-independent and context-dependent <span class="hlt">tree</span> <span class="hlt">species</span>-soil relationships occur simultaneouslyinold-grow the temperate forests, with context-dependent relationships strongest for organically cycled elements, and site-independent relationships strongest for weather able elements with in organic cycling phases. These models provide complementary explanations for patterns of nutrient accumulation and cycling in mixed <span class="hlt">species</span> old-growth temperate forests.</p> <div class="credits"> <p class="dwt_author">Cross, Alison; Perakis, Steven S.</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">270</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013SPIE.8921E..07D"> <span id="translatedtitle">Forest <span class="hlt">tree</span> <span class="hlt">species</span> clssification based on airborne hyper-spectral imagery</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Forest precision classification products were the basic data for surveying of forest resource, updating forest subplot information, logging and design of forest. However, due to the diversity of stand structure, complexity of the forest growth environment, it's difficult to discriminate forest <span class="hlt">tree</span> <span class="hlt">species</span> using multi-spectral image. The airborne hyperspectral images can achieve the high spatial and spectral resolution imagery of forest canopy, so it will good for <span class="hlt">tree</span> <span class="hlt">species</span> level classification. The aim of this paper was to test the effective of combining spatial and spectral features in airborne hyper-spectral image classification. The CASI hyper spectral image data were acquired from Liangshui natural reserves area. Firstly, we use the MNF (minimum noise fraction) transform method for to reduce the hyperspectral image dimensionality and highlighting variation. And secondly, we use the grey level co-occurrence matrix (GLCM) to extract the texture features of forest <span class="hlt">tree</span> canopy from the hyper-spectral image, and thirdly we fused the texture and the spectral features of forest canopy to classify the <span class="hlt">trees</span> <span class="hlt">species</span> using support vector machine (SVM) with different kernel functions. The results showed that when using the SVM classifier, MNF and texture-based features combined with linear kernel function can achieve the best overall accuracy which was 85.92%. It was also confirm that combine the spatial and spectral information can improve the accuracy of <span class="hlt">tree</span> <span class="hlt">species</span> classification.</p> <div class="credits"> <p class="dwt_author">Dian, Yuanyong; Li, Zengyuan; Pang, Yong</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-10-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">271</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/25813032"> <span id="translatedtitle">Statistical analysis of texture in trunk images for biometric identification of <span class="hlt">tree</span> <span class="hlt">species</span>.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">The identification of <span class="hlt">tree</span> <span class="hlt">species</span> is a key step for sustainable management plans of forest resources, as well as for several other applications that are based on such surveys. However, the present available techniques are dependent on the presence of <span class="hlt">tree</span> structures, such as flowers, fruits, and leaves, limiting the identification process to certain periods of the year. Therefore, this article introduces a study on the application of statistical parameters for texture classification of <span class="hlt">tree</span> trunk images. For that, 540 samples from five Brazilian native deciduous <span class="hlt">species</span> were acquired and measures of entropy, uniformity, smoothness, asymmetry (third moment), mean, and standard deviation were obtained from the presented textures. Using a decision <span class="hlt">tree</span>, a biometric <span class="hlt">species</span> identification system was constructed and resulted to a 0.84 average precision rate for <span class="hlt">species</span> classification with 0.83accuracy and 0.79 agreement. Thus, it can be considered that the use of texture presented in trunk images can represent an important advance in <span class="hlt">tree</span> identification, since the limitations of the current techniques can be overcome. PMID:25813032</p> <div class="credits"> <p class="dwt_author">Bressane, Adriano; Roveda, José A F; Martins, Antônio C G</p> <p class="dwt_publisher"></p> <p class="publishDate">2015-04-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">272</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014EnMan..53..783S"> <span id="translatedtitle">The Right <span class="hlt">Tree</span> for the Job? Perceptions of <span class="hlt">Species</span> Suitability for the Provision of Ecosystem Services</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Smaill, Simeon J.; Bayne, Karen M.; Coker, Graham W. R.; Paul, Thomas S. H.; Clinton, Peter W.</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-04-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">273</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Rodríguez-Calcerrada, Jesús; López, Rosana; Salomón, Roberto; Gordaliza, Guillermo G; Valbuena-Carabaña, María; Oleksyn, Jacek; Gil, Luis</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-10-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">274</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/16405190"> <span id="translatedtitle">[The role of historical processes in determining <span class="hlt">tree</span> <span class="hlt">species</span> richness in the forests of Western Caucasus].</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">To estimate the role of history in variation of <span class="hlt">tree</span> <span class="hlt">species</span> richness in the forests of the Western Caucasus we analyzed correlation between their local richness (S--the mean number of <span class="hlt">species</span> per 300 m2) and size of actual <span class="hlt">species</span> pool (N--the number of <span class="hlt">species</span> per 1 ha). If compared communities are differently distant from the point of evolutionary equilibrium one should expect a significant variation in correlation between S and N (determined with the greater sensitivity of N than S in respect of historical factors). The lower value of N/S corresponds to less saturated level of historically determined <span class="hlt">species</span> richness. A mean N/S ratio in Japana temperate broadleaved forests (Masaki et al., 1999) provided the basis for analysis. The present <span class="hlt">tree</span> <span class="hlt">species</span> richness of the forest communities in the 1 ha plots seem essentially determined by the historical processes. The mountain forest communities of Western Caucasus are characterized on the average with lower saturation level of the actual <span class="hlt">tree</span> <span class="hlt">species</span> pool in comparison with the Japan temperate broad-leaved forest communities. On the Western Caucasus the middle mountain beech and coniferous-broadleaved communities (400-1600 m a.s.l.) are characterized with the higher saturation level of the actual <span class="hlt">species</span> pool in comparison with communities located lower and higher. These results confirm published historical reconstructions, according to which the middle mountain forest communities in the Western Caucasus are older than forests located higher or lower. Present low mountain forests of the southern (to Black Sea) and the northern macroslopes of the Western Caucasus are characterized with similar saturation level of the actual <span class="hlt">species</span> pool. These data agree with the assumption of Dolukhanov (1980) that low mountain zone of the southern macroslope was not a refuge for <span class="hlt">tree</span> <span class="hlt">species</span> in Pleistocene. PMID:16405190</p> <div class="credits"> <p class="dwt_author">Akatov, V V; Chefranov, S G; Akatova, T V</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">275</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Wielstra, Ben; Arntzen, Jan W.; van der Gaag, Kristiaan J.; Pabijan, Maciej; Babik, Wieslaw</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">276</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary"><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> <div class="credits"> <p class="dwt_author">Van Nevel, Lotte; Mertens, Jan; De Schrijver, An; Baeten, Lander; De Neve, Stefaan; Tack, Filip M G; Meers, Erik; Verheyen, Kris</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-03-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">277</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.unm.edu/~pockman/pubs/storage.pdf"> <span id="translatedtitle">Summary <span class="hlt">Trees</span> of tropical semi-deciduous forests range from "drought-avoiding" stem-succulent <span class="hlt">species</span> with low-</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p class="result-summary">Summary <span class="hlt">Trees</span> of tropical semi-deciduous forests range from "drought-avoiding" stem, stem-succulent <span class="hlt">trees</span>, stem water storage, tropical dry forest. Introduction <span class="hlt">Trees</span> of tropical semi-deciduous) throughout the year, to "drought-tolerant" deciduous hardwood <span class="hlt">species</span>(wood density > 0.75 g cm­3 ), which</p> <div class="credits"> <p class="dwt_author">Pockman, William T.</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">278</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.plantsciences.ucdavis.edu/affiliates/north/Publications/Influence%20of%20fire%20and%20El%20Nino.pdf"> <span id="translatedtitle">Influence of Fire and El Nin~o on <span class="hlt">Tree</span> Recruitment Varies by <span class="hlt">Species</span> in Sierran Mixed Conifer</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p class="result-summary">fir and incense cedar (84%), including many large-diameter <span class="hlt">trees</span> ( 76 cm dbh), recruited afterInfluence of Fire and El Nin~o on <span class="hlt">Tree</span> Recruitment Varies by <span class="hlt">Species</span> in Sierran Mixed Conifer was the last widespread fire event, the mean interval between scars for an individual <span class="hlt">tree</span> was 17.3 years</p> <div class="credits"> <p class="dwt_author">North, Malcolm</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">279</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/57678619"> <span id="translatedtitle">Mature <span class="hlt">trees</span> as keystone structures in Holarctic ecosystems – a quantitative <span class="hlt">species</span> comparison in a northern English park</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Background: Mature <span class="hlt">trees</span> often provide ecological niches of value to specialised flora and fauna, signalled by such attributes as epiphytes, trunk rot and dead branches. In Britain, they are often found in parklands and wood pastures, which are rare habitats in Europe.Aims: As <span class="hlt">species</span> differences in veteran attributes of such <span class="hlt">trees</span> have not been studied, we surveyed eight Holarctic <span class="hlt">tree</span></p> <div class="credits"> <p class="dwt_author">Stephen J. G. Hall; Robert G. H. Bunce</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">280</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Biological diversity can be defined as variability among living organisms from all sources, including terrestrial organisms, marine and other aquatic ecosystems, and the ecological complexes which they are part of. This includes diversity within <span class="hlt">species</span>, between <span class="hlt">species</span>, and of ecosystems. Numerous diversity indices combine richness and evenness in a single expression, and several climate-based explanations have been proposed to explain broad-scale diversity patterns. However, climate-based water-energy dynamics appears to be an essential factor that determines patterns of diversity. The Mexican Sierra Madre Occidental occupies an area of about 29 million hectares and is located between the Neotropical and Holarctic ecozones. It shelters a high diversity of flora, including 24 different <span class="hlt">species</span> of Pinus (ca. 22% on the whole), 54 <span class="hlt">species</span> of Quercus (ca. 9-14%), 7 <span class="hlt">species</span> of Arbutus (ca. 50%) and many other <span class="hlt">trees</span> <span class="hlt">species</span>. The objectives of this study were to model how <span class="hlt">tree</span> <span class="hlt">species</span> diversity is related to climatic and geographic factors and stand density and to test the Metabolic Theory, Productivity-Diversity Hypothesis, Physiological Tolerance Hypothesis, Mid-Domain Effect, and the Water-Energy Dynamic Theory on the Sierra Madre Occidental, Durango. The results supported the Productivity-Diversity Hypothesis, Physiological Tolerance Hypothesis and Water-Energy Dynamic Theory, but not the Mid-Domain Effect or Metabolic Theory. The annual aridity index was the variable most closely related to the diversity indices analyzed. Contemporary climate was found to have moderate to strong effects on the minimum, median and maximum <span class="hlt">tree</span> <span class="hlt">species</span> diversity. Because water-energy dynamics provided a satisfactory explanation for the patterns of minimum, median and maximum diversity, an understanding of this factor is critical to future biodiversity research. Quantile regression of the data showed that the three diversity parameters of <span class="hlt">tree</span> <span class="hlt">species</span> are generally higher in cold, humid temperate climates than in dry, hot climates. PMID:25127455</p> <div class="credits"> <p class="dwt_author">Silva-Flores, Ramón; Pérez-Verdín, Gustavo; Wehenkel, Christian</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-01-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_13");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return 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title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">281</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Biological diversity can be defined as variability among living organisms from all sources, including terrestrial organisms, marine and other aquatic ecosystems, and the ecological complexes which they are part of. This includes diversity within <span class="hlt">species</span>, between <span class="hlt">species</span>, and of ecosystems. Numerous diversity indices combine richness and evenness in a single expression, and several climate-based explanations have been proposed to explain broad-scale diversity patterns. However, climate-based water-energy dynamics appears to be an essential factor that determines patterns of diversity. The Mexican Sierra Madre Occidental occupies an area of about 29 million hectares and is located between the Neotropical and Holarctic ecozones. It shelters a high diversity of flora, including 24 different <span class="hlt">species</span> of Pinus (ca. 22% on the whole), 54 <span class="hlt">species</span> of Quercus (ca. 9–14%), 7 <span class="hlt">species</span> of Arbutus (ca. 50%) and many other <span class="hlt">trees</span> <span class="hlt">species</span>. The objectives of this study were to model how <span class="hlt">tree</span> <span class="hlt">species</span> diversity is related to climatic and geographic factors and stand density and to test the Metabolic Theory, Productivity-Diversity Hypothesis, Physiological Tolerance Hypothesis, Mid-Domain Effect, and the Water-Energy Dynamic Theory on the Sierra Madre Occidental, Durango. The results supported the Productivity-Diversity Hypothesis, Physiological Tolerance Hypothesis and Water-Energy Dynamic Theory, but not the Mid-Domain Effect or Metabolic Theory. The annual aridity index was the variable most closely related to the diversity indices analyzed. Contemporary climate was found to have moderate to strong effects on the minimum, median and maximum <span class="hlt">tree</span> <span class="hlt">species</span> diversity. Because water-energy dynamics provided a satisfactory explanation for the patterns of minimum, median and maximum diversity, an understanding of this factor is critical to future biodiversity research. Quantile regression of the data showed that the three diversity parameters of <span class="hlt">tree</span> <span class="hlt">species</span> are generally higher in cold, humid temperate climates than in dry, hot climates. PMID:25127455</p> <div class="credits"> <p class="dwt_author">Silva-Flores, Ramón; Pérez-Verdín, Gustavo; Wehenkel, Christian</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">282</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/22367761"> <span id="translatedtitle">Patterns of root respiration rates and morphological traits in 13 <span class="hlt">tree</span> <span class="hlt">species</span> in a tropical forest.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">The root systems of forest <span class="hlt">trees</span> are composed of different diameters and heterogeneous physiological traits. However, the pattern of root respiration rates from finer and coarser roots across various tropical <span class="hlt">species</span> remains unknown. To clarify how respiration is related to the morphological traits of roots, we evaluated specific root respiration and its relationships to mean root diameter (D) of various diameter and root tissue density (RTD; root mass per unit root volume; gcm(-3)) and specific root length (SRL; root length per unit root mass; mg(-1)) of the fine roots among and within 14 <span class="hlt">trees</span> of 13 <span class="hlt">species</span> from a primary tropical rainforest in the Pasoh Forest Reserve in Peninsular Malaysia. Coarse root (2-269mm) respiration rates increased with decreasing D, resulting in significant relationships between root respiration and diameter across <span class="hlt">species</span>. A model based on a radial gradient of respiration rates of coarse roots simulated the exponential decrease in respiration with diameter. The respiration rate of fine roots (<2mm) was much higher and more variable than those of larger diameter roots. For fine roots, the mean respiration rates for each <span class="hlt">species</span> increased with decreasing D. The respiration rates of fine roots declined markedly with increasing RTD and increased with increasing SRL, which explained a significant portion of the variation in the respiration among the 14 <span class="hlt">trees</span> from 13 <span class="hlt">species</span> examined. Our results indicate that coarse root respiration in <span class="hlt">tree</span> <span class="hlt">species</span> follows a basic relationship with D across <span class="hlt">species</span> and that most of the variation in fine root respiration among <span class="hlt">species</span> is explained by D, RTD and SRL. We found that the relationship between root respiration and morphological traits provides a quantitative basis for separating fine roots from coarse roots and that the pattern holds across different <span class="hlt">species</span>. PMID:22367761</p> <div class="credits"> <p class="dwt_author">Makita, Naoki; Kosugi, Yoshiko; Dannoura, Masako; Takanashi, Satoru; Niiyama, Kaoru; Kassim, Abd Rahman; Nik, Abdul Rahim</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-03-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">283</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Cernusak, Lucas A; Aranda, Jorge; Marshall, John D; Winter, Klaus</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">284</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/22284170"> <span id="translatedtitle">Assessment of suitability of <span class="hlt">tree</span> <span class="hlt">species</span> for the production of biomass on trace element contaminated soils.