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Sample records for multipurpose tree species

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

    NASA Astrophysics Data System (ADS)

    Das, Tapasi; Das, Ashesh Kumar

    2013-01-01

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

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

    PubMed

    Das, Tapasi; Das, Ashesh Kumar

    2013-01-01

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

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

    PubMed

    Das, Tapasi; Das, Ashesh Kumar

    2013-01-01

    Traditional homegardens are an important component of the farming systems in many rural communities and have been highlighted considerably due to their sustainability and role in the conservation of biodiversity. However, the functional aspect of the homegardens, which includes the phenological behavior of the dominant tree species in such agroforestry systems, has been undermined till date, and there is a lack of adequate data on this aspect of the traditional homegardens. As a step in this direction the present study was carried out to determine the phenological behavior of important multipurpose trees in the homegardens of the village of Dargakona, Assam, northeast India. The study revealed the dominance of periodic growth deciduous species from a total of 25 tree species selected for phenological observation. The diversity of multipurpose trees in the homegardens is represented by different plant functional types with different phenological behavior which showed significant changes in their responses to inter-annual climatic variations. The diversity of tree species with different phenological behavior has implications for the temporal partitioning of resources, especially during periods of scarcity, thereby resulting in efficient utilization of resources such as water. Also the diverse phenological behavior plays an important role in regulating the food supply for the herbivore population and the year-round availability of products, and such information can be useful in the selection of species for integration into other agroforestry systems which can be sustainable in the long run. PMID:22555388

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

    SciTech Connect

    Wickramasinghe, A.

    1992-01-01

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

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

    PubMed

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

    2012-04-01

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

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

    PubMed

    Shekhawat, Mahipal S; Manokari, M

    2016-01-01

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

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

    PubMed

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

    2013-11-30

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

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

    PubMed

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

    2013-11-30

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

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

    PubMed Central

    2013-01-01

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

  10. Species integrity in trees.

    PubMed

    Ortiz-Barrientos, Daniel; Baack, Eric J

    2014-09-01

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

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

    PubMed

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

    2016-01-01

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

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

    PubMed Central

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

    2016-01-01

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

  13. 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 ...

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

    PubMed

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

    2016-01-01

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

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

    PubMed Central

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

    2016-01-01

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

  16. STRAW: Species TRee Analysis Web server.

    PubMed

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

    2013-07-01

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

  17. The inference of gene trees with species trees.

    PubMed

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

    2015-01-01

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

  18. The Inference of Gene Trees with Species Trees

    PubMed Central

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

    2015-01-01

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

  19. Coalescent Histories for Lodgepole Species Trees.

    PubMed

    Disanto, Filippo; Rosenberg, Noah A

    2015-10-01

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

  20. Tree-growth analyses to estimate tree species' drought tolerance.

    PubMed

    Eilmann, Britta; Rigling, Andreas

    2012-02-01

    Climate change is challenging forestry management and practices. Among other things, tree species with the ability to cope with more extreme climate conditions have to be identified. However, while environmental factors may severely limit tree growth or even cause tree death, assessing a tree species' potential for surviving future aggravated environmental conditions is rather demanding. The aim of this study was to find a tree-ring-based method suitable for identifying very drought-tolerant species, particularly potential substitute species for Scots pine (Pinus sylvestris L.) in Valais. In this inner-Alpine valley, Scots pine used to be the dominating species for dry forests, but today it suffers from high drought-induced mortality. We investigate the growth response of two native tree species, Scots pine and European larch (Larix decidua Mill.), and two non-native species, black pine (Pinus nigra Arnold) and Douglas fir (Pseudotsuga menziesii Mirb. var. menziesii), to drought. This involved analysing how the radial increment of these species responded to increasing water shortage (abandonment of irrigation) and to increasingly frequent drought years. Black pine and Douglas fir are able to cope with drought better than Scots pine and larch, as they show relatively high radial growth even after irrigation has been stopped and a plastic growth response to drought years. European larch does not seem to be able to cope with these dry conditions as it lacks the ability to recover from drought years. The analysis of trees' short-term response to extreme climate events seems to be the most promising and suitable method for detecting how tolerant a tree species is towards drought. However, combining all the methods used in this study provides a complete picture of how water shortage could limit species.

  1. Reconciliation with non-binary species trees.

    PubMed

    Vernot, Benjamin; Stolzer, Maureen; Goldman, Aiton; Durand, Dannie

    2008-10-01

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

  2. Species Tree Inference Using a Mixture Model.

    PubMed

    Ullah, Ikram; Parviainen, Pekka; Lagergren, Jens

    2015-09-01

    Species tree reconstruction has been a subject of substantial research due to its central role across biology and medicine. A species tree is often reconstructed using a set of gene trees or by directly using sequence data. In either of these cases, one of the main confounding phenomena is the discordance between a species tree and a gene tree due to evolutionary events such as duplications and losses. Probabilistic methods can resolve the discordance by coestimating gene trees and the species tree but this approach poses a scalability problem for larger data sets. We present MixTreEM-DLRS: A two-phase approach for reconstructing a species tree in the presence of gene duplications and losses. In the first phase, MixTreEM, a novel structural expectation maximization algorithm based on a mixture model is used to reconstruct a set of candidate species trees, given sequence data for monocopy gene families from the genomes under study. In the second phase, PrIME-DLRS, a method based on the DLRS model (Åkerborg O, Sennblad B, Arvestad L, Lagergren J. 2009. Simultaneous Bayesian gene tree reconstruction and reconciliation analysis. Proc Natl Acad Sci U S A. 106(14):5714-5719), is used for selecting the best species tree. PrIME-DLRS can handle multicopy gene families since DLRS, apart from modeling sequence evolution, models gene duplication and loss using a gene evolution model (Arvestad L, Lagergren J, Sennblad B. 2009. The gene evolution model and computing its associated probabilities. J ACM. 56(2):1-44). We evaluate MixTreEM-DLRS using synthetic and biological data, and compare its performance with a recent genome-scale species tree reconstruction method PHYLDOG (Boussau B, Szöllősi GJ, Duret L, Gouy M, Tannier E, Daubin V. 2013. Genome-scale coestimation of species and gene trees. Genome Res. 23(2):323-330) as well as with a fast parsimony-based algorithm Duptree (Wehe A, Bansal MS, Burleigh JG, Eulenstein O. 2008. Duptree: a program for large-scale phylogenetic

  3. Reconciliation with non-binary species trees.

    PubMed

    Vernot, B; Stolzer, M; Goldman, A; Durand, D

    2007-01-01

    Reconciliation is the process of resolving disagreement between gene and species trees, by invoking gene duplications and losses to explain topological incongruence. The resulting inferred duplication histories are a valuable source of information for a broad range of biological applications, including ortholog identification, estimating gene duplication times, and rooting and correcting gene trees. Reconciliation for binary trees is a tractable and well studied problem. However, a striking proportion of species trees are non-binary. For example, 64% of branch points in the NCBI taxonomy have three or more children. When applied to non-binary species trees, current algorithms overestimate the number of duplications because they cannot distinguish between duplication and deep coalescence. We present the first formal algorithm for reconciling binary gene trees with non-binary species trees under a duplication-loss parsimony model. Using a space efficient mapping from gene to species tree, our algorithm infers the minimum number of duplications and losses in O(|V(G)| . (k(S) + h(S))) time, where V(G) is the number of nodes in the gene tree, h(S) is the height of the species tree and k(S) is the width of its largest multifurcation. We also present a dynamic programming algorithm for a combined loss model, in which losses in sibling species may be represented as a single loss in the common ancestor. Our algorithms have been implemented in NOTUNG, a robust, production quality tree-fitting program, which provides a graphical user interface for exploratory analysis and also supports automated, high-throughput analysis of large data sets.

  4. Irrational exuberance for resolved species trees.

    PubMed

    Hahn, Matthew W; Nakhleh, Luay

    2016-01-01

    Phylogenomics has largely succeeded in its aim of accurately inferring species trees, even when there are high levels of discordance among individual gene trees. These resolved species trees can be used to ask many questions about trait evolution, including the direction of change and number of times traits have evolved. However, the mapping of traits onto trees generally uses only a single representation of the species tree, ignoring variation in the gene trees used to construct it. Recognizing that genes underlie traits, these results imply that many traits follow topologies that are discordant with the species topology. As a consequence, standard methods for character mapping will incorrectly infer the number of times a trait has evolved. This phenomenon, dubbed "hemiplasy," poses many problems in analyses of character evolution. Here we outline these problems, explaining where and when they are likely to occur. We offer several ways in which the possible presence of hemiplasy can be diagnosed, and discuss multiple approaches to dealing with the problems presented by underlying gene tree discordance when carrying out character mapping. Finally, we discuss the implications of hemiplasy for general phylogenetic inference, including the possible drawbacks of the widespread push for "resolved" species trees.

  5. Pushing the Pace of Tree Species Migration

    PubMed Central

    Lazarus, Eli D.; McGill, Brian J.

    2014-01-01

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

  6. Region effects influence local tree species diversity

    PubMed Central

    Ricklefs, Robert E.; He, Fangliang

    2016-01-01

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

  7. Region effects influence local tree species diversity.

    PubMed

    Ricklefs, Robert E; He, Fangliang

    2016-01-19

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

  8. Region effects influence local tree species diversity.

    PubMed

    Ricklefs, Robert E; He, Fangliang

    2016-01-19

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

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

    PubMed

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

    2003-06-01

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

  10. A tree species inventory over Europe

    NASA Astrophysics Data System (ADS)

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

    2009-04-01

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

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

    PubMed

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

    2015-01-01

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

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

    PubMed

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

    2015-01-01

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

  13. Multipurpose Spaces.

    ERIC Educational Resources Information Center

    Butin, Dan

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

  14. ASTRAL: genome-scale coalescent-based species tree estimation

    PubMed Central

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

    2014-01-01

    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

  15. Exploring tree species signature using waveform LiDAR data

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

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

  16. Spatial patterns in the distribution of tropical tree species.

    PubMed

    Condit, R; Ashton, P S; Baker, P; Bunyavejchewin, S; Gunatilleke, S; Gunatilleke, N; Hubbell, S P; Foster, R B; Itoh, A; LaFrankie, J V; Lee, H S; Losos, E; Manokaran, N; Sukumar, R; Yamakura, T

    2000-05-26

    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 1768 tree species is examined based on the average density of conspecific trees in circular neighborhoods around each tree. When all individuals larger than 1 centimeter in stem diameter were included, nearly every species was more aggregated than a random distribution. Considering only larger trees (>/= 10 centimeters in diameter), the pattern persisted, with most species being more aggregated than random. Rare species were more aggregated than common species. All six forests were very similar in all the particulars of these results.

  17. An estimate of the number of tropical tree species

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2015-06-16

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

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

    PubMed

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

    2015-06-16

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

  1. STBase: One Million Species Trees for Comparative Biology

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2015-01-01

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

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

    PubMed

    DeGiorgio, Michael; Degnan, James H

    2014-01-01

    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.

  4. Are temperate canopy spiders tree-species specific?

    PubMed

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

    2014-01-01

    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 Białowieża 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.

  5. Are temperate canopy spiders tree-species specific?

    PubMed

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

    2014-01-01

    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 Białowieża 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

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

    PubMed

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

    2015-09-01

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

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

    PubMed

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

    2015-09-01

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

  8. Inconsistency of Species Tree Methods under Gene Flow.

    PubMed

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

    2016-09-01

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

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

    PubMed Central

    2008-01-01

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

  10. Multipurpose Spaces

    ERIC Educational Resources Information Center

    Gordon, Douglas

    2010-01-01

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

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

    PubMed

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

    2015-08-01

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

  12. Exploring the Taxonomy of Oaks and Related Tree Species

    ERIC Educational Resources Information Center

    McMaster, Robert T.

    2004-01-01

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

  13. Seed maturity indices in Aisandra butyracea--a multipurpose tree species of lower Himalaya.

    PubMed

    Singh, R P; Tewari, Ashish; Shah, Shruti; Tewari, Bhawna

    2010-05-01

    Fruits of Aisandra butyracea (Roxb.) Lamb. were collected from two sites located at different altitudes in Kumaun Himalaya for analyzing the seed maturity in relation to various fruit and seed characters. The mean seed size (length x width) across the collection dates varied between 186.44 +/- 0.05 and 238.17 +/- 0.5 mm2 across both the elevations. The fruit colour changed from dark green in the beginning to pale yellow on the maturity. The range of seed moisture content (62.83 +/- 1.33 to 63.46 +/- 0.89%) coincided with maximum germination. The colour change and seed moisture content appear to be the major indicators of seed maturation in A. butyracea. PMID:21047000

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

    PubMed

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

    2016-01-01

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

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

    PubMed

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

    2012-04-01

    An efficient and reproducible protocol has been developed for in vitro propagation of Pithecellobium dulce (Roxb.) Benth (a multipurpose leguminous tree) from field grown nodal segments (axillary bud). Shoot bud induction occurred from nodal explants of 15-years-old tree on Murashige and Skoog (MS) basal medium supplemented with 4.4 μM 6-benzyladenine (BA) and multiplication was achieved on MS medium supplemented with 4.4 μM BA + 0.73 μM 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 μM BA + 0.73 μM PAA) after every 25 days. In vitro rooting was achieved on MS medium supplemented with 2.46 μM Indole-3-butyric acid (IBA) + 41.63 μM 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.

  16. Tree Species Classification By Multiseasonal High Resolution Satellite Data

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  17. Soil nutrients influence spatial distributions of tropical trees species

    USGS Publications Warehouse

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

    2007-01-01

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

  18. Seedling Growth Strategies in Bauhinia Species: Comparing Lianas and Trees

    PubMed Central

    Cai, Zhi-Quan; Poorter, Lourens; Cao, Kun-Fang; Bongers, Frans

    2007-01-01

    Background and Aims Lianas are expected to differ from trees in their growth strategies. As a result these two groups of woody species will have different spatial distributions: lianas are more common in high light environments. This study determines the differences in growth patterns, biomass allocation and leaf traits in five closely related liana and tree species of the genus Bauhinia. Methods Seedlings of two light-demanding lianas (Bauhinia tenuiflora and B. claviflora), one shade-tolerant liana (B. aurea), and two light-demanding trees (B. purpurea and B. monandra) were grown in a shadehouse at 25 % of full sunlight. A range of physiological, morphological and biomass parameters at the leaf and whole plant level were compared among these five species. Key Results The two light-demanding liana species had higher relative growth rate (RGR), allocated more biomass to leaf production [higher leaf mass fraction (LMF) and higher leaf area ratio (LAR)] and stem mass fraction (SMF), and less biomass to the roots [root mass fraction (RMF)] than the two tree species. The shade-tolerant liana had the lowest RGR of all five species, and had a higher RMF, lower SMF and similar LMF than the two light-demanding liana species. The two light-demanding lianas had lower photosynthetic rates per unit area (Aarea) and similar photosynthetic rates per unit mass (Amass) than the trees. Across species, RGR was positively related to SLA, but not to LAR and Aarea. Conclusions It is concluded that the faster growth of light-demanding lianas compared with light-demanding trees is based on morphological parameters (SLA, LMF and LAR), and cannot be attributed to higher photosynthetic rates at the leaf level. The shade-tolerant liana exhibited a slow-growth strategy, compared with the light-demanding species. PMID:17720978

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

    PubMed Central

    Pollard, Daniel A; Eisen, Michael B

    2006-01-01

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

  20. Phylogenomics-Based Reconstruction of Protozoan Species Tree

    PubMed Central

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

    2011-01-01

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

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

    PubMed Central

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

    2013-01-01

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

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

    PubMed

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

    2011-01-01

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

  3. Why abundant tropical tree species are phylogenetically old

    PubMed Central

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

    2013-01-01

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

  4. Why abundant tropical tree species are phylogenetically old.

    PubMed

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

    2013-10-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

  6. Diagnostics of Tree Diseases Caused by Phytophthora austrocedri Species.

    PubMed

    Mulholland, Vincent; Elliot, Matthew; Green, Sarah

    2015-01-01

    We present methods for the detection and quantification of four Phytophthora species which are pathogenic on trees; Phytophthora ramorum, Phytophthora kernoviae, Phytophthora lateralis, and Phytophthora austrocedri. Nucleic acid extraction methods are presented for phloem tissue from trees, soil, and pure cultures on agar plates. Real-time PCR methods are presented and include primer and probe sets for each species, general advice on real-time PCR setup and data analysis. A method for sequence-based identification, useful for pure cultures, is also included.

  7. Occupancy-abundance models for predicting densities of three leaf beetles damaging the multipurpose tree Sesbania sesban in eastern and southern Africa.

    PubMed

    Sileshi, G; Hailu, G; Mafongoya, P L

    2006-02-01

    Mesoplatys ochroptera Stål, Exosoma and Ootheca spp. seriously damage sesbania, Sesbania sesban (L.) Merril, a multipurpose leguminous tree widely used in tropical agroforestry. This is discouraging farmers from expanding the planting of sesbania in various agroforestry systems in eastern and south-central Africa. Rapid methods are needed for estimation of population densities of these beetles for decision making in pest management. A study was conducted with the objectives of determining the existence of any positive relationship between the occupancy and abundance of Mesoplatys, Exosoma and Ootheca and determining the model that best predicts abundance from occupancy for rapid estimation of population densities. The Poisson model assuming spatial randomness, the negative binomial distribution (NBD) model assuming spatial aggregation, the Nachman model without any distribution assumption, and a General model incorporating spatial variance-abundance and occupancy-abundance relationships were fitted to data on adult M. ochroptera, Exosoma and Ootheca from western Kenya, southern Malawi and eastern Zambia. Very strong variance to abundance relationships were observed in the spatial pattern of all three beetles. The occupancy-abundance relationships were also positive and strong in all beetles. The occupancy and abundance predicted by the four models were closest to the observed at lower densities compared with higher beetle densities. At higher population densities, the NBD and the General model gave better fit for M. ochroptera and Exosoma. For Ootheca populations, the Poisson and NBD models gave better fit at higher population densities. The relationships established here can be used as guide to estimate beetle densities for decision-making in pest management.

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

    PubMed

    Wu, Yufeng

    2012-03-01

    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.

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

    PubMed

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

    2003-04-01

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

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed

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

    2014-01-01

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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-01-01

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

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

    PubMed Central

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

    2015-01-01

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

  15. Space of gene/species trees reconciliations and parsimonious models.

    PubMed

    Doyon, Jean-Philippe; Chauve, Cedric; Hamel, Sylvie

    2009-10-01

    We describe algorithms to study the space of all possible reconciliations between a gene tree and a species tree, that is counting the size of this space, uniformly generate a random reconciliation, and exploring this space in optimal time using combinatorial operators. We also extend these algorithms for optimal and sub-optimal reconciliations according to the three usual combinatorial costs (duplication, loss, and mutation). Applying these algorithms to simulated and real gene family evolutionary scenarios, we observe that the LCA (Last Common Ancestor) based reconciliation is almost always identical to the real one.

  16. Multilocus inference of species trees and DNA barcoding

    PubMed Central

    2016-01-01

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

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

    SciTech Connect

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

    2006-08-28

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

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

    PubMed

    Scholl, Joshua P; Wiens, John J

    2016-09-14

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

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

    PubMed

    Scholl, Joshua P; Wiens, John J

    2016-09-14

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

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

    USGS Publications Warehouse

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

    2009-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

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

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

    PubMed

    Brienen, Roel J W; Zuidema, Pieter A

    2005-11-01

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

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

    PubMed Central

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

    2012-01-01

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

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

    PubMed

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

    2016-01-01

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

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

    PubMed

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

    2016-01-01

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

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

    PubMed Central

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

    2014-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2003-12-01

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

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

    PubMed

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

    2016-03-01

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

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

    PubMed

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

    2010-07-01

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

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

    PubMed

    DeGiorgio, Michael; Rosenberg, Noah A

    2016-08-01

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

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

    PubMed Central

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

    2013-01-01

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

  12. Process-based modeling of species' distributions: what limits temperate tree species' range boundaries?

    PubMed

    Morin, Xavier; Augspurger, Carol; Chuine, Isabelle

    2007-09-01

    Niche-based models are widely used to understand what environmental factors determine species' distributions, but they do not provide a clear framework to study the processes involved in defining species' ranges. Here we used a process-based model to identify these processes and to assess the potential distribution of 17 North American boreal/temperate tree species. Using input of only climate and soil properties, the model reproduced the 17 species' distributions accurately. Our results allowed us to identify the climatic factors as well as the biological processes involved in limiting species' ranges. The model showed that climatic constraints limit species' distributions mainly through their impact on phenological processes, and secondarily through their impact on drought and frost mortality. The northern limit of species' ranges appears to be caused mainly by the inability to undergo full fruit ripening and/or flowering, while the southern limit is caused by the inability to flower or by frost injury to flowers. These findings about the ecological processes shaping tree species' distribution represent a crucial step toward obtaining a more complete picture of the potential impact of climate on species' ranges. PMID:17918406

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

    SciTech Connect

    Not Available

    1980-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-10-01

    The biogenic volatile organic compound (BVOC) emissions of nine urban tree species were studied to assess the air quality impacts from planting a large quantity of these trees in the City and County of Denver, Colorado, through the Mile High Million tree-planting initiative. The deciduous tree species studied were Sugar maple, Ohio buckeye, northern hackberry, Turkish hazelnut, London planetree, American basswood, Littleleaf linden, Valley Forge elm, and Japanese zelkova. These tree species were selected using the i-Tree Species Selector (itreetools.org). BVOC emissions from the selected tree species were investigated to evaluate the Species Selector data under the Colorado climate and environmental growing conditions. Individual tree species were subjected to branch enclosure experiments in which foliar emissions of BVOC were collected onto solid adsorbent cartridges. The cartridge samples were analyzed for monoterpenes (MT), sesquiterpenes (SQT), and other C10-C15 BVOC using thermal desorption-gas chromatography-flame ionization detection/mass spectroscopy (GC-FID/MS). Individual compounds and their emission rates (ER) were identified. MT were observed in all tree species, exhibiting the following total MT basal emission rates (BER; with a 1-σ lower bound, upper bound uncertainty window): Sugar maple, 0.07 (0.02, 0.11) μg g-1 h-1; London planetree, 0.15 (0.02, 0.27) μg g-1 h-1; northern hackberry, 0.33 (0.09, 0.57) μg g-1 h-1; Japanese zelkova, 0.42 (0.26, 0.58) μg g-1 h-1; Littleleaf linden, 0.71 (0.33, 1.09) μg g-1 h-1; Valley Forge elm, 0.96 (0.01, 1.92) μg g-1 h-1; Turkish hazelnut, 1.30 (0.32, 2.23) μg g-1 h-1; American basswood, 1.50 (0.40, 2.70) μg g-1 h-1; and Ohio buckeye, 6.61 (1.76, 11.47) μg g-1 h-1. SQT emissions were seen in five tree species with total SQT BER of: London planetree, 0.11 (0.01, 0.20) μg g-1 h-1; Japanese zelkova, 0.11 (0.05, 0.16) μg g-1 h-1; Littleleaf linden, 0.13 (0.06, 0.21) μg g-1 h-1; northern hackberry, 0.20 (0

  15. Branch-and-bound approach for parsimonious inference of a species tree from a set of gene family trees.

    PubMed

    Doyon, Jean-Philippe; Chauve, Cedric

    2011-01-01

    We describe a Branch-and-Bound algorithm for computing a parsimonious species tree, given a set of gene family trees. Our algorithm can consider three cost measures: number of gene duplications, number of gene losses, and both combined. Moreover, to cope with intrinsic limitations of Branch-and-Bound algorithms for species trees inference regarding the number of taxa that can be considered, our algorithm can naturally take into account predefined relationships between sets of taxa. We test our algorithm on a dataset of eukaryotic gene families spanning 29 taxa.

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

    PubMed

    Bourque, Charles P-A; Bayat, Mahmoud

    2015-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-01-01

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

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

    PubMed

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

    2002-06-01

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

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

    NASA Astrophysics Data System (ADS)

    Menyailo, O.; Matvienko, A.

    2012-12-01

    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.

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

    PubMed

    Akburak, Serdar; Makineci, Ender

    2013-04-01

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

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

    PubMed

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

    2015-03-15

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

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

    PubMed

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

    2015-03-15

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-06-01

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

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

    PubMed

    Lübbe, Torben; Schuldt, Bernhard; Leuschner, Christoph

    2015-01-01

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

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

    PubMed Central

    Lübbe, Torben; Schuldt, Bernhard; Leuschner, Christoph

    2015-01-01

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

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

    PubMed

    Naaz, Afshan; Shahzad, Anwar; Anis, Mohammad

    2014-05-01

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

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

    PubMed Central

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

    2012-01-01

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

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

    PubMed Central

    Sandor, Manette E.; Chazdon, Robin L.

    2014-01-01

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

  9. Remnant trees affect species composition but not structure of tropical second-growth forest.

    PubMed

    Sandor, Manette E; Chazdon, Robin L

    2014-01-01

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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2015-10-01

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

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

    NASA Astrophysics Data System (ADS)

    Heinzel, Johannes; Koch, Barbara

    2012-08-01

    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.

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2009-09-01

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

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

    PubMed

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

    2009-09-01

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    PubMed

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

    2015-01-01

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

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

    PubMed

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

    2015-01-01

    The very rare Mexican Picea chihuahuana tree community covers an area of no more than 300 ha in the Sierra Madre Occidental. This special tree community has been the subject of several studies aimed at learning more about the genetic structure and ecology of the species and the potential effects of climate change. The spatial distribution of trees is a result of many ecological processes and can affect the degree of competition between neighbouring trees, tree density, variability in size and distribution, regeneration, survival, growth, mortality, crown formation and the biological diversity within forest communities. Numerous scale-dependent measures have been established in order to describe spatial forest structure. The overall aim of most of these studies has been to obtain data to help design preservation and conservation strategies. In this study, we examined the spatial distribution pattern of trees in the P. chihuahuana tree community in 12 localities, in relation to i) tree stand density, ii) diameter distribution (vertical structure), iii) tree species diversity, iv) geographical latitude and v) tree dominance at a fine scale (in 0.25 ha plots), with the aim of obtaining a better understanding of the complex ecosystem processes and biological diversity. Because of the strongly mixed nature of this tree community, which often produces low population densities of each tree species and random tree fall gaps caused by tree death, we expect aggregated patterns in individual Picea chihuahuana trees and in the P. chihuahuana tree community, repulsive Picea patterns to other tree species and repulsive patterns of young to adult trees. Each location was represented by one plot of 50 x 50 m (0.25 ha) established in the centre of the tree community. The findings demonstrate that the hypothesis of aggregated tree pattern is not applicable to the mean pattern measured by Clark-Evans index, Uniform Angle index and Mean Directional index of the uneven-aged P

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

    PubMed Central

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

    2015-01-01

    The very rare Mexican Picea chihuahuana tree community covers an area of no more than 300 ha in the Sierra Madre Occidental. This special tree community has been the subject of several studies aimed at learning more about the genetic structure and ecology of the species and the potential effects of climate change. The spatial distribution of trees is a result of many ecological processes and can affect the degree of competition between neighbouring trees, tree density, variability in size and distribution, regeneration, survival, growth, mortality, crown formation and the biological diversity within forest communities. Numerous scale-dependent measures have been established in order to describe spatial forest structure. The overall aim of most of these studies has been to obtain data to help design preservation and conservation strategies. In this study, we examined the spatial distribution pattern of trees in the P. chihuahuana tree community in 12 localities, in relation to i) tree stand density, ii) diameter distribution (vertical structure), iii) tree species diversity, iv) geographical latitude and v) tree dominance at a fine scale (in 0.25 ha plots), with the aim of obtaining a better understanding of the complex ecosystem processes and biological diversity. Because of the strongly mixed nature of this tree community, which often produces low population densities of each tree species and random tree fall gaps caused by tree death, we expect aggregated patterns in individual Picea chihuahuana trees and in the P. chihuahuana tree community, repulsive Picea patterns to other tree species and repulsive patterns of young to adult trees. Each location was represented by one plot of 50 x 50 m (0.25 ha) established in the centre of the tree community. The findings demonstrate that the hypothesis of aggregated tree pattern is not applicable to the mean pattern measured by Clark-Evans index, Uniform Angle index and Mean Directional index of the uneven-aged P

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

    PubMed

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

    2015-01-01

    The very rare Mexican Picea chihuahuana tree community covers an area of no more than 300 ha in the Sierra Madre Occidental. This special tree community has been the subject of several studies aimed at learning more about the genetic structure and ecology of the species and the potential effects of climate change. The spatial distribution of trees is a result of many ecological processes and can affect the degree of competition between neighbouring trees, tree density, variability in size and distribution, regeneration, survival, growth, mortality, crown formation and the biological diversity within forest communities. Numerous scale-dependent measures have been established in order to describe spatial forest structure. The overall aim of most of these studies has been to obtain data to help design preservation and conservation strategies. In this study, we examined the spatial distribution pattern of trees in the P. chihuahuana tree community in 12 localities, in relation to i) tree stand density, ii) diameter distribution (vertical structure), iii) tree species diversity, iv) geographical latitude and v) tree dominance at a fine scale (in 0.25 ha plots), with the aim of obtaining a better understanding of the complex ecosystem processes and biological diversity. Because of the strongly mixed nature of this tree community, which often produces low population densities of each tree species and random tree fall gaps caused by tree death, we expect aggregated patterns in individual Picea chihuahuana trees and in the P. chihuahuana tree community, repulsive Picea patterns to other tree species and repulsive patterns of young to adult trees. Each location was represented by one plot of 50 x 50 m (0.25 ha) established in the centre of the tree community. The findings demonstrate that the hypothesis of aggregated tree pattern is not applicable to the mean pattern measured by Clark-Evans index, Uniform Angle index and Mean Directional index of the uneven-aged P

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2015-01-01

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

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

    PubMed

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

    2014-01-01

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

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

    PubMed

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

    2014-01-01

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

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed

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

    2011-12-01

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

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

    PubMed

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

    2015-03-01

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

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

    PubMed

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

    2014-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

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

    PubMed

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

    2015-10-01

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

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

    PubMed

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

    2015-10-01

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

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

    PubMed

    Xiao, Qingfu; McPherson, E Gregory

    2016-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2011-04-01

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

  14. Thematic and spatial resolutions affect model-based predictions of tree species distribution.

    PubMed

    Liang, Yu; He, Hong S; Fraser, Jacob S; Wu, ZhiWei

    2013-01-01

    Subjective decisions of thematic and spatial resolutions in characterizing environmental heterogeneity may affect the characterizations of spatial pattern and the simulation of occurrence and rate of ecological processes, and in turn, model-based tree species distribution. Thus, this study quantified the importance of thematic and spatial resolutions, and their interaction in predictions of tree species distribution (quantified by species abundance). We investigated how model-predicted species abundances changed and whether tree species with different ecological traits (e.g., seed dispersal distance, competitive capacity) had different responses to varying thematic and spatial resolutions. We used the LANDIS forest landscape model to predict tree species distribution at the landscape scale and designed a series of scenarios with different thematic (different numbers of land types) and spatial resolutions combinations, and then statistically examined the differences of species abundance among these scenarios. Results showed that both thematic and spatial resolutions affected model-based predictions of species distribution, but thematic resolution had a greater effect. Species ecological traits affected the predictions. For species with moderate dispersal distance and relatively abundant seed sources, predicted abundance increased as thematic resolution increased. However, for species with long seeding distance or high shade tolerance, thematic resolution had an inverse effect on predicted abundance. When seed sources and dispersal distance were not limiting, the predicted species abundance increased with spatial resolution and vice versa. Results from this study may provide insights into the choice of thematic and spatial resolutions for model-based predictions of tree species distribution.

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

    USGS Publications Warehouse

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

    2008-01-01

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

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

    PubMed

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

    2008-01-01

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

  17. Root diameter variations explained by anatomy and phylogeny of 50 tropical and temperate tree species.

    PubMed

    Gu, Jiacun; Xu, Yang; Dong, Xueyun; Wang, Hongfeng; Wang, Zhengquan

    2014-04-01

    Root diameter, a critical indicator of root physiological function, varies greatly among tree species, but the underlying mechanism of this high variability is unclear. Here, we sampled 50 tree species across tropical and temperate zones in China, and measured root morphological and anatomical traits along the first five branch orders in each species. Our objectives were (i) to reveal the relationships between root diameter, cortical thickness and stele diameter among tree species in tropical and temperate forests, and (ii) to investigate the relationship of both root morphological and anatomical traits with divergence time during species radiation. The results showed that root diameter was strongly affected by cortical thickness but less by stele diameter in both tropical and temperate species. Changes in cortical thickness explained over 90% of variation in root diameter for the first order, and ∼74-87% for the second and third orders. Thicker roots displayed greater cortical thickness and more cortical cell layers than thinner roots. Phylogenetic analysis demonstrated that root diameter, cortical thickness and number of cortical cell layers significantly correlated with divergence time at the family level, showing similar variation trends in geological time. The results also suggested that trees tend to decrease their root cortical thickness rather than stele diameter during species radiation. The close linkage of variations in root morphology and anatomy to phylogeny as demonstrated by the data from the 50 tree species should provide some insights into the mechanism of root diameter variability among tree species.

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

    USGS Publications Warehouse

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

    1998-01-01

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

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

    PubMed

    Solís, Silvia; Lobo, Jorge; Grimaldo, Mayori

    2009-09-01

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

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

    PubMed

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

    2012-01-01

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

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

    PubMed

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

    2012-01-01

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

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

    PubMed

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

    2014-01-01

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

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed

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

    2010-12-01

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

  5. Species- and site-specific impacts of an invasive herbivore on tree survival in mixed forests.

    PubMed

    Holland, E Penelope; Gormley, Andrew M; Pech, Roger P

    2016-04-01

    Invasive herbivores are often managed to limit their negative impact on plant populations, but herbivore density - plant damage relationships are notoriously spatially and temporally variable. Site and species characteristics (both plant and herbivore) must be considered when assessing the potential for herbivore damage, making it difficult to set thresholds for efficient management. Using the invasive brushtail possum Trichosurus vulpecula in New Zealand as a case study, we parameterized a generic model to predict annual probability of browse-induced mortality of five tree species at 12 sites. We compared predicted and observed tree mortality for each species + site combination to establish herbivore abundance - tree mortality thresholds for each site on a single and combined tree species basis. Model results indicated it is likely that possum browse was the primary cause of all tree mortality at nine of the 12 species-site combinations, allowing us to estimate site-specific thresholds below which possum population numbers should be reduced and maintained to keep tree mortality under a predetermined level, for example 0.5% per year. The browse model can be used to set site- and species-specific management action thresholds, and can be adapted easily for other plant or herbivore species. Results for multiple plant or herbivore species at a single site can be combined to create conservative, site-wide management strategies, and used to: determine which sites will be affected most by changes in herbivore abundance; quantify thresholds for herbivore management; and justify expenditure on herbivore control.

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

    PubMed

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

    2016-02-01

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

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

    PubMed

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

    2016-02-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

    The elevation limit of tree growth (alpine treeline) is considered to be constrained by environmental (i.e., thermal) and genetic (i.e., inability to adapt to climatic conditions) limitations to growth. Warming conditions due to climate change are predicted to cause upward shifts in the elevation of alpine treelines, through relief of cold-induced physiological limitations on seedling recruitment beyond current treeline boundaries. To determine how genetics and climate may interact to affect seedling establishment, we transplanted recently germinated seedlings from high- and low-elevation provenances (HI and LO, respectively) of Pinus flexilis in common gardens arrayed along an elevation and canopy gradient from subalpine forest into the alpine zone at Niwot Ridge, CO. We compared differences in microclimate and seedling ecophysiology among sites and between provenances. During the first summer of growth, frequently cloudy skies resulted in similar solar radiation incidence and air and soil temperatures among sites, despite nearly a 500 m-span in elevation across all sites. Preliminary findings suggest that survival of seedlings was similar between the lowest and highest elevations, with greater survival of LO (60%) compared to HI (40%) seedlings at each of these sites. Photosynthesis, carbon balance (photosynthesis/respiration), and conductance increased more than 2X with elevation for both provenances, and were 35-77% greater in LO seedlings compared to HI seedlings. There were no differences in dark-adapted chlorophyll fluorescence (Fv/Fm) among sites or between provenances. However, in a common-garden study at low elevation, we observed no differences in carbon or water relations between two naturally-germinated mitochondrial haplotypes of P. flexilis (of narrow and wide-ranging distributions). We did observe water-related thresholds on seedling carbon balance and survival that occurred when soil volumetric water content dropped below 10% and seedling water

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

    PubMed

    Smith, Duncan D; Sperry, John S

    2014-12-01

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

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

    PubMed

    Smith, Duncan D; Sperry, John S

    2014-12-01

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

  11. 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...

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

    PubMed

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

    2010-09-01

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

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

    SciTech Connect

    Yaussy, D.A.

    1993-03-01

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

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

    PubMed Central

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

    2014-01-01

    The climbing habit is an evolutionary key innovation in plants because it is associated with enhanced clade diversification. We tested whether patterns of species divergence and variation of three ecophysiological traits that are fundamental for plant adaptation to light environments (maximum photosynthetic rate [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

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

    PubMed

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

    2014-01-01

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

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

    PubMed

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

    2000-05-01

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

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

    PubMed

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

    2000-05-01

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

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

    PubMed

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

    2015-11-01

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

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

    ERIC Educational Resources Information Center

    Lückmann, Katrin; Menzel, Susanne

    2014-01-01

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

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

    PubMed

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

    2015-10-01

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

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

    PubMed

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

    2015-10-01

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

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

    USGS Publications Warehouse

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

    2014-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

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

    PubMed

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

    2016-03-01

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

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

    PubMed

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

    2015-12-01

    Wildlife-associated Cryptosporidium are an emerging cause of cryptosporidiosis in humans. The present study was undertaken to determine the extent to which North American tree squirrels and ground squirrels host zoonotic Cryptosporidium species and genotypes. Fragments of the Cryptosporidium 18S rRNA and actin genes were amplified and sequenced from fecal samples obtained from three tree squirrel and three ground squirrel species. In tree squirrels, Cryptosporidium was identified in 40.5% (17/42) of American red squirrels (Tamiasciurus hudsonicus), 40.4% (55/136) of eastern gray squirrels (Sciurus carolinensis), and 28.6% (2/7) of fox squirrels (Sciurus niger). Human-pathogenic Cryptosporidium ubiquitum and Cryptosporidium skunk genotype were the most prevalent species/genotypes in tree squirrels. Because tree squirrels live in close proximity to humans and are frequently infected with potentially zoonotic Cryptosporidium species/genotypes, they may be a significant reservoir of infection in humans. In ground squirrels, Cryptosporidium was detected in 70.2% (33/47) of 13-lined ground squirrels (Ictidomys tridecemlineatus), 35.1% (27/77) of black-tailed prairie dogs (Cynomys ludovicianus), and the only golden-mantled ground squirrel (Callospermophilus lateralis) that was sampled. Cryptosporidium rubeyi and ground squirrel genotypes I, II, and III were identified in isolates from these ground squirrel species. In contrast to the Cryptosporidium infecting tree squirrels, these species/genotypes appear to be specific for ground squirrels and are not associated with human disease. PMID:26437239

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

    PubMed

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

    2015-12-01

    Wildlife-associated Cryptosporidium are an emerging cause of cryptosporidiosis in humans. The present study was undertaken to determine the extent to which North American tree squirrels and ground squirrels host zoonotic Cryptosporidium species and genotypes. Fragments of the Cryptosporidium 18S rRNA and actin genes were amplified and sequenced from fecal samples obtained from three tree squirrel and three ground squirrel species. In tree squirrels, Cryptosporidium was identified in 40.5% (17/42) of American red squirrels (Tamiasciurus hudsonicus), 40.4% (55/136) of eastern gray squirrels (Sciurus carolinensis), and 28.6% (2/7) of fox squirrels (Sciurus niger). Human-pathogenic Cryptosporidium ubiquitum and Cryptosporidium skunk genotype were the most prevalent species/genotypes in tree squirrels. Because tree squirrels live in close proximity to humans and are frequently infected with potentially zoonotic Cryptosporidium species/genotypes, they may be a significant reservoir of infection in humans. In ground squirrels, Cryptosporidium was detected in 70.2% (33/47) of 13-lined ground squirrels (Ictidomys tridecemlineatus), 35.1% (27/77) of black-tailed prairie dogs (Cynomys ludovicianus), and the only golden-mantled ground squirrel (Callospermophilus lateralis) that was sampled. Cryptosporidium rubeyi and ground squirrel genotypes I, II, and III were identified in isolates from these ground squirrel species. In contrast to the Cryptosporidium infecting tree squirrels, these species/genotypes appear to be specific for ground squirrels and are not associated with human disease.

  7. Growth strategies of tropical tree species: disentangling light and size effects.

    PubMed

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

    2011-01-01

    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.

  8. Inter- and intra-specific variation in stemflow for evergreen species and deciduous tree species in a subtropical forest

    NASA Astrophysics Data System (ADS)

    Su, Lei; Xu, Wenting; Zhao, Changming; Xie, Zongqiang; Ju, Hua

    2016-06-01

    Quantification of stemflow is necessary for the assessment of forest ecosystem hydrological effects. Nevertheless, variation of stemflow among plant functional groups is currently not well understood. Stemflow production of co-occurring evergreen broadleaved trees (Cyclobalanopsis multinervis and Cyclobalanopsis oxyodon) and deciduous broadleaved trees (Fagus engleriana and Quercus serrata var. brevipetiolata) was quantified through field observations in a mixed evergreen and deciduous broadleaved forest. The research results revealed that stemflow increased linearly with increasing rainfall magnitude, with precipitation depths of 6.9, 7.2, 10.0 and 14.8 mm required for the initiation of stemflow for C. multinervis, C. oxyodon, F. engleriana and Q. serrata, respectively. Stemflow percentage and funneling ratio (FR) increased with increasing rainfall in a logarithmic fashion. Stemflow percentage and FR tended to grow rapidly with increasing rainfall magnitude up to a rainfall threshold of 50 mm, above which, further rainfall increases brought about only small increases. For C. multinervis, C. oxyodon, F. engleriana and Q. serrata, FR averaged 19.8, 14.8, 8.9 and 2.8, respectively. The stemflow generating rainfall thresholds for evergreen species were smaller than for deciduous species. Furthermore, stemflow percentage and FR of the former was greater than the latter. For both evergreen species and deciduous species, overall funneling ratio (FRs) decreased with increasing basal area. We concluded that: (1) although stemflow partitioning represented a fairly low percentage of gross rainfall in mixed evergreen and deciduous broadleaved forests, it was capable of providing substantial amount of rainwater to tree boles; (2) the evergreen species were more likely to generate stemflow than deciduous species, and directed more intercepted rainwater to the root zone; (3) small trees were more productive in funneling stemflow than larger trees, which may provide a favorable

  9. Flowering phenological pattern in crowns of four temperate deciduous tree species and its reproductive implications.

    PubMed

    Tal, O

    2011-01-01

    Temperate deciduous forest trees flower in spring, a period that starts when the trees lack leaves and when weather is unpredictable, including frost events, and ends when the forest becomes green and vertical microclimatic gradients are established. This paper asks whether there are spatio-temporal patterns in the development of flowering in trees, and how they relate to reproductive processes. Using a crane, flowering phenology was studied in the crowns of ca. 200 trees of four species, from early spring (ash) through the period of leaf-unfolding (maples) to early summer (lime). Flowering levels in different crown regions were documented quantitatively and repeatedly during the flowering season and compared among individuals and among species. Early-flowering trees displayed a clear and consistent acropetalous and centrifugal flowering pattern, while this pattern disappeared in species that flowered after leaves unfolded. This pattern was superposed on the basic flowering rhythm of each species, and was influenced by effects of direct sunlight, acting at a small scale in early spring and at a large scale in early summer. As this acropetalous centrifugal pattern contrasts the microclimatic gradients that develop only after leaves unfold, it might indicate physiological processes in the 'awakening' of trees, as well as evolutionary processes that took place in temperate trees during adaptation to a temperate climate.

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

    PubMed Central

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

    2009-01-01

    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, which are dominant tree species in this region and are distributed widely in North America. We hypothesized that soil properties would differ among stands dominated by different tree species 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 tree species, 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 tree species, 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 tree species, while the total abundance of nematodes, tardigrades, oribatid mites, and prostigmatid mites did not

  11. ISOPRENE EMISSION CAPACITY FOR U.S. TREE SPECIES

    EPA Science Inventory

    Isoprene emission capacity measurements are presented from 18 North American oak (Quercus) species and species from six other genera previously found to emit significant quantities of isoprene. Sampling was conducted at physiographically diverse locations in North Carolina...

  12. Host preferences and differential contributions of deciduous tree species shape mycorrhizal species richness in a mixed Central European forest.

    PubMed

    Lang, Christa; Seven, Jasmin; Polle, Andrea

    2011-05-01

    Mycorrhizal species richness and host ranges were investigated in mixed deciduous stands composed of Fagus sylvatica, Tilia spp., Carpinus betulus, Acer spp., and Fraxinus excelsior. Acer and Fraxinus were colonized by arbuscular mycorrhizas and contributed 5% to total stand mycorrhizal fungal species richness. Tilia hosted similar and Carpinus half the number of ectomycorrhizal (EM) fungal taxa compared with Fagus (75 putative taxa). The relative abundance of the host tree the EM fungal richness decreased in the order Fagus > Tilia > Carpinus. After correction for similar sampling intensities, EM fungal species richness of Carpinus was still about 30-40% lower than that of Fagus and Tilia. About 10% of the mycorrhizal species were shared among the EM forming trees; 29% were associated with two host tree species and 61% with only one of the hosts. The latter group consisted mainly of rare EM fungal species colonizing about 20% of the root tips and included known specialists but also putative non-host associations such as conifer or shrub mycorrhizas. Our data indicate that EM fungal species richness was associated with tree identity and suggest that Fagus secures EM fungal diversity in an ecosystem since it shared more common EM fungi with Tilia and Carpinus than the latter two among each other.

  13. Relationships among environmental variables and distribution of tree species at high elevation in the Olympic Mountains

    USGS Publications Warehouse

    Woodward, Andrea

    1998-01-01

    Relationships among environmental variables and occurrence of tree species 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 tree species. Tree species 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 tree species 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 tree species distributions within, but not among aspects. Change will be buffered by innate tolerance of adult trees and the inertia of soil properties.

  14. Glacial refugia and modern genetic diversity of 22 western North American tree species.

    PubMed

    Roberts, David R; Hamann, Andreas

    2015-04-01

    North American tree species, 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 trees since the last glacial maximum using species 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 tree species. We find that species with strong genetic differentiation into subspecies had widespread and large glacial refugia, whereas species 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

  15. Glacial refugia and modern genetic diversity of 22 western North American tree species

    PubMed Central

    Roberts, David R.; Hamann, Andreas

    2015-01-01

    North American tree species, 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 trees since the last glacial maximum using species 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 tree species. We find that species with strong genetic differentiation into subspecies had widespread and large glacial refugia, whereas species with restricted refugia show no differentiation among populations and little genetic diversity, despite being common over a wide range of environments today. In addition, a strong relationship between allelic richness and the size of modelled glacial refugia (r2 = 0.55) suggest that population bottlenecks during glacial periods had a pronounced effect on the presence of rare alleles. PMID:25761711

  16. Temporal and Spatial Dynamics of Tree Species Composition in Temperate Mountains of South Korea

    NASA Astrophysics Data System (ADS)

    Lee, Boknam; Park, Juhan; Cho, Sungsik; Ryu, Daun; Zaw Wynn, Khine; Park, Minji; Cho, Sunhee; Yoon, Jongguk; Park, Jongyoung; Kim, Hyun Seok

    2015-04-01

    Long term studies on vegetation dynamics are important to identify changes of ecosystem-level responses to climate change. To learn how tree species composition and stand structure change across temperate mountains, the temporal and spatial variations in tree species diversity and structure were investigated using the species composition and DBH size collected over the fourteen-year period across 134 sites in Jiri and Baekoon Mountains, South Korea. The overall temporal changes over fourteen years showed significant increase in stand density, species diversity and evenness according to the indices of Shannon-Weiner diversity, Bray-Curtis dissimilarity, and Pielou's evenness, contributing to the increase of basal area and biomass growth. The change of tree species composition could be categorized into five species communities, representing gradual increase or decrease, establishment, extinction, fluctuation of species population. However, in general, the change in species composition appeared to have consistent and directional patterns of increase in the annual rate of change in the mean species traits including species richness, pole growth rate, adult growth rate, and adult stature with five common dominant species (Quercus mongolica, Quercus variabilis, Quercus serrata, Carpinus laxiflora, and Styrax japonicus). The spatial patterns of species composition appeared to have a higher stand density and species diversity along with the low latitude and high slope ecosystem. The climate change was another main driver to vary the distribution of species abundance. Overall, both temporal and spatial changes of composition in tree species community was clear and further analysis to clarify the reasons for such fast and species-specific changes is underway especially to separate the effect of successional change and climate change. Keywords species composition; climate change; temporal and spatial variation ; forest structure; temperate forest

  17. [Effects of sampling plot number on tree species distribution prediction under climate change].

    PubMed

    Liang, Yu; He, Hong-Shi; Wu, Zhi-Wei; Li, Xiao-Na; Luo, Xu

    2013-05-01

    Based on the neutral landscapes under different degrees of landscape fragmentation, this paper studied the effects of sampling plot number on the prediction of tree species distribution at landscape scale under climate change. The tree species distribution was predicted by the coupled modeling approach which linked an ecosystem process model with a forest landscape model, and three contingent scenarios and one reference scenario of sampling plot numbers were assumed. The differences between the three scenarios and the reference scenario under different degrees of landscape fragmentation were tested. The results indicated that the effects of sampling plot number on the prediction of tree species distribution depended on the tree species life history attributes. For the generalist species, the prediction of their distribution at landscape scale needed more plots. Except for the extreme specialist, landscape fragmentation degree also affected the effects of sampling plot number on the prediction. With the increase of simulation period, the effects of sampling plot number on the prediction of tree species distribution at landscape scale could be changed. For generalist species, more plots are needed for the long-term simulation.

  18. Light-dependent leaf trait variation in 43 tropical dry forest tree species.

    PubMed

    Markesteijn, Lars; Poorter, Lourens; Bongers, Frans

    2007-04-01

    Our understanding of leaf acclimation in relation to irradiance of fully grown or juvenile trees is mainly based on research involving tropical wet forest species. We studied sun-shade plasticity of 24 leaf traits of 43 tree species in a Bolivian dry deciduous forest. Sampling was confined to small trees. For each species, leaves were taken from five of the most and five of the least illuminated crowns. Trees were selected based on the percentage of the hemisphere uncovered by other crowns. We examined leaf trait variation and the relation between trait plasticity and light demand, maximum adult stature, and ontogenetic changes in crown exposure of the species. Leaf trait variation was mainly related to differences among species and to a minor extent to differences in light availability. Traits related to the palisade layer, thickness of the outer cell wall, and N(area) and P(area) had the greatest plasticity, suggesting their importance for leaf function in different light environments. Short-lived pioneers had the highest trait plasticity. Overall plasticity was modest and rarely associated with juvenile light requirements, adult stature, or ontogenetic changes in crown exposure. Dry forest tree species had a lower light-related plasticity than wet forest species, probably because wet forests cast deeper shade. In dry forests light availability may be less limiting, and low water availability may constrain leaf trait plasticity in response to irradiance.

  19. Regional-scale directional changes in abundance of tree species along a temperature gradient in Japan.

    PubMed

    Suzuki, Satoshi N; Ishihara, Masae I; Hidaka, Amane

    2015-09-01

    Climate changes are assumed to shift the ranges of tree species and forest biomes. Such range shifts result from changes in abundances of tree species or functional types. Owing to global warming, the abundance of a tree species or functional type is expected to increase near the colder edge of its range and decrease near the warmer edge. This study examined directional changes in abundance and demographic parameters of forest trees along a temperature gradient, as well as a successional gradient, in Japan. Changes in the relative abundance of each of four functional types (evergreen broad-leaved, deciduous broad-leaved, evergreen temperate conifer, and evergreen boreal conifer) and the demography of each species (recruitment rate, mortality, and population growth rate) were analyzed in 39 permanent forest plots across the Japanese archipelago. Directional changes in the relative abundance of functional types were detected along the temperature gradient. Relative abundance of evergreen broad-leaved trees increased near their colder range boundaries, especially in secondary forests, coinciding with the decrease in deciduous broad-leaved trees. Similarly, relative abundance of deciduous broad-leaved trees increased near their colder range boundaries, coinciding with the decrease in boreal conifers. These functional-type-level changes were mainly due to higher recruitment rates and partly to the lower mortality of individual species at colder sites. This is the first report to show that tree species abundances in temperate forests are changing directionally along a temperature gradient, which might be due to current or past climate changes as well as recovery from past disturbances.

  20. Regional-scale directional changes in abundance of tree species along a temperature gradient in Japan.

    PubMed

    Suzuki, Satoshi N; Ishihara, Masae I; Hidaka, Amane

    2015-09-01

    Climate changes are assumed to shift the ranges of tree species and forest biomes. Such range shifts result from changes in abundances of tree species or functional types. Owing to global warming, the abundance of a tree species or functional type is expected to increase near the colder edge of its range and decrease near the warmer edge. This study examined directional changes in abundance and demographic parameters of forest trees along a temperature gradient, as well as a successional gradient, in Japan. Changes in the relative abundance of each of four functional types (evergreen broad-leaved, deciduous broad-leaved, evergreen temperate conifer, and evergreen boreal conifer) and the demography of each species (recruitment rate, mortality, and population growth rate) were analyzed in 39 permanent forest plots across the Japanese archipelago. Directional changes in the relative abundance of functional types were detected along the temperature gradient. Relative abundance of evergreen broad-leaved trees increased near their colder range boundaries, especially in secondary forests, coinciding with the decrease in deciduous broad-leaved trees. Similarly, relative abundance of deciduous broad-leaved trees increased near their colder range boundaries, coinciding with the decrease in boreal conifers. These functional-type-level changes were mainly due to higher recruitment rates and partly to the lower mortality of individual species at colder sites. This is the first report to show that tree species abundances in temperate forests are changing directionally along a temperature gradient, which might be due to current or past climate changes as well as recovery from past disturbances. PMID:25712048

  1. Climate warming and precipitation redistribution modify tree-grass interactions and tree species establishment in a warm-temperate savanna.

    PubMed

    Volder, Astrid; Briske, David D; Tjoelker, Mark G

    2013-03-01

    Savanna tree-grass interactions may be particularly sensitive to climate change. Establishment of two tree canopy dominants, post oak (Quercus stellata) and eastern redcedar (Juniperus virginiana), grown with the dominant C4 perennial grass (Schizachyrium scoparium) in southern oak savanna of the United States were evaluated under four climatic scenarios for 6 years. Tree-grass interactions were examined with and without warming (+1.5 °C) in combination with a long-term mean rainfall treatment and a modified rainfall regime that redistributed 40% of summer rainfall to spring and fall, intensifying summer drought. The aim was to determine: (1) the relative growth response of these species, (2) potential shifts in the balance of tree-grass interactions, and (3) the trajectory of juniper encroachment into savannas, under these anticipated climatic conditions. Precipitation redistribution reduced relative growth rate (RGR) of trees grown with grass. Warming increased growth of J. virginiana and strongly reduced Q. stellata survival. Tiller numbers of S. scoparium plants were unaffected by warming, but the number of reproductive tillers was increasingly suppressed by intensified drought each year. Growth rates of J. virginiana and Q. stellata were suppressed by grass presence early, but in subsequent years were higher when grown with grass. Quercus stellata had overall reduced RGR, but enhanced survival when grown with grass, while survival of J. virginiana remained near 100% in all treatments. Once trees surpassed a threshold height of 1.1 m, both tiller number and survival of S. scoparium plants were drastically reduced by the presence of J. virginiana, but not Q. stellata. Juniperus virginiana was the only savanna dominant in which neither survival nor final aboveground mass were adversely affected by the climate scenario of warming and intensified summer drought. These responses indicate that climate warming and altered precipitation patterns will further

  2. Identification, measurement and interpretation of tree rings in woody species from mediterranean climates.

    PubMed

    Cherubini, Paolo; Gartner, Barbara L; Tognetti, Roberto; Bräker, Otto U; Schoch, Werner; Innes, John L

    2003-02-01

    We review the literature dealing with mediterranean climate, vegetation, phenology and ecophysiology relevant to the understanding of tree-ring formation in mediterranean regions. Tree rings have been used extensively in temperate regions to reconstruct responses of forests to past environmental changes. In mediterranean regions, studies of tree 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, tree 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 tree-ring morphology of five species (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 tree-ring formation in mediterranean environments. Mediterranean tree rings can be dated and used for dendrochronological purposes, but great care should be taken in selecting sampling sites, species and sample trees. PMID:12620063

  3. Firewood crops. Shrub and tree species for energy production

    SciTech Connect

    Ruskin, F.R.

    1980-01-01

    The report of an ad hoc panel of the Advisory Committee on Technology Innovation Board on Science and Technology for International Development Commission on International Relations. After an introduction by Eckholm, E., the first chapter, Wood as fuel, discusses firewood plantations, fuelwood management and species, wood-burning stoves, and the use of charcoal. The remaining 3 chapters each describe in alphabetical order: fuelwood species for humid tropics, tropical highlands, and for arid and semiarid regions. For each species there is a general description and data on distribution, use as firewood, yield, other uses, environmental requirements, establishment, pests and diseases, and limitations, with at least one black and white plate. There are 10 appendices: Using fuelwood efficiently; Case study; Ethiopia; Cast study: South Korea (Eckholm, E.); Master list of firewood species; Selected readings (general, and by species); Research contacts (by species); Explanation of terms; Biographical sketches of panel members; Contributors (to the report); and Index of plants.

  4. Does deciduous tree species identity affect carbon storage in temperate soils?

    NASA Astrophysics Data System (ADS)

    Jungkunst, Hermann; Schleuß, Per; Heitkamp, Felix

    2015-04-01

    Forest soils contribute roughly 70 % to the global terrestrial soil organic carbon (SOC) pool and thus play a vital role in the global carbon cycle. It is less clear, however, whether temperate tree species identity affects SOC storage beyond the coarse differentiation between coniferous and deciduous trees. The most important driver for soil SOC storage definitely is the fine mineral fraction (clay and fine silt) because of its high sorption ability. It is difficult to disentangle any additional biotic effects since clay and silt vary considerably in nature. For experimental approaches, the process of soil carbon accumulation is too slow and, therefore, sound results cannot be expected for decades. Here we will present our success to distinguish between the effects of fine particle content (abiotic) and tree species composition (biotic) on the SOC pool in an old-growth broad-leaved forest plots along a tree diversity gradient , i.e., 1- (beech), 3- (plus ash and lime tree)- and 5-(plus maple and hornbeam) species. The particle size fractions were separated first and then the carbon concentrations of each fraction was measured. Hence, the carbon content per unit clay was not calculated, as usually done, but directly measured. As expected, the variation in SOC content was mainly explained by the variations in clay content but not entirely. We found that the carbon concentration per unit clay and fine silt in the subsoil was by 30-35% higher in mixed than in monospecific stands indicating a significant species identity or species diversity effect on C stabilization. In contrast to the subsoil, no tree species effects was identified for the topsoil. Indications are given that the mineral phase was already carbon saturated and thus left no more room for a possible biotic effect. Underlying processes must remain speculative, but we will additionally present our latest microcosm results, including isotopic signatures, to underpin the proposed deciduous tree species

  5. Determination of incoming solar radiation in major tree species in Turkey.

    PubMed

    Yilmaz, Osman Yalcin; Sevgi, Orhan; Koc, Ayhan

    2012-07-01

    Light requirements and spatial distribution of major forest tree species 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 tree species 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 tree species 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 tree species 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 species < Oak species < Scotch pine < Red pine < Cedar < Juniper. The monthly and annual solar radiation values of sites and light requirements of forest trees ranked similarly. PMID:23360013

  6. Evolutionary patterns of range size, abundance and species richness in Amazonian angiosperm trees

    PubMed Central

    Chave, Jérôme

    2016-01-01

    Amazonian tree species vary enormously in their total abundance and range size, while Amazonian tree genera vary greatly in species richness. The drivers of this variation are not well understood. Here, we construct a phylogenetic hypothesis that represents half of Amazonian tree genera in order to contribute to explaining the variation. We find several clear, broad-scale patterns. Firstly, there is significant phylogenetic signal for all three characteristics; closely related genera tend to have similar numbers of species and similar mean range size and abundance. Additionally, the species richness of genera shows a significant, negative relationship with the mean range size and abundance of their constituent species. Our results suggest that phylogenetically correlated intrinsic factors, namely traits of the genera themselves, shape among lineage variation in range size, abundance and species richness. We postulate that tree stature may be one particularly relevant trait. However, other traits may also be relevant, and our study reinforces the need for ambitious compilations of trait data for Amazonian trees. In the meantime, our study shows how large-scale phylogenies can help to elucidate, and contribute to explaining, macroecological and macroevolutionary patterns in hyperdiverse, yet poorly understood regions like the Amazon Basin.