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">To alleviate the demand on fertile agricultural land for production of bioenergy, we investigated the possibility of producing biomass for bioenergy on trace element (TE) contaminated land. Soil samples and plant tissues (leaves, wood and bark) of adult willow (Salix sp.), poplar (Populus sp.), and birch (Betula pendula) <span class="hlt">trees</span> were collected from five contaminated sites in France and Germany and analysed for Zn, Cd, Pb, Cu, Ca, and K. Cadmium concentration in <span class="hlt">tree</span> leaves were correlated with <span class="hlt">tree</span> <span class="hlt">species</span>, whereas Zn concentration in leaves was site correlated. Birch revealed significantly lower leaf Cd concentrations (1.2-8.9 mg kg(-1)) than willow and poplar (5-80 mg kg(-1)), thus posing the lowest risk for TE contamination of surrounding areas. Birch displayed the lowest bark concentrations for Ca (2300-6200 mg kg(-1)) and K (320-1250 mg kg(-1)), indicating that it would be the most suitable <span class="hlt">tree</span> <span class="hlt">species</span> for fuel production, as high concentrations of K and Ca decrease the ash melting point which results in a reduced plant lifetime. Due to higher TE concentrations in bark compared to wood a small bark proportion in relation to the trunk is desirable. In general the bark proportion was reduced with the <span class="hlt">tree</span> age. In summary, birch was amongst the investigated <span class="hlt">species</span> the most suitable for biomass production on TE contaminated land. PMID:22284170</p> <div class="credits"> <p class="dwt_author">Evangelou, Michael W H; Deram, Annabelle; Gogos, Alexander; Studer, Björn; Schulin, Rainer</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-03-30</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">285</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2005SPIE.5888..180T"> <span id="translatedtitle">Polarimetric reflectance and depolarization ratio from several <span class="hlt">tree</span> <span class="hlt">species</span> using a multiwavelength polarimetric lidar</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">There is a growing interest toward using lidar for forest remote sensing. The Multiwavelength Airborne Polarimetric Lidar (MAPL) was designed primarily for vegetation remote sensing purposes. The system has full lidar waveform capture and polarimetric measurement capabilities at 532-nm and 1064-nm wavelengths. To study the polarimetric reflectance from different <span class="hlt">tree</span> <span class="hlt">species</span>, ground experiments were conducted using the MAPL system. Three <span class="hlt">tree</span> canopies with distinct features were selected for this study. These are cottonwood (Populus deltoides), black willow (Salix nigra) and red-cedar (Juniperus virginiana). The test results revealed that the shapes of the lidar waveforms, the depolarization ratios, and the percent reflectance data all have distinct features for different <span class="hlt">tree</span> <span class="hlt">species</span>. The MAPL system is proved to be able to detect all these features. Our study indicates that the MAPL data have the potential to be used toward developing a <span class="hlt">tree</span> <span class="hlt">species</span> discrimination algorithm. In addition, it is also believed that these data can be used to detect <span class="hlt">tree</span> stress conditions.</p> <div class="credits"> <p class="dwt_author">Tan, Songxin; Narayanan, Ram M.; Helder, Dennis L.</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-08-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">286</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4271536"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Groussin, Mathieu; Hobbs, Joanne K.; Szöll?si, Gergely J.; Gribaldo, Simonetta; Arcus, Vickery L.; Gouy, Manolo</p> <p class="dwt_publisher"></p> <p class="publishDate">2015-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">287</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Groussin, Mathieu; Hobbs, Joanne K; Szöll?si, Gergely J; Gribaldo, Simonetta; Arcus, Vickery L; Gouy, Manolo</p> <p class="dwt_publisher"></p> <p class="publishDate">2015-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">288</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/40163902"> <span id="translatedtitle">Stable carbon isotopes in <span class="hlt">tree</span> rings indicate improved water use efficiency and drought responses of a tropical dry forest <span class="hlt">tree</span> <span class="hlt">species</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Understanding the responses of tropical <span class="hlt">trees</span> to increasing [CO2] and climate change is important as tropical forests play an important role in carbon and hydrological cycles. We used stable\\u000a carbon isotopes (?13C) in <span class="hlt">tree</span> rings to study the physiological responses of a tropical dry forest <span class="hlt">tree</span> <span class="hlt">species</span> in southern Mexico, Mimosa acantholoba to changes in atmospheric [CO2] and variation in</p> <div class="credits"> <p class="dwt_author">Roel J. W. BrienenWolfgang; Wolfgang Wanek; Peter Hietz</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">289</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Kharrat, Imen; Mezghani, Maha; Casse, Nathalie; Denis, Françoise; Caruso, Aurore; Makni, Hanem; Capy, Pierre; Rouault, Jacques-Deric; Chénais, Benoît; Makni, Mohamed</p> <p class="dwt_publisher"></p> <p class="publishDate">2015-02-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">290</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013EnMan..51..524M"> <span id="translatedtitle">Certified and Uncertified Logging Concessions Compared in Gabon: Changes in Stand Structure, <span class="hlt">Tree</span> <span class="hlt">Species</span>, and Biomass</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Medjibe, V. P.; Putz, Francis E.; Romero, Claudia</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-03-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">291</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014JHyd..519..446S"> <span id="translatedtitle">Seasonal and meteorological effects on differential stemflow funneling ratios for two deciduous <span class="hlt">tree</span> <span class="hlt">species</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Stemflow is an important subcanopy flux that delivers enriched rainfall to soils immediately surrounding a <span class="hlt">tree</span>. Stemflow volume represents the quantity of this hydrologic flux while funneling ratio (FR) represents the efficiency with which individual <span class="hlt">trees</span> scavenge water during rainfall events. Stemflow hydrology and storm meteorological characteristics were monitored from 2007 through 2012 to determine the interspecific differences in stemflow flux with a focus on FR efficiency. The objective of this study was to examine the influence of <span class="hlt">tree</span> <span class="hlt">species</span> and size on stemflow FR, determine how seasonality affects stemflow FR, and quantify the role of storm meteorological conditions on stemflow FR. The results presented in this paper build upon 2 years of previous hydrologic research from the Fair Hill, MD field site, which strengthen previous findings via larger storm sample size and highlight more complex stemflow hydrologic relationships than originally assumed. Specifically, this study has demonstrated (1) the efficiency with which smaller <span class="hlt">trees</span> gain access to rainfall via higher FR than larger <span class="hlt">trees</span>, (2) the FR variability of F. grandifolia induced by the <span class="hlt">species</span>' ease of generating stemflow under many storm conditions, and (3) the necessity of many years of hydrometeorological sampling to capture long-term rainfall characteristics and trends. The efficiency of smaller <span class="hlt">trees</span> to preferentially funnel water to their <span class="hlt">tree</span> base has implications for forests undergoing change. Forest disturbance and subsequent regrowth is dominated by smaller <span class="hlt">trees</span>, but additional research is necessary to understand how saplings compete among one another to gain access to stemflow and how this may be influenced by changing climates and forest composition.</p> <div class="credits"> <p class="dwt_author">Siegert, C. M.; Levia, D. F.</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-11-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">292</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Page, B.D.; Bullen, T.D.; Mitchell, M.J.</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">293</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">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 class="dwt_publisher"></p> <p class="publishDate">2013-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">294</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/5276531"> <span id="translatedtitle"><span class="hlt">Tree</span> <span class="hlt">species</span> composition and diversity gradients in white-water forests across the Amazon Basin</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">ABSTRACT Aim,Attention has increasingly been,focused,on the floristic variation within forests of the Amazon,Basin. Variations in <span class="hlt">species</span> composition,and,diversity are poorly understood, especially in Amazonian floodplain forests. We investigated <span class="hlt">tree</span> <span class="hlt">species</span> composition, richness and a diversity in the Amazonian white-water (va ´rzea) forest, looking particularly at: (1) the flood-level gradient, (2) the successional stage (stand age), and (3) the geographical location of</p> <div class="credits"> <p class="dwt_author">Florian Wittmann; Jochen Schongart; Juan Carlos Montero; Thomas Motzer; Wolfgang J. Junk; Maria T. F. Piedade; Helder L. Queiroz; Martin Worbes</p> <p class="dwt_publisher"></p> <p class="publishDate">2006-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">295</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Keller, Adrienne B.; Reed, Sasha C.; Townsend, Alan R.; Cleveland, Cory C.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">296</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">We examined nitrate assimilation in several <span class="hlt">tree</span> <span class="hlt">species</span> to test the hypothesis that plant N acquisition is highest in early spring due to the N demands of leaf growth and the seasonal availability of soil N. Specifically, we advance the idea that <span class="hlt">trees</span> acquire N most actively during the leaf expansion period, which serves to offset growth-dilution of foliar N. However, it has been observed that boreal <span class="hlt">species</span> expand their leaves more rapidly than do temperate <span class="hlt">species</span>, suggesting that they exhibit a different seasonal pattern of N acquisition than do temperate <span class="hlt">species</span>. To examine these relationships we measured leaf nitrate reductase activity (NRA) as a proxy for nitrate assimilation, leaf expansion rates, and foliar N concentrations on three boreal <span class="hlt">tree</span> <span class="hlt">species</span> and three temperate <span class="hlt">tree</span> <span class="hlt">species</span> throughout their leaf expansion period. An evergreen <span class="hlt">species</span> (Quercus glauca) and two deciduous <span class="hlt">species</span> (Acer palmatum and Zelkova serrata) were investigated in temperate Japan, and three deciduous <span class="hlt">species</span> Alnus crispa, Betula papyrifera and Populus tremuloides were chosen in a boreal forest in interior Alaska, US. The patterns of foliar N concentrations were very similar across all six <span class="hlt">species</span>, but the mean leaf expansion period was shorter in the boreal <span class="hlt">species</span> (about 25 days) than in temperate <span class="hlt">species</span> (about 29 days). All temperate <span class="hlt">species</span> showed clear peaks of leaf NRA in the middle of leaf expansion period, suggesting that leaves partly compensate for the N dilution during expansion via foliar nitrate assimilation, and that plant nitrate acquisition was effectively timed to coincide with soil N availability generally increased in early spring. By contrast, peak NRA in the boreal <span class="hlt">species</span> were observed in different stage of leaf expansion, but as in the temperate <span class="hlt">species</span> declined to very low levels after the leaves were fully expanded. Our results demonstrate that plant nitrate assimilation is concentrated during leaf expansion in spring and early summer, but declines to very low levels during the remaining part of the growing season. This high rate of acquisition in early spring may reflect the seasonal nature of soil nitrate dynamics as well as acquisition of N liberated over-winter in both biomes.</p> <div class="credits"> <p class="dwt_author">Koyama, L.; Tokuchi, N.; Kielland, K.</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">297</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/19459892"> <span id="translatedtitle">Biodiversity consequences of genetic variation in bark characteristics within a foundation <span class="hlt">tree</span> <span class="hlt">species</span>.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">The developing field of community genetics has the potential to broaden the contribution of genetics to conservation biology by demonstrating that genetic variation within foundation plant <span class="hlt">species</span> can act to structure associated communities of microorganisms, invertebrates, and vertebrates. We assessed the biodiversity consequences of natural patterns of intraspecific genetic variation within the widely distributed Australian forest <span class="hlt">tree</span>, Eucalyptus globulus. We assessed genetic variation among geographic races of E. globulus (i.e., provenances, seed zones) in the characteristics of <span class="hlt">tree</span>-trunk bark in a 17-year-old common garden and the associated response of a dependent macroarthropod community. In total, 180 macroarthropod taxa were identified following a collection from 100 <span class="hlt">trees</span> of five races. We found substantial genetically based variation within E. globulus in the quantity and type of decorticating bark. In the community of organisms associated with this bark, significant variation existed among <span class="hlt">trees</span> of different races in composition, and there was a two-fold difference in <span class="hlt">species</span> richness (7-14 <span class="hlt">species</span>) and abundance (22-55 individuals) among races. This community variation was tightly linked with genetically based variation in bark, with 60% of variation in community composition driven by bark characteristics. No detectable correlation was found, however, with neutral molecular markers. These community-level effects of <span class="hlt">tree</span> genetics are expected to extend to higher trophic levels because of the extensive use of <span class="hlt">tree</span> trunks as foraging zones by birds and marsupials. Our results demonstrate the potential biodiversity benefits that may be gained through conservation of intraspecific genetic variation within broadly distributed foundation <span class="hlt">species</span>. The opportunities for enhancing biodiversity values of forestry and restoration plantings are also highlighted because such planted forests are increasingly becoming the dominant forest type in many areas of the world. PMID:19459892</p> <div class="credits"> <p class="dwt_author">Barbour, Robert C; Forster, Lynne G; Baker, Susan C; Steane, Dorothy A; Potts, Bradley M</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-10-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">298</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://people.bu.edu/ptempler/docs/2005_TemplerEtAl_Ecosystems.pdf"> <span id="translatedtitle">Influence of <span class="hlt">Tree</span> <span class="hlt">Species</span> on Forest Nitrogen Retention in the Catskill</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p class="result-summary">of the Smoky Mountains (Johnson and others 1991), as well as hardwood forests of the Adirondack Mountains, NYInfluence of <span class="hlt">Tree</span> <span class="hlt">Species</span> on Forest Nitrogen Retention in the Catskill Mountains, New York, USA of the Catskill Mountains, New York (NY). We conducted a 300-day 15 N field tracer experi- ment to determine how N</p> <div class="credits"> <p class="dwt_author">Templer, Pamela</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">299</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://landscape.forest.wisc.edu/PDF/Scheller_Mladenoff2005_GCB.pdf"> <span id="translatedtitle">A spatially interactive simulation of climate change, harvesting, wind, and <span class="hlt">tree</span> <span class="hlt">species</span> migration and</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p class="result-summary">A spatially interactive simulation of climate change, harvesting, wind, and <span class="hlt">tree</span> <span class="hlt">species</span> migration and projected changes to forest composition and biomass in northern Wisconsin, USA R O B E R T M . S C H E L L E R and D AV I D J . M L A D E N O F F Department of Forest Ecology and Management, University</p> <div class="credits"> <p class="dwt_author">Mladenoff, David</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">300</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://wp.natsci.colostate.edu/walllab/files/2011/04/Ayres-et-al-2009-PLoS-One.pdf"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p class="result-summary">Mountains, Colorado. Leaf litter quality differed among the <span class="hlt">tree</span> <span class="hlt">species</span>, with the highest nitrogen (N, but lignin:N was highest in pine litter. Soil temperature and moisture were highest in aspen stands, which structure, which, combined with higher quality litter, would result in increased soil respiration rates</p> <div class="credits"> <p class="dwt_author">Wall, Diana</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_14");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> 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showDiv("page_17");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">301</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://labs.russell.wisc.edu/eab/files/2012/03/Alternatives-to-Ash-for-Professionals.pdf"> <span id="translatedtitle">Alternative to Ash <span class="hlt">Trees</span>: Commercially Available <span class="hlt">Species</span> and Cultivars Dr. Laura G. Jull</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p class="result-summary">Ã? freemanii, Acer rubrum, Acer platanoides, Acer saccharum, etc. Plant no more than 10% of a <span class="hlt">species</span>: i.e. Acer platanoides Large to medium-sized Street/Urban <span class="hlt">Trees</span> Acer Ã? freemanii: Freeman maple, Zone 3b-4 Acer platanoides: Norway maple, Zone 4b, native to Europe, wide-spreading, rounded, dense form, 40</p> <div class="credits"> <p class="dwt_author">Balser, Teri C.