  7. Evolutionary patterns of range size, abundance and species richness in Amazonian angiosperm trees

    PubMed Central

    Chave, Jérôme

    2016-01-01

    Amazonian tree species vary enormously in their total abundance and range size, while Amazonian tree genera vary greatly in species richness. The drivers of this variation are not well understood. Here, we construct a phylogenetic hypothesis that represents half of Amazonian tree genera in order to contribute to explaining the variation. We find several clear, broad-scale patterns. Firstly, there is significant phylogenetic signal for all three characteristics; closely related genera tend to have similar numbers of species and similar mean range size and abundance. Additionally, the species richness of genera shows a significant, negative relationship with the mean range size and abundance of their constituent species. Our results suggest that phylogenetically correlated intrinsic factors, namely traits of the genera themselves, shape among lineage variation in range size, abundance and species richness. We postulate that tree stature may be one particularly relevant trait. However, other traits may also be relevant, and our study reinforces the need for ambitious compilations of trait data for Amazonian trees. In the meantime, our study shows how large-scale phylogenies can help to elucidate, and contribute to explaining, macroecological and macroevolutionary patterns in hyperdiverse, yet poorly understood regions like the Amazon Basin. PMID:27651991

  8. Evolutionary patterns of range size, abundance and species richness in Amazonian angiosperm trees.

    PubMed

    Dexter, Kyle; Chave, Jérôme

    2016-01-01

    Amazonian tree species vary enormously in their total abundance and range size, while Amazonian tree genera vary greatly in species richness. The drivers of this variation are not well understood. Here, we construct a phylogenetic hypothesis that represents half of Amazonian tree genera in order to contribute to explaining the variation. We find several clear, broad-scale patterns. Firstly, there is significant phylogenetic signal for all three characteristics; closely related genera tend to have similar numbers of species and similar mean range size and abundance. Additionally, the species richness of genera shows a significant, negative relationship with the mean range size and abundance of their constituent species. Our results suggest that phylogenetically correlated intrinsic factors, namely traits of the genera themselves, shape among lineage variation in range size, abundance and species richness. We postulate that tree stature may be one particularly relevant trait. However, other traits may also be relevant, and our study reinforces the need for ambitious compilations of trait data for Amazonian trees. In the meantime, our study shows how large-scale phylogenies can help to elucidate, and contribute to explaining, macroecological and macroevolutionary patterns in hyperdiverse, yet poorly understood regions like the Amazon Basin.

  9. Evolutionary patterns of range size, abundance and species richness in Amazonian angiosperm trees.

    PubMed

    Dexter, Kyle; Chave, Jérôme

    2016-01-01

    Amazonian tree species vary enormously in their total abundance and range size, while Amazonian tree genera vary greatly in species richness. The drivers of this variation are not well understood. Here, we construct a phylogenetic hypothesis that represents half of Amazonian tree genera in order to contribute to explaining the variation. We find several clear, broad-scale patterns. Firstly, there is significant phylogenetic signal for all three characteristics; closely related genera tend to have similar numbers of species and similar mean range size and abundance. Additionally, the species richness of genera shows a significant, negative relationship with the mean range size and abundance of their constituent species. Our results suggest that phylogenetically correlated intrinsic factors, namely traits of the genera themselves, shape among lineage variation in range size, abundance and species richness. We postulate that tree stature may be one particularly relevant trait. However, other traits may also be relevant, and our study reinforces the need for ambitious compilations of trait data for Amazonian trees. In the meantime, our study shows how large-scale phylogenies can help to elucidate, and contribute to explaining, macroecological and macroevolutionary patterns in hyperdiverse, yet poorly understood regions like the Amazon Basin. PMID:27651991

  10. BOREAS TE-4 Branch Bag Data From Boreal Tree Species

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Papagno, Andrea (Editor); Berry, Joseph A.; Fu, Wei; Fredeen, Art; Gamon, John

    2000-01-01

    The BOREAS TE-4 team collected continuous records of gas exchange under ambient conditions from intact boreal forest trees 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).

  11. Ambrosia Beetle (Coleoptera: Scolytidae) Species, Flight, and Attack on Living Eastern Cottonwood Trees.

    SciTech Connect

    Coyle, D R; D.C. Booth: M.S. Wallace

    2005-12-01

    ABSTRACT In spring 2002, ambrosia beetles (Coleoptera: Scolytidae) infested an intensively managed 22-ha tree plantation on the upper coastal plain of South Carolina. Nearly 3,500 scolytids representing 28 species were captured in ethanol-baited traps from 18 June 2002 to 18 April 2004. More than 88% of total captures were exotic species. Five species [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 tree species in the plantation, eastern cottonwood, Populus deltoides Bartram, was the only one attacked, with nearly 40% of the trees sustaining ambrosia beetle damage. Clone ST66 sustained more damage than clone S7C15. ST66 trees receiving fertilization were attacked more frequently than trees receiving irrigation, irrigation_fertilization, or controls, although the number of S7C15 trees 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.

  12. Wind Disturbance Produced Changes in Tree Species Assemblage in the Peruvian Amazon

    NASA Astrophysics Data System (ADS)

    Rifai, S. W.; Chambers, J. Q.; Negron Juarez, R. I.; Ramirez, F.; Tello, R.; Alegria Muñoz, W.

    2010-12-01

    Wind disturbance has been a frequently overlooked abiotic cause of mass tree 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 tree 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 tree mortality and change in NPV. It is hypothesized that these mass tree mortality events result in changes in the tree species assemblage of affected forests. Here we present preliminary tree species 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 trees greater than 10 cm diameter at breast height were measured for diameter, height and were identified to the species. Stem density of trees with diameter at breast height > 10 cm, and tree height appear to be similar both inside and outside the blowdown affected areas of the forests at both sites. At the ALP

  13. Vertical distribution and species coexistence of tree hole mosquitoes in Louisiana.

    PubMed

    Schreiber, E T; Meek, C L; Yates, M M

    1988-03-01

    Vertical distribution and species coexistence of mosquitoes inhabiting a deciduous forest in southern Louisiana were determined using 470 ml black jars for larval collections at ground level and 1, 3, 5, 7 and 9 m on selected trees. Specific preferences for discrete microhabitats by Aedes triseriatus, Ae. hendersoni, Ae. vexans and Ae. albopictus were not evident. Niche overlap indices, however, showed little overlap of these species and seemed to indicate that the mosquitoes partitioned the ovipositional/larval sites. Competition between the most abundant species, Ae. triseriatus and Ae. albopictus, was not apparent. The tree hole mosquito community structure appeared to be mediated by the predator, Toxorhynchites rutilus septentrionalis.

  14. Selective logging in tropical forests decreases the robustness of liana-tree interaction networks to the loss of host tree species.

    PubMed

    Magrach, Ainhoa; Senior, Rebecca A; Rogers, Andrew; Nurdin, Deddy; Benedick, Suzan; Laurance, William F; Santamaria, Luis; Edwards, David P

    2016-03-16

    Selective logging is one of the major drivers of tropical forest degradation, causing important shifts in species composition. Whether such changes modify interactions between species and the networks in which they are embedded remain fundamental questions to assess the 'health' and ecosystem functionality of logged forests. We focus on interactions between lianas and their tree hosts within primary and selectively logged forests in the biodiversity hotspot of Malaysian Borneo. We found that lianas were more abundant, had higher species richness, and different species compositions in logged than in primary forests. Logged forests showed heavier liana loads disparately affecting slow-growing tree species, which could exacerbate the loss of timber value and carbon storage already associated with logging. Moreover, simulation scenarios of host tree local species loss indicated that logging might decrease the robustness of liana-tree interaction networks if heavily infested trees (i.e. the most connected ones) were more likely to disappear. This effect is partially mitigated in the short term by the colonization of host trees by a greater diversity of liana species within logged forests, yet this might not compensate for the loss of preferred tree hosts in the long term. As a consequence, species interaction networks may show a lagged response to disturbance, which may trigger sudden collapses in species richness and ecosystem function in response to additional disturbances, representing a new type of 'extinction debt'. PMID:26936241

  15. Selective logging in tropical forests decreases the robustness of liana-tree interaction networks to the loss of host tree species.

    PubMed

    Magrach, Ainhoa; Senior, Rebecca A; Rogers, Andrew; Nurdin, Deddy; Benedick, Suzan; Laurance, William F; Santamaria, Luis; Edwards, David P

    2016-03-16

    Selective logging is one of the major drivers of tropical forest degradation, causing important shifts in species composition. Whether such changes modify interactions between species and the networks in which they are embedded remain fundamental questions to assess the 'health' and ecosystem functionality of logged forests. We focus on interactions between lianas and their tree hosts within primary and selectively logged forests in the biodiversity hotspot of Malaysian Borneo. We found that lianas were more abundant, had higher species richness, and different species compositions in logged than in primary forests. Logged forests showed heavier liana loads disparately affecting slow-growing tree species, which could exacerbate the loss of timber value and carbon storage already associated with logging. Moreover, simulation scenarios of host tree local species loss indicated that logging might decrease the robustness of liana-tree interaction networks if heavily infested trees (i.e. the most connected ones) were more likely to disappear. This effect is partially mitigated in the short term by the colonization of host trees by a greater diversity of liana species within logged forests, yet this might not compensate for the loss of preferred tree hosts in the long term. As a consequence, species interaction networks may show a lagged response to disturbance, which may trigger sudden collapses in species richness and ecosystem function in response to additional disturbances, representing a new type of 'extinction debt'.

  16. Phylogenetic Structure of Tree Species across Different Life Stages from Seedlings to Canopy Trees in a Subtropical Evergreen Broad-Leaved Forest.

    PubMed

    Jin, Yi; Qian, Hong; Yu, Mingjian

    2015-01-01

    Investigating patterns of phylogenetic structure across different life stages of tree species in forests is crucial to understanding forest community assembly, and investigating forest gap influence on the phylogenetic structure of forest regeneration is necessary for understanding forest community assembly. Here, we examine the phylogenetic structure of tree species across life stages from seedlings to canopy trees, as well as forest gap influence on the phylogenetic structure of forest regeneration in a forest of the subtropical region in China. We investigate changes in phylogenetic relatedness (measured as NRI) of tree species from seedlings, saplings, treelets to canopy trees; we compare the phylogenetic turnover (measured as βNRI) between canopy trees and seedlings in forest understory with that between canopy trees and seedlings in forest gaps. We found that phylogenetic relatedness generally increases from seedlings through saplings and treelets up to canopy trees, and that phylogenetic relatedness does not differ between seedlings in forest understory and those in forest gaps, but phylogenetic turnover between canopy trees and seedlings in forest understory is lower than that between canopy trees and seedlings in forest gaps. We conclude that tree species tend to be more closely related from seedling to canopy layers, and that forest gaps alter the seedling phylogenetic turnover of the studied forest. It is likely that the increasing trend of phylogenetic clustering as tree stem size increases observed in this subtropical forest is primarily driven by abiotic filtering processes, which select a set of closely related evergreen broad-leaved tree species whose regeneration has adapted to the closed canopy environments of the subtropical forest developed under the regional monsoon climate.

  17. Spatial distribution and interspecific associations of tree species in a tropical seasonal rain forest of China.

    PubMed

    Lan, Guoyu; Getzin, Stephan; Wiegand, Thorsten; Hu, Yuehua; Xie, Guishui; Zhu, Hua; Cao, Min

    2012-01-01

    Studying the spatial pattern and interspecific associations of plant species may provide valuable insights into processes and mechanisms that maintain species coexistence. Point pattern analysis was used to analyze the spatial distribution patterns of twenty dominant tree species, their interspecific spatial associations and changes across life stages in a 20-ha permanent plot of seasonal tropical rainforest in Xishuangbanna, China, to test mechanisms maintaining species coexistence. Torus-translation tests were used to quantify positive or negative associations of the species to topographic habitats. The results showed: (1) fourteen of the twenty tree species were negatively (or positively) associated with one or two of the topographic variables, which evidences that the niche contributes to the spatial pattern of these species. (2) Most saplings of the study species showed a significantly clumped distribution at small scales (0-10 m) which was lost at larger scales (10-30 m). (3) The degree of spatial clumping deceases from saplings, to poles, to adults indicates that density-dependent mortality of the offspring is ubiquitous in species. (4) It is notable that a high number of positive small-scale interactions were found among the twenty species. For saplings, 42.6% of all combinations of species pairs showed positive associations at neighborhood scales up to five meters, but only 38.4% were negative. For poles and adults, positive associations at these distances still made up 45.5% and 29.5%, respectively. In conclusion, there is considerable evidence for the presence of positive interactions among the tree species, which suggests that species herd protection may occur in our plot. In addition, niche assembly and limited dispersal (likely) contribute to the spatial patterns of tree species in the tropical seasonal rain forest in Xishuangbanna, China. PMID:23029394

  18. Spatial distribution and interspecific associations of tree species in a tropical seasonal rain forest of China.

    PubMed

    Lan, Guoyu; Getzin, Stephan; Wiegand, Thorsten; Hu, Yuehua; Xie, Guishui; Zhu, Hua; Cao, Min

    2012-01-01

    Studying the spatial pattern and interspecific associations of plant species may provide valuable insights into processes and mechanisms that maintain species coexistence. Point pattern analysis was used to analyze the spatial distribution patterns of twenty dominant tree species, their interspecific spatial associations and changes across life stages in a 20-ha permanent plot of seasonal tropical rainforest in Xishuangbanna, China, to test mechanisms maintaining species coexistence. Torus-translation tests were used to quantify positive or negative associations of the species to topographic habitats. The results showed: (1) fourteen of the twenty tree species were negatively (or positively) associated with one or two of the topographic variables, which evidences that the niche contributes to the spatial pattern of these species. (2) Most saplings of the study species showed a significantly clumped distribution at small scales (0-10 m) which was lost at larger scales (10-30 m). (3) The degree of spatial clumping deceases from saplings, to poles, to adults indicates that density-dependent mortality of the offspring is ubiquitous in species. (4) It is notable that a high number of positive small-scale interactions were found among the twenty species. For saplings, 42.6% of all combinations of species pairs showed positive associations at neighborhood scales up to five meters, but only 38.4% were negative. For poles and adults, positive associations at these distances still made up 45.5% and 29.5%, respectively. In conclusion, there is considerable evidence for the presence of positive interactions among the tree species, which suggests that species herd protection may occur in our plot. In addition, niche assembly and limited dispersal (likely) contribute to the spatial patterns of tree species in the tropical seasonal rain forest in Xishuangbanna, China.

  19. Spatial Distribution and Interspecific Associations of Tree Species in a Tropical Seasonal Rain Forest of China

    PubMed Central

    Lan, Guoyu; Getzin, Stephan; Wiegand, Thorsten; Hu, Yuehua; Xie, Guishui; Zhu, Hua; Cao, Min

    2012-01-01

    Studying the spatial pattern and interspecific associations of plant species may provide valuable insights into processes and mechanisms that maintain species coexistence. Point pattern analysis was used to analyze the spatial distribution patterns of twenty dominant tree species, their interspecific spatial associations and changes across life stages in a 20-ha permanent plot of seasonal tropical rainforest in Xishuangbanna, China, to test mechanisms maintaining species coexistence. Torus-translation tests were used to quantify positive or negative associations of the species to topographic habitats. The results showed: (1) fourteen of the twenty tree species were negatively (or positively) associated with one or two of the topographic variables, which evidences that the niche contributes to the spatial pattern of these species. (2) Most saplings of the study species showed a significantly clumped distribution at small scales (0–10 m) which was lost at larger scales (10–30 m). (3) The degree of spatial clumping deceases from saplings, to poles, to adults indicates that density-dependent mortality of the offspring is ubiquitous in species. (4) It is notable that a high number of positive small-scale interactions were found among the twenty species. For saplings, 42.6% of all combinations of species pairs showed positive associations at neighborhood scales up to five meters, but only 38.4% were negative. For poles and adults, positive associations at these distances still made up 45.5% and 29.5%, respectively. In conclusion, there is considerable evidence for the presence of positive interactions among the tree species, which suggests that species herd protection may occur in our plot. In addition, niche assembly and limited dispersal (likely) contribute to the spatial patterns of tree species in the tropical seasonal rain forest in Xishuangbanna, China. PMID:23029394

  20. Fuel wood properties of some oak tree species of Manipur, India.

    PubMed

    Meetei, Shougrakpam Bijen; Singh, E J; Das, Ashesh Kumar

    2015-07-01

    Five indigenous oak tree species, i.e., Castanopsis indica (Roxb. ex Lindl.) A.DC., Lithocarpus fenestratus (Roxb.) Rehder, Lithocarpus pachyphyllus (Kurz) Rehder, Lithocarpus polystachyus (Wall. ex A.DC.) Rehder and Quercus serrata Murray were estimated for their wood properties such as calorific value, density, moisture content and ash content from a sub-tropical forest of Haraothel hill, Senapati District, Manipur. Wood biomass components were found to have higher calorific value (kJ g(-)) than bark components. The calorific values for tree species were found highest in L. pachyphyllus (17.99 kJ g(-1)) followed by C. indica (17.98 kJ g1), L. fenestratus (17.96 kJ g"), L. polystachyus (17.80 kJ g(-1)) and Q. serrata (17.49 kJ g(-1)). Calorific values for bole bark, bole wood and branch bark were found significantly different (F > 3.48 at p = 0.05) in five oak tree species. Percentage of ash on dry weight basis was found to be highest in Q. serrata (4.73%) and lowest in C. indica (2.19%). Ash content of tree components gives a singnificant factor in determining fuelwood value index (FVI). Of all the five oak tree species, Q. serrata exhibited highest value of wood density (0.78 g cm-) and lowest was observed in C. indica (0.63 g cm(-3)). There was significant correlation between wood density (p<0.05), ash content (p<0.01) with calorific value in oak tree species. Fuelwood value index (FVI) was in the following order: C. indica (1109.70) > L. pachyphyllus (898.41)> L. polystachyus (879.02)> L. fenestratus (824.61)> Q. serrata (792.50). Thus, the present study suggests that C. indica may be considered as a fuelwood oak tree species in Manipur. PMID:26364482

  1. Fuel wood properties of some oak tree species of Manipur, India.

    PubMed

    Meetei, Shougrakpam Bijen; Singh, E J; Das, Ashesh Kumar

    2015-07-01

    Five indigenous oak tree species, i.e., Castanopsis indica (Roxb. ex Lindl.) A.DC., Lithocarpus fenestratus (Roxb.) Rehder, Lithocarpus pachyphyllus (Kurz) Rehder, Lithocarpus polystachyus (Wall. ex A.DC.) Rehder and Quercus serrata Murray were estimated for their wood properties such as calorific value, density, moisture content and ash content from a sub-tropical forest of Haraothel hill, Senapati District, Manipur. Wood biomass components were found to have higher calorific value (kJ g(-)) than bark components. The calorific values for tree species were found highest in L. pachyphyllus (17.99 kJ g(-1)) followed by C. indica (17.98 kJ g1), L. fenestratus (17.96 kJ g"), L. polystachyus (17.80 kJ g(-1)) and Q. serrata (17.49 kJ g(-1)). Calorific values for bole bark, bole wood and branch bark were found significantly different (F > 3.48 at p = 0.05) in five oak tree species. Percentage of ash on dry weight basis was found to be highest in Q. serrata (4.73%) and lowest in C. indica (2.19%). Ash content of tree components gives a singnificant factor in determining fuelwood value index (FVI). Of all the five oak tree species, Q. serrata exhibited highest value of wood density (0.78 g cm-) and lowest was observed in C. indica (0.63 g cm(-3)). There was significant correlation between wood density (p<0.05), ash content (p<0.01) with calorific value in oak tree species. Fuelwood value index (FVI) was in the following order: C. indica (1109.70) > L. pachyphyllus (898.41)> L. polystachyus (879.02)> L. fenestratus (824.61)> Q. serrata (792.50). Thus, the present study suggests that C. indica may be considered as a fuelwood oak tree species in Manipur.

  2. Early establishment of trees at the alpine treeline: idiosyncratic species responses to temperature-moisture interactions

    PubMed Central

    Loranger, Hannah; Zotz, Gerhard; Bader, Maaike Y.

    2016-01-01

    On a global scale, temperature is the main determinant of arctic and alpine treeline position. However on a local scale, treeline form and position vary considerably due to other climatic factors, tree species ecology and life-stage-dependent responses. For treelines to advance poleward or uphill, the first steps are germination and seedling establishment. These earliest life stages may be major bottlenecks for treeline tree populations and will depend differently on climatic conditions than adult trees. We investigated the effect of soil temperature and moisture on germination and early seedling survival in a field experiment in the French Alps near the local treeline (2100 m a.s.l.) using passive temperature manipulations and two watering regimes. Five European treeline tree species were studied: Larix decidua, Picea abies, Pinus cembra, Pinus uncinata and Sorbus aucuparia. In addition, we monitored the germination response of three of these species to low temperatures under controlled conditions in growth chambers. The early establishment of these trees at the alpine treeline was limited either by temperature or by moisture, the sensitivity to one factor often depending on the intensity of the other. The results showed that the relative importance of the two factors and the direction of the effects are highly species-specific, while both factors tend to have consistent effects on both germination and early seedling survival within each species. We show that temperature and water availability are both important contributors to establishment patterns of treeline trees and hence to species-specific forms and positions of alpine treelines. The observed idiosyncratic species responses highlight the need for studies including several species and life-stages to create predictive power concerning future treeline dynamics. PMID:27402618

  3. Early establishment of trees at the alpine treeline: idiosyncratic species responses to temperature-moisture interactions.

    PubMed

    Loranger, Hannah; Zotz, Gerhard; Bader, Maaike Y

    2016-01-01

    On a global scale, temperature is the main determinant of arctic and alpine treeline position. However on a local scale, treeline form and position vary considerably due to other climatic factors, tree species ecology and life-stage-dependent responses. For treelines to advance poleward or uphill, the first steps are germination and seedling establishment. These earliest life stages may be major bottlenecks for treeline tree populations and will depend differently on climatic conditions than adult trees. We investigated the effect of soil temperature and moisture on germination and early seedling survival in a field experiment in the French Alps near the local treeline (2100 m a.s.l.) using passive temperature manipulations and two watering regimes. Five European treeline tree species were studied: Larix decidua, Picea abies, Pinus cembra, Pinus uncinata and Sorbus aucuparia In addition, we monitored the germination response of three of these species to low temperatures under controlled conditions in growth chambers. The early establishment of these trees at the alpine treeline was limited either by temperature or by moisture, the sensitivity to one factor often depending on the intensity of the other. The results showed that the relative importance of the two factors and the direction of the effects are highly species-specific, while both factors tend to have consistent effects on both germination and early seedling survival within each species. We show that temperature and water availability are both important contributors to establishment patterns of treeline trees and hence to species-specific forms and positions of alpine treelines. The observed idiosyncratic species responses highlight the need for studies including several species and life-stages to create predictive power concerning future treeline dynamics. PMID:27402618

  4. Discrimination of Deciduous Tree Species from Time Series of Unmanned Aerial System Imagery.

    PubMed

    Lisein, Jonathan; Michez, Adrien; Claessens, Hugues; Lejeune, Philippe

    2015-01-01

    Technology advances can revolutionize Precision Forestry by providing accurate and fine forest information at tree level. This paper addresses the question of how and particularly when Unmanned Aerial System (UAS) should be used in order to efficiently discriminate deciduous tree species. The goal of this research is to determine when is the best time window to achieve an optimal species discrimination. A time series of high resolution UAS imagery was collected to cover the growing season from leaf flush to leaf fall. Full benefit was taken of the temporal resolution of UAS acquisition, one of the most promising features of small drones. The disparity in forest tree phenology is at the maximum during early spring and late autumn. But the phenology state that optimized the classification result is the one that minimizes the spectral variation within tree species groups and, at the same time, maximizes the phenologic differences between species. Sunlit tree crowns (5 deciduous species groups) were classified using a Random Forest approach for monotemporal, two-date and three-date combinations. The end of leaf flushing was the most efficient single-date time window. Multitemporal datasets definitely improve the overall classification accuracy. But single-date high resolution orthophotomosaics, acquired on optimal time-windows, result in a very good classification accuracy (overall out of bag error of 16%).

  5. PoMo: An Allele Frequency-Based Approach for Species Tree Estimation

    PubMed Central

    De Maio, Nicola; Schrempf, Dominik; Kosiol, Carolin

    2015-01-01

    Incomplete lineage sorting can cause incongruencies of the overall species-level phylogenetic tree with the phylogenetic trees for individual genes or genomic segments. If these incongruencies are not accounted for, it is possible to incur several biases in species tree estimation. Here, we present a simple maximum likelihood approach that accounts for ancestral variation and incomplete lineage sorting. We use a POlymorphisms-aware phylogenetic MOdel (PoMo) that we have recently shown to efficiently estimate mutation rates and fixation biases from within and between-species variation data. We extend this model to perform efficient estimation of species trees. We test the performance of PoMo in several different scenarios of incomplete lineage sorting using simulations and compare it with existing methods both in accuracy and computational speed. In contrast to other approaches, our model does not use coalescent theory but is allele frequency based. We show that PoMo is well suited for genome-wide species tree estimation and that on such data it is more accurate than previous approaches. PMID:26209413

  6. Discrimination of Deciduous Tree Species from Time Series of Unmanned Aerial System Imagery.

    PubMed

    Lisein, Jonathan; Michez, Adrien; Claessens, Hugues; Lejeune, Philippe

    2015-01-01

    Technology advances can revolutionize Precision Forestry by providing accurate and fine forest information at tree level. This paper addresses the question of how and particularly when Unmanned Aerial System (UAS) should be used in order to efficiently discriminate deciduous tree species. The goal of this research is to determine when is the best time window to achieve an optimal species discrimination. A time series of high resolution UAS imagery was collected to cover the growing season from leaf flush to leaf fall. Full benefit was taken of the temporal resolution of UAS acquisition, one of the most promising features of small drones. The disparity in forest tree phenology is at the maximum during early spring and late autumn. But the phenology state that optimized the classification result is the one that minimizes the spectral variation within tree species groups and, at the same time, maximizes the phenologic differences between species. Sunlit tree crowns (5 deciduous species groups) were classified using a Random Forest approach for monotemporal, two-date and three-date combinations. The end of leaf flushing was the most efficient single-date time window. Multitemporal datasets definitely improve the overall classification accuracy. But single-date high resolution orthophotomosaics, acquired on optimal time-windows, result in a very good classification accuracy (overall out of bag error of 16%). PMID:26600422

  7. Multiple species of wild tree peonies gave rise to the 'king of flowers', Paeonia suffruticosa Andrews.

    PubMed

    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

    2014-12-22

    The origin of cultivated tree 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 tree peonies and all wild species 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 species inferred from the nuclear markers was fully resolved and largely congruent with morphology and classification. The incongruence between the nuclear and chloroplast trees suggested that there had been gene flow between the wild species. The comparison of nuclear and chloroplast phylogenies including cultivars showed that the cultivated tree peonies originated from homoploid hybridization among five wild species. Since the origin, thousands of cultivated varieties have spread worldwide, whereas four parental species are currently endangered or on the verge of extinction. The documentation of extensive homoploid hybridization involved in tree peony domestication provides new insights into the mechanisms underlying the origins of garden ornamentals and the way of preserving natural genetic resources through domestication.

  8. Discrimination of Deciduous Tree Species from Time Series of Unmanned Aerial System Imagery

    PubMed Central

    Lisein, Jonathan; Michez, Adrien; Claessens, Hugues; Lejeune, Philippe

    2015-01-01

    Technology advances can revolutionize Precision Forestry by providing accurate and fine forest information at tree level. This paper addresses the question of how and particularly when Unmanned Aerial System (UAS) should be used in order to efficiently discriminate deciduous tree species. The goal of this research is to determine when is the best time window to achieve an optimal species discrimination. A time series of high resolution UAS imagery was collected to cover the growing season from leaf flush to leaf fall. Full benefit was taken of the temporal resolution of UAS acquisition, one of the most promising features of small drones. The disparity in forest tree phenology is at the maximum during early spring and late autumn. But the phenology state that optimized the classification result is the one that minimizes the spectral variation within tree species groups and, at the same time, maximizes the phenologic differences between species. Sunlit tree crowns (5 deciduous species groups) were classified using a Random Forest approach for monotemporal, two-date and three-date combinations. The end of leaf flushing was the most efficient single-date time window. Multitemporal datasets definitely improve the overall classification accuracy. But single-date high resolution orthophotomosaics, acquired on optimal time-windows, result in a very good classification accuracy (overall out of bag error of 16%). PMID:26600422

  9. [Effects of temperature on CH4 emission from subtropical common tree species leaves].

    PubMed

    Yang, Yan-Hua; Yi, Li-Ming; Xie, Jin-Sheng; Yang, Zhi-Jie; Jiang, Jun; Xu, Chao; Yang, Yu-Sheng

    2013-06-01

    Laboratory incubation test was conducted to study the effects of temperature on the CH4 emission from the leaves of subtropical common tree species Castanopsis carlesii, Schima superb, Cinnamomum chekiangense, Castsanopsis fabri, Cunninghamia lanceolata, and Citrus reticulata. Among the six tree species, only S. superb, C. reticulate, and C. fabri emitted CH4 at 10 degrees C. At above 20 degrees C, all the six species emitted CH4, and the average CH4 emission rate at above 30 degrees C (1.010 ng CH4 x g(-1) DM x h(-1)) was 2.96 times higher than that at 10-30 degrees C (0.255 ng CH4 x g(-1) DM x h(-1)). Moreover, increasing temperature had much more effects on the CH4 emission rate of C. reticulata and C. lanceolata than on that of the other four tree species. Incubation time affected the CH4 emission rate of all test tree species significantly, suggesting that the effects of temperature stress on the CH4 emission could be controlled by plant activity. Dry leaves could not emit CH4 no matter the temperature was very high or low. It was suggested that high temperature stress had important effects on the CH4 emission from subtropical tree leaves, and global warming could increase the CH4 emission from plants. PMID:24066538

  10. Effects of colonization processes on genetic diversity: differences between annual plants and tree species.

    PubMed Central

    Austerlitz, F; Mariette, S; Machon, N; Gouyon, P H; Godelle, B

    2000-01-01

    Tree species are striking for their high within-population diversity and low among-population differentiation for nuclear genes. In contrast, annual plants show much more differentiation for nuclear genes but much less diversity than trees. The usual explanation for this difference is that pollen flow, and therefore gene flow, is much higher for trees. This explanation is problematic because it relies on equilibrium hypotheses. Because trees have very recently recolonized temperate areas, they have experienced many foundation events, which usually reduce within-population diversity and increase differentiation. Only extremely high levels of gene flow could counterbalance these successive founder effects. We develop a model to study the impact of life cycle of forest trees, in particular of the length of their juvenile phase, on genetic diversity and differentiation during the glacial period and the following colonization period. We show that both a reasonably high level of pollen flow and the life-cycle characteristics of trees are needed to explain the observed structure of genetic diversity. We also show that gene flow and life cycle both have an impact on maternally inherited cytoplasmic genes, which are characterized both in trees and annual species by much less diversity and much more differentiation than nuclear genes. PMID:10757772

  11. Hydraulics and life history of tropical dry forest tree species: coordination of species' drought and shade tolerance.

    PubMed

    Markesteijn, Lars; Poorter, Lourens; Bongers, Frans; Paz, Horacio; Sack, Lawren

    2011-07-01

    Plant hydraulic architecture has been studied extensively, yet we know little about how hydraulic properties relate to species' life history strategies, such as drought and shade tolerance. The prevailing theories seem contradictory. We measured the sapwood (K(s) ) and leaf (K(l) ) hydraulic conductivities of 40 coexisting tree species in a Bolivian dry forest, and examined associations with functional stem and leaf traits and indices of species' drought (dry-season leaf water potential) and shade (juvenile crown exposure) tolerance. Hydraulic properties varied across species and between life-history groups (pioneers vs shade-tolerant, and deciduous vs evergreen species). In addition to the expected negative correlation of K(l) with drought tolerance, we found a strong, negative correlation between K(l) and species' shade tolerance. Across species, K(s) and K(l) were negatively correlated with wood density and positively with maximum vessel length. Consequently, drought and shade tolerance scaled similarly with hydraulic properties, wood density and leaf dry matter content. We found that deciduous species also had traits conferring efficient water transport relative to evergreen species. Hydraulic properties varied across species, corresponding to the classical trade-off between hydraulic efficiency and safety, which for these dry forest trees resulted in coordinated drought and shade tolerance across species rather than the frequently hypothesized trade-off.

  12. Supplemental planting of early successional tree species during bottomland hardwood afforestation

    USGS Publications Warehouse

    Twedt, D.J.; Wilson, R.R.; Outcalt, Kenneth W.

    2002-01-01

    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 species are slow to develop vertical forest structure. However, vertical forest structure is key to colonization of afforested sites by forest birds. Although early-successional tree species often enhance vertical structure, few of these species invade afforested sites that are distant from seed sources. Furthermore, many land mangers are reluctant to establish and maintain stands of fast-growing plantation trees. Therefore, on 40 afforested bottomland sites, we supplemented heavy-seeded seedlings with 8 patches of fast-growing trees: 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, tree 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 trees 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. Tree heights did not differ between species or among weed control treatments. Girdling of trees by deer often destroyed saplings. Thus, little increase in vertical structure was detected between growing seasons. Application of fertilizer and protection via tree shelters did not improve survival or vertical development of sycamore or cottonwood.

  13. Survival and development of Lymantria monacha (Lepidoptera: Lymantriidae) on North American and introduced Eurasian tree species.

    PubMed

    Keena, M A

    2003-02-01

    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 tree species were examined. Seven conifer species (Abies concolor, Picea abies, P. glauca, P. pungens, Pinus sylvestris with male cones, P. menziesii variety glance, and Tsuga canadensis) and six broadleaf species (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 species tested were rated as intermediate in suitability, four conifer species (Larix occidentalis, P. nigra, P. ponderosa, P. strobus, and Pseudotsuga menziesii variety menziesii) and six broadleaf species (Carpinus caroliniana, Carya ovata, Fagus grandifolia, Populus grandidentata, Q. alba, and Tilia cordata) and the remaining 10 species 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 trees had a major impact on establishment, survival, and development of L. monacha on many of the tree species tested. Several of the deciduous tree species 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 tree species on which it can survive and develop, and the ability of mated females to fly and colonize new areas.

  14. Operational Tree Species Mapping in a Diverse Tropical Forest with Airborne Imaging Spectroscopy

    PubMed Central

    Baldeck, Claire A.; Asner, Gregory P.; Martin, Robin E.; Anderson, Christopher B.; Knapp, David E.; Kellner, James R.; Wright, S. Joseph

    2015-01-01

    Remote identification and mapping of canopy tree species can contribute valuable information towards our understanding of ecosystem biodiversity and function over large spatial scales. However, the extreme challenges posed by highly diverse, closed-canopy tropical forests have prevented automated remote species mapping of non-flowering tree crowns in these ecosystems. We set out to identify individuals of three focal canopy tree species amongst a diverse background of tree and liana species on Barro Colorado Island, Panama, using airborne imaging spectroscopy data. First, we compared two leading single-class classification methods—binary support vector machine (SVM) and biased SVM—for their performance in identifying pixels of a single focal species. From this comparison we determined that biased SVM was more precise and created a multi-species classification model by combining the three biased SVM models. This model was applied to the imagery to identify pixels belonging to the three focal species and the prediction results were then processed to create a map of focal species crown objects. Crown-level cross-validation of the training data indicated that the multi-species classification model had pixel-level producer’s accuracies of 94–97% for the three focal species, and field validation of the predicted crown objects indicated that these had user’s accuracies of 94–100%. Our results demonstrate the ability of high spatial and spectral resolution remote sensing to accurately detect non-flowering crowns of focal species within a diverse tropical forest. We attribute the success of our model to recent classification and mapping techniques adapted to species detection in diverse closed-canopy forests, which can pave the way for remote species mapping in a wider variety of ecosystems. PMID:26153693

  15. Operational Tree Species Mapping in a Diverse Tropical Forest with Airborne Imaging Spectroscopy.

    PubMed

    Baldeck, Claire A; Asner, Gregory P; Martin, Robin E; Anderson, Christopher B; Knapp, David E; Kellner, James R; Wright, S Joseph

    2015-01-01

    Remote identification and mapping of canopy tree species can contribute valuable information towards our understanding of ecosystem biodiversity and function over large spatial scales. However, the extreme challenges posed by highly diverse, closed-canopy tropical forests have prevented automated remote species mapping of non-flowering tree crowns in these ecosystems. We set out to identify individuals of three focal canopy tree species amongst a diverse background of tree and liana species on Barro Colorado Island, Panama, using airborne imaging spectroscopy data. First, we compared two leading single-class classification methods--binary support vector machine (SVM) and biased SVM--for their performance in identifying pixels of a single focal species. From this comparison we determined that biased SVM was more precise and created a multi-species classification model by combining the three biased SVM models. This model was applied to the imagery to identify pixels belonging to the three focal species and the prediction results were then processed to create a map of focal species crown objects. Crown-level cross-validation of the training data indicated that the multi-species classification model had pixel-level producer's accuracies of 94-97% for the three focal species, and field validation of the predicted crown objects indicated that these had user's accuracies of 94-100%. Our results demonstrate the ability of high spatial and spectral resolution remote sensing to accurately detect non-flowering crowns of focal species within a diverse tropical forest. We attribute the success of our model to recent classification and mapping techniques adapted to species detection in diverse closed-canopy forests, which can pave the way for remote species mapping in a wider variety of ecosystems.

  16. Quantifying tree mortality in a mixed species woodland using multitemporal high spatial resolution satellite imagery

    USGS Publications Warehouse

    Garrity, Steven R.; Allen, Craig D.; Brumby, Steven P.; Gangodagamage, Chandana; McDowell, Nate G.; Cai, D. Michael

    2013-01-01

    Widespread tree mortality events have recently been observed in several biomes. To effectively quantify the severity and extent of these events, tools that allow for rapid assessment at the landscape scale are required. Past studies using high spatial resolution satellite imagery have primarily focused on detecting green, red, and gray tree canopies during and shortly after tree damage or mortality has occurred. However, detecting trees in various stages of death is not always possible due to limited availability of archived satellite imagery. Here we assess the capability of high spatial resolution satellite imagery for tree mortality detection in a southwestern U.S. mixed species woodland using archived satellite images acquired prior to mortality and well after dead trees had dropped their leaves. We developed a multistep classification approach that uses: supervised masking of non-tree image elements; bi-temporal (pre- and post-mortality) differencing of normalized difference vegetation index (NDVI) and red:green ratio (RGI); and unsupervised multivariate clustering of pixels into live and dead tree classes using a Gaussian mixture model. Classification accuracies were improved in a final step by tuning the rules of pixel classification using the posterior probabilities of class membership obtained from the Gaussian mixture model. Classifications were produced for two images acquired post-mortality with overall accuracies of 97.9% and 98.5%, respectively. Classified images were combined with land cover data to characterize the spatiotemporal characteristics of tree mortality across areas with differences in tree species composition. We found that 38% of tree crown area was lost during the drought period between 2002 and 2006. The majority of tree mortality during this period was concentrated in piñon-juniper (Pinus edulis-Juniperus monosperma) woodlands. An additional 20% of the tree canopy died or was removed between 2006 and 2011, primarily in areas

  17. Dominant tree species are at risk from exaggerated drought under climate change.

    PubMed

    Fensham, Roderick J; Fraser, Josie; MacDermott, Harry J; Firn, Jenifer

    2015-10-01

    Predicting the consequences of climate change on forest systems is difficult because trees may display species-specific responses to exaggerated droughts that may not be reflected by the climatic envelope of their geographic range. Furthermore, few studies have examined the postdrought recovery potential of drought-susceptible tree species. This study develops a robust ranking of the drought susceptibility of 21 tree species based on their mortality after two droughts (1990s and 2000s) in the savanna of north-eastern Australia. Drought-induced mortality was positively related to species dominance, negatively related to the ratio of postdrought seedlings to adults and had no relationship to the magnitude of extreme drought within the species current geographic ranges. These results suggest that predicting the consequences of exaggerated drought on species' geographic ranges is difficult, but that dominant species like Eucalyptus with relatively slow rates of population recovery and dispersal are the most susceptible. The implications for savanna ecosystems are lower tree densities and basal area.

  18. Identification and Mapping of Tree Species in Urban Areas Using WORLDVIEW-2 Imagery

    NASA Astrophysics Data System (ADS)

    Mustafa, Y. T.; Habeeb, H. N.; Stein, A.; Sulaiman, F. Y.

    2015-10-01

    Monitoring and mapping of urban trees are essential to provide urban forestry authorities with timely and consistent information. Modern techniques increasingly facilitate these tasks, but require the development of semi-automatic tree detection and classification methods. In this article, we propose an approach to delineate and map the crown of 15 tree species in the city of Duhok, Kurdistan Region of Iraq using WorldView-2 (WV-2) imagery. A tree crown object is identified first and is subsequently delineated as an image object (IO) using vegetation indices and texture measurements. Next, three classification methods: Maximum Likelihood, Neural Network, and Support Vector Machine were used to classify IOs using selected IO features. The best results are obtained with Support Vector Machine classification that gives the best map of urban tree species in Duhok. The overall accuracy was between 60.93% to 88.92% and κ-coefficient was between 0.57 to 0.75. We conclude that fifteen tree species were identified and mapped at a satisfactory accuracy in urban areas of this study.

  19. Architecture of 54 moist-forest tree species: traits, trade-offs, and functional groups.

    PubMed

    Poorter, Lourens; Bongers, Laurent; Bongers, Frans

    2006-05-01

    Tree architecture is an important determinant of the height extension, light capture, and mechanical stability of trees, and it allows species to exploit the vertical height gradient in the forest canopy and horizontal light gradients at the forest floor. Tropical tree species partition these gradients through variation in adult stature (Hmax) and light demand. In this study we compare 22 architectural traits for 54 Bolivian moist-forest tree species. We evaluate how architectural traits related to Hmax vary with tree size, and we present a conceptual scheme in which we combine the two axes into four different functional groups. Interspecific correlations between architecture and Hmax varied strongly from negative to positive, depending on the reference sizes used. Stem height was positively related to Hmax at larger reference diameters (14-80 cm). Species height vs. diameter curves often flattened toward their upper ends in association with reproductive maturity for species of all sizes. Thus, adult understory trees were typically shorter than similar-diameter juveniles of larger species. Crown area was negatively correlated with Hmax at small reference heights and positively correlated at larger reference heights (15-34 m). Wide crowns allow the small understory species to intercept light over a large area at the expense of a reduced height growth. Crown length was negatively correlated with Hmax at intermediate reference heights (4-14 m). A long crown enables small understory species to maximize light interception in a light-limited environment. Light-demanding species were characterized by orthotropic stems and branches, large leaves, and a monolayer leaf arrangement. They realized an efficient height growth through the formation of narrow and shallow crowns. Light demand turned out to be a much stronger predictor of tree architecture than Hmax, probably because of the relatively low, open, and semi-evergreen canopy at the research site. The existence of four

  20. Trees

    ERIC Educational Resources Information Center

    Al-Khaja, Nawal

    2007-01-01

    This is a thematic lesson plan for young learners about palm trees and the importance of taking care of them. The two part lesson teaches listening, reading and speaking skills. The lesson includes parts of a tree; the modal auxiliary, can; dialogues and a role play activity.

  1. Novel Phaeoacremonium species associated with necrotic wood of Prunus trees.

    PubMed

    Damm, U; Mostert, L; Crous, P W; Fourie, P H

    2008-06-01

    The genus Phaeoacremonium is associated with opportunistic human infections, as well as stunted growth and die-back of various woody hosts, especially grapevines. In this study, Phaeoacremonium species were isolated from necrotic woody tissue of Prunus spp. (plum, peach, nectarine and apricot) from different stone fruit growing areas in South Africa. Morphological and cultural characteristics as well as DNA sequence data (5.8S rDNA, ITS1, ITS2, beta-tubulin, actin and 18S rDNA) were used to identify known, and describe novel species. From the total number of wood samples collected (257), 42 Phaeoacremonium isolates were obtained, from which 14 species were identified. Phaeoacremonium scolyti was most frequently isolated, and present on all Prunus species sampled, followed by Togninia minima (anamorph: Pm. aleophilum) and Pm. australiense. Almost all taxa isolated represent new records on Prunus. Furthermore, Pm. australiense,Pm. iranianum, T. fraxinopennsylvanica and Pm. griseorubrum represent new records for South Africa, while Pm. griseorubrum, hitherto only known from humans, is newly reported from a plant host. Five species are newly described, two of which produce a Togninia sexual state. Togninia africana, T. griseo-olivacea and Pm. pallidum are newly described from Prunus armeniaca, while Pm. prunicolum and Pm. fuscum are described from Prunus salicina.

  2. Warming effects on photosynthesis of subtropical tree species: a translocation experiment along an altitudinal gradient.

    PubMed

    Li, Yiyong; Liu, Juxiu; Zhou, Guoyi; Huang, Wenjuan; Duan, Honglang

    2016-01-01

    Ongoing climate warming induced by human activities may have great impacts on trees, yet it remains unresolved how subtropical tree species respond to rising temperature in the field. Here, we used downward translocation to investigate the effects of climate warming on leaf photosynthesis of six common tree species in subtropical China. During the experimental period between 2012 and 2014, the mean average photosynthetic rates (Asat) under saturating light for Schima superba, Machilus breviflora, Pinus massoniana and Ardisia lindleyana in the warm site were7%, 19%, 20% and 29% higher than those in the control site. In contrast, seasonal Asat for Castanopsis hystrix in the warm site were lower compared to the control site. Changes in Asat in response to translocation were mainly associated with those in leaf stomatal conductance (gs) and photosynthetic capacity (RuBP carboxylation, RuBP regeneration capacity). Our results imply that climate warming could have potential impacts on species composition and community structure in subtropical forests. PMID:27102064

  3. Functional traits explain light and size response of growth rates in tropical tree species.

    PubMed

    Rüger, Nadja; Wirth, Christian; Wright, S Joseph; Condit, Richard

    2012-12-01

    Relationships between functional traits and average or potential demographic rates have provided insight into the functional constraints and trade-offs underlying life-history strategies of tropical tree species. We have extended this framework by decomposing growth rates of -130 000 trees of 171 Neotropical tree species into intrinsic growth and the response of growth to light and size. We related these growth characteristics to multiple functional traits (wood density, adult stature, seed mass, leaf traits) in a hierarchical Bayesian model that accounted for measurement error and intraspecific variability of functional traits. Wood density was the most important trait determining all three growth characteristics. Intrinsic growth rates were additionally strongly related to adult stature, while all traits contributed to light response. Our analysis yielded a predictive model that allows estimation of growth characteristics for rare species on the basis of a few easily measurable morphological traits.

  4. Warming effects on photosynthesis of subtropical tree species: a translocation experiment along an altitudinal gradient

    PubMed Central

    Li, Yiyong; Liu, Juxiu; Zhou, Guoyi; Huang, Wenjuan; Duan, Honglang

    2016-01-01

    Ongoing climate warming induced by human activities may have great impacts on trees, yet it remains unresolved how subtropical tree species respond to rising temperature in the field. Here, we used downward translocation to investigate the effects of climate warming on leaf photosynthesis of six common tree species in subtropical China. During the experimental period between 2012 and 2014, the mean average photosynthetic rates (Asat) under saturating light for Schima superba, Machilus breviflora, Pinus massoniana and Ardisia lindleyana in the warm site were7%, 19%, 20% and 29% higher than those in the control site. In contrast, seasonal Asat for Castanopsis hystrix in the warm site were lower compared to the control site. Changes in Asat in response to translocation were mainly associated with those in leaf stomatal conductance (gs) and photosynthetic capacity (RuBP carboxylation, RuBP regeneration capacity). Our results imply that climate warming could have potential impacts on species composition and community structure in subtropical forests. PMID:27102064

  5. Influences of forest structure, climate and species composition on tree mortality across the eastern US.

    PubMed

    Lines, Emily R; Coomes, David A; Purves, Drew W

    2010-10-13

    Few studies have quantified regional variation in tree mortality, or explored whether species compositional changes or within-species variation are responsible for regional patterns, despite the fact that mortality has direct effects on the dynamics of woody biomass, species composition, stand structure, wood production and forest response to climate change. Using bayesian analysis of over 430,000 tree records from a large eastern US forest database we characterised tree mortality as a function of climate, soils, species and size (stem diameter). We found (1) mortality is U-shaped vs. stem diameter for all 21 species examined; (2) mortality is hump-shaped vs. plot basal area for most species; (3) geographical variation in mortality is substantial, and correlated with several environmental factors; and (4) individual species 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 species composition combined with highly varied mortality-environment correlations within species. 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.

  6. Statistical analysis of texture in trunk images for biometric identification of tree species.

    PubMed

    Bressane, Adriano; Roveda, José A F; Martins, Antônio C G

    2015-04-01

    The identification of tree species 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 tree 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 tree trunk images. For that, 540 samples from five Brazilian native deciduous species were acquired and measures of entropy, uniformity, smoothness, asymmetry (third moment), mean, and standard deviation were obtained from the presented textures. Using a decision tree, a biometric species identification system was constructed and resulted to a 0.84 average precision rate for species 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 tree identification, since the limitations of the current techniques can be overcome.

  7. Toward more accurate ancestral protein genotype-phenotype reconstructions with the use of species tree-aware gene trees.

    PubMed

    Groussin, Mathieu; Hobbs, Joanne K; Szöllősi, Gergely J; Gribaldo, Simonetta; Arcus, Vickery L; Gouy, Manolo

    2015-01-01

    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 species 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 tree 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 species 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 species tree-aware gene trees 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.

  8. Toward more accurate ancestral protein genotype-phenotype reconstructions with the use of species tree-aware gene trees.

    PubMed

    Groussin, Mathieu; Hobbs, Joanne K; Szöllősi, Gergely J; Gribaldo, Simonetta; Arcus, Vickery L; Gouy, Manolo

    2015-01-01

    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 species 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 tree 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 species 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 species tree-aware gene trees 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

  9. Negative density dependence regulates two tree species at later life stage in a temperate forest.

    PubMed

    Piao, Tiefeng; Chun, Jung Hwa; Yang, Hee Moon; Cheon, Kwangil

    2014-01-01

    Numerous studies have demonstrated that tree survival is influenced by negative density dependence (NDD) and differences among species in shade tolerance could enhance coexistence via resource partitioning, but it is still unclear how NDD affects tree species with different shade-tolerance guilds at later life stages. In this study, we analyzed the spatial patterns for trees 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) species. We found NDD existed for both species 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 tree species at later life stages and it is important to consider variation in species' shade tolerance in NDD study. PMID:25058660

  10. The role of selected tree species in industrial sewage sludge/flotation tailing management.

    PubMed

    Mleczek, Mirosław; Rutkowski, Paweł; Niedzielski, Przemysław; Goliński, Piotr; Gąsecka, Monika; Kozubik, Tomisław; Dąbrowski, Jędrzej; Budzyńska, Sylwia; Pakuła, Jarosław

    2016-11-01

    The aim of the study was to estimate the ability of ten tree and bush species to tolerate and accumulate Cd, Cu, Pb, Zn, and As species [As(III), As(V), and total organic arsenic] in industrial sewage sludge extremely contaminated with arsenic (almost 27.5 g kg(-1)) in a pot experiment. The premise being that it will then be possible to select the most promising tree/bush species, able to grow in the vicinity of dams where sewage sludge/flotation tailings are used as landfill. Six of the ten tested tree species were able to grow on the sludge. The highest content of total As was observed in Betula pendula roots (30.0 ± 1.3 mg kg(-1) DW), where the dominant As species was the toxic As(V). The highest biomass of Quercus Q1 robur (77.3 § 2.6 g) and Acer platanoides (76.0 § 4.9 g) was observed. A proper planting of selected tree species that are able to thrive on sewage sludge/flotation tailings could be an interesting and promising way to protect dams. By utilizing differences in their root systems and water needs, we will be able to reduce the risk of fatal environmental disasters. PMID:27348264

  11. Diversity and utilization of tree species in Meitei homegardens of Barak Valley, Assam.

    PubMed

    Devi, N Linthoingambi; Das, Ashesh Kumar

    2013-03-01

    An inventory of tree 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 tree species 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 species) followed by Meliaceae (5 genus and 5 species), Arecaceae (4 genus and 4 species) and Moraceae (3 genus and 5 species). Total 7946 tree 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 species with the maximum number of individuals. Other dominant trees 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.

  12. Diversity and utilization of tree species in Meitei homegardens of Barak Valley, Assam.

    PubMed

    Devi, N Linthoingambi; Das, Ashesh Kumar

    2013-03-01

    An inventory of tree 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 tree species 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 species) followed by Meliaceae (5 genus and 5 species), Arecaceae (4 genus and 4 species) and Moraceae (3 genus and 5 species). Total 7946 tree 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 species with the maximum number of individuals. Other dominant trees 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

  13. An empirical evaluation of two-stage species tree inference strategies using a multilocus dataset from North American pines

    PubMed Central

    2014-01-01

    Background As it becomes increasingly possible to obtain DNA sequences of orthologous genes from diverse sets of taxa, species trees are frequently being inferred from multilocus data. However, the behavior of many methods for performing this inference has remained largely unexplored. Some methods have been proven to be consistent given certain evolutionary models, whereas others rely on criteria that, although appropriate for many parameter values, have peculiar zones of the parameter space in which they fail to converge on the correct estimate as data sets increase in size. Results Here, using North American pines, we empirically evaluate the behavior of 24 strategies for species tree inference using three alternative outgroups (72 strategies total). The data consist of 120 individuals sampled in eight ingroup species from subsection Strobus and three outgroup species from subsection Gerardianae, spanning ∼47 kilobases of sequence at 121 loci. Each “strategy” for inferring species trees consists of three features: a species tree construction method, a gene tree inference method, and a choice of outgroup. We use multivariate analysis techniques such as principal components analysis and hierarchical clustering to identify tree characteristics that are robustly observed across strategies, as well as to identify groups of strategies that produce trees with similar features. We find that strategies that construct species trees using only topological information cluster together and that strategies that use additional non-topological information (e.g., branch lengths) also cluster together. Strategies that utilize more than one individual within a species to infer gene trees tend to produce estimates of species trees that contain clades present in trees estimated by other strategies. Strategies that use the minimize-deep-coalescences criterion to construct species trees tend to produce species tree estimates that contain clades that are not present in trees

  14. [Biomass allometric equations of nine common tree species in an evergreen broadleaved forest of subtropical China].

    PubMed

    Zuo, Shu-di; Ren, Yin; Weng, Xian; Ding, Hong-feng; Luo, Yun-jian

    2015-02-01

    Biomass allometric equation (BAE) considered as a simple and reliable method in the estimation of forest biomass and carbon was used widely. In China, numerous studies focused on the BAEs for coniferous forest and pure broadleaved forest, and generalized BAEs were frequently used to estimate the biomass and carbon of mixed broadleaved forest, although they could induce large uncertainty in the estimates. In this study, we developed the species-specific and generalized BAEs using biomass measurement for 9 common broadleaved trees (Castanopsis fargesii, C. lamontii, C. tibetana, Lithocarpus glaber, Sloanea sinensis, Daphniphyllum oldhami, Alniphyllum fortunei, Manglietia yuyuanensis, and Engelhardtia fenzlii) of subtropical evergreen broadleaved forest, and compared differences in species-specific and generalized BAEs. The results showed that D (diameter at breast height) was a better independent variable in estimating the biomass of branch, leaf, root, aboveground section and total tree than a combined variable (D2 H) of D and H (tree height) , but D2H was better than D in estimating stem biomass. R2 (coefficient of determination) values of BAEs for 6 species decreased when adding H as the second independent variable into D- only BAEs, where R2 value for S. sinensis decreased by 5.6%. Compared with generalized D- and D2H-based BAEs, standard errors of estimate (SEE) of BAEs for 8 tree species decreased, and similar decreasing trend was observed for different components, where SEEs of the branch decreased by 13.0% and 20.3%. Therefore, the biomass carbon storage and its dynamic estimates were influenced largely by tree species and model types. In order to improve the accuracy of the estimates of biomass and carbon, we should consider the differences in tree species and model types.

  15. Effects of sample survey design on the accuracy of classification tree models in species distribution models

    USGS Publications Warehouse

    Edwards, T.C.; Cutler, D.R.; Zimmermann, N.E.; Geiser, L.; Moisen, G.G.

    2006-01-01

    We evaluated the effects of probabilistic (hereafter DESIGN) and non-probabilistic (PURPOSIVE) sample surveys on resultant classification tree models for predicting the presence of four lichen species in the Pacific Northwest, USA. Models derived from both survey forms were assessed using an independent data set (EVALUATION). Measures of accuracy as gauged by resubstitution rates were similar for each lichen species irrespective of the underlying sample survey form. Cross-validation estimates of prediction accuracies were lower than resubstitution accuracies for all species and both design types, and in all cases were closer to the true prediction accuracies based on the EVALUATION data set. We argue that greater emphasis should be placed on calculating and reporting cross-validation accuracy rates rather than simple resubstitution accuracy rates. Evaluation of the DESIGN and PURPOSIVE tree models on the EVALUATION data set shows significantly lower prediction accuracy for the PURPOSIVE tree models relative to the DESIGN models, indicating that non-probabilistic sample surveys may generate models with limited predictive capability. These differences were consistent across all four lichen species, with 11 of the 12 possible species and sample survey type comparisons having significantly lower accuracy rates. Some differences in accuracy were as large as 50%. The classification tree structures also differed considerably both among and within the modelled species, depending on the sample survey form. Overlap in the predictor variables selected by the DESIGN and PURPOSIVE tree models ranged from only 20% to 38%, indicating the classification trees fit the two evaluated survey forms on different sets of predictor variables. The magnitude of these differences in predictor variables throws doubt on ecological interpretation derived from prediction models based on non-probabilistic sample surveys. ?? 2006 Elsevier B.V. All rights reserved.

  16. The abundance and diversity of legume-nodulating rhizobia in 28-year-old plantations of tropical, subtropical, and exotic tree species: a case study from the Forest Reserve of Bandia, Senegal.

    PubMed

    Sene, Godar; Thiao, Mansour; Samba-Mbaye, Ramatoulaye; Khasa, Damase; Kane, Aboubacry; Mbaye, Mame Samba; Beaulieu, Marie-Ève; Manga, Anicet; Sylla, Samba Ndao

    2013-01-01

    Several fast-growing and multipurpose tree species have been widely used in West Africa to both reverse the tendency of land degradation and restore soil productivity. Although beneficial effects have been reported on soil stabilization, there still remains a lack of information about their impact on soil microorganisms. Our investigation has been carried out in exotic and native tree plantations of 28 years and aimed to survey and compare the abundance and genetic diversity of natural legume-nodulating rhizobia (LNR). The study of LNR is supported by the phylogenetic analysis which clustered the isolates into three genera: Bradyrhizobium, Mesorhizobium, and Sinorhizobium. The results showed close positive correlations between the sizes of LNR populations estimated both in the dry and rainy seasons and the presence of legume tree hosts. There were significant increases in Rhizobium spp. population densities in response to planting with Acacia spp., and high genetic diversities and richness of genotypes were fittest in these tree plantations. This suggests that enrichment of soil Rhizobium spp. populations is host specific. The results indicated also that species of genera Mesorhizobium and Sinorhizobium were lacking in plantations of non-host species. By contrast, there was a widespread distribution of Bradyrhizobium spp. strains across the tree plantations, with no evident specialization in regard to plantation type. Finally, the study provides information about the LNR communities associated with a range of old tree plantations and some aspects of their relationships to soil factors, which may facilitate the management of man-made forest systems that target ecosystem rehabilitation and preservation of soil biota. PMID:22864803

  17. Effects of pioneer tree species hyperabundance on forest fragments in northeastern Brazil.

    PubMed

    Tabarelli, Marcelo; Aguiar, Antonio V; Girão, Luciana C; Peres, Carlos A; Lopes, Ariadna V

    2010-12-01

    Despite many studies on fragmentation of tropical forests, the extent to which plant and animal communities are altered in small, isolated forest fragments remains obscure if not controversial. We examined the hypothesis that fragmentation alters the relative abundance of tree species with different vegetative and reproductive traits. In a fragmented landscape (670 km(2) ) of the Atlantic Forest of northeastern Brazil, we categorized 4056 trees of 182 species by leafing pattern, reproductive phenology, and morphology of seeds and fruit. We calculated relative abundance of traits in 50 1-ha plots in three types of forest configurations: forest edges, small forest fragments (3.4-83.6 ha), and interior of the largest forest fragment (3500 ha, old growth). Although evergreen species were the most abundant across all configurations, forest edges and small fragments had more deciduous and semideciduous species than interior forest. Edges lacked supra-annual flowering and fruiting species and had more species and stems with drupes and small seeds than small forest fragments and forest interior areas. In an ordination of species similarity and life-history traits, the three types of configurations formed clearly segregated clusters. Furthermore, the differences in the taxonomic and functional (i.e., trait-based) composition of tree assemblages we documented were driven primarily by the higher abundance of pioneer species in the forest edge and small forest fragments. Our work provides strong evidence that long-term transitions in phenology and seed and fruit morphology of tree functional groups are occurring in fragmented tropical forests. Our results also suggest that edge-induced shifts in tree assemblages of tropical forests can be larger than previously documented.

  18. Complementary models of tree species-soil relationships in old-growth temperate forests

    USGS Publications Warehouse

    Cross, Alison; Perakis, Steven S.