</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">302</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://hal.archives-ouvertes.fr/docs/00/88/25/06/PDF/hal-00882506.pdf"> <span id="translatedtitle">Germination and storage of recalcitrant seeds of some tropical forest <span class="hlt">tree</span> <span class="hlt">species</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p class="result-summary">Germination and storage of recalcitrant seeds of some tropical forest <span class="hlt">tree</span> <span class="hlt">species</span> F. Corbineau D and Roberts, 1979). The aim of the present study was to analyze the germination of some recalci- trant seeds (Guttiferae) collected in the dense forest near Kourou, French Guiana. Germination tests were performed</p> <div class="credits"> <p class="dwt_author">Paris-Sud XI, Université de</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">303</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ars.usda.gov/services/TekTran.htm">Technology Transfer Automated Retrieval System (TEKTRAN)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author"></p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">304</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Teskey, Robert; Wertin, Timothy; Bauweraerts, Ingvar; Ameye, Maarten; McGuire, Mary Anne; Steppe, Kathy</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-07-28</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">305</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/18571956"> <span id="translatedtitle">Classifying individual <span class="hlt">tree</span> <span class="hlt">species</span> under leaf-off and leaf-on conditions using airborne lidar</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">In this paper, a methodology for individual <span class="hlt">tree</span>-based <span class="hlt">species</span> classification using high sampling density and small footprint lidar data is clarified, corrected and improved. For this purpose, a well-defined directed graph (digraph) is introduced and it plays a fundamental role in the approach. It is argued that there exists one and only one such unique digraph that describes all four</p> <div class="credits"> <p class="dwt_author">Tomas Brandtberg</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">306</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www2.cedarcrest.edu/academic/bio/jcigliano/consbio/BrownTreeSnake.pdf"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Predation by brown <span class="hlt">tree</span> snakes ( Boiga irregularis ) devastated the avifauna of Guam in the Mari- ana 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 na- tive forest birds but have not considered</p> <div class="credits"> <p class="dwt_author">Gary J. Wiles; Jonathan Bart; ROBERT E. BECK JR.; Celestino F. Aguon</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">307</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ib.berkeley.edu/labs/fine/Site/Gabriel_files/geiger%20et%20al%202011.pdf"> <span id="translatedtitle">Distinct roles of savanna and forest <span class="hlt">tree</span> <span class="hlt">species</span> in regeneration under fire suppression in a</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p class="result-summary">Distinct roles of savanna and forest <span class="hlt">tree</span> <span class="hlt">species</span> in regeneration under fire suppression in a Brazilian savanna Erika L. Geiger, Sybil G. Gotsch, Gabriel Damasco, M. Haridasan, Augusto C. Franco & William A. Hoffmann Keywords Cerrado; fire; forest expansion; forest­savanna boundary; tropical savanna</p> <div class="credits"> <p class="dwt_author">Fine, Paul V.A.</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">308</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/53247875"> <span id="translatedtitle">Polarimetric reflectance and depolarization ratio from several <span class="hlt">tree</span> <span class="hlt">species</span> using a multiwavelength polarimetric lidar</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">There is a growing interest toward using lidar for forest remote sensing. The Multiwavelength Airborne Polarimetric Lidar (MAPL) was designed primarily for vegetation remote sensing purposes. The system has full lidar waveform capture and polarimetric measurement capabilities at 532-nm and 1064-nm wavelengths. To study the polarimetric reflectance from different <span class="hlt">tree</span> <span class="hlt">species</span>, ground experiments were conducted using the MAPL system. Three</p> <div class="credits"> <p class="dwt_author">Songxin Tan; Ram M. Narayanan; Dennis L. Helder</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">309</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/49322360"> <span id="translatedtitle">Estimating the vulnerability of fifteen <span class="hlt">tree</span> <span class="hlt">species</span> under changing climate in Northwest North America</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">In the Pacific northwestern (PNW) region of North America, climatic conditions have significantly warmed since a predominantly cool phase of the Pacific North American circulation patterns between 1950 and 1975. What are the implications of this shift in climate for the vulnerability of native <span class="hlt">tree</span> <span class="hlt">species</span>? To address this question, we combined mechanistic and statistical models to assess where a</p> <div class="credits"> <p class="dwt_author">Nicholas C. Coops; Richard H. Waring</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">310</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/60348071"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">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),</p> <div class="credits"> <p class="dwt_author">M. R. Vaitkus; T. G. Ciravolo; K. W. McLeod; E. M. Mavity; K. L. Novak</p> <p class="dwt_publisher"></p> <p class="publishDate">1993-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">311</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://hort.ifas.ufl.edu/treesandhurricanes/documents/pdf/EffectsOnSEUSCoastalPlainTreeSpecies.pdf"> <span id="translatedtitle">Hurricanes and the Urban Forest: I. Effects on Southeastern United States Coastal Plain <span class="hlt">Tree</span> <span class="hlt">Species</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p class="result-summary">Hurricanes and the Urban Forest: I. Effects on Southeastern United States Coastal Plain <span class="hlt">Tree</span> <span class="hlt">Species</span> Mary L. Duryea, Eliana Kampf, and Ramon C. Littell Abstract. Several hurricanes struck Florida, U of these hurricanes on the urban forest and combined these results with four other hurricanes to present an assessment</p> <div class="credits"> <p class="dwt_author">Jawitz, James W.</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">312</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://hort.ifas.ufl.edu/treesandhurricanes/documents/pdf/EffectsOnTropicalAndSubtropicalTreeSpecies.pdf"> <span id="translatedtitle">Hurricanes and the Urban Forest: II. Effects on Tropical and Subtropical <span class="hlt">Tree</span> <span class="hlt">Species</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p class="result-summary">Hurricanes and the Urban Forest: II. Effects on Tropical and Subtropical <span class="hlt">Tree</span> <span class="hlt">Species</span> Mary L. Duryea, Eliana Kampf, Ramon C. Littell, and Carlos D. Rodríguez-Pedraza Abstract. In 1998 when Hurricane Georges (177 km/h) crossed over the entire island of Puerto Rico, and in 2004 when Hurricanes Jeanne (193</p> <div class="credits"> <p class="dwt_author">Jawitz, James W.</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">313</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.victoria.ac.nz/sbs/research/ecology-biodiversity-research/island-ecology-research/pdf/IntJPlantSci_2010.pdf"> <span id="translatedtitle">HIDING FROM THE GHOST OF HERBIVORY PAST: EVIDENCE FOR CRYPSIS IN AN INSULAR <span class="hlt">TREE</span> <span class="hlt">SPECIES</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p class="result-summary">HIDING FROM THE GHOST OF HERBIVORY PAST: EVIDENCE FOR CRYPSIS IN AN INSULAR <span class="hlt">TREE</span> <span class="hlt">SPECIES</span> Nik Fadzly difficult for predators to locate. However, quantitative examples of crypsis in plants are comparatively reach of flightless browsing birds. Keywords: color, crypsis, herbivory, heteroblasty, moa, Elaeocarpus</p> <div class="credits"> <p class="dwt_author"></p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">314</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://web.mit.edu/manoli/www/publications/Rasmussen_GenomeResearch_07.pdf"> <span id="translatedtitle">Accurate gene-<span class="hlt">tree</span> reconstruction by learning gene-and <span class="hlt">species</span>-specific substitution rates</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p class="result-summary">, Drosophila #12;Comparative genomics provides a general methodology for discovering functional DNA elements sequenced Drosophila genomes and 9 fungal genomes to address the problem of accurate gene <span class="hlt">tree</span> the long-branch-attraction problem, and enabling studies of gene evolution in the context of <span class="hlt">species</span></p> <div class="credits"> <p class="dwt_author">Kellis, Manolis</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">315</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://science.gsfc.nasa.gov/691/cv/kletetschka/telomere.pdf"> <span id="translatedtitle">Research article Analysis of telomere length and telomerase activity in <span class="hlt">tree</span> <span class="hlt">species</span> of various</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p class="result-summary">life-span and longevity of P. longaeva with age, as well as in other <span class="hlt">tree</span> <span class="hlt">species</span> of various life life-spans, and with age in the bristlecone pine Pinus longaeva Barry E. Flanary1, * & Gunther, Catholic University of America, Washington, DC, USA; 3 Goddard Space Flight Center, National Aeronautics</p> <div class="credits"> <p class="dwt_author">Kletetschka, Gunther</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">316</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pol.j.ecol.cbe-pan.pl/article/ar56_2_04.pdf"> <span id="translatedtitle">FOLIAR RESORPTION OF NUTRIENTS IN SELECTED SYMPATRIC <span class="hlt">TREE</span> <span class="hlt">SPECIES</span> IN GALLERY FOREST ?BLACK SEA REGION</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Gallery forests in Central Black Sea Region are dominated by Platanus orientalis L. The studies were performed in four sites (Mert River, Adalar, Kurupelit and Taflan Regions) located in V-shaped river valleys and differing with soil conditions. Nutrient concen- trations were measured in green and senescent leaves in selected sympatric <span class="hlt">tree</span> <span class="hlt">species</span>. Foliar nutrient resorption efficiency (RE; as the ratio</p> <div class="credits"> <p class="dwt_author">Hamdi Güray KUTBAY; Duygu KILIC; Hasan KORKMAZ; Erkan YALÇIN; Zeki APAYDIN</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">317</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.fabinet.up.ac.za/publication/pdfs/308-2010_van_wyk_wingfield_marin_wingfield_fungal_div.pdf"> <span id="translatedtitle">New Ceratocystis <span class="hlt">species</span> infecting coffee, cacao, citrus and native <span class="hlt">trees</span> in Colombia</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p class="result-summary">New Ceratocystis <span class="hlt">species</span> infecting coffee, cacao, citrus and native <span class="hlt">trees</span> in Colombia M. Van Wyk. The aim of this study was to compare representatives of these two groups of isolates from coffee, citrus. fimbriata s.l. in Colombia is found on a wide range of hosts other than coffee. These include citrus (Citrus</p> <div class="credits"> <p class="dwt_author"></p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">318</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.rnr.lsu.edu/people/wu/PDFFiles/Kofuwood2001.pdf"> <span id="translatedtitle">WOOD PROPERTIES AND THEIR VARIATIONS WITHIN THE <span class="hlt">TREE</span> STEM OF LESSER-USED <span class="hlt">SPECIES</span> OF TROPICAL</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p class="result-summary">of the <span class="hlt">tree</span>. Specific gravity correlates positively with all the wood's properties, making it a good indicator for selection of the wood for use. The wood of Petersianthus macrocarpus is dense (specific gravity of 0: Lesser-used <span class="hlt">species</span>, specific gravity, shrinkage, compression parallel to the grain. INTRODUCTION</p> <div class="credits"> <p class="dwt_author"></p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">319</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://elizabethderryberry.tulane.edu/derryberrylab/Publications_files/McCormack%20et%20al%202012%20NGS%20methods.pdf"> <span id="translatedtitle">Next-generation sequencing reveals phylogeographic structure and a <span class="hlt">species</span> <span class="hlt">tree</span> for recent bird divergences</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p class="result-summary">Next-generation sequencing reveals phylogeographic structure and a <span class="hlt">species</span> <span class="hlt">tree</span> for recent bird Pyrosequencing Reduced representation library a b s t r a c t Next generation sequencing (NGS) technologies al., 2010), applications of next-generation sequencing (NGS) have lagged in this discipline</p> <div class="credits"> <p class="dwt_author">Derryberry, Elizabeth</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">320</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ecostudies.org/reprints/Finzi_et_al_1998_Ecol_Appl_8_440-446.pdf"> <span id="translatedtitle">Canopy <span class="hlt">tree</span>-soil interactions within temperate forest: <span class="hlt">species</span> effects on soil carbon and nitrogen</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">In a northwestern Connecticut forest, we quantified the carbon (C) and ni- trogen (N) content of the forest floor and the top 15 cm of mineral soil and the rate of midsummer net N mineralization beneath six different <span class="hlt">tree</span> <span class="hlt">species</span>. There were large in- terspecific differences in forest floor depth and mass, in the size and distribution of C and</p> <div class="credits"> <p class="dwt_author">Adrien C. Finzi; Nico Van Breemen; Charles D. Canham</p> <p class="dwt_publisher"></p> <p class="publishDate">1998-01-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_15");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a onClick='return showDiv("page_4");' 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onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">321</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://biology.unm.edu/jhbrown/Documents/Publications/2000s/2009-12%20Temperature%20dependence.pdf"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p class="result-summary">Temperature dependence, spatial scale, and <span class="hlt">tree</span> <span class="hlt">species</span> diversity in eastern Asia and North America in eastern Asia and North America to investigate the roles of environmental temperature and spatial scale and temperature is much steeper in eastern Asia than in North America: in cold climates at high latitudes</p> <div class="credits"> <p class="dwt_author">Brown, James H.</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">322</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Randhawa, H S; Kowshik, T; Chowdhary, Anuradha; Preeti Sinha, K; Khan, Z U; Sun, Sheng; Xu, Jianping</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">323</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Hanberry, Brice B.; Palik, Brian J.; He, Hong S.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">324</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Wang, Zhiheng; Brown, James H.; Tang, Zhiyao; Fang, Jingyun</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">325</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/23613911"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Hanberry, Brice B; Palik, Brian J; He, Hong S</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">326</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p class="result-summary">Historical data have increasingly become appreciated for insight into the past conditions of ecosystems. Uses of such data include assessing the extent of ecosystem change; deriving ecological baselines for management, restoration, and modeling; and assessing the importance of past conditions on the composition and function of current systems. One historical data set of this type is the Public Land Survey (PLS) of the United States General Land Office, which contains data on multiple <span class="hlt">tree</span> <span class="hlt">species</span>, sizes, and distances recorded at each survey point, located at half-mile (0.8 km) intervals on a 1-mi (1.6 km) grid. This survey method was begun in the 1790s on US federal lands extending westward from Ohio. Thus, the data have the potential of providing a view of much of the US landscape from the mid-1800s, and they have been used extensively for this purpose. However, historical data sources, such as those describing the <span class="hlt">species</span> composition of forests, can often be limited in the detail recorded and the reliability of the data, since the information was often not originally recorded for ecological purposes. Forest <span class="hlt">trees</span> are sometimes recorded ambiguously, using generic or obscure common names. For the PLS data of northern Wisconsin, USA, we developed a method to classify ambiguously identified <span class="hlt">tree</span> <span class="hlt">species</span> using logistic regression analysis, using data on <span class="hlt">trees</span> that were clearly identified to <span class="hlt">species</span> and a set of independent predictor variables to build the models. The models were first created on partial data sets for each <span class="hlt">species</span> and then tested for fit against the remaining data. Validations were conducted using repeated, random subsets of the data. Model prediction accuracy ranged from 81% to 96% in differentiating congeneric <span class="hlt">species</span> among oak, pine, ash, maple, birch, and elm. Major predictor variables were <span class="hlt">tree</span> size, associated <span class="hlt">species</span>, landscape classes indicative of soil type, and spatial location within the study region. Results help to clarify ambiguities formerly present in maps of historic ecosystems for the region and can be applied to PLS datasets elsewhere, as well as other sources of ambiguous historical data. Mapping the newly classified data with ecological land units provides additional information on the distribution, abundance, and associations of <span class="hlt">tree</span> <span class="hlt">species</span>, as well as their relationships to environmental gradients before the industrial period, and clarifies the identities of <span class="hlt">species</span> formerly mapped only to genus. We offer some caveats on the appropriate use of data derived in this way, as well as describing their potential.</p> <div class="credits"> <p class="dwt_author">Mladenoff, D.J.; Dahir, S.E.; Nordheim, E.V.; Schulte, L.A.; Guntenspergen, G.R.</p> <p class="dwt_publisher"></p> <p class="publishDate">2002-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">327</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20010004211&hterms=white+oaks+species&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dwhite%2Boaks%2Bspecies"> <span id="translatedtitle">BOREAS TE-4 Gas Exchange Data from Boreal <span class="hlt">Tree</span> <span class="hlt">Species</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Hall, Forrest G. (Editor); Curd, Shelaine (Editor); Collatz, G. James; Berry, Joseph A.; Gamon, John; Fredeen, Art; Fu, Wei</p> <p class="dwt_publisher"></p> <p class="publishDate">2000-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">328</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://pure.rhul.ac.uk/portal/files/17730240/Effects_of_Tree_Species_Diversity_on_Insect_Herbivory.pdf"> <span id="translatedtitle">Effects of <span class="hlt">tree</span> <span class="hlt">species</span> diversity on insect herbivory A thesis submitted to the University of London in partial fulfilment</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p class="result-summary">It is generally believed that <span class="hlt">tree</span> <span class="hlt">species</span> growing in mixed forest stands are less susceptible to insect herbivore she has spent reading and commenting on Chapter drafts has helped improve the quality of the thesis mainly on <span class="hlt">tree</span> <span class="hlt">species</span> richness effects. In this thesis, I examined effects of three components of forest</p> <div class="credits"> <p class="dwt_author">Chittka, Lars</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">329</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.cerambycoidea.com/titles/morewood2003.pdf"> <span id="translatedtitle">Oviposition Preference and Larval Performance of Anoplophora glabripennis (Coleoptera: Cerambycidae) in Four Eastern North American Hardwood <span class="hlt">Tree</span> <span class="hlt">Species</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Anoplophora glabripennis (Motschulsky) is an invasive wood-boring cerambycid beetle that kills hardwood <span class="hlt">trees</span>. The host range of this <span class="hlt">species</span> is unusually broad but is not well deÞned in the available literature and may include <span class="hlt">tree</span> <span class="hlt">species</span> that have not been reported as hosts because they have not previously been exposed to the beetle. We evaluated oviposition by A. glabripennis offered</p> <div class="credits"> <p class="dwt_author">W. D. Morewood; P. R. Neiner; J. R. McNeil; J. C. Sellmer; K. Hoover</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">330</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">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 determining <span class="hlt">species</span> effects on forest floor leaf litter dynamics among these 14 <span class="hlt">tree</span> <span class="hlt">species</span>, apparently because of the influence of litter Ca on earthworm activity. The overall influence of these <span class="hlt">tree</span> <span class="hlt">species</span> on leaf litter decomposition via effects on both microbial and faunal processing will only become clear when we can quantify the decay dynamics of litter that is translocated belowground by earthworms. PMID:16995629</p> <div class="credits"> <p class="dwt_author">Hobbie, Sarah E; Reich, Peter B; Oleksyn, Jacek; Ogdahl, Megan; Zytkowiak, Roma; Hale, Cynthia; Karolewski, Piotr</p> <p class="dwt_publisher"></p> <p class="publishDate">2006-09-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">331</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Cutter, B.E.; Guyette, R.P. [Univ. of Missouri, Columbia, MO (United States)</p> <p class="dwt_publisher"></p> <p class="publishDate">1993-07-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">332</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Wiles, G.J.; Bart, J.; Beck, R.E., Jr.; Aguon, C.F.