    2011-01-01

    Ecosystem level studies identify plant soil feed backs as important controls on soil nutrient availability,particularly for nitrogen and phosphorus. Although site and species specific studies of tree species 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 tree species across eight undisturbed old-growth forests in Oregon, USA, and used two complementary conceptual models to assess tree species soil relationships. Plant soil feedbacks that could reinforce sitelevel differences in nutrient availability were assessed using the context dependent relationships model, where by relative species based differences in each soil nutrient divergedorconvergedas nutrient status changed across sites. Tree species 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 tree species across sites,without variation in deeper mineral soils. We found that theorganically cycled elements carbon, nitrogen, and phosphorus exhibited context-dependent differences among species in both forest floor and mineral soil, and most of ten followed adivergence model,where by species 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 species differences were strongest for pool so if the weather able cations calcium, magnesium, potassium,as well as phosphorus, in mineral soils. Site independent species differences in forest floor nutrients we reattributable too nespecies that displayed significant greater forest floor mass accumulation. Our finding confirmed that site-independent and

  19. Global correlations in tropical tree species richness and abundance reject neutrality.

    PubMed

    Ricklefs, Robert E; Renner, Susanne S

    2012-01-27

    Patterns of species richness and relative abundance at some scales cannot be distinguished from predictions of null models, including zero-sum neutral models of population change and random speciation-extinction models of evolutionary diversification. Both models predict that species richness or population abundance produced by independent iterations of the same processes in different regions should be uncorrelated. We find instead that the number of species and individuals in families of trees in forest plots are strongly correlated across Southeast Asia, Africa, and tropical America. These correlations imply that deterministic processes influenced by evolutionarily conservative family-level traits constrain the number of confamilial tree species and individuals that can be supported in regional species pools and local assemblages in humid tropical forests.

  20. Investigating the limitations of tree species classification using the Combined Cluster and Discriminant Analysis method for low density ALS data from a dense forest region in Aggtelek (Hungary)

    NASA Astrophysics Data System (ADS)

    Koma, Zsófia; Deák, Márton; Kovács, József; Székely, Balázs; Kelemen, Kristóf; Standovár, Tibor

    2016-04-01

    Airborne Laser Scanning (ALS) is a widely used technology for forestry classification applications. However, single tree detection and species classification from low density ALS point cloud is limited in a dense forest region. In this study we investigate the division of a forest into homogenous groups at stand level. The study area is located in the Aggtelek karst region (Northeast Hungary) with a complex relief topography. The ALS dataset contained only 4 discrete echoes (at 2-4 pt/m2 density) from the study area during leaf-on season. Ground-truth measurements about canopy closure and proportion of tree species cover are available for every 70 meter in 500 square meter circular plots. In the first step, ALS data were processed and geometrical and intensity based features were calculated into a 5×5 meter raster based grid. The derived features contained: basic statistics of relative height, canopy RMS, echo ratio, openness, pulse penetration ratio, basic statistics of radiometric feature. In the second step the data were investigated using Combined Cluster and Discriminant Analysis (CCDA, Kovács et al., 2014). The CCDA method first determines a basic grouping for the multiple circle shaped sampling locations using hierarchical clustering and then for the arising grouping possibilities a core cycle is executed comparing the goodness of the investigated groupings with random ones. Out of these comparisons difference values arise, yielding information about the optimal grouping out of the investigated ones. If sub-groups are then further investigated, one might even find homogeneous groups. We found that low density ALS data classification into homogeneous groups are highly dependent on canopy closure, and the proportion of the dominant tree species. The presented results show high potential using CCDA for determination of homogenous separable groups in LiDAR based tree species classification. Aggtelek Karst/Slovakian Karst Caves" (HUSK/1101/221/0180, Aggtelek NP

  1. How tree species fill geographic and ecological space in eastern North America

    PubMed Central

    Ricklefs, Robert E.

    2015-01-01

    Background and Aims Ecologists broadly accept that the number of species present within a region balances regional processes of immigration and speciation against competitive and other interactions between populations that limit distribution and constrain diversity. Although ecological theory has, for a long time, addressed the premise that ecological space can be filled to ‘capacity’ with species, only with the availability of time-calibrated phylogenies has it been possible to test the hypothesis that diversification slows as the number of species in a region increases. Focusing on the deciduous trees of eastern North America, this study tested predictions from competition theory concerning the distribution and abundance of species. Methods Local assemblages of trees tabulated in a previous study published in 1950 were analysed. Assemblages were ordinated with respect to species composition by non-metric multidimensional scaling (NMS). Distributions of trees were analysed by taxonomically nested analysis of variance, discriminant analysis based on NMS scores, and canonical correlation analysis of NMS scores and Bioclim climate variables. Key Results Most of the variance in species abundance and distribution was concentrated among closely related (i.e. congeneric) species, indicating evolutionary lability. Species distribution and abundance were unrelated to the number of close relatives, suggesting that competitive effects are diffuse. Distances between pairs of congeneric species in NMS space did not differ significantly from distances between more distantly related species, in contrast to the predictions of both competitive habitat partitioning and ecological sorting of species. Conclusions Eastern deciduous forests of North America do not appear to be saturated with species. The distributions and abundances of individual species provide little evidence of being shaped by competition from related (i.e. ecologically similar) species and, by inference, that

  2. A phylogenetic perspective on the individual species-area relationship in temperate and tropical tree communities.

    PubMed

    Yang, Jie; Swenson, Nathan G; Cao, Min; Chuyong, George B; Ewango, Corneille E N; Howe, Robert; Kenfack, David; Thomas, Duncan; Wolf, Amy; Lin, Luxiang

    2013-01-01

    Ecologists have historically used species-area relationships (SARs) as a tool to understand the spatial distribution of species. Recent work has extended SARs to focus on individual-level distributions to generate individual species area relationships (ISARs). The ISAR approach quantifies whether individuals of a species tend have more or less species 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 species are treated as evolutionarily independent and that a large amount of work has now shown that local tree neighborhoods exhibit non-random phylogenetic structure given the species 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 species accumulators and repellers higher or lower than that expected given the observed species richness?; and (iii) do species accumulators, repellers distributed non-randomly on the community phylogenetic tree? The results indicate no clear trend in ISARs from the temperate zone to the tropics and that the phylogenetic diversity surrounding the individuals of species is generally only non-random on very local scales. Interestingly the distribution of species accumulators and repellers was non-random on the community phylogenies suggesting the presence of phylogenetic signal in the ISAR across latitude.

  3. The right tree for the job? perceptions of species suitability for the provision of ecosystem services.

    PubMed

    Smaill, Simeon J; Bayne, Karen M; Coker, Graham W R; Paul, Thomas S H; Clinton, Peter W

    2014-04-01

    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 species other than Pinus radiata D. Don (the dominant plantation species) in the belief that alternative species 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 species were likely to be planted to deliver ecosystem services, a survey was distributed to examine stakeholder perceptions. Stakeholders were asked which of 15 tree 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 tree species possessed those attributes. These data were combined to identify the species 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 species. Stakeholder perceptions substantially influence tree species 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.

  4. The Right Tree for the Job? Perceptions of Species Suitability for the Provision of Ecosystem Services

    NASA Astrophysics Data System (ADS)

    Smaill, Simeon J.; Bayne, Karen M.; Coker, Graham W. R.; Paul, Thomas S. H.; Clinton, Peter W.

    2014-04-01

    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 species other than Pinus radiata D. Don (the dominant plantation species) in the belief that alternative species 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 species were likely to be planted to deliver ecosystem services, a survey was distributed to examine stakeholder perceptions. Stakeholders were asked which of 15 tree 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 tree species possessed those attributes. These data were combined to identify the species 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 species. Stakeholder perceptions substantially influence tree species 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.

  5. Stem CO2 efflux in six co-occurring tree species: underlying factors and ecological implications.

    PubMed

    Rodríguez-Calcerrada, Jesús; López, Rosana; Salomón, Roberto; Gordaliza, Guillermo G; Valbuena-Carabaña, María; Oleksyn, Jacek; Gil, Luis

    2015-06-01

    Stem respiration plays a role in species coexistence and forest dynamics. Here we examined the intra- and inter-specific variability of stem CO2 efflux (E) in dominant and suppressed trees of six deciduous species 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 species, dominants had higher E per unit stem surface area (Es ) mainly because sapwood depth was higher than in suppressed trees. Across species, however, differences in Es corresponded with differences in the proportion of living parenchyma in sapwood and concentration of non-structural carbohydrates (NSC). Across species, Es was strongly and NSC marginally positively related with an index of drought tolerance, suggesting that slow growth of drought-tolerant trees 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 species, such as drought resistance; that sapwood depth is the main factor explaining variability in Es within species; and that the proportion of NSC in the sapwood is the main factor behind variability in Es among species.

  6. Genetic variation in a tropical tree species influences the associated epiphytic plant and invertebrate communities in a complex forest ecosystem

    PubMed Central

    Zytynska, Sharon E.; Fay, Michael F.; Penney, David; Preziosi, Richard F.

    2011-01-01

    Genetic differences among tree species, their hybrids and within tree species are known to influence associated ecological communities and ecosystem processes in areas of limited species diversity. The extent to which this same phenomenon occurs based on genetic variation within a single tree species, in a diverse complex ecosystem such as a tropical forest, is unknown. The level of biodiversity and complexity of the ecosystem may reduce the impact of a single tree species on associated communities. We assessed the influence of within-species genetic variation in the tree Brosimum alicastrum (Moraceae) on associated epiphytic and invertebrate communities in a neotropical rainforest. We found a significant positive association between genetic distance of trees and community difference of the epiphytic plants growing on the tree, the invertebrates living among the leaf litter around the base of the tree, and the invertebrates found on the tree trunk. This means that the more genetically similar trees are host to more similar epiphyte and invertebrate communities. Our work has implications for whole ecosystem conservation management, since maintaining sufficient genetic diversity at the primary producer level will enhance species diversity of other plants and animals. PMID:21444307

  7. Genetic variation in a tropical tree species influences the associated epiphytic plant and invertebrate communities in a complex forest ecosystem.

    PubMed

    Zytynska, Sharon E; Fay, Michael F; Penney, David; Preziosi, Richard F

    2011-05-12

    Genetic differences among tree species, their hybrids and within tree species are known to influence associated ecological communities and ecosystem processes in areas of limited species diversity. The extent to which this same phenomenon occurs based on genetic variation within a single tree species, in a diverse complex ecosystem such as a tropical forest, is unknown. The level of biodiversity and complexity of the ecosystem may reduce the impact of a single tree species on associated communities. We assessed the influence of within-species genetic variation in the tree Brosimum alicastrum (Moraceae) on associated epiphytic and invertebrate communities in a neotropical rainforest. We found a significant positive association between genetic distance of trees and community difference of the epiphytic plants growing on the tree, the invertebrates living among the leaf litter around the base of the tree, and the invertebrates found on the tree trunk. This means that the more genetically similar trees are host to more similar epiphyte and invertebrate communities. Our work has implications for whole ecosystem conservation management, since maintaining sufficient genetic diversity at the primary producer level will enhance species diversity of other plants and animals.

  8. Tree cover at fine and coarse spatial grains interacts with shade tolerance to shape plant species distributions across the Alps

    PubMed Central

    Nieto-Lugilde, Diego; Lenoir, Jonathan; Abdulhak, Sylvain; Aeschimann, David; Dullinger, Stefan; Gégout, Jean-Claude; Guisan, Antoine; Pauli, Harald; Renaud, Julien; Theurillat, Jean-Paul; Thuiller, Wilfried; Van Es, Jérémie; Vittoz, Pascal; Willner, Wolfgang; Wohlgemuth, Thomas; Zimmermann, Niklaus E.; Svenning, Jens-Christian

    2015-01-01

    The role of competition for light among plants has long been recognised at local scales, but its importance for plant species distributions at larger spatial scales has generally been ignored. Tree cover modifies the local abiotic conditions below the canopy, notably by reducing light availability, and thus, also the performance of species that are not adapted to low-light conditions. However, this local effect may propagate to coarser spatial grains, by affecting colonisation probabilities and local extinction risks of herbs and shrubs. To assess the effect of tree cover at both the plot- and landscape-grain sizes (approximately 10-m and 1-km), we fit Generalised Linear Models (GLMs) for the plot-level distributions of 960 species of herbs and shrubs using 6,935 vegetation plots across the European Alps. We ran four models with different combinations of variables (climate, soil and tree cover) at both spatial grains for each species. We used partial regressions to evaluate the independent effects of plot- and landscape-grain tree cover on plot-level plant communities. Finally, the effects on species-specific elevational range limits were assessed by simulating a removal experiment comparing the species distributions under high and low tree cover. Accounting for tree cover improved the model performance, with the probability of the presence of shade-tolerant species increasing with increasing tree cover, whereas shade-intolerant species showed the opposite pattern. The tree cover effect occurred consistently at both the plot and landscape spatial grains, albeit most strongly at the former. Importantly, tree cover at the two grain sizes had partially independent effects on plot-level plant communities. With high tree cover, shade-intolerant species exhibited narrower elevational ranges than with low tree cover whereas shade-tolerant species showed wider elevational ranges at both limits. These findings suggest that forecasts of climate-related range shifts for herb

  9. Interspecific variation in growth responses to climate and competition of five eastern tree species.

    PubMed

    Rollinson, Christine R; Kaye, Margot W; Canham, Charles D

    2016-04-01

    Climate and competition are often presented from two opposing views of the dominant driver of individual tree growth and species distribution in temperate forests, such as those in the eastern United States. Previous studies have provided abundant evidence indicating that both factors influence tree growth, and we argue that these effects are not independent of one another and rather that interactions between climate, competition, and size best describe tree growth. To illustrate this point, we describe the growth responses of five common eastern tree species to interacting effects of temperature, precipitation, competition, and individual size using maximum likelihood estimation. Models that explicitly include interactions among these four factors explained over half of the variance in annual growth for four out of five species using annual climate. Expanding temperature and precipitation analyses to include seasonal interactions resulted in slightly improved models with a mean R2 of 0.61 (SD 0.10). Growth responses to individual factors as well their interactions varied greatly among species. For example, growth sensitivity to temperature for Quercus rubra increased with maximum annual precipitation, but other species showed no change in sensitivity or slightly reduced annual growth. Our results also indicate that three-way interactions among individual stem size, competition, and temperature may determine which of the five co-occurring species in our study could have the highest growth rate in a given year. Continued consideration and quantification of interactions among climate, competition, and individual-based characteristics are likely to increase understanding of key biological processes such as tree growth. Greater parameterization of interactions between traditionally segregated factors such as climate and competition may also help build a framework to reconcile drivers of individual-based processes such as growth with larger-scale patterns of species

  10. Interspecific variation in growth responses to climate and competition of five eastern tree species.

    PubMed

    Rollinson, Christine R; Kaye, Margot W; Canham, Charles D

    2016-04-01

    Climate and competition are often presented from two opposing views of the dominant driver of individual tree growth and species distribution in temperate forests, such as those in the eastern United States. Previous studies have provided abundant evidence indicating that both factors influence tree growth, and we argue that these effects are not independent of one another and rather that interactions between climate, competition, and size best describe tree growth. To illustrate this point, we describe the growth responses of five common eastern tree species to interacting effects of temperature, precipitation, competition, and individual size using maximum likelihood estimation. Models that explicitly include interactions among these four factors explained over half of the variance in annual growth for four out of five species using annual climate. Expanding temperature and precipitation analyses to include seasonal interactions resulted in slightly improved models with a mean R2 of 0.61 (SD 0.10). Growth responses to individual factors as well their interactions varied greatly among species. For example, growth sensitivity to temperature for Quercus rubra increased with maximum annual precipitation, but other species showed no change in sensitivity or slightly reduced annual growth. Our results also indicate that three-way interactions among individual stem size, competition, and temperature may determine which of the five co-occurring species in our study could have the highest growth rate in a given year. Continued consideration and quantification of interactions among climate, competition, and individual-based characteristics are likely to increase understanding of key biological processes such as tree growth. Greater parameterization of interactions between traditionally segregated factors such as climate and competition may also help build a framework to reconcile drivers of individual-based processes such as growth with larger-scale patterns of species

  11. Tree Species Suitability to Bioswales and Impact on the Urban Water Budget.

    PubMed

    Scharenbroch, Bryant C; Morgenroth, Justin; Maule, Brian

    2016-01-01

    Water movement between soil and the atmosphere is restricted by hardscapes in the urban environment. Some green infrastructure is intended to increase infiltration and storage of water, thus decreasing runoff and discharge of urban stormwater. Bioswales are a critical component of a water-sensitive urban design (or a low-impact urban design), and incorporation of trees into these green infrastructural components is believed to be a novel way to return stored water to the atmosphere via transpiration. This research was conducted in The Morton Arboretum's main parking lot, which is one of the first and largest green infrastructure installations in the midwestern United States. The parking lot is constructed of permeable pavers and tree bioswales. Trees in bioswales were evaluated for growth and condition and for their effects on water cycling via transpiration. Our data indicate that trees in bioswales accounted for 46 to 72% of total water outputs via transpiration, thereby reducing runoff and discharge from the parking lot. By evaluating the stomatal conductance, diameter growth, and condition of a variety of tree species in these bioswales, we found that not all species are equally suited for bioswales and that not all are equivalent in their transpiration and growth rates, thereby contributing differentially to the functional capacity of bioswales. We conclude that species with high stomatal conductance and large mature form are likely to contribute best to bioswale function. PMID:26828175

  12. A Section-based Method For Tree Species Classification Using Airborne LiDAR Discrete Points In Urban Areas

    NASA Astrophysics Data System (ADS)

    Chunjing, Y. C.; Hui, T.; Zhongjie, R.; Guikai, B.

    2015-12-01

    As a new approach to forest inventory utilizing, LiDAR remote sensing has become an important research issue in the past. Lidar researches initially concentrate on the investigation for mapping forests at the tree level and identifying important structural parameters, such as tree height, crown size, crown base height, individual tree species, and stem volume etc. But for the virtual city visualization and mapping, the traditional methods of tree classification can't satisfy the more complex conditions. Recently, the advanced LiDAR technology has generated new full waveform scanners that provide a higher point density and additional information about the reflecting characteristics of trees. Subsequently, it was demonstrated that it is feasible to detect individual overstorey trees in forests and classify species. But the important issues like the calibration and the decomposition of full waveform data with a series of Gaussian functions usually take a lot of works. What's more, the detection and classification of vegetation results relay much on the prior outcomes. From all above, the section-based method for tree species classification using small footprint and high sampling density lidar data is proposed in this paper, which can overcome the tree species classification issues in urban areas. More specific objectives are to: (1)use local maximum height decision and four direction sections certification methods to get the precise locations of the trees;(2) develop new lidar-derived features processing techniques for characterizing the section structure of individual tree crowns;(3) investigate several techniques for filtering and analyzing vertical profiles of individual trees to classify the trees, and using the expert decision skills based on percentile analysis;(4) assess the accuracy of estimating tree species for each tree, and (5) investigate which type of lidar data, point frequency or intensity, provides the most accurate estimate of tree species

  13. Certified and Uncertified Logging Concessions Compared in Gabon: Changes in Stand Structure, Tree Species, and Biomass

    NASA Astrophysics Data System (ADS)

    Medjibe, V. P.; Putz, Francis E.; Romero, Claudia

    2013-03-01

    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 tree species diversity and composition. Before logging, we marked, mapped, and measured all trees >10 cm dbh in 20 and twelve 1-ha permanent plots in the FSC and CL areas, respectively. Soil and tree 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 trees/ha) and 11.4 m3/ha (0.76 trees/ha). For each tree felled, averages of 9.1 and 20.9 other trees 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 tree species 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.

  14. Certified and uncertified logging concessions compared in Gabon: changes in stand structure, tree species, and biomass.

    PubMed

    Medjibe, V P; Putz, Francis E; Romero, Claudia

    2013-03-01

    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 tree species diversity and composition. Before logging, we marked, mapped, and measured all trees >10 cm dbh in 20 and twelve 1-ha permanent plots in the FSC and CL areas, respectively. Soil and tree damage due to felling, skidding, and road-related activities was then assessed 2-3 months after the 508 ha FSC study area and the 200 ha CL study area were selectively logged at respective intensities of 5.7 m(3)/ha (0.39 trees/ha) and 11.4 m(3)/ha (0.76 trees/ha). For each tree felled, averages of 9.1 and 20.9 other trees 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 tree species 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.

  15. Certified and uncertified logging concessions compared in Gabon: changes in stand structure, tree species, and biomass.

    PubMed

    Medjibe, V P; Putz, Francis E; Romero, Claudia

    2013-03-01

    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 tree species diversity and composition. Before logging, we marked, mapped, and measured all trees >10 cm dbh in 20 and twelve 1-ha permanent plots in the FSC and CL areas, respectively. Soil and tree damage due to felling, skidding, and road-related activities was then assessed 2-3 months after the 508 ha FSC study area and the 200 ha CL study area were selectively logged at respective intensities of 5.7 m(3)/ha (0.39 trees/ha) and 11.4 m(3)/ha (0.76 trees/ha). For each tree felled, averages of 9.1 and 20.9 other trees 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 tree species composition were small but greater for the CL site. Based on these findings and in light of the pseudoreplicated study design with less-than perfect counterfactual, we cautiously conclude that certification yields environmental benefits even after accounting for differences in logging intensities. PMID:23277438

  16. BOREAS TE-4 Gas Exchange Data from Boreal Tree Species

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Curd, Shelaine (Editor); Collatz, G. James; Berry, Joseph A.; Gamon, John; Fredeen, Art; Fu, Wei

    2000-01-01

    The BOREAS TE-4 team collected steady-state gas exchange and reflectance data from several species 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 species 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).

  17. Influences of calcium availability and tree species on Ca isotope fractionation in soil and vegetation

    USGS Publications Warehouse

    Page, B.D.; Bullen, T.D.; Mitchell, M.J.

    2008-01-01

    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 trees were considerably lighter than those of soil pools at these sites, suggesting that the trees 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 tree species 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 tree species 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 tree species demand for Ca and soil Ca concentrations together may influence Ca isotope distribution within the trees. Inter-catchment differences in Ca isotope distributions in soils and trees 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.

  18. Patterns of Tree Species Diversity in Relation to Climatic Factors on the Sierra Madre Occidental, Mexico

    PubMed Central

    Silva-Flores, Ramón; Pérez-Verdín, Gustavo; Wehenkel, Christian

    2014-01-01

    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 species, between species, 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 species of Pinus (ca. 22% on the whole), 54 species of Quercus (ca. 9–14%), 7 species of Arbutus (ca. 50%) and many other trees species. The objectives of this study were to model how tree species 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 tree species 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 tree species are generally higher in cold

  19. Patterns of tree species diversity in relation to climatic factors on the Sierra Madre Occidental, Mexico.

    PubMed

    Silva-Flores, Ramón; Pérez-Verdín, Gustavo; Wehenkel, Christian

    2014-01-01

    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 species, between species, 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 species of Pinus (ca. 22% on the whole), 54 species of Quercus (ca. 9-14%), 7 species of Arbutus (ca. 50%) and many other trees species. The objectives of this study were to model how tree species 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 tree species 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 tree species are generally higher in cold

  20. Tree species identity and interactions with neighbors determine nutrient leaching in model tropical forests.

    PubMed

    Ewel, John J; Bigelow, Seth W

    2011-12-01

    An ecosystem containing a mixture of species that differ in phenology, morphology, and physiology might be expected to resist leaching of soil nutrients to a greater extent than one composed of a single species. We tested the effects of species identity and plant-life-form richness on nutrient leaching at a lowland tropical site where deep infiltration averages >2 m year(-1). Three indigenous tree species with contrasting leafing phenologies (evergreen, dry-season deciduous, and wet-season deciduous) were grown in monoculture and together with two other life-forms with which they commonly occur in tropical forests: a palm and a giant, perennial herb. To calculate nutrient leaching over an 11-year period, concentrations of nutrients in soil water were multiplied by drainage rates estimated from a water balance. The effect of plant-life-form richness on retention differed according to tree species identity and nutrient. Nitrate retention was greater in polycultures of the dry-season deciduous tree species (mean of 7.4 kg ha(-1) year(-1) of NO(3)-N lost compared to 12.7 in monoculture), and calcium and magnesium retention were greater in polycultures of the evergreen and wet-season deciduous tree species. Complementary use of light led to intensification of soil exploitation by roots, the main agent responsible for enhanced nutrient retention in some polycultures. Other mechanisms included differences in nutrient demand among species, and avoidance of catastrophic failure due to episodic weather events or pest outbreaks. Even unrealistically simple multi-life-form mimics of tropical forest can safeguard a site's nutrient capital if careful attention is paid to species' characteristics and temporal changes in interspecific interactions. PMID:21691855

  1. Tree species identity and interactions with neighbors determine nutrient leaching in model tropical forests.

    PubMed

    Ewel, John J; Bigelow, Seth W

    2011-12-01

    An ecosystem containing a mixture of species that differ in phenology, morphology, and physiology might be expected to resist leaching of soil nutrients to a greater extent than one composed of a single species. We tested the effects of species identity and plant-life-form richness on nutrient leaching at a lowland tropical site where deep infiltration averages >2 m year(-1). Three indigenous tree species with contrasting leafing phenologies (evergreen, dry-season deciduous, and wet-season deciduous) were grown in monoculture and together with two other life-forms with which they commonly occur in tropical forests: a palm and a giant, perennial herb. To calculate nutrient leaching over an 11-year period, concentrations of nutrients in soil water were multiplied by drainage rates estimated from a water balance. The effect of plant-life-form richness on retention differed according to tree species identity and nutrient. Nitrate retention was greater in polycultures of the dry-season deciduous tree species (mean of 7.4 kg ha(-1) year(-1) of NO(3)-N lost compared to 12.7 in monoculture), and calcium and magnesium retention were greater in polycultures of the evergreen and wet-season deciduous tree species. Complementary use of light led to intensification of soil exploitation by roots, the main agent responsible for enhanced nutrient retention in some polycultures. Other mechanisms included differences in nutrient demand among species, and avoidance of catastrophic failure due to episodic weather events or pest outbreaks. Even unrealistically simple multi-life-form mimics of tropical forest can safeguard a site's nutrient capital if careful attention is paid to species' characteristics and temporal changes in interspecific interactions.

  2. Patterns of tree species diversity in relation to climatic factors on the Sierra Madre Occidental, Mexico.

    PubMed

    Silva-Flores, Ramón; Pérez-Verdín, Gustavo; Wehenkel, Christian

    2014-01-01

    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 species, between species, 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 species of Pinus (ca. 22% on the whole), 54 species of Quercus (ca. 9-14%), 7 species of Arbutus (ca. 50%) and many other trees species. The objectives of this study were to model how tree species 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 tree species 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 tree species are generally higher in cold

  3. Patterns of root respiration rates and morphological traits in 13 tree species in a tropical forest.

    PubMed

    Makita, Naoki; Kosugi, Yoshiko; Dannoura, Masako; Takanashi, Satoru; Niiyama, Kaoru; Kassim, Abd Rahman; Nik, Abdul Rahim

    2012-03-01

    The root systems of forest trees are composed of different diameters and heterogeneous physiological traits. However, the pattern of root respiration rates from finer and coarser roots across various tropical species 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 trees of 13 species 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 species. 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 species 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 trees from 13 species examined. Our results indicate that coarse root respiration in tree species follows a basic relationship with D across species and that most of the variation in fine root respiration among species 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 species.

  4. Direct vs. Microclimate-Driven Effects of Tree Species Diversity on Litter Decomposition in Young Subtropical Forest Stands

    PubMed Central

    Seidelmann, Katrin N.; Scherer-Lorenzen, Michael; Niklaus, Pascal A.

    2016-01-01

    Effects of tree species diversity on decomposition can operate via a multitude of mechanism, including alterations of microclimate by the forest canopy. Studying such effects in natural settings is complicated by the fact that topography also affects microclimate and thus decomposition, so that effects of diversity are more difficult to isolate. Here, we quantified decomposition rates of standard litter in young subtropical forest stands, separating effects of canopy tree species richness and topography, and quantifying their direct and micro-climate-mediated components. Our litterbag study was carried out at two experimental sites of a biodiversity-ecosystem functioning field experiment in south-east China (BEF-China). The field sites display strong topographical heterogeneity and were planted with tree communities ranging from monocultures to mixtures of 24 native subtropical tree species. Litter bags filled with senescent leaves of three native tree species were placed from Nov. 2011 to Oct. 2012 on 134 plots along the tree species diversity gradient. Topographic features were measured for all and microclimate in a subset of plots. Stand species richness, topography and microclimate explained important fractions of the variations in litter decomposition rates, with diversity and topographic effects in part mediated by microclimatic changes. Tree stands were 2–3 years old, but nevertheless tree species diversity explained more variation (54.3%) in decomposition than topography (7.7%). Tree species richness slowed litter decomposition, an effect that slightly depended on litter species identity. A large part of the variance in decomposition was explained by tree species composition, with the presence of three tree species playing a significant role. Microclimate explained 31.4% of the variance in decomposition, and was related to lower soil moisture. Within this microclimate effect, species diversity (without composition) explained 8.9% and topography 34.4% of

  5. Direct vs. Microclimate-Driven Effects of Tree Species Diversity on Litter Decomposition in Young Subtropical Forest Stands.

    PubMed

    Seidelmann, Katrin N; Scherer-Lorenzen, Michael; Niklaus, Pascal A

    2016-01-01

    Effects of tree species diversity on decomposition can operate via a multitude of mechanism, including alterations of microclimate by the forest canopy. Studying such effects in natural settings is complicated by the fact that topography also affects microclimate and thus decomposition, so that effects of diversity are more difficult to isolate. Here, we quantified decomposition rates of standard litter in young subtropical forest stands, separating effects of canopy tree species richness and topography, and quantifying their direct and micro-climate-mediated components. Our litterbag study was carried out at two experimental sites of a biodiversity-ecosystem functioning field experiment in south-east China (BEF-China). The field sites display strong topographical heterogeneity and were planted with tree communities ranging from monocultures to mixtures of 24 native subtropical tree species. Litter bags filled with senescent leaves of three native tree species were placed from Nov. 2011 to Oct. 2012 on 134 plots along the tree species diversity gradient. Topographic features were measured for all and microclimate in a subset of plots. Stand species richness, topography and microclimate explained important fractions of the variations in litter decomposition rates, with diversity and topographic effects in part mediated by microclimatic changes. Tree stands were 2-3 years old, but nevertheless tree species diversity explained more variation (54.3%) in decomposition than topography (7.7%). Tree species richness slowed litter decomposition, an effect that slightly depended on litter species identity. A large part of the variance in decomposition was explained by tree species composition, with the presence of three tree species playing a significant role. Microclimate explained 31.4% of the variance in decomposition, and was related to lower soil moisture. Within this microclimate effect, species diversity (without composition) explained 8.9% and topography 34.4% of

  6. Direct vs. Microclimate-Driven Effects of Tree Species Diversity on Litter Decomposition in Young Subtropical Forest Stands.