</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">333</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/19484478"> <span id="translatedtitle">Fine root decay rates vary widely among lowland tropical <span class="hlt">tree</span> <span class="hlt">species</span>.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Prolific fine root growth coupled with small accumulations of dead fine roots indicate rapid rates of fine root production, mortality and decay in young <span class="hlt">tree</span> plantations in lowland Costa Rica. However, published studies indicate that fine roots decay relatively slowly in tropical forests. To resolve this discrepancy, we used the intact-core technique to quantify first-year decay rates of fine roots in four single-<span class="hlt">species</span> plantations of native <span class="hlt">tree</span> <span class="hlt">species</span>. We tested three hypotheses: first, that fine roots from different <span class="hlt">tree</span> <span class="hlt">species</span> would decay at different rates; second, that <span class="hlt">species</span> having rapid fine root growth rates would also have rapid rates of fine root decay; and third, that differences in fine root decay among <span class="hlt">species</span> could be explained by fine root chemistry variables previously identified as influencing decay rates. Fine roots in Virola koschnyi plantations decayed very slowly (k = 0.29 +/- 0.15 year(-1)); those of Vochysia guatemalensis decayed seven times faster (k = 2.00 +/- 0.13 year(-1)). Decay rates of the remaining two <span class="hlt">species</span>, Hieronyma alchorneoides and Pentaclethra macroloba, were 1.36 and 1.28 year(-1), respectively. We found a positive, marginally significant correlation between fine root decay rates and the relative growth rates of live fine roots (R = 0.93, n = 4, P = 0.072). There was a highly significant negative correlation between fine root decay and fine root lignin:N (R = 0.99, P = 0.01), which supports the use of lignin:N as a decay-controlling factor within terrestrial ecosystem models. The decay rates that we observed in this single study location encompassed the entire range of fine root decay rates previously observed in moist tropical forests, and thus suggest great potential for individual <span class="hlt">tree</span> <span class="hlt">species</span> to alter belowground organic matter and nutrient dynamics within a biotically rich rainforest environment. PMID:19484478</p> <div class="credits"> <p class="dwt_author">Raich, James W; Russell, Ann E; Valverde-Barrantes, Oscar</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-08-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">334</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.gfawesome.org/~flashVersion=true/school/lessons/ECOLOGY-2/01_-_Trees/"> <span id="translatedtitle"><span class="hlt">Trees</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://nsdl.org/nsdl_dds/services/ddsws1-1/service_explorer.jsp">NSDL National Science Digital Library</a></p> <p class="result-summary">This tutorial covers various aspects of <span class="hlt">trees</span>. It explains which chemicals cause leaves to change colors, how the process of photosynthesis works, the functions of bark, roots, pollen and leaves, and the effect of <span class="hlt">trees</span> on nearby temperature.</p> <div class="credits"> <p class="dwt_author"></p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">335</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The responses of soil methane (CH4) net fluxes to nitrogen (N) addition in a N-fixing <span class="hlt">tree</span> <span class="hlt">species</span> (Acacia auriculiformis (AA)) and a non-N-fixing <span class="hlt">tree</span> <span class="hlt">species</span> (Eucalyptus citriodora (EU)) plantation were studied in southern China. Treatments were conducted at each plantation with three N levels (0, 50, and 100 kg N ha-1 yr-1 for control, medium-N, and high-N treatment, respectively, abbreviated as C, MN, and HN). From August 2010 to July 2011, CH4 flux was measured biweekly using a static chamber and gas chromatography technique. The soils of both sites acted as sink of atmospheric CH4. The CH4 uptake rate in control of the AA site (36.3 ± 3.2 ?g CH4-C m-2 h-1) was greater than that of the EU plantation (29.9 ± 0.9 ?g CH4-C m-2 h-1). In the AA plantation, the averaged rates of CH4 uptake for the MN (28.6 ± 2.3 ?g CH4-C m-2 h-1) and HN treatment (23.8 ± 2.8 ?g CH4-C m-2 h-1) were decreased by 21% and 35%, respectively, compared to the control. However, there was no change of soil CH4 uptake between N-treated plots and the controls in the EU site. Our results indicated that there might be large difference of inhibitive effect of N deposition on soil CH4 oxidation between the AA and EU plantations. The projected increase of N deposition would weaken the capability of N-fixing <span class="hlt">tree</span> <span class="hlt">species</span> plantations for atmospheric CH4 sink in tropical and subtropical regions.</p> <div class="credits"> <p class="dwt_author">Zhang, Wei; Zhu, Xiaomin; Liu, Lei; Fu, Shenglei; Chen, Hao; Huang, Juan; Lu, Xiankai; Liu, Zhanfeng; Mo, Jiangming</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">336</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20140009601&hterms=Trees&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DTrees"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Gonzalez, Patrick; Tucker, Compton J.; Sy, H.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">337</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3419709"> <span id="translatedtitle">Avian <span class="hlt">Species</span> Richness in Relation to Intensive Forest Management Practices in Early Seral <span class="hlt">Tree</span> Plantations</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Background Managers of landscapes dedicated to forest commodity production require information about how practices influence biological diversity. Individual <span class="hlt">species</span> and communities may be threatened if management practices truncate or simplify forest age classes that are essential for reproduction and survival. For instance, the degradation and loss of complex diverse forest in young age classes have been associated with declines in forest-associated Neotropical migrant bird populations in the Pacific Northwest, USA. These declines may be exacerbated by intensive forest management practices that reduce hardwood and broadleaf shrub cover in order to promote growth of economically valuable <span class="hlt">tree</span> <span class="hlt">species</span> in plantations. Methodology and Principal Findings We used a Bayesian hierarchical model to evaluate relationships between avian <span class="hlt">species</span> richness and vegetation variables that reflect stand management intensity (primarily via herbicide application) on 212 <span class="hlt">tree</span> plantations in the Coast Range, Oregon, USA. Specifically, we estimated the influence of broadleaf hardwood vegetation cover, which is reduced through herbicide applications, on bird <span class="hlt">species</span> richness and individual <span class="hlt">species</span> occupancy. Our model accounted for imperfect detection. We used average predictive comparisons to quantify the degree of association between vegetation variables and <span class="hlt">species</span> richness. Both conifer and hardwood cover were positively associated with total <span class="hlt">species</span> richness, suggesting that these components of forest stand composition may be important predictors of alpha diversity. Estimates of <span class="hlt">species</span> richness were 35–80% lower when imperfect detection was ignored (depending on covariate values), a result that has critical implications for previous efforts that have examined relationships between forest composition and <span class="hlt">species</span> richness. Conclusion and Significance Our results revealed that individual and community responses were positively associated with both conifer and hardwood cover. In our system, patterns of bird community assembly appear to be associated with stand management strategies that retain or increase hardwood vegetation while simultaneously regenerating the conifer cover in commercial <span class="hlt">tree</span> plantations. PMID:22905249</p> <div class="credits"> <p class="dwt_author">Jones, Jay E.; Kroll, Andrew J.; Giovanini, Jack; Duke, Steven D.; Ellis, Tana M.; Betts, Matthew G.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">338</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2008AcO....34..370B"> <span id="translatedtitle">Hydraulic redistribution study in two native <span class="hlt">tree</span> <span class="hlt">species</span> of agroforestry parklands of West African dry savanna</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Hydraulic redistribution (HR) in karité ( Vitellaria paradoxa) and néré ( Parkia biglobosa) <span class="hlt">tree</span> <span class="hlt">species</span> was studied by monitoring the soil water potential ( ?s) using thermocouple psychrometers at four compass directions, various distances from <span class="hlt">trees</span> and at different soil depths (max depth 80 cm) during the dry seasons of 2004 and 2005. A modified WaNuLCAS model was then used to infer the amount of water redistribued based on ?s values. <span class="hlt">Tree</span> transpiration rate was also estimated from sap velocity using thermal dissipative probes (TDP) and sapwood area, and the contribution of hydraulically redistributed water in <span class="hlt">tree</span> transpiration was determined. The results revealed on average that 46% of the psychrometer readings under karité and 33% under néré showed the occurrence of HR for the two years. Soil under néré displayed significantly lower fluctuations of ?s (0.16 MPa) compared to soil under karité (0.21 MPa). The results of this study indicated that the existence of HR leads to a higher ?s in the plant rhizosphere and hence is important for soil water dynamics and plant nutrition by making more accessible the soluble elements. The simulation showed that the amount of water redistributed would be approximately 73.0 L and 247.1 L per <span class="hlt">tree</span> per day in 2005 for karité and néré, and would represent respectively 60% and 53% of the amount transpired a day. Even though the model has certainly overestimated the volume of water hydraulically redistributed by the two <span class="hlt">species</span>, this water may play a key role in maintaining fine root viability and ensuring the well adaptation of these <span class="hlt">species</span> to the dry areas. Therefore, knowledge of the extent of such transfers and of the seasonal patterns is required and is of paramount importance in parkland systems both for <span class="hlt">trees</span> and associated crops.</p> <div class="credits"> <p class="dwt_author">Bayala, Jules; Heng, Lee Kheng; van Noordwijk, Meine; Ouedraogo, Sibiri Jean</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-11-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">339</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Gary D. Kronrad</p> <p class="dwt_publisher"></p> <p class="publishDate">2006-09-19</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">340</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/25740149"> <span id="translatedtitle">Frost hardiness of <span class="hlt">tree</span> <span class="hlt">species</span> is independent of phenology and macroclimatic niche.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">The differences in timing in bud burst between <span class="hlt">species</span> have been interpreted as an adaptation to late frost events in spring. Thus, it has been suggested that the degree of frost susceptibility of leaves is <span class="hlt">species</span>-specific and depends on the <span class="hlt">species</span>' phenology and geographic distribution range. To test for relationships between frost tolerance and phenology as well as between frost tolerance and distribution range across Central European <span class="hlt">tree</span> <span class="hlt">species</span>, we studied the frost hardiness of closed buds before bud burst and of freshly opened buds at the time of bud burst. We hypothesized that <span class="hlt">species</span> with early bud burst and <span class="hlt">species</span> distributed in eastern and northern areas were more frost tolerant than <span class="hlt">species</span> with late bud burst and <span class="hlt">species</span> distributed in western and southern areas. Frost hardiness was estimated by exposing twigs to 11 frost temperatures between -4 degrees Centigrade and -80 degrees Centigrade and by assessing tissue damage by the electrolyte leakage method. In contrast to our hypotheses, neither frost hardiness of closed buds nor frost hardiness of freshly opened buds were related to any variable describing <span class="hlt">species</span>' macroclimatic niche. Furthermore, frost hardiness of freshly opened buds did not differ among <span class="hlt">species</span>. Thus, the investigated <span class="hlt">species</span> with early bud burst take higher risks of frost damage than the <span class="hlt">species</span> with late bud bursts. These findings indicate that frost hardiness might not play the key role in limiting the geographic distribution ranges previously anticipated. PMID:25740149</p> <div class="credits"> <p class="dwt_author">Hofmann, M; Bruelheide, H</p> <p class="dwt_publisher"></p> <p class="publishDate">2015-03-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_16");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return 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<a onClick='return showDiv("page_11");' href="#">11</a> <a onClick='return showDiv("page_12");' href="#">12</a> <a onClick='return showDiv("page_13");' href="#">13</a> <a onClick='return showDiv("page_14");' href="#">14</a> <a onClick='return showDiv("page_15");' href="#">15</a> <a onClick='return showDiv("page_16");' href="#">16</a> <a onClick='return showDiv("page_17");' href="#">17</a> <a style="font-weight: bold;">18</a> <a onClick='return showDiv("page_19");' href="#">19</a> <a onClick='return showDiv("page_20");' href="#">20</a> <a onClick='return showDiv("page_21");' href="#">21</a> <a onClick='return showDiv("page_22");' href="#">22</a> <a onClick='return showDiv("page_23");' href="#">23</a> <a onClick='return showDiv("page_24");' href="#">24</a> <a onClick='return showDiv("page_25");' href="#">25</a> </span> </span> <a id="NextPageLink" onclick='return showDiv("page_19");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">341</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Hanewinkel, Marc; Cullmann, Dominik A; Michiels, Hans-Gerd; Kändler, Gerald</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-02-15</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">342</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/18830633"> <span id="translatedtitle">The water relations of two evergreen <span class="hlt">tree</span> <span class="hlt">species</span> in a karst savanna.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">The ecohydrology of karst has not received much attention, despite the disproportionally large contribution of karst aquifers to freshwater supplies. Karst savannas, like many savannas elsewhere, are encroached by woody plants, with possibly negative consequences on aquifer recharge. However, the role of savanna <span class="hlt">tree</span> <span class="hlt">species</span> in hydrological processes remains unclear, not least because the location and water absorption zones of <span class="hlt">tree</span> roots in the spatially complex subsurface strata are unknown. This study examined the water sources and water relations of two savanna <span class="hlt">trees</span>, Quercus fusiformis (Small) and Juniperus ashei (Buchholz) in the karst region of the eastern Edwards Plateau, Texas (USA). Stable isotope analysis of stem water revealed that both <span class="hlt">species</span> took up evaporatively enriched water during the warm season, suggesting a relatively shallow water source in the epikarst, the transition zone between soil and bedrock. Q. fusiformis had consistently higher predawn water potentials than J. ashei during drought, and thus was probably deeper-rooted and less capable of maintaining gas exchange at low water potentials. Although the water potential of both <span class="hlt">species</span> recovered after drought-breaking spring and summer rain events, associated shifts in stem water isotope ratios did not indicate significant uptake of rainwater from the shallow soil. A hypothesis is developed to explain this phenomenon invoking a piston-flow mechanism that pushes water stored in macropores into the active root zones of the <span class="hlt">trees</span>. Epikarst structure varied greatly with parent material and topography, and had strong effects on seasonal fluctuations in plant water status. The study suggests that <span class="hlt">tree</span> <span class="hlt">species</span> of the Edwards Plateau do not commonly reduce aquifer recharge by tapping directly into perched water tables, but more likely by reducing water storage in the epikarst. A more general conclusion is that models of savanna water relations based on Walter's two-layer model may not apply unequivocally to karst savannas. PMID:18830633</p> <div class="credits"> <p class="dwt_author">Schwinning, Susanne</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">343</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/40914303"> <span id="translatedtitle">The influence of canopy gaps on overstory <span class="hlt">tree</span> and forest growth rates in a mature mixed-age, mixed-<span class="hlt">species</span> forest</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The death of overstory <span class="hlt">trees</span> creates gaps in forest canopies. These canopy gaps have positive impacts on forests, including enhancing <span class="hlt">species</span> diversity. The relative contributions to canopy gap closure made by understory <span class="hlt">trees</span> within gaps and overstory <span class="hlt">trees</span> at gap edges determines the future structure and <span class="hlt">species</span> composition of a forest.Most studies of <span class="hlt">tree</span> growth responses to gaps have focused</p> <div class="credits"> <p class="dwt_author">Brian S Pedersen; Jessica L Howard</p> <p class="dwt_publisher"></p> <p class="publishDate">2004-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">344</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">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 biloba, Hibiscus syriacus, Koelreuteria paniculata, Ligustrum obtusifolium, Liriodendron tulipifera, Pinus koraiensis, Pinus thunbergii, and Sophora japonica. As a result of a comparison of the total ratio (sum of shoot extension and diameter growth at the landfill relative to a reference site) and mortality, six <span class="hlt">species</span> (Liriodendron tulipifera, Albizzia julibrissin, Ligustrum obtusifolium, Buxus microphylla var. koreana, Hibiscus syriacus, and Sophora japonica), which had a total ratio >1 and experienced low mortality, are recommended as potentially suitable <span class="hlt">species</span> for waste landfill remediation. We suggest that mixed plantations of ubiquitous adaptable <span class="hlt">species</span> and naturally occurring black locust will enhance the landscape through synergistic effects. PMID:16132448</p> <div class="credits"> <p class="dwt_author">Kim, Kee Dae; Lee, Eun Ju</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-07-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">345</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/6118730"> <span id="translatedtitle"><span class="hlt">Multi-purpose</span> seismic transducer</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">A <span class="hlt">multi-purpose</span> seismic transducer includes a first seismic sensor having a first transfer function. A transfer-function shaping filter is coupled to the output of the first seismic sensor. The filter is adjustable to shape the first transfer function to match a plurality of different second transfer functions.</p> <div class="credits"> <p class="dwt_author">Hall, E.M.</p> <p class="dwt_publisher"></p> <p class="publishDate">1981-02-24</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">346</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/25173280"> <span id="translatedtitle">High field electron paramagnetic resonance spectroscopy under ultrahigh vacuum conditions--a <span class="hlt">multipurpose</span> machine to study paramagnetic <span class="hlt">species</span> on well defined single crystal surfaces.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">A new ultrahigh vacuum (UHV) electron paramagnetic resonance (EPR) spectrometer operating at 94 GHz to investigate paramagnetic centers on single crystal surfaces is described. It is particularly designed to study paramagnetic centers on well-defined model catalysts using epitaxial thin oxide films grown on metal single crystals. The EPR setup is based on a commercial Bruker E600 spectrometer, which is adapted to ultrahigh vacuum conditions using a home made Fabry Perot resonator. The key idea of the resonator is to use the planar metal single crystal required to grow the single crystalline oxide films as one of the mirrors of the resonator. EPR spectroscopy is solely sensitive to paramagnetic <span class="hlt">species</span>, which are typically minority <span class="hlt">species</span> in such a system. Hence, additional experimental characterization tools are required to allow for a comprehensive investigation of the surface. The apparatus includes a preparation chamber hosting equipment, which is required to prepare supported model catalysts. In addition, surface characterization tools such as low energy electron diffraction (LEED)/Auger spectroscopy, temperature programmed desorption (TPD), and infrared reflection absorption spectroscopy (IRAS) are available to characterize the surfaces. A second chamber used to perform EPR spectroscopy at 94 GHz has a room temperature scanning tunneling microscope attached to it, which allows for real space structural characterization. The heart of the UHV adaptation of the EPR experiment is the sealing of the Fabry-Perot resonator against atmosphere. To this end it is possible to use a thin sapphire window glued to the backside of the coupling orifice of the Fabry Perot resonator. With the help of a variety of stabilization measures reducing vibrations as well as thermal drift it is possible to accumulate data for a time span, which is for low temperature measurements only limited by the amount of liquid helium. Test measurements show that the system can detect paramagnetic <span class="hlt">species</span> with a density of approximately 5 × 10(11) spins/cm(2), which is comparable to the limit obtained for the presently available UHV-EPR spectrometer operating at 10 GHz (X-band). Investigation of electron trapped centers in MgO(001) films shows that the increased resolution offered by the experiments at W-band allows to identify new paramagnetic <span class="hlt">species</span>, that cannot be differentiated with the currently available methodology. PMID:25173280</p> <div class="credits"> <p class="dwt_author">Rocker, J; Cornu, D; Kieseritzky, E; Seiler, A; Bondarchuk, O; Hänsel-Ziegler, W; Risse, T; Freund, H-J</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-08-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">347</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014RScI...85h3903R"> <span id="translatedtitle">High field electron paramagnetic resonance spectroscopy under ultrahigh vacuum conditions—A <span class="hlt">multipurpose</span> machine to study paramagnetic <span class="hlt">species</span> on well defined single crystal surfaces</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">A new ultrahigh vacuum (UHV) electron paramagnetic resonance (EPR) spectrometer operating at 94 GHz to investigate paramagnetic centers on single crystal surfaces is described. It is particularly designed to study paramagnetic centers on well-defined model catalysts using epitaxial thin oxide films grown on metal single crystals. The EPR setup is based on a commercial Bruker E600 spectrometer, which is adapted to ultrahigh vacuum conditions using a home made Fabry Perot resonator. The key idea of the resonator is to use the planar metal single crystal required to grow the single crystalline oxide films as one of the mirrors of the resonator. EPR spectroscopy is solely sensitive to paramagnetic <span class="hlt">species</span>, which are typically minority <span class="hlt">species</span> in such a system. Hence, additional experimental characterization tools are required to allow for a comprehensive investigation of the surface. The apparatus includes a preparation chamber hosting equipment, which is required to prepare supported model catalysts. In addition, surface characterization tools such as low energy electron diffraction (LEED)/Auger spectroscopy, temperature programmed desorption (TPD), and infrared reflection absorption spectroscopy (IRAS) are available to characterize the surfaces. A second chamber used to perform EPR spectroscopy at 94 GHz has a room temperature scanning tunneling microscope attached to it, which allows for real space structural characterization. The heart of the UHV adaptation of the EPR experiment is the sealing of the Fabry-Perot resonator against atmosphere. To this end it is possible to use a thin sapphire window glued to the backside of the coupling orifice of the Fabry Perot resonator. With the help of a variety of stabilization measures reducing vibrations as well as thermal drift it is possible to accumulate data for a time span, which is for low temperature measurements only limited by the amount of liquid helium. Test measurements show that the system can detect paramagnetic <span class="hlt">species</span> with a density of approximately 5 × 1011 spins/cm2, which is comparable to the limit obtained for the presently available UHV-EPR spectrometer operating at 10 GHz (X-band). Investigation of electron trapped centers in MgO(001) films shows that the increased resolution offered by the experiments at W-band allows to identify new paramagnetic <span class="hlt">species</span>, that cannot be differentiated with the currently available methodology.</p> <div class="credits"> <p class="dwt_author">Rocker, J.; Cornu, D.; Kieseritzky, E.; Seiler, A.; Bondarchuk, O.; Hänsel-Ziegler, W.; Risse, T.; Freund, H.-J.</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-08-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">348</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/22320362"> <span id="translatedtitle">High field electron paramagnetic resonance spectroscopy under ultrahigh vacuum conditions—A <span class="hlt">multipurpose</span> machine to study paramagnetic <span class="hlt">species</span> on well defined single crystal surfaces</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">A new ultrahigh vacuum (UHV) electron paramagnetic resonance (EPR) spectrometer operating at 94 GHz to investigate paramagnetic centers on single crystal surfaces is described. It is particularly designed to study paramagnetic centers on well-defined model catalysts using epitaxial thin oxide films grown on metal single crystals. The EPR setup is based on a commercial Bruker E600 spectrometer, which is adapted to ultrahigh vacuum conditions using a home made Fabry Perot resonator. The key idea of the resonator is to use the planar metal single crystal required to grow the single crystalline oxide films as one of the mirrors of the resonator. EPR spectroscopy is solely sensitive to paramagnetic <span class="hlt">species</span>, which are typically minority <span class="hlt">species</span> in such a system. Hence, additional experimental characterization tools are required to allow for a comprehensive investigation of the surface. The apparatus includes a preparation chamber hosting equipment, which is required to prepare supported model catalysts. In addition, surface characterization tools such as low energy electron diffraction (LEED)/Auger spectroscopy, temperature programmed desorption (TPD), and infrared reflection absorption spectroscopy (IRAS) are available to characterize the surfaces. A second chamber used to perform EPR spectroscopy at 94 GHz has a room temperature scanning tunneling microscope attached to it, which allows for real space structural characterization. The heart of the UHV adaptation of the EPR experiment is the sealing of the Fabry-Perot resonator against atmosphere. To this end it is possible to use a thin sapphire window glued to the backside of the coupling orifice of the Fabry Perot resonator. With the help of a variety of stabilization measures reducing vibrations as well as thermal drift it is possible to accumulate data for a time span, which is for low temperature measurements only limited by the amount of liquid helium. Test measurements show that the system can detect paramagnetic <span class="hlt">species</span> with a density of approximately 5 × 10{sup 11} spins/cm{sup 2}, which is comparable to the limit obtained for the presently available UHV-EPR spectrometer operating at 10 GHz (X-band). Investigation of electron trapped centers in MgO(001) films shows that the increased resolution offered by the experiments at W-band allows to identify new paramagnetic <span class="hlt">species</span>, that cannot be differentiated with the currently available methodology.</p> <div class="credits"> <p class="dwt_author">Rocker, J.; Cornu, D.; Kieseritzky, E.; Hänsel-Ziegler, W.; Freund, H.-J. [Fritz-Haber-Institut der MPG, Faradayweg 4-6, 14195 Berlin (Germany); Seiler, A. [Fritz-Haber-Institut der MPG, Faradayweg 4-6, 14195 Berlin (Germany); Laboratorium für Applikationen der Synchrotronstrahlung, KIT Campus Süd, Kaiserstr. 12, 76131 Karlsruhe (Germany); Bondarchuk, O. [Fritz-Haber-Institut der MPG, Faradayweg 4-6, 14195 Berlin (Germany); CIC energiGUNE, Parque Tecnologico, C/Albert Einstein 48, CP 01510 Minano (Alava) (Spain); Risse, T., E-mail: risse@chemie.fu-berlin.de [Fritz-Haber-Institut der MPG, Faradayweg 4-6, 14195 Berlin (Germany); Institut für Chemie und Biochemie, Freie Universität Berlin, Takustr. 3, 14195 Berlin (Germany)</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-08-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">349</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/22445447"> <span id="translatedtitle">Gene <span class="hlt">trees</span>, <span class="hlt">species</span> <span class="hlt">trees</span>, and morphology converge on a similar phylogeny of living gars (Actinopterygii: Holostei: Lepisosteidae), an ancient clade of ray-finned fishes.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Extant gars represent the remaining members of a formerly diverse assemblage of ancient ray-finned fishes and have been the subject of multiple phylogenetic analyses using morphological data. Here, we present the first hypothesis of phylogenetic relationships among living gar <span class="hlt">species</span> based on molecular data, through the examination of gene <span class="hlt">tree</span> heterogeneity and coalescent <span class="hlt">species</span> <span class="hlt">tree</span> analyses of a portion of one mitochondrial (COI) and seven nuclear (ENC1, myh6, plagl2, S7 ribosomal protein intron 1, sreb2, tbr1, and zic1) genes. Individual gene <span class="hlt">trees</span> displayed varying degrees of resolution with regards to <span class="hlt">species</span>-level relationships, and the gene <span class="hlt">trees</span> inferred from COI and the S7 intron were the only two that were completely resolved. Coalescent <span class="hlt">species</span> <span class="hlt">tree</span> analyses of nuclear genes resulted in a well-resolved and strongly supported phylogenetic <span class="hlt">tree</span> of living gar <span class="hlt">species</span>, for which Bayesian posterior node support was further improved by the inclusion of the mitochondrial gene. <span class="hlt">Species</span>-level relationships among gars inferred from our molecular data set were highly congruent with previously published morphological phylogenies, with the exception of the placement of two <span class="hlt">species</span>, Lepisosteus osseus and L. platostomus. Re-examination of the character coding used by previous authors provided partial resolution of this topological discordance, resulting in broad concordance in the phylogenies inferred from individual genes, the coalescent <span class="hlt">species</span> <span class="hlt">tree</span> analysis, and morphology. The completely resolved phylogeny inferred from the molecular data set with strong Bayesian posterior support at all nodes provided insights into the potential for introgressive hybridization and patterns of allopatric speciation in the evolutionary history of living gars, as well as a solid foundation for future examinations of functional diversification and evolutionary stasis in a "living fossil" lineage. PMID:22445447</p> <div class="credits"> <p class="dwt_author">Wright, Jeremy J; David, Solomon R; Near, Thomas J</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-06-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">350</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Fritts, Thomas H.; Rodda, Gordon H.</p> <p class="dwt_publisher"></p> <p class="publishDate">1989-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">351</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/22902686"> <span id="translatedtitle">Tuning of color contrast signals to visual sensitivity maxima of <span class="hlt">tree</span> shrews by three Bornean highland Nepenthes <span class="hlt">species</span>.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Three <span class="hlt">species</span> of Nepenthes pitcher plants (Nepenthes rajah, Nepenthes lowii and Nepenthes macrophylla) specialize in harvesting nutrients from <span class="hlt">tree</span> shrew excreta in their pitchers. In all three <span class="hlt">species</span>, nectaries on the underside of the pitcher lid are the focus of the <span class="hlt">tree</span> shrews' attention. <span class="hlt">Tree</span> shrews are dichromats, with visual sensitivity in the blue and green wavebands. All three Nepenthes <span class="hlt">species</span> were shown to produce visual signals, in which the underside of the pitcher lid (the area of highest nectar production) stood out in high contrast to the adjacent area on the pitcher (i.e., was brighter), in the blue and green wavebands visible to the <span class="hlt">tree</span> shrews. N. rajah showed the tightest degree of "tuning," notably in the green waveband. Conversely, pitchers of Nepenthes burbidgeae, a typical insectivorous <span class="hlt">species</span> sympatric with N. rajah, did not produce a color pattern tuned to <span class="hlt">tree</span> shrew sensitivity maxima. PMID:22902686</p> <div class="credits"> <p class="dwt_author">Moran, Jonathan A; Clarke, Charles; Greenwood, Melinda; Chin, Lijin</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-10-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">352</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3493410"> <span id="translatedtitle">Tuning of color contrast signals to visual sensitivity maxima of <span class="hlt">tree</span> shrews by three Bornean highland Nepenthes <span class="hlt">species</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Three <span class="hlt">species</span> of Nepenthes pitcher plants (Nepenthes rajah, Nepenthes lowii and Nepenthes macrophylla) specialize in harvesting nutrients from <span class="hlt">tree</span> shrew excreta in their pitchers. In all three <span class="hlt">species</span>, nectaries on the underside of the pitcher lid are the focus of the <span class="hlt">tree</span> shrews' attention. <span class="hlt">Tree</span> shrews are dichromats, with visual sensitivity in the blue and green wavebands. All three Nepenthes <span class="hlt">species</span> were shown to produce visual signals, in which the underside of the pitcher lid (the area of highest nectar production) stood out in high contrast to the adjacent area on the pitcher (i.e., was brighter), in the blue and green wavebands visible to the <span class="hlt">tree</span> shrews. N. rajah showed the tightest degree of “tuning,” notably in the green waveband. Conversely, pitchers of Nepenthes burbidgeae, a typical insectivorous <span class="hlt">species</span> sympatric with N. rajah, did not produce a color pattern tuned to <span class="hlt">tree</span> shrew sensitivity maxima. PMID:22902686</p> <div class="credits"> <p class="dwt_author">Moran, Jonathan A.; Clarke, Charles; Greenwood, Melinda; Chin, Lijin</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">353</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary"><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> <div class="credits"> <p class="dwt_author">Bassow, S.L.; Bazzaz, F.A. [Harvard Univ., Cambridge, MA (United States). Dept. of Organismic and Evolutionary Biology</p> <p class="dwt_publisher"></p> <p class="publishDate">1998-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">354</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Rogers, Brendan M.; Soja, Amber J.; Goulden, Michael L.; Randerson, James T.</p> <p class="dwt_publisher"></p> <p class="publishDate">2015-03-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">355</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://pubs.er.usgs.gov/publication/70003746"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Cross, Alison; Perakis, Steven S.</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">356</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/22659458"> <span id="translatedtitle">Environmental control of daily stem growth patterns in five temperate broad-leaved <span class="hlt">tree</span> <span class="hlt">species</span>.