    PubMed

    Seidelmann, Katrin N; Scherer-Lorenzen, Michael; Niklaus, Pascal A

    2016-01-01

    Effects of tree species diversity on decomposition can operate via a multitude of mechanism, including alterations of microclimate by the forest canopy. Studying such effects in natural settings is complicated by the fact that topography also affects microclimate and thus decomposition, so that effects of diversity are more difficult to isolate. Here, we quantified decomposition rates of standard litter in young subtropical forest stands, separating effects of canopy tree species richness and topography, and quantifying their direct and micro-climate-mediated components. Our litterbag study was carried out at two experimental sites of a biodiversity-ecosystem functioning field experiment in south-east China (BEF-China). The field sites display strong topographical heterogeneity and were planted with tree communities ranging from monocultures to mixtures of 24 native subtropical tree species. Litter bags filled with senescent leaves of three native tree species were placed from Nov. 2011 to Oct. 2012 on 134 plots along the tree species diversity gradient. Topographic features were measured for all and microclimate in a subset of plots. Stand species richness, topography and microclimate explained important fractions of the variations in litter decomposition rates, with diversity and topographic effects in part mediated by microclimatic changes. Tree stands were 2-3 years old, but nevertheless tree species diversity explained more variation (54.3%) in decomposition than topography (7.7%). Tree species richness slowed litter decomposition, an effect that slightly depended on litter species identity. A large part of the variance in decomposition was explained by tree species composition, with the presence of three tree species playing a significant role. Microclimate explained 31.4% of the variance in decomposition, and was related to lower soil moisture. Within this microclimate effect, species diversity (without composition) explained 8.9% and topography 34.4% of

  7. Leaf gas exchange traits of domestic and exotic tree species in Cambodia

    NASA Astrophysics Data System (ADS)

    Miyazawa, Y.; Tateishi, M.; Kumagai, T.; Otsuki, K.

    2009-12-01

    In forests under the management by community villagers, exotic tree species with rapid growth rate are introduced in wide range of Cambodia. To evaluate the influence of the introduction on the forest gas exchange and water budget, we investigated the leaf gas exchange traits of two domestic (Dipterocarpus obtusifolius and Shorea roxburghii) and exotic tree species (Acasia auriculiformis and Eucalyptus camadilansis). We sampled shoots of each species and measured the leaf gas exchange traits (photosynthetic rates under different CO2 concentrations, transpiration rate and stomatal conductance) (6 leaves x 3 trees x 4 species). We carried out this measurement at 2 months intervals for a year from the beginning of rainy season and compared the obtained traits among species. Light saturated rate of net photosynthesis was higher in E. camadilansis but did not differ among other species both in rainy and dry seasons. Seasonal patter in photosynthetic traits was not obvious. Each species changed stomatal conductance in response to changes in environmental conditions. The response was more sensitive than reported values. In this presentation, we show details about the basic information about the leaf-level gas exchange traits, which are required to run soil- vegetation - atmosphere transfer model.

  8. Data concatenation, Bayesian concordance and coalescent-based analyses of the species tree for the rapid radiation of Triturus newts.

    PubMed

    Wielstra, Ben; Arntzen, Jan W; van der Gaag, Kristiaan J; Pabijan, Maciej; Babik, Wieslaw

    2014-01-01

    The phylogenetic relationships for rapid species 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 species. Bayesian analysis of population structure allocates all individuals to their respective species. The branching patterns obtained by data concatenation, Bayesian concordance analysis and coalescent-based estimations of the species tree differ from one another. The data concatenation based species tree 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 trees for part of the Triturus species tree as low concordance factors. The coalescent-based species tree is relatively similar to a previously published species tree based upon morphology and full mtDNA and any conflicting internal branches are not highly supported. Our findings reflect high gene tree 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 species radiations). This case study highlights the complexity of resolving rapid radiations and we acknowledge that to convincingly resolve the Triturus species tree even more genes will have to be consulted.

  9. Epigenetic regulation of adaptive responses of forest tree species to the environment

    PubMed Central

    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

    2013-01-01

    Epigenetic variation is likely to contribute to the phenotypic plasticity and adaptative capacity of plant species, and may be especially important for long-lived organisms with complex life cycles, including forest trees. 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 tree species. We consider the possible role of forest tree epigenetics as a new source of adaptive traits in plant breeding, biotechnology, and ecosystem conservation under rapid climate change. PMID:23467802

  10. Eco-physiological adaptation of dominant tree species at two contrasting karst habitats in southwestern China.

    PubMed

    Zhang, Shouren; Fan, Dayong; Wu, Qian; Yan, Hui; Xu, Xinwu

    2013-01-01

    The purpose of this study was to investigate the eco-physiological adaptation of indigenous woody species to their habitats in karst areas of southwestern China. Two contrasting forest habitats were studied: a degraded habitat in Daxiagu and a well-developed habitat in Tianlongshan, and the eco-physiological characteristics of the trees were measured for three growth seasons. Photosynthetic rate (Pn), stomatal conductance (gs), and transpiration rate (Tr) of the tree species in Daxiagu were 2-3 times higher than those in Tianlongshan under ambient conditions. However, this habitat effect was not significant when measurements were taken under controlled conditions. Under controlled conditions, Pn, gs, and Tr of the deciduous species were markedly higher than those for the evergreen species. Habitat had no significant effect on water use efficiency (WUE) or photochemical characteristics of PSII. The stomatal sensitivity of woody species in the degraded habitat was much higher than that in the well-developed habitat. Similarly, the leaf total nitrogen (N) and phosphorus (P) contents expressed on the basis of either dry mass or leaf area were also much higher in Daxiagu than they were in Tianlongshan. The mass-based leaf total N content of deciduous species was much higher than that of evergreen species, while leaf area-based total N and P contents of evergreens were significantly higher than those of deciduous species. The photosynthetic nitrogen- and phosphorus-use efficiencies (PNUE and PPUE) of deciduous species were much higher than those of evergreens. Further, the PPUE of the woody species in Tianlongshan was much higher than that  of the woody species in Daxiagu. The results from three growth seasons imply that the tree species were able to adapt well to their growth habitats. Furthermore, it seems that so-called "temporary drought stress" may not occur, or may not be severe for most woody plants in karst areas of southwestern China.

  11. Dynamics of Tree Species Composition in Temperate Mountains of South Korea over Fourteen Years using 880 Permanent Plots

    NASA Astrophysics Data System (ADS)

    Lee, B.; Kim, H. S.; Park, J.; Moon, M.; Cho, S.; Ryu, D.; Wynn, K. Z.; Park, J.

    2014-12-01

    The structure of forest and diversity of tree species in temperate mountains have been influenced by changing climate conditions as well as successional changes. To understand how tree species composition and stand structure change across temperate mountains, the species composition, size, and environmental information were collected over the past fourteen years in 880 quadrats of 20 m x 50 m of woodland communities distributed across Jiri and Baekoon Mountains, South Korea. The preliminary investigation on variations of tree species revealed that overall composition of tree species increased in terms of both diversity and biomass growth of tree species, reflecting fast and wide changes in temperate forests of Korea. Among dominant trees, the Quercus mongolica, Styrax japonicu, and Acer pseudosieboldianum recorded the highest increase in stand density, implying the most prosperous species under current conditions, while the species of Quercus variabilis and Fraxinus mandshurica appeared as fast declining species in the number. In terms of biomass growth of dominant species, the Stewartia pseudocamellia showed the largest increase of biomass, followed by Quercus serrata and Quercus mongolica., while the Fraxinus mandshurica appeared to have a rapid decline, followed by Alnus japonica and Quercus dentata. Overall, the fast change of composition in tree species is clear and further analysis to clarify the reasons for such fast and species-specific changes is underway especially to separate the effect of successional change and climate change.

  12. Characterization of mariner-like transposons of the mauritiana Subfamily in seven tree aphid species.

    PubMed

    Kharrat, Imen; Mezghani, Maha; Casse, Nathalie; Denis, Françoise; Caruso, Aurore; Makni, Hanem; Capy, Pierre; Rouault, Jacques-Deric; Chénais, Benoît; Makni, Mohamed

    2015-02-01

    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 tree aphid species out of eight species 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 tree aphid species occurred, and that they have been maintained in this species via vertical transmissions. This is the first evidence of the widespread occurrence of MLEs in aphids.

  13. [Reproductive phenology of tree species in the Tenosique tropical forest, Tabasco, Mexico].

    PubMed

    Ochoa-Gaona, Susana; Hernández, Isidro Pérez; de Jong, Bernardus H J

    2008-06-01

    Between August 2003 and August 2005 we registered the flowering and fruiting of 75 tree species (341 individual trees) in a tropical rain forest at Tenosique, Tabasco, Mexico. Monthly we checked five transects (500 m long; 5 m wide). To test the homogeneity of flowering and fruiting during the year, and between adjacent months, we applied a chi2 test. The flowering was bimodal, with a highest peak in March and April, coinciding with the dry season, and a second lower peak in July when precipitation is relatively low. The highest number of fruiting tree species occur between May and July, with its peak in May. Each of the most common botanical families showed a particular phenological pattern. Monthly rainfall and the number of species flowering or fruiting were not significantly correlated. This means that trees are flowering and fruiting all year long, with seasonal increases of both phenological phenomena in the dryer periods. We conclude that phenological patterns vary between individuals and between years and are not seasonally correlated. The data we generated are relevant to program the best periods of seed collections according to individual or groups of species, as part of forest management and conservation practices. PMID:19256435

  14. [Compatible biomass models for main tree species with measurement error in Heilongjiang Province of Northeast China].

    PubMed

    Dong, Li-hu; Li, Feng-ri; Jia, Wei-wei; Liu, Fu-xiang; Wang, He-zhi

    2011-10-01

    Based on the biomass data of 516 sampling trees, and by using non-linear error-in-variable modeling approach, the compatible models for the total biomass and the biomass of six components including aboveground part, underground part, stem, crown, branch, and foliage of 15 major tree species (or groups) in Heilongjiang Province were established, and the best models for the total biomass and components biomass were selected. The compatible models based on total biomass were developed by adopting the method of joint control different level ratio function. The heteroscedasticity of the models for total biomass was eliminated with log transformation, and the weighted regression was applied to the models for each individual component. Among the compatible biomass models established for the 15 major species (or groups) , the model for total biomass had the highest prediction precision (90% or more), followed by the models for aboveground part and stem biomass, with a precision of 87.5% or more. The prediction precision of the biomass models for other components was relatively low, but it was still greater than 80% for most test tree species. The modeling efficiency (EF) values of the total, aboveground part, and stem biomass models for all the tree species (or groups) were over 0.9, and the EF values of the underground part, crown, branch, and foliage biomass models were over 0.8.

  15. Responses of tree species to heat waves and extreme heat events.

    PubMed

    Teskey, Robert; Wertin, Timothy; Bauweraerts, Ingvar; Ameye, Maarten; McGuire, Mary Anne; Steppe, Kathy

    2015-09-01

    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 tree functions. At the leaf level, photosynthesis is reduced, photooxidative stress increases, leaves abscise and the growth rate of remaining leaves decreases. In some species, 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 tree mortality. However, some species 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-species genetic variation in thermal tolerance, which could be important to exploit in production forestry systems. Understanding the mechanisms of differing tree responses to extreme temperature events may be critically important for understanding how tree species will be affected by climate change.

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

    PubMed

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

    2015-11-01

    To derive O3 dose-response relationships (DRR) for five European forest trees species and broadleaf deciduous and needleleaf tree plant functional types (PFTs), phytotoxic O3 doses (PODy) were related to biomass reductions. PODy was calculated using a stomatal flux model with a range of cut-off thresholds (y) indicative of varying detoxification capacities. Linear regression analysis showed that DRR for PFT and individual tree species differed in their robustness. A simplified parameterisation of the flux model was tested and showed that for most non-Mediterranean tree species, this simplified model led to similarly robust DRR as compared to a species- and climate region-specific parameterisation. Experimentally induced soil water stress was not found to substantially reduce PODy, mainly due to the short duration of soil water stress periods. This study validates the stomatal O3 flux concept and represents a step forward in predicting O3 damage to forests in a spatially and temporally varying climate. PMID:26164201

  17. Effects of canopy tree species on belowground biogeochemistry in a lowland wet tropical forest

    USGS Publications Warehouse

    Keller, Adrienne B.; Reed, Sasha C.; Townsend, Alan R.; Cleveland, Cory C.

    2013-01-01

    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 species-rich forests of the wet tropics. To investigate the effects of individual tree species 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 tree species – including three legume and six non-legume species – 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 tree species: total C, N and P pools in standing litter varied by species, as did total soil and microbial C and N pools. Rates of soil extracellular acid phosphatase activity also varied significantly among species and functional groups, with higher rates of phosphatase activity under legumes. In addition, across all tree species, 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.

  18. Multipurpose Cargo Transfer Bag

    NASA Technical Reports Server (NTRS)

    Broyan, James; Baccus, Shelley

    2014-01-01

    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.

  19. Narrowing historical uncertainty: probabilistic classification of ambiguously identified tree species in historical forest survey data

    USGS Publications Warehouse

    Mladenoff, D.J.; Dahir, S.E.; Nordheim, E.V.; Schulte, L.A.; Guntenspergen, G.R.

    2002-01-01

    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 tree species, 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 species 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 trees 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 tree species using logistic regression analysis, using data on trees that were clearly identified to species and a set of independent predictor variables to build the models. The models were first created on partial data sets for each species 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 species among oak, pine, ash, maple, birch, and elm. Major predictor variables were tree size, associated species, landscape classes indicative of soil type, and spatial location within the study region. Results help to clarify ambiguities

  20. The Trichoptera barcode initiative: a strategy for generating a species-level Tree of Life.

    PubMed

    Zhou, Xin; Frandsen, Paul B; Holzenthal, Ralph W; Beet, Clare R; Bennett, Kristi R; Blahnik, Roger J; Bonada, Núria; Cartwright, David; Chuluunbat, Suvdtsetseg; Cocks, Graeme V; Collins, Gemma E; deWaard, Jeremy; Dean, John; Flint, Oliver S; Hausmann, Axel; Hendrich, Lars; Hess, Monika; Hogg, Ian D; Kondratieff, Boris C; Malicky, Hans; Milton, Megan A; Morinière, Jérôme; Morse, John C; Mwangi, François Ngera; Pauls, Steffen U; Gonzalez, María Razo; Rinne, Aki; Robinson, Jason L; Salokannel, Juha; Shackleton, Michael; Smith, Brian; Stamatakis, Alexandros; StClair, Ros; Thomas, Jessica A; Zamora-Muñoz, Carmen; Ziesmann, Tanja; Kjer, Karl M

    2016-09-01

    DNA barcoding was intended as a means to provide species-level identifications through associating DNA sequences from unknown specimens to those from curated reference specimens. Although barcodes were not designed for phylogenetics, they can be beneficial to the completion of the Tree of Life. The barcode database for Trichoptera is relatively comprehensive, with data from every family, approximately two-thirds of the genera, and one-third of the described species. Most Trichoptera, as with most of life's species, have never been subjected to any formal phylogenetic analysis. Here, we present a phylogeny with over 16 000 unique haplotypes as a working hypothesis that can be updated as our estimates improve. We suggest a strategy of implementing constrained tree searches, which allow larger datasets to dictate the backbone phylogeny, while the barcode data fill out the tips of the tree. We also discuss how this phylogeny could be used to focus taxonomic attention on ambiguous species boundaries and hidden biodiversity. We suggest that systematists continue to differentiate between 'Barcode Index Numbers' (BINs) and 'species' that have been formally described. Each has utility, but they are not synonyms. We highlight examples of integrative taxonomy, using both barcodes and morphology for species description.This article is part of the themed issue 'From DNA barcodes to biomes'.

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

    PubMed

    Reich, P B; Amundson, R G

    1985-11-01

    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 United States during the summer, and in more heavily polluted air. However, the highest concentrations of ozone used were lower than those found regularly in the Los Angeles area. The mean pH of the simulated acid rain treatments ranged from more alkaline to much more acidic than the mean pH of precipitation in the United States. Exposure to any increase in ozone reduced net photosynthesis in all species tested. In contrast, acidic rain had no negative effect on photosynthesis in tree species, and no interaction between ozone and acidic rain was observed. Ozone-induced reductions in photosynthesis were related to declines in growth or yield. Species with higher stomatal conductances and thus higher potential for pollutant uptake exhibited greater negative responses to similar ozone treatments. Since exposure to ozone concentrations typical of levels of the pollutant observed in the eastern half of the United States reduced the rates of net photosynthesis of all species tested, reductions in net photosynthesis may be occurring over much of the eastern United States.

  2. Ambient Levels of Ozone Reduce Net Photosynthesis in Tree and Crop Species

    NASA Astrophysics Data System (ADS)

    Reich, Peter B.; Amundson, Robert G.

    1985-11-01

    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 United States during the summer, and in more heavily polluted air. However, the highest concentrations of ozone used were lower than those found regularly in the Los Angeles area. The mean pH of the simulated acid rain treatments ranged from more alkaline to much more acidic than the mean pH of precipitation in the United States. Exposure to any increase in ozone reduced net photosynthesis in all species tested. In contrast, acidic rain had no negative effect on photosynthesis in tree species, and no interaction between ozone and acidic rain was observed. Ozone-induced reductions in photosynthesis were related to declines in growth or yield. Species with higher stomatal conductances and thus higher potential for pollutant uptake exhibited greater negative responses to similar ozone treatments. Since exposure to ozone concentrations typical of levels of the pollutant observed in the eastern half of the United States reduced the rates of net photosynthesis of all species tested, reductions in net photosynthesis may be occurring over much of the eastern United States.

  3. The Trichoptera barcode initiative: a strategy for generating a species-level Tree of Life.

    PubMed

    Zhou, Xin; Frandsen, Paul B; Holzenthal, Ralph W; Beet, Clare R; Bennett, Kristi R; Blahnik, Roger J; Bonada, Núria; Cartwright, David; Chuluunbat, Suvdtsetseg; Cocks, Graeme V; Collins, Gemma E; deWaard, Jeremy; Dean, John; Flint, Oliver S; Hausmann, Axel; Hendrich, Lars; Hess, Monika; Hogg, Ian D; Kondratieff, Boris C; Malicky, Hans; Milton, Megan A; Morinière, Jérôme; Morse, John C; Mwangi, François Ngera; Pauls, Steffen U; Gonzalez, María Razo; Rinne, Aki; Robinson, Jason L; Salokannel, Juha; Shackleton, Michael; Smith, Brian; Stamatakis, Alexandros; StClair, Ros; Thomas, Jessica A; Zamora-Muñoz, Carmen; Ziesmann, Tanja; Kjer, Karl M

    2016-09-01

    DNA barcoding was intended as a means to provide species-level identifications through associating DNA sequences from unknown specimens to those from curated reference specimens. Although barcodes were not designed for phylogenetics, they can be beneficial to the completion of the Tree of Life. The barcode database for Trichoptera is relatively comprehensive, with data from every family, approximately two-thirds of the genera, and one-third of the described species. Most Trichoptera, as with most of life's species, have never been subjected to any formal phylogenetic analysis. Here, we present a phylogeny with over 16 000 unique haplotypes as a working hypothesis that can be updated as our estimates improve. We suggest a strategy of implementing constrained tree searches, which allow larger datasets to dictate the backbone phylogeny, while the barcode data fill out the tips of the tree. We also discuss how this phylogeny could be used to focus taxonomic attention on ambiguous species boundaries and hidden biodiversity. We suggest that systematists continue to differentiate between 'Barcode Index Numbers' (BINs) and 'species' that have been formally described. Each has utility, but they are not synonyms. We highlight examples of integrative taxonomy, using both barcodes and morphology for species description.This article is part of the themed issue 'From DNA barcodes to biomes'. PMID:27481793

  4. Mapping and Characterizing Selected Canopy Tree Species at the Angkor World Heritage Site in Cambodia Using Aerial Data

    PubMed Central

    Singh, Minerva; Evans, Damian; Tan, Boun Suy; Nin, Chan Samean

    2015-01-01

    At present, there is very limited information on the ecology, distribution, and structure of Cambodia’s tree species to warrant suitable conservation measures. The aim of this study was to assess various methods of analysis of aerial imagery for characterization of the forest mensuration variables (i.e., tree height and crown width) of selected tree species found in the forested region around the temples of Angkor Thom, Cambodia. Object-based image analysis (OBIA) was used (using multiresolution segmentation) to delineate individual tree crowns from very-high-resolution (VHR) aerial imagery and light detection and ranging (LiDAR) data. Crown width and tree height values that were extracted using multiresolution segmentation showed a high level of congruence with field-measured values of the trees (Spearman’s rho 0.782 and 0.589, respectively). Individual tree crowns that were delineated from aerial imagery using multiresolution segmentation had a high level of segmentation accuracy (69.22%), whereas tree crowns delineated using watershed segmentation underestimated the field-measured tree crown widths. Both spectral angle mapper (SAM) and maximum likelihood (ML) classifications were applied to the aerial imagery for mapping of selected tree species. The latter was found to be more suitable for tree species classification. Individual tree species were identified with high accuracy. Inclusion of textural information further improved species identification, albeit marginally. Our findings suggest that VHR aerial imagery, in conjunction with OBIA-based segmentation methods (such as multiresolution segmentation) and supervised classification techniques are useful for tree species mapping and for studies of the forest mensuration variables. PMID:25902148

  5. Mapping and characterizing selected canopy tree species at the Angkor World Heritage site in Cambodia using aerial data.

    PubMed

    Singh, Minerva; Evans, Damian; Tan, Boun Suy; Nin, Chan Samean

    2015-01-01

    At present, there is very limited information on the ecology, distribution, and structure of Cambodia's tree species to warrant suitable conservation measures. The aim of this study was to assess various methods of analysis of aerial imagery for characterization of the forest mensuration variables (i.e., tree height and crown width) of selected tree species found in the forested region around the temples of Angkor Thom, Cambodia. Object-based image analysis (OBIA) was used (using multiresolution segmentation) to delineate individual tree crowns from very-high-resolution (VHR) aerial imagery and light detection and ranging (LiDAR) data. Crown width and tree height values that were extracted using multiresolution segmentation showed a high level of congruence with field-measured values of the trees (Spearman's rho 0.782 and 0.589, respectively). Individual tree crowns that were delineated from aerial imagery using multiresolution segmentation had a high level of segmentation accuracy (69.22%), whereas tree crowns delineated using watershed segmentation underestimated the field-measured tree crown widths. Both spectral angle mapper (SAM) and maximum likelihood (ML) classifications were applied to the aerial imagery for mapping of selected tree species. The latter was found to be more suitable for tree species classification. Individual tree species were identified with high accuracy. Inclusion of textural information further improved species identification, albeit marginally. Our findings suggest that VHR aerial imagery, in conjunction with OBIA-based segmentation methods (such as multiresolution segmentation) and supervised classification techniques are useful for tree species mapping and for studies of the forest mensuration variables. PMID:25902148

  6. Mapping and characterizing selected canopy tree species at the Angkor World Heritage site in Cambodia using aerial data.

    PubMed

    Singh, Minerva; Evans, Damian; Tan, Boun Suy; Nin, Chan Samean

    2015-01-01

    At present, there is very limited information on the ecology, distribution, and structure of Cambodia's tree species to warrant suitable conservation measures. The aim of this study was to assess various methods of analysis of aerial imagery for characterization of the forest mensuration variables (i.e., tree height and crown width) of selected tree species found in the forested region around the temples of Angkor Thom, Cambodia. Object-based image analysis (OBIA) was used (using multiresolution segmentation) to delineate individual tree crowns from very-high-resolution (VHR) aerial imagery and light detection and ranging (LiDAR) data. Crown width and tree height values that were extracted using multiresolution segmentation showed a high level of congruence with field-measured values of the trees (Spearman's rho 0.782 and 0.589, respectively). Individual tree crowns that were delineated from aerial imagery using multiresolution segmentation had a high level of segmentation accuracy (69.22%), whereas tree crowns delineated using watershed segmentation underestimated the field-measured tree crown widths. Both spectral angle mapper (SAM) and maximum likelihood (ML) classifications were applied to the aerial imagery for mapping of selected tree species. The latter was found to be more suitable for tree species classification. Individual tree species were identified with high accuracy. Inclusion of textural information further improved species identification, albeit marginally. Our findings suggest that VHR aerial imagery, in conjunction with OBIA-based segmentation methods (such as multiresolution segmentation) and supervised classification techniques are useful for tree species mapping and for studies of the forest mensuration variables.

  7. Tree Density and Species Decline in the African Sahel Attributable to Climate

    NASA Technical Reports Server (NTRS)

    Gonzalez, Patrick; Tucker, Compton J.; Sy, H.

    2012-01-01

    Increased aridity and human population have reduced tree cover in parts of the African Sahel and degraded resources for local people. Yet, tree 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 tree 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 species 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 tree cover changes. Multivariate and bivariate tests and field observations indicated the dominance of temperature and precipitation, supporting attribution of tree 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 tree cover changes to global climate change. This suggests roles for global action and local adaptation to address ecological change in the Sahel.

  8. Tree species diversity mitigates disturbance impacts on the forest carbon cycle.

    PubMed

    Pedro, Mariana Silva; Rammer, Werner; Seidl, Rupert

    2015-03-01

    Biodiversity fosters the functioning and stability of forest ecosystems and, consequently, the provision of crucial ecosystem services that support human well-being and quality of life. In particular, it has been suggested that tree species diversity buffers ecosystems against the impacts of disturbances, a relationship known as the "insurance hypothesis". Natural disturbances have increased across Europe in recent decades and climate change is expected to amplify the frequency and severity of disturbance events. In this context, mitigating disturbance impacts and increasing the resilience of forest ecosystems is of growing importance. We have tested how tree species diversity modulates the impact of disturbance on net primary production and the total carbon stored in living biomass for a temperate forest landscape in Central Europe. Using the simulation model iLand to study the effect of different disturbance regimes on landscapes with varying levels of tree species richness, we found that increasing diversity generally reduces the disturbance impact on carbon storage and uptake, but that this effect weakens or even reverses with successional development. Our simulations indicate a clear positive relationship between diversity and resilience, with more diverse systems experiencing lower disturbance-induced variability in their trajectories of ecosystem functioning. We found that positive effects of tree species diversity are mainly driven by an increase in functional diversity and a modulation of traits related to recolonization and resource usage. The results of our study suggest that increasing tree species diversity could mitigate the effects of intensifying disturbance regimes on ecosystem functioning and improve the robustness of forest carbon storage and the role of forests in climate change mitigation. PMID:25526843

  9. Tree species diversity mitigates disturbance impacts on the forest carbon cycle.

    PubMed

    Pedro, Mariana Silva; Rammer, Werner; Seidl, Rupert

    2015-03-01

    Biodiversity fosters the functioning and stability of forest ecosystems and, consequently, the provision of crucial ecosystem services that support human well-being and quality of life. In particular, it has been suggested that tree species diversity buffers ecosystems against the impacts of disturbances, a relationship known as the "insurance hypothesis". Natural disturbances have increased across Europe in recent decades and climate change is expected to amplify the frequency and severity of disturbance events. In this context, mitigating disturbance impacts and increasing the resilience of forest ecosystems is of growing importance. We have tested how tree species diversity modulates the impact of disturbance on net primary production and the total carbon stored in living biomass for a temperate forest landscape in Central Europe. Using the simulation model iLand to study the effect of different disturbance regimes on landscapes with varying levels of tree species richness, we found that increasing diversity generally reduces the disturbance impact on carbon storage and uptake, but that this effect weakens or even reverses with successional development. Our simulations indicate a clear positive relationship between diversity and resilience, with more diverse systems experiencing lower disturbance-induced variability in their trajectories of ecosystem functioning. We found that positive effects of tree species diversity are mainly driven by an increase in functional diversity and a modulation of traits related to recolonization and resource usage. The results of our study suggest that increasing tree species diversity could mitigate the effects of intensifying disturbance regimes on ecosystem functioning and improve the robustness of forest carbon storage and the role of forests in climate change mitigation.

  10. Leaf size and leaf display of thirty-eight tropical tree species.

    PubMed

    Poorter, Lourens; Rozendaal, Danaë M A

    2008-11-01

    Trees forage for light through optimal leaf display. Effective leaf display is determined by metamer traits (i.e., the internode, petiole, and corresponding leaf), and thus these traits strongly co-determine carbon gain and as a result competitive advantage in a light-limited environment. We examined 11 metamer traits of sun and shade trees of 38 coexisting moist forest tree species and determined the relative strengths of intra- and interspecific variation. Species-specific metamer traits were related to two variables that represent important life history variation; the regeneration light requirements and average leaf size of the species. Metamer traits varied strongly across species and, in contrast to our expectation, showed only modest changes in response to light. Intra- and interspecific responses to light were only congruent for a third of the traits evaluated. Four traits, amongst which leaf size, specific leaf area (SLA), and leaf area ratio at the metamer level (LAR) showed even opposite intra- and interspecific responses to light. Strikingly, these are classic traits that are thought to be of paramount importance for plant performance but that have completely different consequences within and across species. Sun trees of a given species had small leaves to reduce the heat load, but light-demanding species had large leaves compared to shade-tolerants, probably to outcompete their neighbors. Shade trees of a given species had a high SLA and LAR to capture more light in a light-limited environment, whereas shade-tolerant species have well-protected leaves with a low SLA compared to light-demanding species, probably to deter herbivores and enhance leaf lifespan. There was a leaf-size-mediated trade-off between biomechanical and hydraulic safety, and the efficiency with which species can space their leaves and forage for light. Unexpectedly, metamer traits were more closely linked to leaf size than to regeneration light requirements, probably because leaf

  11. Tree species effects on decomposition and forest floor dynamics in a common garden.

    PubMed

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

    2006-09-01

    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 litter bag experiments to tease apart species 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 species. 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 tree species influenced microbial decomposition primarily via differences in litter lignin (and secondarily, via differences in litter Ca), with high-lignin (and low-Ca) species 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 species influence microbially mediated decomposition primarily through differences in litter lignin, differences among species in litter Ca are most important in

  12. Winning and Losing Tree Species of Reassembly in Minnesota’s Mixed and Broadleaf Forests

    PubMed Central

    Hanberry, Brice B.; Palik, Brian J.; He, Hong S.