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary"><span class="hlt">Tree</span> ring analysis investigates growth processes at time horizons of several weeks to millennia, but lacks the detail of short-term fluctuation in cambial activity. This study used electronic high-precision dendrometry for analyzing the environmental factors controlling stem diameter variation and radial growth in daily resolution in five co-existing temperate broad-leaved <span class="hlt">tree</span> <span class="hlt">species</span> (genera Fraxinus, Acer, Carpinus, Tilia and Fagus) with different growth and survival strategies. Daily stem radius change (SRC(d)) was primarily influenced by the atmospheric demand for water vapor (expressed either as vapor pressure deficit (D) or relative air humidity (RH)) while rainfall, soil matrix potential, temperature and radiation were only secondary factors. SRC(d) increased linearly with increasing RH and decreasing D in all <span class="hlt">species</span>. The positive effect of a low atmospheric water vapor demand on SRC(d) was largest in June during the period of maximal radial growth rate and persisted when observation windows of 7 or 21 days instead of 1 day were used. We found a high synchronicity in the day-to-day growth rate fluctuation among the <span class="hlt">species</span> with increment peaks corresponding to air humidity maxima, even though the mean daily radial growth rate differed fivefold among the <span class="hlt">species</span>. The five -<span class="hlt">species</span> also differed in the positive slope of the growth/RH relationship with the steepest increase found in Fraxinus and the lowest in Fagus. We explain the strong positive effect of high RH and low D on radial stem increment by lowered transpiration which reduces negative pressure in the conducting system and increases turgor in the stem cambium cells, thereby favoring cell division and expansion. The results suggest that mechanistic models of <span class="hlt">tree</span> growth need to consider the atmospheric water status in addition to the known controlling environmental factors: temperature, soil moisture and precipitation. The results further have implications for sensitivity analyses of <span class="hlt">tree</span> growth to climatic changes. PMID:22659458</p> <div class="credits"> <p class="dwt_author">Köcher, Paul; Horna, Viviana; Leuschner, Christoph</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-08-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">357</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3986928"> <span id="translatedtitle">High-throughput transcriptome sequencing and preliminary functional analysis in four Neotropical <span class="hlt">tree</span> <span class="hlt">species</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Background The Amazonian rainforest is predicted to suffer from ongoing environmental changes. Despite the need to evaluate the impact of such changes on <span class="hlt">tree</span> genetic diversity, we almost entirely lack genomic resources. Results In this study, we analysed the transcriptome of four tropical <span class="hlt">tree</span> <span class="hlt">species</span> (Carapa guianensis, Eperua falcata, Symphonia globulifera and Virola michelii) with contrasting ecological features, belonging to four widespread botanical families (respectively Meliaceae, Fabaceae, Clusiaceae and Myristicaceae). We sequenced cDNA libraries from three organs (leaves, stems, and roots) using 454 pyrosequencing. We have developed an R and bioperl-based bioinformatic procedure for de novo assembly, gene functional annotation and marker discovery. Mismatch identification takes into account single-base quality values as well as the likelihood of false variants as a function of contig depth and number of sequenced chromosomes. Between 17103 (for Symphonia globulifera) and 23390 (for Eperua falcata) contigs were assembled. Organs varied in the numbers of unigenes they apparently express, with higher number in roots. Patterns of gene expression were similar across <span class="hlt">species</span>, with metabolism of aromatic compounds standing out as an overrepresented gene function. Transcripts corresponding to several gene functions were found to be over- or underrepresented in each organ. We identified between 4434 (for Symphonia globulifera) and 9076 (for Virola surinamensis) well-supported mismatches. The resulting overall mismatch density was comprised between 0.89 (S. globulifera) and 1.05 (V. surinamensis) mismatches/100 bp in variation-containing contigs. Conclusion The relative representation of gene functions in the four transcriptomes suggests that secondary metabolism may be particularly important in tropical <span class="hlt">trees</span>. The differential representation of transcripts among tissues suggests differential gene expression, which opens the way to functional studies in these non-model, ecologically important <span class="hlt">species</span>. We found substantial amounts of mismatches in the four <span class="hlt">species</span>. These newly identified putative variants are a first step towards acquiring much needed genomic resources for tropical <span class="hlt">tree</span> <span class="hlt">species</span>. PMID:24673733</p> <div class="credits"> <p class="dwt_author"></p> <p class="dwt_publisher"></p> <p class="publishDate">2014-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">358</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/40150306"> <span id="translatedtitle">Carbon dioxide exchange of C 3 and C 4 <span class="hlt">tree</span> <span class="hlt">species</span> in the understory of a Hawaiian forest</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Field measurements of photosynthetic CO2 exchange were made on saplings of a C4 <span class="hlt">tree</span> <span class="hlt">species</span>, Euphorbia forbesii, and a C3 <span class="hlt">tree</span> <span class="hlt">species</span>, Claoxylon sandwicense, in a shaded mesic forest on Oahu, Hawaii. Both <span class="hlt">species</span> had light responses typical of those generally found in shade plants. Light saturated photosynthetic rates were 7.15 and 4.09 µmol m2 s1 and light compensation points</p> <div class="credits"> <p class="dwt_author">Robert W. Pearcy; Howard W. Calkin</p> <p class="dwt_publisher"></p> <p class="publishDate">1983-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">359</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Kubisch, Petra; Hertel, Dietrich; Leuschner, Christoph</p> <p class="dwt_publisher"></p> <p class="publishDate">2015-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">360</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4183311"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Stahl, Ulrike; Reu, Björn; Wirth, Christian</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-01-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_17");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> 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src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">361</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Stahl, Ulrike; Reu, Björn; Wirth, Christian</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-09-23</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">362</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Schrago, Carlos G.; Menezes, Albert N.; Furtado, Carolina; Bonvicino, Cibele R.; Seuanez, Hector N.</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">363</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Sáez-Laguna, Enrique; Guevara, María-Ángeles; Díaz, Luis-Manuel; Sánchez-Gómez, David; Collada, Carmen; Aranda, Ismael; Cervera, María-Teresa</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">364</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Montelius, Malin; Thiry, Yves; Marang, Laura; Ranger, Jacques; Cornelis, Jean-Thomas; Svensson, Teresia; Bastviken, David</p> <p class="dwt_publisher"></p> <p class="publishDate">2015-04-21</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">365</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Masaki, T; Hata, S; Ide, Y</p> <p class="dwt_publisher"></p> <p class="publishDate">2015-03-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">366</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Vijayan, R; Bedi, S J</p> <p class="dwt_publisher"></p> <p class="publishDate">1989-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">367</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/23416882"> <span id="translatedtitle">Analyzing lead absorption by the sycamore <span class="hlt">tree</span> <span class="hlt">species</span> in the industrial park of Rasht, Iran.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">In this study, the subject of heavy metal concentration in soil, rock, sediment, surface water and groundwater, which can be caused by natural or man-posed pollution, was analyzed in the industrial park of Rasht. These concentrations were compared with the standard range of environmental data. Heavy metals are important environmental pollutants that can cause health hazards to humans, plants and microorganisms by entering food chain. This study aimed to investigate the absorption of lead by the leaves of sycamore <span class="hlt">tree</span> <span class="hlt">species</span> in the industrial park of Rasht. For this purpose, a sample of 32 sycamore <span class="hlt">tree</span> <span class="hlt">species</span> were randomly selected at a specified time, and the concentration of lead were measured using an atomic absorption device. Results showed that the amount of lead absorption by sycamore leaves is remarkable. The highest amount of lead absorption by sycamore leaves was detected at station 1 (Khazar Steel) and the lowest amount at station 2 (control station). PMID:23416882</p> <div class="credits"> <p class="dwt_author">Hashemi, Seyed Armin; Fallahchay, Mir Mozaffar; Tarighi, Fattaneh</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-02-15</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">368</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.outdoorbiology.com/files/resources/activities/TreeTally.pdf"> <span id="translatedtitle"><span class="hlt">Tree</span> Tally</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://nsdl.org/nsdl_dds/services/ddsws1-1/service_explorer.jsp">NSDL National Science Digital Library</a></p> <p class="result-summary">In this outdoor activity and fun race, learners first find the most common type of <span class="hlt">tree</span> in a forest site. Learners use a "transect," a kind of sampling technique, to estimate the number of different kinds of <span class="hlt">trees</span>, and a histogram, or simple graph, to record how frequently different <span class="hlt">tree</span> <span class="hlt">species</span> occur in the forest. Learners also select one <span class="hlt">species</span> of <span class="hlt">tree</span>, and run a forest leap frog race between <span class="hlt">trees</span> of that <span class="hlt">species</span>. (Older learners can just run between <span class="hlt">trees</span> without leapfrogging.)</p> <div class="credits"> <p class="dwt_author">Lawrence Hall of Science</p> <p class="dwt_publisher"></p> <p class="publishDate">1982-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">369</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.springerlink.com/index/m7vp1751027p5103.pdf"> <span id="translatedtitle">Ecophysiological responses of Japanese forest <span class="hlt">tree</span> <span class="hlt">species</span> to ozone, simulated acid rain and soil acidification</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">In this review, I summarized the results obtained from experimental studies on the ecophysiological responses of Japanese\\u000a forest <span class="hlt">tree</span> <span class="hlt">species</span> to O3, simulated acid rain and soil acidification. Based on the studies conducted in Japan, exposure to ambient levels of O3 below 100 nl·l?1 (ppb) for several months is sufficient to inhibit dry matter production and net photosynthesis of sensitive</p> <div class="credits"> <p class="dwt_author">Takeshi Izuta</p> <p class="dwt_publisher"></p> <p class="publishDate">1998-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">370</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.springerlink.com/index/ap807hm116k71567.pdf"> <span id="translatedtitle">Correlation between leaf litter and fine root decomposition among subtropical <span class="hlt">tree</span> <span class="hlt">species</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Elucidating the processes of leaf litter and fine root decomposition has been a major research focus, while how the correlation\\u000a between leaf litter and fine root decomposition is unclear. We studied the in situ decomposition and N dynamics of leaf litter\\u000a and fine root of four subtropical <span class="hlt">tree</span> <span class="hlt">species</span> (Pinus massoniana, Castanopsis hystrix, Michelia macclurei and Mytilaria laosensis) to determine</p> <div class="credits"> <p class="dwt_author">Hui Wang; Shirong Liu; Jiangming Mo</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">371</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.springerlink.com/index/l0l2575148816001.pdf"> <span id="translatedtitle">Leaf litter decomposition of dominant <span class="hlt">tree</span> <span class="hlt">species</span> of Namdapha National Park, Arunachal Pradesh, northeast India</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Rates of weight loss and nutrient (N and P) release patterns were studied in the leaf litter of the dominant <span class="hlt">tree</span> <span class="hlt">species</span>\\u000a (Ailanthus grandis, Altingia excelsa, Castanopsis indica, Duabanga sonneriatioides, Dysoxylum binectariferum, Mesua ferrea,\\u000a Shorea assamica, Taluma hodgsonii, Terminalia myriocarpa and Vatica lancefolia) of a tropical wet evergreen forest of northeast India. Nitrogen and phosphorus mineralization rate and decay pattern</p> <div class="credits"> <p class="dwt_author">Atiqur Rahman Barbhuiya; Ayyanadar Arunachalam; Prabhat Chandra Nath; Mohammed Latif Khan; Kusum Arunachalam</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">372</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.bio.txstate.edu/%7eschwinn/SchwinningHP/downloads/Schwinning08.pdf"> <span id="translatedtitle">The water relations of two evergreen <span class="hlt">tree</span> <span class="hlt">species</span> in a karst savanna</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The ecohydrology of karst has not received much attention, despite the disproportionally large contribution of karst aquifers\\u000a to freshwater supplies. Karst savannas, like many savannas elsewhere, are encroached by woody plants, with possibly negative\\u000a consequences on aquifer recharge. However, the role of savanna <span class="hlt">tree</span> <span class="hlt">species</span> in hydrological processes remains unclear, not\\u000a least because the location and water absorption zones of</p> <div class="credits"> <p class="dwt_author">Susanne Schwinning</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">373</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://redbuttecanyon.net/literature/Hultine_Oecologia_2007.pdf"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The global water cycle is intimately linked to vegetation structure and function. Nowhere is this more apparent than in the\\u000a arid west where riparian forests serve as ribbons of productivity in otherwise mostly unproductive landscapes. Dioecy is common\\u000a 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\\u000a male and female dioecious riparian</p> <div class="credits"> <p class="dwt_author">K. R. Hultine; S. E. Bush; A. G. West; J. R. Ehleringer</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">374</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/19798976"> <span id="translatedtitle">[Research on identification of <span class="hlt">species</span> of fruit <span class="hlt">trees</span> by spectral analysis].</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Using the spectral reflectance data (R2) of canopies, the present paper identifies seven <span class="hlt">species</span> of fruit <span class="hlt">trees</span> bearing fruit in the fruit mature period. Firstly, it compares the fruit <span class="hlt">tree</span> <span class="hlt">species</span> identification capability of six kinds of satellite sensors and four kinds of vegetation index through re-sampling the spectral data with six kinds of pre-defined filter function and the related data processing of calculating vegetation indexes. Then, it structures a BP neural network model for identifying seven <span class="hlt">species</span> of fruit <span class="hlt">trees</span> on the basis of choosing the best transformation of R(lambda) and optimizing the model parameters. The main conclusions are: (1) the order of the identification capability of the six kinds of satellite sensors from strong to weak is: MODIS, ASTER, ETM+, HRG, QUICKBIRD and IKONOS; (2) among the four kinds of vegetation indexes, the identification capability of RVI is the most powerful, the next is NDVI, while the identification capability of SAVI or DVI is relatively weak; (3) The identification capability of RVI and NDVI calculated with the reflectance of near-infrared and red channels of ETM+ or MODIS sensor is relatively powerful; (4) Among R(lambda) and its 22 kinds of transformation data, d1 [log(1/R(lambda))](derivative gap is set 9 nm) is the best transformation for structuring BP neural network model; (5) The paper structures a 3-layer BP neural network model for identifying seven <span class="hlt">species</span> of fruit <span class="hlt">trees</span> using the best transformation of R(lambda) which is d1 [log(1/R(lambda))](derivative gap is set 9 nm). PMID:19798976</p> <div class="credits"> <p class="dwt_author">Xing, Dong-Xing; Chang, Qing-Rui</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-07-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">375</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/41923155"> <span id="translatedtitle">Core and Satellite <span class="hlt">Species</span> in Degraded Habitats: an Analysis Using Malagasy <span class="hlt">Tree</span> Communities</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Core-satellite theory predicts that, via the “rescue effect”, widespread, abundant <span class="hlt">species</span> should have reduced risk of local\\u000a extinctions. We test this hypothesis in southeastern Malagasy littoral forest using data on distribution and abundance of\\u000a <span class="hlt">trees</span> and woody understory vegetation in tropical forest fragments along a disturbance gradient. We partition the mortality\\u000a risk into two kinds of extinction factors, separately operating</p> <div class="credits"> <p class="dwt_author">Marc W. Cadotte; Jon Lovett-Doust</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">376</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/39795528"> <span id="translatedtitle">Fine-root mass, growth and nitrogen content for six tropical <span class="hlt">tree</span> <span class="hlt">species</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Although fine roots might account for 50% of the annual net primary productivity in moist tropical forests, there are relatively\\u000a few studies of fine-root dynamics in this biome. We examined fine-root distributions, mass, growth and tissue N and C concentrations\\u000a for six <span class="hlt">tree</span> <span class="hlt">species</span> established in 16-year-old plantations in the Caribbean lowlands of Costa Rica in a randomized-block\\u000a design (n?=?4).</p> <div class="credits"> <p class="dwt_author">Oscar J. Valverde-Barrantes; James W. Raich; Ann E. Russell</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">377</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/45706818"> <span id="translatedtitle">Coniochaeta (Lecythophora), Collophora gen. nov. and Phaeomoniella <span class="hlt">species</span> associated with wood necroses of Prunus <span class="hlt">trees</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary"><span class="hlt">Species</span> of the genus Coniochaeta (anamorph: Lecythophora) are known as pathogens of woody hosts, but can also cause opportunistic human infections. Several fungi with conidial stages resembling Lecythophora were isolated from necrotic wood samples of Prunus <span class="hlt">trees</span> in South Africa. In order to reveal their phylogenetic relationships, these fungi were studied on a morphological and molecular (5.8S nrDNA, ITS-1, ITS-2,</p> <div class="credits"> <p class="dwt_author">U. Damm; P. H. Fourie; P. W. Crous</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">378</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/47606351"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">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\\u000a floodplain forests. The importance of these disturbances may be most notable during the germination and establishment phases\\u000a of plant succession. Channelization of most alluvial systems in the southeastern United States has caused dramatic and systematic\\u000a alterations to both hydrologic and sedimentation processes of</p> <div class="credits"> <p class="dwt_author">Aaron R. Pierce; Sammy L. King</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">379</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">In tropical forests light and water availability are the most important factors for seedling growth and survival but an increasing frequency of drought may affect <span class="hlt">tree</span> regeneration. One central question is whether drought and shade have interactive effects on seedling growth and survival. Here, we present results of a greenhouse experiment, in which seedlings of 10 Ghanaian <span class="hlt">tree</span> <span class="hlt">species</span> were exposed to combinations of strong seasonal drought (continuous watering versus withholding water for nine weeks) and shade (5% irradiance versus 20% irradiance). We evaluated the effects of drought and shade on seedling survival and growth and plasticity of 11 underlying traits related to biomass allocation, morphology and physiology. Seedling survival under dry conditions was higher in shade than in high light, thus providing support for the “facilitation hypothesis” that shade enhances plant performance through improved microclimatic conditions, and rejecting the trade-off hypothesis that drought should have stronger impact in shade because of reduced root investment. Shaded plants had low biomass fraction in roots, in line with the trade-off hypothesis, but they compensated for this with a higher specific root length (i.e., root length per unit root mass), resulting in a similar root length per plant mass and, hence, similar water uptake capacity as high-light plants. The majority (60%) of traits studied responded independently to drought and shade, indicating that within <span class="hlt">species</span> shade- and drought tolerances are not in trade-off, but largely uncoupled. When individual <span class="hlt">species</span> responses were analysed, then for most of the traits only one to three <span class="hlt">species</span> showed significant interactive effects between drought and shade. The uncoupled response of most <span class="hlt">species</span> to drought and shade should provide ample opportunity for niche differentiation and <span class="hlt">species</span> coexistence under a range of water and light conditions. Overall our greenhouse results suggest that, in the absence of root competition shaded tropical forest <span class="hlt">tree</span> seedlings may be able to survive prolonged drought. PMID:25836337</p> <div class="credits"> <p class="dwt_author">Amissah, Lucy; Mohren, Godefridus M. J.; Kyereh, Boateng; Poorter, Lourens</p> <p class="dwt_publisher"></p> <p class="publishDate">2015-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">380</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/19882174"> <span id="translatedtitle">Fine root decomposition rates do not mirror those of leaf litter among temperate <span class="hlt">tree</span> <span class="hlt">species</span>.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Elucidating the function of and patterns among plant traits above ground has been a major research focus, while the patterns and functioning of belowground traits remain less well understood. Even less well known is whether <span class="hlt">species</span> differences in leaf traits and their associated biogeochemical effects are mirrored by differences in root traits and their effects. We studied fine root decomposition and N dynamics in a common garden study of 11 temperate European and North American <span class="hlt">tree</span> <span class="hlt">species</span> (Abies alba, Acer platanoides, Acer pseudoplatanus, Carpinus betulus, Fagus sylvatica, Larix decidua, Picea abies, Pseudotsuga menziesii, Quercus robur, Quercus rubra and Tilia cordata) to determine whether leaf litter and fine root decomposition rates are correlated across <span class="hlt">species</span> as well as which <span class="hlt">species</span> traits influence microbial decomposition above versus below ground. Decomposition and N immobilization rates of fine roots were unrelated to those of leaf litter across <span class="hlt">species</span>. The lack of correspondence of above- and belowground processes arose partly because the tissue traits that influenced decomposition and detritus N dynamics different for roots versus leaves, and partly because influential traits were unrelated between roots and leaves across <span class="hlt">species</span>. For example, while high hemicellulose concentrations and thinner roots were associated with more rapid decomposition below ground, low lignin and high Ca concentrations were associated with rapid aboveground leaf decomposition. Our study suggests that among these temperate <span class="hlt">trees</span>, <span class="hlt">species</span> effects on C and N dynamics in decomposing fine roots and leaf litter may not reinforce each other. Thus, <span class="hlt">species</span> differences in rates of microbially mediated decomposition may not be as large as they would be if above- and belowground processes were working in similar directions (i.e., if faster decomposition above ground corresponded to faster decomposition below ground). Our results imply that studies that focus solely on aboveground traits may obscure some of the important mechanisms by which plant <span class="hlt">species</span> influence ecosystem processes. PMID:19882174</p> <div class="credits"> <p class="dwt_author">Hobbie, Sarah E; Oleksyn, Jacek; Eissenstat, David M; Reich, Peter B</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-02-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_18");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return 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title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">381</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/19997929"> <span id="translatedtitle">Altered resource availability and the population dynamics of <span class="hlt">tree</span> <span class="hlt">species</span> in Amazonian secondary forests.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Despite research demonstrating that water and nutrient availability exert strong effects on multiple ecosystem processes in tropical forests, little is known about the effect of these factors on the demography and population dynamics of tropical <span class="hlt">trees</span>. Over the course of 5 years, we monitored two common Amazonian secondary forest <span class="hlt">species</span>-Lacistema pubescens and Myrcia sylvatica-in dry-season irrigation, litter-removal and control plots. We then evaluated the effects of altered water and nutrient availability on population demography and dynamics using matrix models and life table response experiments. Our results show that despite prolonged experimental manipulation of water and nutrient availability, there were nearly no consistent and unidirectional treatment effects on the demography of either <span class="hlt">species</span>. The patterns and significance of observed treatment effects were largely dependent on cross-year variability not related to rainfall patterns, and disappeared once we pooled data across years. Furthermore, most of these transient treatment effects had little effect on population growth rates. Our results suggest that despite major experimental manipulations of water and nutrient availability-factors considered critical to the ecology of tropical pioneer <span class="hlt">tree</span> <span class="hlt">species</span>-autogenic light limitation appears to be the primary regulator of <span class="hlt">tree</span> demography at early/mid successional stages. Indeed, the effects of light availability may completely override those of other factors thought to influence the successional development of Amazonian secondary forests. PMID:19997929</p> <div class="credits"> <p class="dwt_author">Fortini, Lucas Berio; Bruna, Emilio M; Zarin, Daniel J; Vasconcelos, Steel S; Miranda, Izildinha S</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-04-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">382</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">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 class="dwt_publisher"></p> <p class="publishDate">2012-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">383</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Condit, Richard; Engelbrecht, Bettina M. J.; Pino, Delicia; Pérez, Rolando; Turner, Benjamin L.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">384</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/20444211"> <span id="translatedtitle">Flooding induced emissions of volatile signalling compounds in three <span class="hlt">tree</span> <span class="hlt">species</span> with differing waterlogging tolerance.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">To gain insight into variations in waterlogging responsiveness, net assimilation rate, stomatal conductance, emissions of isoprene and marker compounds of anoxic metabolism ethanol and acetaldehyde, and stress marker compounds nitric oxide (NO), volatile products of lipoxygenase (LOX) pathway and methanol were studied in seedlings of temperate deciduous <span class="hlt">tree</span> <span class="hlt">species</span> Alnus glutinosa, Populus tremula and Quercus rubra (from highest to lowest waterlogging tolerance) throughout sustained root zone waterlogging of up to three weeks. In all <span class="hlt">species</span>, waterlogging initially resulted in reductions in net assimilation and stomatal conductance and enhanced emissions of ethanol, acetaldehyde, NO, LOX products and methanol, followed by full or partial recovery depending on process and <span class="hlt">species</span>. Strong negative correlations between g(s) and internal NO concentration and NO flux, valid within and across <span class="hlt">species</span>, were observed throughout the experiment. Isoprene emission capacity was not related to waterlogging tolerance. Less waterlogging tolerant <span class="hlt">species</span> had greater reduction and smaller acclimation capacity in foliage physiological potentials, and larger emission bursts of volatile stress marker compounds. These data collectively provide encouraging evidence that emissions of volatile organics and NO can be used as quantitative measures of stress tolerance and acclimation kinetics in temperate <span class="hlt">trees</span>. PMID:20444211</p> <div class="credits"> <p class="dwt_author">Copolovici, Lucian; Niinemets, Ulo</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-09-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">385</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/48109703"> <span id="translatedtitle">Agroforestry <span class="hlt">tree</span> selection in central Chile: biological nitrogen fixation and early plant growth in six dryland <span class="hlt">species</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Growth rate, resource partitioning, and several biological traits related to biological N2 fixation for six native or non-native <span class="hlt">tree</span> <span class="hlt">species</span> were compared using 15N isotope dilution techniques. The <span class="hlt">trees</span> were field grown for six years in a semiarid mediterranean-climate region with five to six months a year of absolute drought. <span class="hlt">Trees</span> were tested as candidates for new agroforestry systems being</p> <div class="credits"> <p class="dwt_author">James Aronson; C. Ovalle; J. Avendaño; L. Longeri; A. Del Pozo</p> <p class="dwt_publisher"></p> <p class="publishDate">2002-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">386</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3040169"> <span id="translatedtitle">The Influence of Recent Climate Change on <span class="hlt">Tree</span> Height Growth Differs with <span class="hlt">Species</span> and Spatial Environment</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary"><span class="hlt">Tree</span> growth has been reported to increase in response to recent global climate change in controlled and semi-controlled experiments, but few studies have reported response of <span class="hlt">tree</span> growth to increased temperature and atmospheric carbon dioxide (CO2) concentration in natural environments. This study addresses how recent global climate change has affected height growth of trembling aspen (Populus tremuloides Michx) and black spruce (Picea mariana Mill B.S.) in their natural environments. We sampled 145 stands dominated by aspen and 82 dominated by spruce over the entire range of their distributions in British Columbia, Canada. These stands were established naturally after fire between the 19th and 20th centuries. Height growth was quantified as total heights of sampled dominant and co-dominant <span class="hlt">trees</span> at breast-height age of 50 years. We assessed the relationships between 50-year height growth and environmental factors at both spatial and temporal scales. We also tested whether the <span class="hlt">tree</span> growth associated with global climate change differed with spatial environment (latitude, longitude and elevation). As expected, height growth of both <span class="hlt">species</span> was positively related to temperature variables at the regional scale and with soil moisture and nutrient availability at the local scale. While height growth of trembling aspen was not significantly related to any of the temporal variables we examined, that of black spruce increased significantly with stand establishment date, the anomaly of the average maximum summer temperature between May-August, and atmospheric CO2 concentration, but not with the Palmer Drought Severity Index. Furthermore, the increase of spruce height growth associated with recent climate change was higher in the western than in eastern part of British Columbia. This study demonstrates that the response of height growth to recent climate change, i.e., increasing temperature and atmospheric CO2 concentration, did not only differ with <span class="hlt">tree</span> <span class="hlt">species</span>, but also their growing spatial environment. PMID:21358817</p> <div class="credits"> <p class="dwt_author">Messaoud, Yassine; Chen, Han Y. H.</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">387</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">The section Moutan of the genus Paeonia consists of eight <span class="hlt">species</span> that are confined to a small area in China. A wide range of metabolites, including monoterpenoid glucosides, flavonoids, tannins, stilbenes, triterpenoids, steroids, paeonols, and phenols, have been found in the <span class="hlt">species</span> belonging to section Moutan. However, although previous studies have analyzed the metabolites found in these <span class="hlt">species</span>, the metabolic similarities that can be used for the chemotaxonomic distinction of section Moutan <span class="hlt">species</span> are not yet clear. In this study, HPLC-DAD-based metabolic fingerprinting was applied to the classification of eight <span class="hlt">species</span>: Paeoniasuffruticosa, Paeoniaqiui, Paeoniaostii, Paeoniarockii, Paeoniajishanensis, Paeoniadecomposita, Paeoniadelavayi, and Paeonialudlowii. In total, of the 47 peaks that exhibited an occurrence frequency of 75% in all 23 <span class="hlt">tree</span> peony samples, 43 of these metabolites were identified according to their retention times and UV absorption spectra, together with combined HPLC-QTOF-MS. These data were compared with reference standard compounds. The 43 isolated compounds included 17 monoterpenoid glucosides, 11 galloyl glucoses, 5 flavonoids, 6 paeonols and 4 phenols. Principal component analysis (PCA), and hierarchical cluster analysis (HCA), showed a clear separation between the <span class="hlt">species</span> based on metabolomics similarities and four groups were identified. The results exhibited good agreement with the classical classification based on the morphological characteristics and geographical distributions of the subsections Vaginatae F.C. Stern and Delavayanae F.C. Stern with the exception of P. decomposita, which was found to be a transition <span class="hlt">species</span> between these two subsections. According to their metabolic fingerprinting characteristics, P. ostii and P. suffruticosa can be considered one <span class="hlt">species</span>, and this result is consistent with the viewpoint of medicinal plant scientists but different from that of classical morphological processing. Significantly large variations were obtained in the metabolic profiles of P. delavayi, whereas no significant difference was found between P. delavayi and P. ludlowii. This indicates that these two <span class="hlt">species</span> have a close genetic relationship. In conclusion, the combination of HPLC-DAD and multivariate analyses has great potential for guiding future chemotaxonomic studies to examine the potential pharmaceutical value of the effective constituents of <span class="hlt">tree</span> peony <span class="hlt">species</span> and appears to be able to clarify the confusion and skepticism associated with the reported morphology- and molecular phylogenetics-based taxonomy of <span class="hlt">tree</span> peonies. PMID:25220499</p> <div class="credits"> <p class="dwt_author">He, Chunnian; Peng, Bing; Dan, Yang; Peng, Yong; Xiao, Peigen</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-11-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">388</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Background Plant leaves, as the main photosynthetic organs and the high energy converters among primary producers in terrestrial ecosystems, have attracted significant research attention. Leaf lifespan is an adaptive characteristic formed by plants to obtain the maximum carbon in the long-term adaption process. It determines important functional and structural characteristics exhibited in the environmental adaptation of plants. However, the leaf lifespan and leaf characteristics of urban forests were not studied up to now. Methods By using statistic, linear regression methods and correlation analysis, leaf phenological characters of main <span class="hlt">tree</span> <span class="hlt">species</span> in urban forest of Shenyang were observed for five years to obtain the leafing phenology (including leafing start time, end time, and duration), defoliating phenology (including defoliation start time, end time, and duration), and the leaf lifespan of the main <span class="hlt">tree</span> <span class="hlt">species</span>. Moreover, the relationships between temperature and leafing phenology, defoliating phenology, and leaf lifespan were analyzed. Findings The timing of leafing differed greatly among <span class="hlt">species</span>. The early leafing <span class="hlt">species</span> would have relatively early end of leafing; the longer it took to the end of leafing would have a later time of completed leafing. The timing of defoliation among different <span class="hlt">species</span> varied significantly, the early defoliation <span class="hlt">species</span> would have relatively longer duration of defoliation. If the mean temperature rise for 1°C in spring, the time of leafing would experience 5 days earlier in spring. If the mean temperature decline for 1°C, the time of defoliation would experience 3 days delay in autumn. Interpretation There is significant correlation between leaf longevity and the time of leafing and defoliation. According to correlation analysis and regression analysis, there is significant correlation between temperature and leafing and defoliation phenology. Early leafing <span class="hlt">species</span> would have a longer life span and consequently have advantage on carbon accumulation compared with later defoliation <span class="hlt">species</span>. PMID:24963625</p> <div class="credits"> <p class="dwt_author">Xu, Sheng; Xu, Wenduo; Chen, Wei; He, Xingyuan; Huang, Yanqing; Wen, Hua</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">389</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2008AGUFM.B31G0384N"> <span id="translatedtitle">Detecting CO2 Fertilization in <span class="hlt">Tree</span> Ring Records: Evidence from Natural Populations of Boreal Forest <span class="hlt">Species</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Global increases of atmospheric CO2 concentration are predicted to enhance <span class="hlt">tree</span> growth, particularly where water limitation is important, but evidence of CO2 fertilization in Canada's forests is limited. This study examined the effect of increasing atmospheric CO2 concentration on <span class="hlt">tree</span> ring increments in south-east Yukon, west-central Manitoba and northern Ontario, sampling the dominant <span class="hlt">tree</span> <span class="hlt">species</span> at each site: lodgepole pine (Pinus contorta), white spruce (Picea glauca) and black spruce (Picea mariana), respectively. Over 50 <span class="hlt">tree</span> cores from each site were sampled, analysed for ring-width, cross- dated and averaged, generating a ~100 y chronology for each population. We examined the residuals following a regression with climate variables for a positive trend over time, which has been interpreted in prior studies as evidence for a CO2 fertilization effect. We were only able to detect an increase in ring width residuals over time in the Manitoba white spruce population, which were located at the most water-limited site. We did further analyses to see whether CO2 fertilization was stronger or more detectable in younger <span class="hlt">trees</span> or more water-limited years. Although we were unable to find any evidence that drier years experienced increases in relative growth as a result of increased CO2 availability, we did find stronger CO2 responses in younger <span class="hlt">trees</span>. In conclusion, forest populations that are water-limited or young in age are more likely to benefit from global increases in atmospheric CO2 concentration, and are better able to contribute to overall boreal forest carbon sequestration.