    2013-01-01

    We examined reassembly of winning and losing tree species, species 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 species 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 tree species. 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 species on mesic sites. The proportion of shade-tolerant species 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 species, converging to forests similar to broadleaf forests. A functional group framework provided a perspective of winning and losing species and traits, selective filters, and forest ecosystems that can be generalized to other regions, regardless of species identity. PMID:23613911

  13. Temperature dependence, spatial scale, and tree species diversity in eastern Asia and North America

    PubMed Central

    Wang, Zhiheng; Brown, James H.; Tang, Zhiyao; Fang, Jingyun

    2009-01-01

    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 species 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 species richness, in terms of the effects of temperature and body size on the metabolism of organisms. Here we use 2 comparable databases of tree distributions in eastern Asia and North America to investigate the roles of environmental temperature and spatial scale in shaping geographical patterns of species diversity. We find that number of species increases exponentially with environmental temperature as predicted by the MTE, and so does the rate of spatial turnover in species composition (slope of the species-area relationship). The magnitude of temperature dependence of species richness increases with spatial scale. Moreover, the relationship between species richness and temperature is much steeper in eastern Asia than in North America: in cold climates at high latitudes there are more tree species 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

  14. Temperature dependence, spatial scale, and tree species diversity in eastern Asia and North America.

    PubMed

    Wang, Zhiheng; Brown, James H; Tang, Zhiyao; Fang, Jingyun

    2009-08-11

    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 species 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 species richness, in terms of the effects of temperature and body size on the metabolism of organisms. Here we use 2 comparable databases of tree distributions in eastern Asia and North America to investigate the roles of environmental temperature and spatial scale in shaping geographical patterns of species diversity. We find that number of species increases exponentially with environmental temperature as predicted by the MTE, and so does the rate of spatial turnover in species composition (slope of the species-area relationship). The magnitude of temperature dependence of species richness increases with spatial scale. Moreover, the relationship between species richness and temperature is much steeper in eastern Asia than in North America: in cold climates at high latitudes there are more tree species 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.

  15. Anatomical, chemical, and ecological factors affecting tree species choice in dendrochemistry studies

    SciTech Connect

    Cutter, B.E.; Guyette, R.P.

    1993-07-01

    Recently, element concentrations in tree rings have been used to monitor metal contamination, fertilization, and the effects of acid precipitation on soils. This has stimulated interest in which tree species 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 species which minimizes radial translocation of elements can be critical to the success of dendrochemical research. Criteria for selection of species 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 tree species because all elements are not equally mobile or detectable in the xylem. Ideally, the tree species 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 species 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, species 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.

  16. The trait contribution to wood decomposition rates of 15 Neotropical tree species.

    PubMed

    van Geffen, Koert G; Poorter, Lourens; Sass-Klaassen, Ute; van Logtestijn, Richard S P; Cornelissen, Johannes H C

    2010-12-01

    The decomposition of dead wood is a critical uncertainty in models of the global carbon cycle. Despite this, relatively few studies have focused on dead wood decomposition, with a strong bias to higher latitudes. Especially the effect of interspecific variation in species traits on differences in wood decomposition rates remains unknown. In order to fill these gaps, we applied a novel method to study long-term wood decomposition of 15 tree species in a Bolivian semi-evergreen tropical moist forest. We hypothesized that interspecific differences in species traits are important drivers of variation in wood decomposition rates. Wood decomposition rates (fractional mass loss) varied between 0.01 and 0.31 yr(-1). We measured 10 different chemical, anatomical, and morphological traits for all species. The species' average traits were useful predictors of wood decomposition rates, particularly the average diameter (dbh) of the tree species (R2 = 0.41). Lignin concentration further increased the proportion of explained inter-specific variation in wood decomposition (both negative relations, cumulative R2 = 0.55), although it did not significantly explain variation in wood decomposition rates if considered alone. When dbh values of the actual dead trees sampled for decomposition rate determination were used as a predictor variable, the final model (including dead tree dbh and lignin concentration) explained even more variation in wood decomposition rates (R2 = 0.71), underlining the importance of dbh in wood decomposition. Other traits, including wood density, wood anatomical traits, macronutrient concentrations, and the amount of phenolic extractives could not significantly explain the variation in wood decomposition rates. The surprising results of this multi-species study, in which for the first time a large set of traits is explicitly linked to wood decomposition rates, merits further testing in other forest ecosystems. PMID:21302839

  17. Impacts of the Brown Tree Snake: Patterns of Decline and Species Persistence in Guam's Avifauna

    USGS Publications Warehouse

    Wiles, G.J.; Bart, J.; Beck, R.E.; Aguon, C.F.

    2003-01-01

    Predation by brown tree 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 species. Past studies have provided qualitative descriptions of the decline of native forest birds but have not considered all species 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 tree snakes on the island's birds. Our results indicate that 22 species, including 17 of 18 native species, were severely affected by snakes. Twelve species 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 species. The most important factor predisposing a species to coexistence with brown tree 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 tree 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.

  18. Independence of stem and leaf hydraulic traits in six Euphorbiaceae tree species with contrasting leaf phenology.

    PubMed

    Chen, Jun-Wen; Zhang, Qiang; Li, Xiao-Shuang; Cao, Kun-Fang

    2009-08-01

    Hydraulic traits and hydraulic-related structural properties were examined in three deciduous (Hevea brasiliensis, Macaranga denticulate, and Bischofia javanica) and three evergreen (Drypetes indica, Aleurites moluccana, and Codiaeum variegatum) Euphorbiaceae tree species from a seasonally tropical forest in south-western China. Xylem water potential at 50% loss of stem hydraulic conductivity (P50(stem)) was more negative in the evergreen tree, but leaf water potential at 50% loss of leaf hydraulic conductivity (P50(leaf)) did not function as P50(stem) did. Furthermore, P50(stem) was more negative than P50(leaf) in the evergreen tree; contrarily, this pattern was not observed in the deciduous tree. Leaf hydraulic conductivity overlapped considerably, but stem hydraulic conductivity diverged between the evergreen and deciduous tree. Correspondingly, structural properties of leaves overlapped substantially; however, structural properties of stem diverged markedly. Consequently, leaf and stem hydraulic traits were closely correlated with leaf and stem structural properties, respectively. Additionally, stem hydraulic efficiency was significantly correlated with stem hydraulic resistance to embolism; nevertheless, such a hydraulic pattern was not found in leaf hydraulics. Thus, these results suggest: (1) that the evergreen and deciduous tree mainly diverge in stem hydraulics, but not in leaf hydraulics, (2) that regardless of leaf or stem, their hydraulic traits result primarily from structural properties, and not from leaf phenology, (3) that leaves are more vulnerable to drought-induced embolism than stem in the evergreen tree, but not always in the deciduous tree and (4) that there exists a trade-off between hydraulic efficiency and safety for stem hydraulics, but not for leaf hydraulics.

  19. Oxygen isotopes in tree rings show good coherence between species and sites in Bolivia

    NASA Astrophysics Data System (ADS)

    Baker, Jessica C. A.; Hunt, Sarah F. P.; Clerici, Santiago J.; Newton, Robert J.; Bottrell, Simon H.; Leng, Melanie J.; Heaton, Timothy H. E.; Helle, Gerhard; Argollo, Jaime; Gloor, Manuel; Brienen, Roel J. W.

    2015-10-01

    A tree ring oxygen isotope (δ18OTR) chronology developed from one species (Cedrela odorata) growing in a single site has been shown to be a sensitive proxy for rainfall over the Amazon Basin, thus allowing reconstructions of precipitation in a region where meteorological records are short and scarce. Although these results suggest that there should be large-scale (> 100 km) spatial coherence of δ18OTR records in the Amazon, this has not been tested. Furthermore, it is of interest to investigate whether other, possibly longer-lived, species similarly record interannual variation of Amazon precipitation, and can be used to develop climate sensitive isotope chronologies. In this study, we measured δ18O in tree rings from seven lowland and one highland tree species from Bolivia. We found that cross-dating with δ18OTR gave more accurate tree ring dates than using ring width. Our "isotope cross-dating approach" is confirmed with radiocarbon "bomb-peak" dates, and has the potential to greatly facilitate development of δ18OTR records in the tropics, identify dating errors, and check annual ring formation in tropical trees. Six of the seven lowland species correlated significantly with C. odorata, showing that variation in δ18OTR has a coherent imprint across very different species, most likely arising from a dominant influence of source water δ18O on δ18OTR. In addition we show that δ18OTR series cohere over large distances, within and between species. Comparison of two C. odorata δ18OTR chronologies from sites several hundreds of kilometres apart showed a very strong correlation (r = 0.80, p < 0.001, 1901-2001), and a significant (but weaker) relationship was found between lowland C. odorata trees and a Polylepis tarapacana tree growing in the distant Altiplano (r = 0.39, p < 0.01, 1931-2001). This large-scale coherence of δ18OTR records is probably triggered by a strong spatial coherence in precipitation δ18O due to large-scale controls. These results

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

    NASA Astrophysics Data System (ADS)

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

    2008-11-01

    Hydraulic redistribution (HR) in karité ( Vitellaria paradoxa) and néré ( Parkia biglobosa) tree species was studied by monitoring the soil water potential ( ψs) using thermocouple psychrometers at four compass directions, various distances from trees and at different soil depths (max depth 80 cm) during the dry seasons of 2004 and 2005. A modified WaNuLCAS model was then used to infer the amount of water redistribued based on ψs values. Tree transpiration rate was also estimated from sap velocity using thermal dissipative probes (TDP) and sapwood area, and the contribution of hydraulically redistributed water in tree transpiration was determined. The results revealed on average that 46% of the psychrometer readings under karité and 33% under néré showed the occurrence of HR for the two years. Soil under néré displayed significantly lower fluctuations of ψs (0.16 MPa) compared to soil under karité (0.21 MPa). The results of this study indicated that the existence of HR leads to a higher ψs in the plant rhizosphere and hence is important for soil water dynamics and plant nutrition by making more accessible the soluble elements. The simulation showed that the amount of water redistributed would be approximately 73.0 L and 247.1 L per tree 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 species, this water may play a key role in maintaining fine root viability and ensuring the well adaptation of these species 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 trees and associated crops.

  1. Drought stress limits the geographic ranges of two tree species via different physiological mechanisms.

    PubMed

    Anderegg, Leander D L; HilleRisLambers, Janneke

    2016-03-01

    Range shifts are among the most ubiquitous ecological responses to anthropogenic climate change and have large consequences for ecosystems. Unfortunately, the ecophysiological forces that constrain range boundaries are poorly understood, making it difficult to mechanistically project range shifts. To explore the physiological mechanisms by which drought stress controls dry range boundaries in trees, we quantified elevational variation in drought tolerance and in drought avoidance-related functional traits of a widespread gymnosperm (ponderosa pine - Pinus ponderosa) and angiosperm (trembling aspen - Populus tremuloides) tree species in the southwestern USA. Specifically, we quantified tree-to-tree variation in growth, water stress (predawn and midday xylem tension), drought avoidance traits (branch conductivity, leaf/needle size, tree height, leaf area-to-sapwood area ratio), and drought tolerance traits (xylem resistance to embolism, hydraulic safety margin, wood density) at the range margins and range center of each species. Although water stress increased and growth declined strongly at lower range margins of both species, ponderosa pine and aspen showed contrasting patterns of clinal trait variation. Trembling aspen increased its drought tolerance at its dry range edge by growing stronger but more carbon dense branch and leaf tissues, implying an increased cost of growth at its range boundary. By contrast, ponderosa pine showed little elevational variation in drought-related traits but avoided drought stress at low elevations by limiting transpiration through stomatal closure, such that its dry range boundary is associated with limited carbon assimilation even in average climatic conditions. Thus, the same climatic factor (drought) may drive range boundaries through different physiological mechanisms - a result that has important implications for process-based modeling approaches to tree biogeography. Further, we show that comparing intraspecific patterns of

  2. Drought stress limits the geographic ranges of two tree species via different physiological mechanisms.

    PubMed

    Anderegg, Leander D L; HilleRisLambers, Janneke

    2016-03-01

    Range shifts are among the most ubiquitous ecological responses to anthropogenic climate change and have large consequences for ecosystems. Unfortunately, the ecophysiological forces that constrain range boundaries are poorly understood, making it difficult to mechanistically project range shifts. To explore the physiological mechanisms by which drought stress controls dry range boundaries in trees, we quantified elevational variation in drought tolerance and in drought avoidance-related functional traits of a widespread gymnosperm (ponderosa pine - Pinus ponderosa) and angiosperm (trembling aspen - Populus tremuloides) tree species in the southwestern USA. Specifically, we quantified tree-to-tree variation in growth, water stress (predawn and midday xylem tension), drought avoidance traits (branch conductivity, leaf/needle size, tree height, leaf area-to-sapwood area ratio), and drought tolerance traits (xylem resistance to embolism, hydraulic safety margin, wood density) at the range margins and range center of each species. Although water stress increased and growth declined strongly at lower range margins of both species, ponderosa pine and aspen showed contrasting patterns of clinal trait variation. Trembling aspen increased its drought tolerance at its dry range edge by growing stronger but more carbon dense branch and leaf tissues, implying an increased cost of growth at its range boundary. By contrast, ponderosa pine showed little elevational variation in drought-related traits but avoided drought stress at low elevations by limiting transpiration through stomatal closure, such that its dry range boundary is associated with limited carbon assimilation even in average climatic conditions. Thus, the same climatic factor (drought) may drive range boundaries through different physiological mechanisms - a result that has important implications for process-based modeling approaches to tree biogeography. Further, we show that comparing intraspecific patterns of

  3. Different tree species affect soil respiration spatial distribution in a subtropical forest of southern Taiwan

    NASA Astrophysics Data System (ADS)

    Chiang, Po-Neng; Yu, Jui-Chu; Wang, Ya-nan; Lai, Yen-Jen

    2014-05-01

    Global forests contain 69% of total carbon stored in forest soil and litter. But the carbon storage ability and release rate of warming gases of forest soil also affect global climate change. Soil carbon cycling processes are paid much attention by ecological scientists and policy makers because of the possibility of carbon being stored in soil via land use management. Soil respiration contributed large part of terrestrial carbon flux, but the relationship of soil respiration and climate change was still obscurity. Most of soil respiration researches focus on template and tropical area, little was known that in subtropical area. Afforestation is one of solutions to mitigate CO2 increase and to sequestrate CO2 in tree and soil. Therefore, the objective of this study is to clarify the relationship of tree species and soil respiration distribution in subtropical broad-leaves plantation in southern Taiwan. The research site located on southern Taiwan was sugarcane farm before 2002. The sugarcane was removed and fourteen broadleaved tree species were planted in 2002-2005. Sixteen plots (250m*250m) were set on 1 km2 area, each plot contained 4 subplots (170m2). The forest biomass (i.e. tree height, DBH) understory biomass, litter, and soil C were measured and analyzed at 2011 to 2012. Soil respiration measurement was sampled in each subplot in each month. The soil belongs to Entisol with over 60% of sandstone. The soil pH is 5.5 with low base cations because of high sand percentage. Soil carbon storage showed significantly negative relationship with soil bulk density (p<0.001) in research site. The differences of distribution of live tree C pool among 16 plots were affected by growth characteristic of tree species. Data showed that the accumulation amount of litterfall was highest in December to February and lowest in June. Different tree species planted in 16 plots, resulting in high spatial variation of litterfall amount. It also affected total amount of litterfall

  4. SimPhy: Phylogenomic Simulation of Gene, Locus, and Species Trees

    PubMed Central

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

    2016-01-01

    We present a fast and flexible software package—SimPhy—for the simulation of multiple gene families evolving under incomplete lineage sorting, gene duplication and loss, horizontal gene transfer—all three potentially leading to species tree/gene tree discordance—and gene conversion. SimPhy implements a hierarchical phylogenetic model in which the evolution of species, locus, and gene trees is governed by global and local parameters (e.g., genome-wide, species-specific, locus-specific), that can be fixed or be sampled from a priori statistical distributions. SimPhy also incorporates comprehensive models of substitution rate variation among lineages (uncorrelated relaxed clocks) and the capability of simulating partitioned nucleotide, codon, and protein multilocus sequence alignments under a plethora of substitution models using the program INDELible. We validate SimPhy's output using theoretical expectations and other programs, and show that it scales extremely well with complex models and/or large trees, being an order of magnitude faster than the most similar program (DLCoal-Sim). In addition, we demonstrate how SimPhy can be useful to understand interactions among different evolutionary processes, conducting a simulation study to characterize the systematic overestimation of the duplication time when using standard reconciliation methods. SimPhy is available at https://github.com/adamallo/SimPhy, where users can find the source code, precompiled executables, a detailed manual and example cases. PMID:26526427

  5. Patterns and determinants of wood physical and mechanical properties across major tree species in China.

    PubMed

    Zhu, JiangLing; Shi, Yue; Fang, LeQi; Liu, XingE; Ji, ChengJun

    2015-06-01

    The physical and mechanical properties of wood affect the growth and development of trees, and also act as the main criteria when determining wood usage. Our understanding on patterns and controls of wood physical and mechanical properties could provide benefits for forestry management and bases for wood application and forest tree breeding. However, current studies on wood properties mainly focus on wood density and ignore other wood physical properties. In this study, we established a comprehensive database of wood physical properties across major tree species in China. Based on this database, we explored spatial patterns and driving factors of wood properties across major tree species in China. Our results showed that (i) compared with wood density, air-dried density, tangential shrinkage coefficient and resilience provide more accuracy and higher explanation power when used as the evaluation index of wood physical properties. (ii) Among life form, climatic and edaphic variables, life form is the dominant factor shaping spatial patterns of wood physical properties, climatic factors the next, and edaphic factors have the least effects, suggesting that the effects of climatic factors on spatial variations of wood properties are indirectly induced by their effects on species distribution.

  6. Mechanism Underlying the Spatial Pattern Formation of Dominant Tree Species in a Natural Secondary Forest

    PubMed Central

    Jia, Guodong; Yu, Xinxiao; Fan, Dengxing; Jia, Jianbo

    2016-01-01

    Studying the spatial pattern of plant species may provide significant insights into processes and mechanisms that maintain stand stability. To better understand the dynamics of naturally regenerated secondary forests, univariate and bivariate Ripley’s L(r) functions were employed to evaluate intra-/interspecific relationships of four dominant tree species (Populus davidiana, Betula platyphylla, Larix gmelinii and Acer mono) and to distinguish the underlying mechanism of spatial distribution. The results showed that the distribution of soil, water and nutrients was not fragmented but presented clear gradients. An overall aggregated distribution existed at most distances. No correlation was found between the spatial pattern of soil conditions and that of trees. Both positive and negative intra- and interspecific relationships were found between different DBH classes at various distances. Large trees did not show systematic inhibition of the saplings. By contrast, the inhibition intensified as the height differences increased between the compared pairs. Except for Larix, universal inhibition of saplings by upper layer trees occurred among other species, and this reflected the vertical competition for light. Therefore, we believe that competition for light rather than soil nutrients underlies the mechanism driving the formation of stand spatial pattern in the rocky mountainous areas examined. PMID:27028757

  7. Mechanism Underlying the Spatial Pattern Formation of Dominant Tree Species in a Natural Secondary Forest.

    PubMed

    Jia, Guodong; Yu, Xinxiao; Fan, Dengxing; Jia, Jianbo

    2016-01-01

    Studying the spatial pattern of plant species may provide significant insights into processes and mechanisms that maintain stand stability. To better understand the dynamics of naturally regenerated secondary forests, univariate and bivariate Ripley's L(r) functions were employed to evaluate intra-/interspecific relationships of four dominant tree species (Populus davidiana, Betula platyphylla, Larix gmelinii and Acer mono) and to distinguish the underlying mechanism of spatial distribution. The results showed that the distribution of soil, water and nutrients was not fragmented but presented clear gradients. An overall aggregated distribution existed at most distances. No correlation was found between the spatial pattern of soil conditions and that of trees. Both positive and negative intra- and interspecific relationships were found between different DBH classes at various distances. Large trees did not show systematic inhibition of the saplings. By contrast, the inhibition intensified as the height differences increased between the compared pairs. Except for Larix, universal inhibition of saplings by upper layer trees occurred among other species, and this reflected the vertical competition for light. Therefore, we believe that competition for light rather than soil nutrients underlies the mechanism driving the formation of stand spatial pattern in the rocky mountainous areas examined. PMID:27028757

  8. Drivers of Tree Growth, Mortality and Harvest Preferences in Species-Rich Plantations for Smallholders and Communities in the Tropics

    PubMed Central

    Nguyen, Huong; Vanclay, Jerome; Herbohn, John; Firn, Jennifer

    2016-01-01

    There is growing interest in multi-species tropical plantations but little information exists to guide their design and silviculture. The Rainforestation Farming system is the oldest tropical polyculture planting system in the Philippines and provides a unique opportunity to understand the underlying processes affecting tree performance within diverse plantings. Data collected from 85 plots distributed across the 18 mixed-species plantations in the Philippines was used to identify the factors influencing growth, probability of harvest, and death of trees in these complex plantings. The 18 sites (aged from 6 to 11 years at time of first measurement) were measured on three occasions over a 6-year period. We used data from the first period of data collection to develop models predicting harvesting probability and growth of trees in the second period. We found little evidence that tree species diversity had an effect on tree growth and tree loss at the community level, although a negative effect was found on tree growth of specific species such as Parashorea plicata and Swietenia macrophylla. While tree density of stands at age 10+ years (more than 1000 trees/ha with diameter > 5cm) did not have an impact on growth, growth rates were decreasing in stands with a high basal area. Tree size in the first period of measure was a good predictor for both tree growth and tree status in the next period, with larger trees tending to grow faster and having a greater chance of being harvested, and a lower possibility of mortality than smaller trees. Shade-intolerant trees were both more likely to be harvested, and had a higher probability of death, than shade-tolerant individuals. Native species and exotic species were equally likely to have been lost from the plots between measurement periods. However, shade-tolerant native trees were likely to grow faster than the others at age 10+ years. Our findings suggest that species traits (e.g. shade tolerance) could play an important

  9. The Trichoptera barcode initiative: a strategy for generating a species-level Tree of Life

    PubMed Central

    Frandsen, Paul B.; Holzenthal, Ralph W.; Beet, Clare R.; Bennett, Kristi R.; Blahnik, Roger J.; Bonada, Núria; Cartwright, David; Chuluunbat, Suvdtsetseg; Cocks, Graeme V.; Collins, Gemma E.; deWaard, Jeremy; Dean, John; Flint, Oliver S.; Hausmann, Axel; Hendrich, Lars; Hess, Monika; Hogg, Ian D.; Kondratieff, Boris C.; Malicky, Hans; Milton, Megan A.; Morinière, Jérôme; Morse, John C.; Mwangi, François Ngera; Pauls, Steffen U.; Gonzalez, María Razo; Rinne, Aki; Robinson, Jason L.; Salokannel, Juha; Shackleton, Michael; Smith, Brian; Stamatakis, Alexandros; StClair, Ros; Thomas, Jessica A.; Zamora-Muñoz, Carmen; Ziesmann, Tanja

    2016-01-01

    DNA barcoding was intended as a means to provide species-level identifications through associating DNA sequences from unknown specimens to those from curated reference specimens. Although barcodes were not designed for phylogenetics, they can be beneficial to the completion of the Tree of Life. The barcode database for Trichoptera is relatively comprehensive, with data from every family, approximately two-thirds of the genera, and one-third of the described species. Most Trichoptera, as with most of life's species, have never been subjected to any formal phylogenetic analysis. Here, we present a phylogeny with over 16 000 unique haplotypes as a working hypothesis that can be updated as our estimates improve. We suggest a strategy of implementing constrained tree searches, which allow larger datasets to dictate the backbone phylogeny, while the barcode data fill out the tips of the tree. We also discuss how this phylogeny could be used to focus taxonomic attention on ambiguous species boundaries and hidden biodiversity. We suggest that systematists continue to differentiate between ‘Barcode Index Numbers’ (BINs) and ‘species’ that have been formally described. Each has utility, but they are not synonyms. We highlight examples of integrative taxonomy, using both barcodes and morphology for species description. This article is part of the themed issue ‘From DNA barcodes to biomes’. PMID:27481793

  10. Floristic diversity of regenerated tree species in Dipterocarp forests in Western Ghats of Karnataka, India.

    PubMed

    Prasad, A G Devi; Al-Sagheer, Nageeb A

    2012-07-01

    The research was focused on exploring the structure, diversity and form of regeneration process of the Dipterocarp forests in Western Ghats in relation to environmental factors. Eight populations in the distribution range of Dipterocarp forests were selected. In each population 32 plots of 2mx2m were laid down randomly. Atotal of 1243 seedlings < or = 10 cm dbh (diameter at breast height) belonging to 99 species and 48 families were recorded. The number of regenerated tree species was found to be high in the populations of Mudigere (40), Sakleshpura (40) and Makuta (39), which are characterized by favorable locality factors and lower disturbances. The highest similarity index in species composition was recorded between the populations of Sampaje in Kodagu district and Gundya in Dakshina Kannada (60%) whereas the lowest similarity index was observed between the population of Sringeri in Chikmagalore and Sampaje (53%) and Gundya and Makuta (35%) in Kodagu district. Dipterocarpus indicus was found to be dominant among the regenerated tree species in all the sites studied except Gundy and Sampaje. The frequencies of regeneration classes (seedlings, saplings, poles and adult trees) were shaped as inverse J curve indicating the normal regeneration pattern under the present disturbance. The average disturbance of litter collection, grazing, fire, weeds and canopy opening were significant among different populations (p < or = 0.05). Negative correlation was observed between disturbance and species richness, number of individuals and density. PMID:23360009

  11. Estimating the global conservation status of more than 15,000 Amazonian tree species

    PubMed Central

    ter Steege, Hans; Pitman, Nigel C. A.; Killeen, Timothy J.; Laurance, William F.; Peres, Carlos A.; Guevara, Juan Ernesto; Salomão, Rafael P.; Castilho, Carolina V.; Amaral, Iêda Leão; de Almeida Matos, Francisca Dionízia; de Souza Coelho, Luiz; Magnusson, William E.; Phillips, Oliver L.; de Andrade Lima Filho, Diogenes; de Jesus Veiga Carim, Marcelo; Irume, Mariana Victória; Martins, Maria Pires; Molino, Jean-François; Sabatier, Daniel; Wittmann, Florian; López, Dairon Cárdenas; da Silva Guimarães, José Renan; Mendoza, Abel Monteagudo; Vargas, Percy Núñez; Manzatto, Angelo Gilberto; Reis, Neidiane Farias Costa; Terborgh, John; Casula, Katia Regina; Montero, Juan Carlos; Feldpausch, Ted R.; Honorio Coronado, Euridice N.; Montoya, Alvaro Javier Duque; Zartman, Charles Eugene; Mostacedo, Bonifacio; Vasquez, Rodolfo; Assis, Rafael L.; Medeiros, Marcelo Brilhante; Simon, Marcelo Fragomeni; Andrade, Ana; Camargo, José Luís; Laurance, Susan G. W.; Nascimento, Henrique Eduardo Mendonça; Marimon, Beatriz S.; Marimon, Ben-Hur; Costa, Flávia; Targhetta, Natalia; Vieira, Ima Célia Guimarães; Brienen, Roel; Castellanos, Hernán; Duivenvoorden, Joost F.; Mogollón, Hugo F.; Piedade, Maria Teresa Fernandez; Aymard C., Gerardo A.; Comiskey, James A.; Damasco, Gabriel; Dávila, Nállarett; García-Villacorta, Roosevelt; Diaz, Pablo Roberto Stevenson; Vincentini, Alberto; Emilio, Thaise; Levis, Carolina; Schietti, Juliana; Souza, Priscila; Alonso, Alfonso; Dallmeier, Francisco; Ferreira, Leandro Valle; Neill, David; Araujo-Murakami, Alejandro; Arroyo, Luzmila; Carvalho, Fernanda Antunes; Souza, Fernanda Coelho; do Amaral, Dário Dantas; Gribel, Rogerio; Luize, Bruno Garcia; Pansonato, Marcelo Petrati; Venticinque, Eduardo; Fine, Paul; Toledo, Marisol; Baraloto, Chris; Cerón, Carlos; Engel, Julien; Henkel, Terry W.; Jimenez, Eliana M.; Maas, Paul; Mora, Maria Cristina Peñuela; Petronelli, Pascal; Revilla, Juan David Cardenas; Silveira, Marcos; Stropp, Juliana; Thomas-Caesar, Raquel; Baker, Tim R.; Daly, Doug; Paredes, Marcos Ríos; da Silva, Naara Ferreira; Fuentes, Alfredo; Jørgensen, Peter Møller; Schöngart, Jochen; Silman, Miles R.; Arboleda, Nicolás Castaño; Cintra, Bruno Barçante Ladvocat; Valverde, Fernando Cornejo; Di Fiore, Anthony; Phillips, Juan Fernando; van Andel, Tinde R.; von Hildebrand, Patricio; Barbosa, Edelcilio Marques; de Matos Bonates, Luiz Carlos; de Castro, Deborah; de Sousa Farias, Emanuelle; Gonzales, Therany; Guillaumet, Jean-Louis; Hoffman, Bruce; Malhi, Yadvinder; de Andrade Miranda, Ires Paula; Prieto, Adriana; Rudas, Agustín; Ruschell, Ademir R.; Silva, Natalino; Vela, César I. A.; Vos, Vincent A.; Zent, Eglée L.; Zent, Stanford; Cano, Angela; Nascimento, Marcelo Trindade; Oliveira, Alexandre A.; Ramirez-Angulo, Hirma; Ramos, José Ferreira; Sierra, Rodrigo; Tirado, Milton; Medina, Maria Natalia Umaña; van der Heijden, Geertje; Torre, Emilio Vilanova; Vriesendorp, Corine; Wang, Ophelia; Young, Kenneth R.; Baider, Claudia; Balslev, Henrik; de Castro, Natalia; Farfan-Rios, William; Ferreira, Cid; Mendoza, Casimiro; Mesones, Italo; Torres-Lezama, Armando; Giraldo, Ligia Estela Urrego; Villarroel, Daniel; Zagt, Roderick; Alexiades, Miguel N.; Garcia-Cabrera, Karina; Hernandez, Lionel; Huamantupa-Chuquimaco, Isau; Milliken, William; Cuenca, Walter Palacios; Pansini, Susamar; Pauletto, Daniela; Arevalo, Freddy Ramirez; Sampaio, Adeilza Felipe; Valderrama Sandoval, Elvis H.; Gamarra, Luis Valenzuela

    2015-01-01

    Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree species are likely to qualify as globally threatened under International Union for Conservation of Nature (IUCN) Red List criteria. If confirmed, these results would increase the number of threatened plant species on Earth by 22%. We show that the trends observed in Amazonia apply to trees throughout the tropics, and we predict that most of the world’s >40,000 tropical tree species now qualify as globally threatened. A gap analysis suggests that existing Amazonian protected areas and indigenous territories will protect viable populations of most threatened species if these areas suffer no further degradation, highlighting the key roles that protected areas, indigenous peoples, and improved governance can play in preventing large-scale extinctions in the tropics in this century. PMID:26702442