</p> <div class="credits"> <p class="dwt_author">Nelson, E. A.; Thomas, S. C.</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">390</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2005AGUSMNB22F..03S"> <span id="translatedtitle">The Role of Native <span class="hlt">Tree</span> <span class="hlt">Species</span> on Leaf Breakdown Dynamics of the Invasive <span class="hlt">Tree</span> of Heaven ( Ailanthus altissima) in an Urban Stream</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Anthropogenic disturbance of ecosystem processes is increasingly being explored in urban settings. One profound impact is the striking increase in the distribution of invasive plant <span class="hlt">species</span>. For example, <span class="hlt">Tree</span> of Heaven (Ailanthus altissima, TOH), introduced into the U.S. from Asia in 1784, is a successful colonist of recently deforested habitats. As a result, remnant patches in urban ecosystems have become overrun with this <span class="hlt">tree</span> <span class="hlt">species</span>, excluding native <span class="hlt">species</span> via fast growth and allelopathy. While suffering from human-induced degradation, urban streams still support food webs that function to process riparian-derived organic matter (e.g., leaves, wood). The purpose of this study was to (1) estimate leaf litter breakdown of native <span class="hlt">tree</span> leaves and those of TOH in an urban stream, (2) study the detritivore feeding rate of the same leaf <span class="hlt">species</span>, and (3) determine if increasing native <span class="hlt">species</span> richness of leaf litter can alter breakdown of TOH leaves. Field manipulations of leaf pack composition were done in a highly urbanized stream (>30% upstream urban land use) in Baltimore County, Maryland, USA. This was complimented by a series of laboratory feeding experiments employing similar leaf treatments and local shredding invertebrate taxa. Breakdown of TOH alone was extremely rapid, significantly exceeding that of all native <span class="hlt">tree</span> <span class="hlt">species</span> employed. Furthermore, mixing TOH with native <span class="hlt">tree</span> <span class="hlt">species</span>, red maple and white oak, substantially reduced TOH decay compared to decay of TOH alone. However, supporting laboratory studies showed that TOH was a preferred resource by shredding invertebrates over all native <span class="hlt">species</span>. Subsequent analysis of the structural integrity of all leaf <span class="hlt">species</span> revealed that TOH was the least resistant to force, possibly explaining the counterintuitive decrease of TOH decay in mixtures. We interpret this as meaning the stream invertebrates, while preferring to consume TOH, appeared not to influence TOH decay in mixtures with native <span class="hlt">species</span>. Instead, the relatively tougher nature of native <span class="hlt">species</span> appeared to slow TOH breakdown by armoring the invasive from the highly-variable flow regime characteristic of urban streams. Therefore, the presence of native <span class="hlt">tree</span> <span class="hlt">species</span> in urban riparian zones may be critical to how invasive <span class="hlt">trees</span>, like TOH, could alter carbon flux in urban streams.</p> <div class="credits"> <p class="dwt_author">Swan, C.; Healey, B.</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-05-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">391</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2010PhDT.......140B"> <span id="translatedtitle">Seasonal trends in separability of leaf reflectance spectra for Ailanthus altissima and four other <span class="hlt">tree</span> <span class="hlt">species</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">This project investigated the spectral separability of the invasive <span class="hlt">species</span> Ailanthus altissima, commonly called <span class="hlt">tree</span> of heaven, and four other native <span class="hlt">species</span>. Leaves were collected from Ailanthus and four native <span class="hlt">tree</span> <span class="hlt">species</span> from May 13 through August 24, 2008, and spectral reflectance factor measurements were gathered for each <span class="hlt">tree</span> using an ASD (Boulder, Colorado) FieldSpec Pro full-range spectroradiometer. The original data covered the range from 350-2500 nm, with one reflectance measurement collected per one nm wavelength. To reduce dimensionality, the measurements were resampled to the actual resolution of the spectrometer's sensors, and regions of atmospheric absorption were removed. Continuum removal was performed on the reflectance data, resulting in a second dataset. For both the reflectance and continuum removed datasets, least angle regression (LARS) and random forest classification were used to identify a single set of optimal wavelengths across all sampled dates, a set of optimal wavelengths for each date, and the dates for which Ailanthus is most separable from other <span class="hlt">species</span>. It was found that classification accuracy varies both with dates and bands used. Contrary to expectations that early spring would provide the best separability, the lowest classification error was observed on July 22 for the reflectance data, and on May 13, July 11 and August 1 for the continuum removed data. This suggests that July and August are also potentially good months for <span class="hlt">species</span> differentiation. Applying continuum removal in many cases reduced classification error, although not consistently. Band selection seems to be more important for reflectance data in that it results in greater improvement in classification accuracy, and LARS appears to be an effective band selection tool. The optimal spectral bands were selected from across the spectrum, often with bands from the blue (401-431 nm), NIR (1115 nm) and SWIR (1985-1995 nm), suggesting that hyperspectral sensors with broad wavelength sensitivity are important for mapping and identification of Ailanthus.</p> <div class="credits"> <p class="dwt_author">Burkholder, Aaron</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">392</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Pierce, A.R.; King, S.L.</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">393</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.amjbot.org/cgi/reprint/88/6/1041.pdf"> <span id="translatedtitle">Cross-Fertility in Two Tropical <span class="hlt">Tree</span> <span class="hlt">Species</span>: Evidence of Inbreeding Depression within Populations and Genetic Divergence among Populations</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Knowing the spatial patterns of cross-fertility in natural plant populations yields key insight into biparental inbreeding depression, isolation by distance, and, ultimately, speciation. Three adults each of two tropical <span class="hlt">tree</span> <span class="hlt">species</span> ( Syzygium rubicundum and Shorea cordifolia) were each crossed with five conspecific pollen donors ranging from self to <span class="hlt">trees</span> occurring in separate forest reserves (12 and 35 km distance</p> <div class="credits"> <p class="dwt_author">Elizabeth A. Stacy</p> <p class="dwt_publisher"></p> <p class="publishDate">2001-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">394</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ars.usda.gov/research/publications/Publications.htm?seq_no_115=186752"> <span id="translatedtitle"><span class="hlt">TREE</span> <span class="hlt">SPECIES</span> DIFFER IN THEIR LONG-TERM EFFECTS ON SOIL CARBON DYNAMICS AND BIOCHEMISTRY IN LOWLAND COSTA RICA</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ars.usda.gov/services/TekTran.htm">Technology Transfer Automated Retrieval System (TEKTRAN)</a></p> <p class="result-summary">In long-term experimental plantations at La Selva Biological Station, Costa Rica, we investigated the effects of six <span class="hlt">tree</span> <span class="hlt">species</span> on soil properties. In 1988, <span class="hlt">trees</span> were established on degraded pasture in a randomized complete block design. Soil organic Carbon (SOC) differed significantly among spec...</p> <div class="credits"> <p class="dwt_author"></p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">395</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ehleringer.net/Jim/Publications/394.pdf"> <span id="translatedtitle">Elevated stream inorganic nitrogen impacts on a dominant riparian <span class="hlt">tree</span> <span class="hlt">species</span>: Results from an experimental riparian stream system</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p class="result-summary">was 15% greater in the fertilized <span class="hlt">trees</span>, although there were no differences in either canopy radialElevated stream inorganic nitrogen impacts on a dominant riparian <span class="hlt">tree</span> <span class="hlt">species</span>: Results from 2008. [1] The release of inorganic nitrogen from intensive agricultural practices and urbanization has</p> <div class="credits"> <p class="dwt_author">Ehleringer, Jim</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">396</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19860000172&hterms=drawing&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Ddrawing"> <span id="translatedtitle"><span class="hlt">Multipurpose</span> Scribing and Drawing Tool</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">Two-part tool reconfigured for variety of jobs. Tool performs several functions useful in layout. Lines, curves, and angles made visible as either bright scribe marks or as dark pencil (or ink) marks. <span class="hlt">Multipurpose</span> tool speeds up laying out of patterns on sheet metal, wood, plastic, or paper. Tool is carried in pocket, then quickly assembled for service as height gauge, pair of dividers, protractor, surface gauge, or square.</p> <div class="credits"> <p class="dwt_author">Ellis, J. M.</p> <p class="dwt_publisher"></p> <p class="publishDate">1986-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">397</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2000AcO....21...37K"> <span id="translatedtitle">Some autecological characteristics of early to late successional <span class="hlt">tree</span> <span class="hlt">species</span> in Venezuela</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The breadth of the continuum concept of strategy with respect to succession was tested on 21 <span class="hlt">tree</span> and shrub <span class="hlt">species</span> common in either unlogged or logged stands, respectively, in the Forest Reserve of Caparo, Venezuela, by examining morphological, physiological and population characteristics. Based on a preliminary abundance analysis, `early', `mid' and `late' successional <span class="hlt">species</span> as well as `generalists' were distinguished. Early successional <span class="hlt">species</span>, i.e. Ochroma lagopus, Heliocarpus popayanensis and Cecropia peltata were similar in many autecological aspects, e.g. monolayered leaf arrangement, orthotropic architectural models, no adaptive reiteration, clumped distribution, but differed in gap association and distribution along a drainage gradient. Mid-successional <span class="hlt">species</span> established themselves both in large and small gaps (> 300 m[sup2 ]; 80-300 m[sup2 ]) and showed a clumped to regular distribution pattern in logged areas; they exhibited more diverse crown and leaf characteristics than early successional <span class="hlt">species</span>. Late successional <span class="hlt">species</span> established themselves only in small gaps and understorey, and showed a regular spatial pattern in undisturbed areas. All late successional <span class="hlt">species</span> displayed architectural models with plagiotropic lateral axes and showed a multilayered leaf arrangement. Adaptive reiteration was a common feature of late successional <span class="hlt">species</span> which could be further subdivided into large, medium-sized and small <span class="hlt">trees</span>, indicating different light requirements at maturity. Generalists were common treelet and shrub <span class="hlt">species</span> in both disturbed and undisturbed sites where they are also capable of completing their life cycle. The light compensation point (LCP) of an individual plant was strongly influenced by its crown illuminance. Large late successional <span class="hlt">species</span> showed the widest range of LCP values, reflecting the increasing light availability with increasing height in mature forest. On the basis of many autecological characteristics, it was found (i) that there is in fact a continuum of <span class="hlt">species</span> strategies with respect to succession even among early and mid-successional <span class="hlt">species</span> and (ii) that the latter group of <span class="hlt">species</span> showed the widest breadth of autecological traits, reflecting the heterogeneous environment in which they establish and mature.</p> <div class="credits"> <p class="dwt_author">Kammesheidt, Ludwig</p> <p class="dwt_publisher"></p> <p class="publishDate">2000-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">398</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2556410"> <span id="translatedtitle">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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">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 ?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 ?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> <div class="credits"> <p class="dwt_author">Hubbell, Stephen P.; He, Fangliang; Condit, Richard; Borda-de-Água, Luís; Kellner, James; ter Steege, Hans</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">399</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Wang, Hua; Ouyang, Zhi-yun; Zheng, Hua; Wang, Xiao-ke; Ni, Yong-ming; Ren, Yu-fen</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-09-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">400</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Nasser, Ramadan A; Al-Mefarrej, H A; Abdel-Aal, M A; Alshahrani, T S</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-09-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_19");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return 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title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">401</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4177404"> <span id="translatedtitle">Size-Class Effect Contributes to <span class="hlt">Tree</span> <span class="hlt">Species</span> Assembly through Influencing Dispersal in Tropical Forests</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">We have investigated the processes of community assembly using size classes of <span class="hlt">trees</span>. Specifically our work examined (1) whether point process models incorporating an effect of size-class produce more realistic summary outcomes than do models without this effect; (2) which of three selected models incorporating, respectively environmental effects, dispersal and the joint-effect of both of these, is most useful in explaining <span class="hlt">species</span>-area relationships (SARs) and point dispersion patterns. For this evaluation we used <span class="hlt">tree</span> <span class="hlt">species</span> data from the 50-ha forest dynamics plot in Barro Colorado Island, Panama and the comparable 20 ha plot at Bubeng, Southwest China. Our results demonstrated that incorporating an size-class effect dramatically improved the SAR estimation at both the plots when the dispersal only model was used. The joint effect model produced similar improvement but only for the 50-ha plot in Panama. The point patterns results were not improved by incorporation of size-class effects using any of the three models. Our results indicate that dispersal is likely to be a key process determining both SARs and point patterns. The environment-only model and joint-effects model were effective at the <span class="hlt">species</span> level and the community level, respectively. We conclude that it is critical to use multiple summary characteristics when modelling spatial patterns at the <span class="hlt">species</span> and community levels if a comprehensive understanding of the ecological processes that shape <span class="hlt">species</span>’ distributions is sought; without this results may have inherent biases. By influencing dispersal, the effect of size-class contributes to <span class="hlt">species</span> assembly and enhances our understanding of <span class="hlt">species</span> coexistence. PMID:25251538</p> <div class="credits"> <p class="dwt_author">Hu, Yue-Hua; Kitching, Roger L.; Lan, Guo-Yu; Zhang, Jiao-Lin; Sha, Li-Qing; Cao, Min</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">402</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Narayan, Lakshmi; Dodd, Richard S.; O’Hara, Kevin L.</p> <p class="dwt_publisher"></p> <p class="publishDate">2015-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">403</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/18593032"> <span id="translatedtitle">[Characteristics of caloric value and nutrient content of four garden <span class="hlt">tree</span> <span class="hlt">species</span>].</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">In this study, the caloric value, nutrient content, and ash content in the stem, leaf, and root of four garden <span class="hlt">tree</span> <span class="hlt">species</span> Prunus mume Meiren, P. serrulata, Magnolia denudata and M. grandiflora were determined to explore the distribution characteristics of caloric value in different <span class="hlt">tree</span> organs at different development stages, and related affecting factors. The results showed that the gross caloric value (GCV) and ash free caloric value (AFCV) in different organs of the <span class="hlt">tree</span> <span class="hlt">species</span> ranged from 17.02 to 21.93 kJ g(-1) and from 18.42 to 22.57 kJ g(-1), respectively. Leaf and fine root had relatively higher GCV and AFCV than stem, and AFCV had a decreasing trend with the development of stem and root. P. mume Meiren and P. serrulata had higher GCV and AFCV than M. grandiflora and M. denudate. Both GCV and AFCV of fine root were significantly correlated with its nutrient and ash contents (P <0.01). With the development of root, the correlations of GCV and AFCV with organic carbon content declined gradually, while the GCV of different organs had the strongest correlation with total nitrogen content. PMID:18593032</p> <div class="credits"> <p class="dwt_author">Chen, Mei-ling; Shangguan, Zhou-ping</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-04-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">404</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/18941286"> <span id="translatedtitle">Physiological characteristics of tropical rain forest <span class="hlt">tree</span> <span class="hlt">species</span>: a basis for the development of silvicultural technology.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Sasaki, Satohiko</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">405</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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 forest cover may result in long-term changes ecosystem N and P availability.</p> <div class="credits"> <p class="dwt_author">Melvin, A. M.; Mack, M. C.; Johnstone, J. F.; Schuur, E. A.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">406</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Reich, Peter B.; Sendall, Kerrie M.; Rice, Karen; Rich, Roy L.; Stefanski, Artur; Hobbie, Sarah E.; Montgomery, Rebecca A.</p> <p class="dwt_publisher"></p> <p class="publishDate">2015-02-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">407</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/25537154"> <span id="translatedtitle">Seasonal and local differences in leaf litter flammability of six mediterranean <span class=