  12. Estimating the global conservation status of more than 15,000 Amazonian tree species.

    PubMed

    Ter Steege, Hans; Pitman, Nigel C A; Killeen, Timothy J; Laurance, William F; Peres, Carlos A; Guevara, Juan Ernesto; Salomão, Rafael P; Castilho, Carolina V; Amaral, Iêda Leão; de Almeida Matos, Francisca Dionízia; de Souza Coelho, Luiz; Magnusson, William E; Phillips, Oliver L; de Andrade Lima Filho, Diogenes; de Jesus Veiga Carim, Marcelo; Irume, Mariana Victória; Martins, Maria Pires; Molino, Jean-François; Sabatier, Daniel; Wittmann, Florian; López, Dairon Cárdenas; da Silva Guimarães, José Renan; Mendoza, Abel Monteagudo; Vargas, Percy Núñez; Manzatto, Angelo Gilberto; Reis, Neidiane Farias Costa; Terborgh, John; Casula, Katia Regina; Montero, Juan Carlos; Feldpausch, Ted R; Honorio Coronado, Euridice N; Montoya, Alvaro Javier Duque; Zartman, Charles Eugene; Mostacedo, Bonifacio; Vasquez, Rodolfo; Assis, Rafael L; Medeiros, Marcelo Brilhante; Simon, Marcelo Fragomeni; Andrade, Ana; Camargo, José Luís; Laurance, Susan G W; Nascimento, Henrique Eduardo Mendonça; Marimon, Beatriz S; Marimon, Ben-Hur; Costa, Flávia; Targhetta, Natalia; Vieira, Ima Célia Guimarães; Brienen, Roel; Castellanos, Hernán; Duivenvoorden, Joost F; Mogollón, Hugo F; Piedade, Maria Teresa Fernandez; Aymard C, Gerardo A; Comiskey, James A; Damasco, Gabriel; Dávila, Nállarett; García-Villacorta, Roosevelt; Diaz, Pablo Roberto Stevenson; Vincentini, Alberto; Emilio, Thaise; Levis, Carolina; Schietti, Juliana; Souza, Priscila; Alonso, Alfonso; Dallmeier, Francisco; Ferreira, Leandro Valle; Neill, David; Araujo-Murakami, Alejandro; Arroyo, Luzmila; Carvalho, Fernanda Antunes; Souza, Fernanda Coelho; do Amaral, Dário Dantas; Gribel, Rogerio; Luize, Bruno Garcia; Pansonato, Marcelo Petrati; Venticinque, Eduardo; Fine, Paul; Toledo, Marisol; Baraloto, Chris; Cerón, Carlos; Engel, Julien; Henkel, Terry W; Jimenez, Eliana M; Maas, Paul; Mora, Maria Cristina Peñuela; Petronelli, Pascal; Revilla, Juan David Cardenas; Silveira, Marcos; Stropp, Juliana; Thomas-Caesar, Raquel; Baker, Tim R; Daly, Doug; Paredes, Marcos Ríos; da Silva, Naara Ferreira; Fuentes, Alfredo; Jørgensen, Peter Møller; Schöngart, Jochen; Silman, Miles R; Arboleda, Nicolás Castaño; Cintra, Bruno Barçante Ladvocat; Valverde, Fernando Cornejo; Di Fiore, Anthony; Phillips, Juan Fernando; van Andel, Tinde R; von Hildebrand, Patricio; Barbosa, Edelcilio Marques; de Matos Bonates, Luiz Carlos; de Castro, Deborah; de Sousa Farias, Emanuelle; Gonzales, Therany; Guillaumet, Jean-Louis; Hoffman, Bruce; Malhi, Yadvinder; de Andrade Miranda, Ires Paula; Prieto, Adriana; Rudas, Agustín; Ruschell, Ademir R; Silva, Natalino; Vela, César I A; Vos, Vincent A; Zent, Eglée L; Zent, Stanford; Cano, Angela; Nascimento, Marcelo Trindade; Oliveira, Alexandre A; Ramirez-Angulo, Hirma; Ramos, José Ferreira; Sierra, Rodrigo; Tirado, Milton; Medina, Maria Natalia Umaña; van der Heijden, Geertje; Torre, Emilio Vilanova; Vriesendorp, Corine; Wang, Ophelia; Young, Kenneth R; Baider, Claudia; Balslev, Henrik; de Castro, Natalia; Farfan-Rios, William; Ferreira, Cid; Mendoza, Casimiro; Mesones, Italo; Torres-Lezama, Armando; Giraldo, Ligia Estela Urrego; Villarroel, Daniel; Zagt, Roderick; Alexiades, Miguel N; Garcia-Cabrera, Karina; Hernandez, Lionel; Huamantupa-Chuquimaco, Isau; Milliken, William; Cuenca, Walter Palacios; Pansini, Susamar; Pauletto, Daniela; Arevalo, Freddy Ramirez; Sampaio, Adeilza Felipe; Valderrama Sandoval, Elvis H; Gamarra, Luis Valenzuela

    2015-11-01

    Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree species are likely to qualify as globally threatened under International Union for Conservation of Nature (IUCN) Red List criteria. If confirmed, these results would increase the number of threatened plant species on Earth by 22%. We show that the trends observed in Amazonia apply to trees throughout the tropics, and we predict that most of the world's >40,000 tropical tree species now qualify as globally threatened. A gap analysis suggests that existing Amazonian protected areas and indigenous territories will protect viable populations of most threatened species if these areas suffer no further degradation, highlighting the key roles that protected areas, indigenous peoples, and improved governance can play in preventing large-scale extinctions in the tropics in this century.

  13. Estimating the global conservation status of more than 15,000 Amazonian tree species.

    PubMed

    Ter Steege, Hans; Pitman, Nigel C A; Killeen, Timothy J; Laurance, William F; Peres, Carlos A; Guevara, Juan Ernesto; Salomão, Rafael P; Castilho, Carolina V; Amaral, Iêda Leão; de Almeida Matos, Francisca Dionízia; de Souza Coelho, Luiz; Magnusson, William E; Phillips, Oliver L; de Andrade Lima Filho, Diogenes; de Jesus Veiga Carim, Marcelo; Irume, Mariana Victória; Martins, Maria Pires; Molino, Jean-François; Sabatier, Daniel; Wittmann, Florian; López, Dairon Cárdenas; da Silva Guimarães, José Renan; Mendoza, Abel Monteagudo; Vargas, Percy Núñez; Manzatto, Angelo Gilberto; Reis, Neidiane Farias Costa; Terborgh, John; Casula, Katia Regina; Montero, Juan Carlos; Feldpausch, Ted R; Honorio Coronado, Euridice N; Montoya, Alvaro Javier Duque; Zartman, Charles Eugene; Mostacedo, Bonifacio; Vasquez, Rodolfo; Assis, Rafael L; Medeiros, Marcelo Brilhante; Simon, Marcelo Fragomeni; Andrade, Ana; Camargo, José Luís; Laurance, Susan G W; Nascimento, Henrique Eduardo Mendonça; Marimon, Beatriz S; Marimon, Ben-Hur; Costa, Flávia; Targhetta, Natalia; Vieira, Ima Célia Guimarães; Brienen, Roel; Castellanos, Hernán; Duivenvoorden, Joost F; Mogollón, Hugo F; Piedade, Maria Teresa Fernandez; Aymard C, Gerardo A; Comiskey, James A; Damasco, Gabriel; Dávila, Nállarett; García-Villacorta, Roosevelt; Diaz, Pablo Roberto Stevenson; Vincentini, Alberto; Emilio, Thaise; Levis, Carolina; Schietti, Juliana; Souza, Priscila; Alonso, Alfonso; Dallmeier, Francisco; Ferreira, Leandro Valle; Neill, David; Araujo-Murakami, Alejandro; Arroyo, Luzmila; Carvalho, Fernanda Antunes; Souza, Fernanda Coelho; do Amaral, Dário Dantas; Gribel, Rogerio; Luize, Bruno Garcia; Pansonato, Marcelo Petrati; Venticinque, Eduardo; Fine, Paul; Toledo, Marisol; Baraloto, Chris; Cerón, Carlos; Engel, Julien; Henkel, Terry W; Jimenez, Eliana M; Maas, Paul; Mora, Maria Cristina Peñuela; Petronelli, Pascal; Revilla, Juan David Cardenas; Silveira, Marcos; Stropp, Juliana; Thomas-Caesar, Raquel; Baker, Tim R; Daly, Doug; Paredes, Marcos Ríos; da Silva, Naara Ferreira; Fuentes, Alfredo; Jørgensen, Peter Møller; Schöngart, Jochen; Silman, Miles R; Arboleda, Nicolás Castaño; Cintra, Bruno Barçante Ladvocat; Valverde, Fernando Cornejo; Di Fiore, Anthony; Phillips, Juan Fernando; van Andel, Tinde R; von Hildebrand, Patricio; Barbosa, Edelcilio Marques; de Matos Bonates, Luiz Carlos; de Castro, Deborah; de Sousa Farias, Emanuelle; Gonzales, Therany; Guillaumet, Jean-Louis; Hoffman, Bruce; Malhi, Yadvinder; de Andrade Miranda, Ires Paula; Prieto, Adriana; Rudas, Agustín; Ruschell, Ademir R; Silva, Natalino; Vela, César I A; Vos, Vincent A; Zent, Eglée L; Zent, Stanford; Cano, Angela; Nascimento, Marcelo Trindade; Oliveira, Alexandre A; Ramirez-Angulo, Hirma; Ramos, José Ferreira; Sierra, Rodrigo; Tirado, Milton; Medina, Maria Natalia Umaña; van der Heijden, Geertje; Torre, Emilio Vilanova; Vriesendorp, Corine; Wang, Ophelia; Young, Kenneth R; Baider, Claudia; Balslev, Henrik; de Castro, Natalia; Farfan-Rios, William; Ferreira, Cid; Mendoza, Casimiro; Mesones, Italo; Torres-Lezama, Armando; Giraldo, Ligia Estela Urrego; Villarroel, Daniel; Zagt, Roderick; Alexiades, Miguel N; Garcia-Cabrera, Karina; Hernandez, Lionel; Huamantupa-Chuquimaco, Isau; Milliken, William; Cuenca, Walter Palacios; Pansini, Susamar; Pauletto, Daniela; Arevalo, Freddy Ramirez; Sampaio, Adeilza Felipe; Valderrama Sandoval, Elvis H; Gamarra, Luis Valenzuela

    2015-11-01

    Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree species are likely to qualify as globally threatened under International Union for Conservation of Nature (IUCN) Red List criteria. If confirmed, these results would increase the number of threatened plant species on Earth by 22%. We show that the trends observed in Amazonia apply to trees throughout the tropics, and we predict that most of the world's >40,000 tropical tree species now qualify as globally threatened. A gap analysis suggests that existing Amazonian protected areas and indigenous territories will protect viable populations of most threatened species if these areas suffer no further degradation, highlighting the key roles that protected areas, indigenous peoples, and improved governance can play in preventing large-scale extinctions in the tropics in this century. PMID:26702442

  14. Managing Commercial Tree Species for Timber Production and Carbon Sequestration: Management Guidelines and Financial Returns

    SciTech Connect

    Gary D. Kronrad

    2006-09-19

    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 tree species 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 tree species, site quality and management regimes utilized, analyses have determined how to optimize carbon sequestration by determining how to optimally manage each species, 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.

  15. The demography of range boundaries versus range cores in eastern US tree species.

    PubMed

    Purves, Drew W

    2009-04-22

    Regional species-climate correlations are well documented, but little is known about the ecological processes responsible for generating these patterns. Using the data from over 690,000 individual trees I estimated five demographic rates--canopy growth, understorey growth, canopy lifespan, understorey lifespan and per capita reproduction--for 19 common eastern US tree species, within the core and the northern and southern boundaries, of the species range. Most species showed statistically significant boundary versus core differences in most rates at both boundary types. Differences in canopy and understorey growth were relatively small in magnitude but consistent among species, being lower at the northern (average -17%) and higher at the southern (average +12%) boundaries. Differences in lifespan were larger in magnitude but highly variable among species, except for a marked trend for reduced canopy lifespan at the northern boundary (average -49%). Differences in per capita reproduction were large and statistically significant for some species, but highly variable among species. The rate estimates were combined to calculate two performance indices: R(0) (a measure of lifetime fitness in the absence of competition) was consistently lower at the northern boundary (average -86%) whereas Z* (a measure of competitive ability in closed forest) showed no sign of a consistent boundary-core difference at either boundary.

  16. Tree Species Linked to Large Differences in Ecosystem Carbon Distribution in the Boreal Forest of Alaska

    NASA Astrophysics Data System (ADS)

    Melvin, A. M.; Mack, M. C.; Johnstone, J. F.; Schuur, E. A. G.; Genet, H.; McGuire, A. D.

    2014-12-01

    In the boreal forest of Alaska, increased fire severity associated with climate change is altering plant-soil-microbial feedbacks and ecosystem carbon (C) dynamics. The boreal landscape has historically been dominated by black spruce (Picea mariana), a tree species associated with slow C turnover and large soil organic matter (SOM) accumulation. Historically, low severity fires have led to black spruce regeneration post-fire, thereby maintaining slow C cycling rates and large SOM pools. In recent decades however, an increase in high severity fires has led to greater consumption of the soil organic layer (SOL) during fire and subsequent establishment of deciduous tree species in areas previously dominated by black spruce. This shift to a more deciduous dominated landscape has many implications for ecosystem structure and function, as well as feedbacks to global C cycling. To improve our understanding of how boreal tree species affect C cycling, we quantified above- and belowground C stocks and fluxes in adjacent, mid-successional stands of black spruce and Alaska paper birch (Betula neoalaskana) that established following a 1958 fire near Fairbanks, Alaska. Although total ecosystem C pools (aboveground live tree biomass + dead wood + SOL + top 10 cm of mineral soil) were similar for the two stand types, the distribution of C among pools was markedly different. In black spruce, 78% of measured C was found in soil pools, primarily in the SOL, where spruce contained twice the C stored in paper birch (4.8 ± 0.3 vs. 2.4 ± 0.1 kg C m-2). In contrast, aboveground biomass dominated ecosystem C pools in birch forest (6.0 ± 0.3 vs. 2.5 ± 0.2 kg C m-2 in birch and spruce, respectively). Our findings suggest that tree species exert a strong influence over plant-soil-microbial feedbacks and may have long-term effects on ecosystem C sequestration and storage that feedback to the climate system.

  17. Taxonomic and ecological relevance of the chlorophyll a fluorescence signature of tree species in mixed European forests.

    PubMed

    Pollastrini, Martina; Holland, Vera; Brüggemann, Wolfgang; Bruelheide, Helge; Dănilă, Iulian; Jaroszewicz, Bogdan; Valladares, Fernando; Bussotti, Filippo

    2016-10-01

    The variability of chlorophyll a fluorescence (ChlF) parameters of forest tree species was investigated in 209 stands belonging to six European forests, from Mediterranean to boreal regions. The modifying role of environmental factors, forest structure and tree diversity (species richness and composition) on ChlF signature was analysed. At the European level, conifers showed higher potential performance than broadleaf species. Forests in central Europe performed better than those in Mediterranean and boreal regions. At the site level, homogeneous clusters of tree species were identified by means of a principal component analysis (PCA) of ChlF parameters. The discrimination of the clusters of species was influenced by their taxonomic position and ecological characteristics. The species richness influenced the tree ChlF properties in different ways depending on tree species and site. Tree species and site also affected the relationships between ChlF parameters and other plant functional traits (specific leaf area, leaf nitrogen content, light-saturated photosynthesis, wood density, leaf carbon isotope composition). The assessment of the photosynthetic properties of tree species, by means of ChlF parameters, in relation to their functional traits, is a relevant issue for studies in forest ecology. The connections of data from field surveys with remotely assessed parameters must be carefully explored.

  18. Seed rain under native and non-native tree species in the Cabo Rojo National Wildlife Refuge, Puerto Rico.

    PubMed

    Arias Garcia, Andrea; Chinea, J Danilo

    2014-09-01

    Seed dispersal is a fundamental process in plant ecology and is of critical importance for the restoration of tropical communities. The lands of the Cabo Rojo National Wildlife Refuge (CRNWR), formerly under agriculture, were abandoned in the 1970s and colonized mainly by non-native tree species of degraded pastures. Here we described the seed rain under the most common native and non-native trees in the refuge in an attempt to determine if focal tree geographic origin (native versus non-native) influences seed dispersal. For this, seed rain was sampled for one year under the canopies of four native and four non-native tree species common in this refuge using 40 seed traps. No significant differences were found for the abundance of seeds, or their diversity, dispersing under native versus non-native focal tree species, nor under the different tree species. A significantly different seed species composition was observed reaching native versus non-native focal species. However, this last result could be more easily explained as a function of distance of the closest adults of the two most abundantly dispersed plant species to the seed traps than as a function of the geographic origin of the focal species. We suggest to continue the practice of planting native tree species, not only as a way to restore the community to a condition similar to the original one, but also to reduce the distances needed for effective dispersal.

  19. Taxonomic and ecological relevance of the chlorophyll a fluorescence signature of tree species in mixed European forests.

    PubMed

    Pollastrini, Martina; Holland, Vera; Brüggemann, Wolfgang; Bruelheide, Helge; Dănilă, Iulian; Jaroszewicz, Bogdan; Valladares, Fernando; Bussotti, Filippo

    2016-10-01

    The variability of chlorophyll a fluorescence (ChlF) parameters of forest tree species was investigated in 209 stands belonging to six European forests, from Mediterranean to boreal regions. The modifying role of environmental factors, forest structure and tree diversity (species richness and composition) on ChlF signature was analysed. At the European level, conifers showed higher potential performance than broadleaf species. Forests in central Europe performed better than those in Mediterranean and boreal regions. At the site level, homogeneous clusters of tree species were identified by means of a principal component analysis (PCA) of ChlF parameters. The discrimination of the clusters of species was influenced by their taxonomic position and ecological characteristics. The species richness influenced the tree ChlF properties in different ways depending on tree species and site. Tree species and site also affected the relationships between ChlF parameters and other plant functional traits (specific leaf area, leaf nitrogen content, light-saturated photosynthesis, wood density, leaf carbon isotope composition). The assessment of the photosynthetic properties of tree species, by means of ChlF parameters, in relation to their functional traits, is a relevant issue for studies in forest ecology. The connections of data from field surveys with remotely assessed parameters must be carefully explored. PMID:27265248

  20. Exemplifying whole-plant ozone uptake in adult forest trees of contrasting species and site conditions.

    PubMed

    Nunn, Angela J; Wieser, Gerhard; Metzger, Ursula; Löw, Markus; Wipfler, Philip; Häberle, Karl-Heinz; Matyssek, Rainer

    2007-04-01

    Whole-tree O3 uptake was exemplified for Picea abies, Fagus sylvatica and Larix decidua in stands at high and low altitude and contrasting water availability through sap flow measurement in tree trunks, intrinsically accounting for drought and boundary layer effects on O3 flux. O3 uptake of evergreen spruce per unit foliage area was enhanced by 100% at high relative to low elevation, whereas deciduous beech and larch showed similar uptake regardless of altitude. The responsiveness of the canopy conductance to water vapor and, as a consequence, O3 uptake to soil moisture and air humidity did not differ between species. Unifying findings at the whole-tree level will promote cause-effect based O3 risk assessment and modeling. PMID:16996178

  1. The brown tree snake, an introduced pest species in the central Pacific Islands

    USGS Publications Warehouse

    Fritts, Thomas H.; Rodda, Gordon H.

    1989-01-01

    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 tree trunks and judicious pruning of adjacent trees are used in attempts to exclude snakes from nest trees. 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 species, in captivity and on nearby islands, are underway to bolster our biological understanding of their behavior, reproduction, habitat use, and population biology.

  2. Exemplifying whole-plant ozone uptake in adult forest trees of contrasting species and site conditions.

    PubMed

    Nunn, Angela J; Wieser, Gerhard; Metzger, Ursula; Löw, Markus; Wipfler, Philip; Häberle, Karl-Heinz; Matyssek, Rainer

    2007-04-01

    Whole-tree O3 uptake was exemplified for Picea abies, Fagus sylvatica and Larix decidua in stands at high and low altitude and contrasting water availability through sap flow measurement in tree trunks, intrinsically accounting for drought and boundary layer effects on O3 flux. O3 uptake of evergreen spruce per unit foliage area was enhanced by 100% at high relative to low elevation, whereas deciduous beech and larch showed similar uptake regardless of altitude. The responsiveness of the canopy conductance to water vapor and, as a consequence, O3 uptake to soil moisture and air humidity did not differ between species. Unifying findings at the whole-tree level will promote cause-effect based O3 risk assessment and modeling.

  3. Tree species richness decreases while species evenness increases with disturbance frequency in a natural boreal forest landscape.

    PubMed

    Yeboah, Daniel; Chen, Han Y H; Kingston, Steve

    2016-02-01

    Understanding species diversity and disturbance relationships is important for biodiversity conservation in disturbance-driven boreal forests. Species richness and evenness may respond differently with stand development following fire. Furthermore, few studies have simultaneously accounted for the influences of climate and local site conditions on species diversity. Using forest inventory data, we examined the relationships between species richness, Shannon's index, evenness, and time since last stand-replacing fire (TSF) in a large landscape of disturbance-driven boreal forest. TSF has negative effect on species richness and Shannon's index, and a positive effect on species evenness. Path analysis revealed that the environmental variables affect richness and Shannon's index only through their effects on TSF while affecting evenness directly as well as through their effects on TSF. Synthesis and applications. Our results demonstrate that species richness and Shannon's index decrease while species evenness increases with TSF in a boreal forest landscape. Furthermore, we show that disturbance frequency, local site conditions, and climate simultaneously influence tree species diversity through complex direct and indirect effects in the studied boreal forest. PMID:26865971

  4. Tree species richness decreases while species evenness increases with disturbance frequency in a natural boreal forest landscape.

    PubMed

    Yeboah, Daniel; Chen, Han Y H; Kingston, Steve

    2016-02-01

    Understanding species diversity and disturbance relationships is important for biodiversity conservation in disturbance-driven boreal forests. Species richness and evenness may respond differently with stand development following fire. Furthermore, few studies have simultaneously accounted for the influences of climate and local site conditions on species diversity. Using forest inventory data, we examined the relationships between species richness, Shannon's index, evenness, and time since last stand-replacing fire (TSF) in a large landscape of disturbance-driven boreal forest. TSF has negative effect on species richness and Shannon's index, and a positive effect on species evenness. Path analysis revealed that the environmental variables affect richness and Shannon's index only through their effects on TSF while affecting evenness directly as well as through their effects on TSF. Synthesis and applications. Our results demonstrate that species richness and Shannon's index decrease while species evenness increases with TSF in a boreal forest landscape. Furthermore, we show that disturbance frequency, local site conditions, and climate simultaneously influence tree species diversity through complex direct and indirect effects in the studied boreal forest.

  5. Tree species from different functional groups respond differently to environmental changes during establishment.

    PubMed

    Barbosa, Eduardo R M; van Langevelde, Frank; Tomlinson, Kyle W; Carvalheiro, Luísa G; Kirkman, Kevin; de Bie, Steven; Prins, Herbert H T

    2014-04-01

    Savanna plant communities change considerably across time and space. The processes driving savanna plant species diversity, coexistence and turnover along environmental gradients are still unclear. Understanding how species respond differently to varying environmental conditions during the seedling stage, a critical stage for plant population dynamics, is needed to explain the current composition of plant communities and to enable us to predict their responses to future environmental changes. Here we investigate whether seedling response to changes in resource availability, and to competition with grass, varied between two functional groups of African savanna trees: species with small leaves, spines and N-fixing associations (fine-leaved species), and species with broad leaves, no spines, and lacking N-fixing associations (broad-leaved species). We show that while tree species were strongly suppressed by grass, the effect of resource availability on seedling performance varied considerably between the two functional groups. Nutrient inputs increased stem length only of broad-leaved species and only under an even watering treatment. Low light conditions benefited mostly broad-leaved species' growth. Savannas are susceptible to ongoing global environment changes. Our results suggest that an increase in woody cover is only likely to occur in savannas if grass cover is strongly suppressed (e.g. by fire or overgrazing). However, if woody cover does increase, broad-leaved species will benefit most from the resulting shaded environments, potentially leading to an expansion of the distribution of these species. Eutrophication and changes in rainfall patterns may also affect the balance between fine- and broad-leaved species. PMID:24337711

  6. Within-stand variability of leaf phenology in deciduous tree species: characterization and ecological implications

    NASA Astrophysics Data System (ADS)

    Delpierre, N.; Cecchini, S.; Dufrêne, E.; Guillemot, J.; Nicolas, M.

    2014-12-01

    The vast majority of phenological studies address questions relative to the spatial or temporal variability of phenological timings integrated at the forest stand (i.e. tree population) scale. Within a forest stand, the inter-individual variability of phenological timings is expected to affect a range of tree functions among which the access to light, the use of carbon and nitrogen reserves, the absorption of minerals and the sensitivity to pathogens. Hence the individual's phenological traits are likely to be strongly selected, resulting in an adaptation of the population to local conditions, as evidenced by latitudinal and altitudinal clines observed in common garden experiments. Studies dedicated to the within-stand variability of the timing of phenophases have to date been mostly designed for contrasting the behaviours of understory versus overstory species or seedlings compared to their adult conspecifics. The few published papers studying the phenological timings among adult conspecifics revealed unclear patterns. We aimed at clarifying the understanding of the within-stand variability of tree phenology of three of the main European deciduous species (Quercus petraea, Quercus robur and Fagus sylvatica) through the analysis of a unique phenological database collected over 44 (28 Oak sites, 16 Beech stands) forest stands at the tree level for 4 years over France. We show that within a forest stand, individual trees have a distinct "phenological identity" resulting in a year to year conservation of (a) the individuals' spring and autumn phenological rankings and (b) the individuals' critical temperature sums required for budburst and senescence. The individual's spring "phenological identity" affects its functioning and, ultimately, its competitive ability: big trees burst earlier. Acknowledging that Angiosperms show low genetic diversity between populations, we show that the between-site variability of critical temperature sums needed for budburst or senescence

  7. Comparative hydraulic architecture of tropical tree species representing a range of successional stages and wood density.

    PubMed

    McCulloh, Katherine A; Meinzer, Frederick C; Sperry, John S; Lachenbruch, Barbara; Voelker, Steven L; Woodruff, David R; Domec, Jean-Christophe

    2011-09-01

    Plant hydraulic architecture (PHA) has been linked to water transport sufficiency, photosynthetic rates, growth form and attendant carbon allocation. Despite its influence on traits central to conferring an overall competitive advantage in a given environment, few studies have examined whether key aspects of PHA are indicative of successional stage, especially within mature individuals. While it is well established that wood density (WD) tends to be lower in early versus late successional tree species, and that WD can influence other aspects of PHA, the interaction of WD, successional stage and the consequent implications for PHA have not been sufficiently explored. Here, we studied differences in PHA at the scales of wood anatomy to whole-tree hydraulic conductance in species in early versus late successional Panamanian tropical forests. Although the trunk WD was indistinguishable between the successional groups, the branch WD was lower in the early successional species. Across all species, WD correlated negatively with vessel diameter and positively with vessel packing density. The ratio of branch:trunk vessel diameter, branch sap flux and whole-tree leaf-specific conductance scaled negatively with branch WD across species. Pioneer species showed greater sap flux in branches than in trunks and a greater leaf-specific hydraulic conductance, suggesting that pioneer species can move greater quantities of water at a given tension gradient. In combination with the greater water storage capacitance associated with lower WD, these results suggest these pioneer species can save on the carbon expenditure needed to build safer xylem and instead allow more carbon to be allocated to rapid growth.

  8. Geological Substrates Shape Tree Species and Trait Distributions in African Moist Forests

    PubMed Central

    Fayolle, Adeline; Engelbrecht, Bettina; Freycon, Vincent; Mortier, Frédéric; Swaine, Michael; Réjou-Méchain, Maxime; Doucet, Jean-Louis; Fauvet, Nicolas; Cornu, Guillaume; Gourlet-Fleury, Sylvie

    2012-01-01

    Background Understanding the factors that shape the distribution of tropical tree species at large scales is a central issue in ecology, conservation and forest management. The aims of this study were to (i) assess the importance of environmental factors relative to historical factors for tree species distributions in the semi-evergreen forests of the northern Congo basin; and to (ii) identify potential mechanisms explaining distribution patterns through a trait-based approach. Methodology/Principal Findings We analyzed the distribution patterns of 31 common tree species in an area of more than 700,000 km2 spanning the borders of Cameroon, the Central African Republic, and the Republic of Congo using forest inventory data from 56,445 0.5-ha plots. Spatial variation of environmental (climate, topography and geology) and historical factors (human disturbance) were quantified from maps and satellite records. Four key functional traits (leaf phenology, shade tolerance, wood density, and maximum growth rate) were extracted from the literature. The geological substrate was of major importance for the distribution of the focal species, while climate and past human disturbances had a significant but lesser impact. Species distribution patterns were significantly related to functional traits. Species associated with sandy soils typical of sandstone and alluvium were characterized by slow growth rates, shade tolerance, evergreen leaves, and high wood density, traits allowing persistence on resource-poor soils. In contrast, fast-growing pioneer species rarely occurred on sandy soils, except for Lophira alata. Conclusions/Significance The results indicate strong environmental filtering due to differential soil resource availability across geological substrates. Additionally, long-term human disturbances in resource-rich areas may have accentuated the observed patterns of species and trait distributions. Trait differences across geological substrates imply pronounced

  9. Comparative hydraulic architecture of tropical tree species representing a range of successional stages and wood density.

    PubMed

    McCulloh, Katherine A; Meinzer, Frederick C; Sperry, John S; Lachenbruch, Barbara; Voelker, Steven L; Woodruff, David R; Domec, Jean-Christophe

    2011-09-01

    Plant hydraulic architecture (PHA) has been linked to water transport sufficiency, photosynthetic rates, growth form and attendant carbon allocation. Despite its influence on traits central to conferring an overall competitive advantage in a given environment, few studies have examined whether key aspects of PHA are indicative of successional stage, especially within mature individuals. While it is well established that wood density (WD) tends to be lower in early versus late successional tree species, and that WD can influence other aspects of PHA, the interaction of WD, successional stage and the consequent implications for PHA have not been sufficiently explored. Here, we studied differences in PHA at the scales of wood anatomy to whole-tree hydraulic conductance in species in early versus late successional Panamanian tropical forests. Although the trunk WD was indistinguishable between the successional groups, the branch WD was lower in the early successional species. Across all species, WD correlated negatively with vessel diameter and positively with vessel packing density. The ratio of branch:trunk vessel diameter, branch sap flux and whole-tree leaf-specific conductance scaled negatively with branch WD across species. Pioneer species showed greater sap flux in branches than in trunks and a greater leaf-specific hydraulic conductance, suggesting that pioneer species can move greater quantities of water at a given tension gradient. In combination with the greater water storage capacitance associated with lower WD, these results suggest these pioneer species can save on the carbon expenditure needed to build safer xylem and instead allow more carbon to be allocated to rapid growth. PMID:21445684

  10. The relationship between tree growth patterns and likelihood of mortality: A study of two tree species in the Sierra Nevada

    USGS Publications Warehouse

    Das, A.J.; Battles, J.J.; Stephenson, N.L.; van Mantgem, P.J.

    2007-01-01

    We examined mortality of Abies concolor (Gord. & Glend.) Lindl. (white fir) and Pinus lambertiana Dougl. (sugar pine) by developing logistic models using three growth indices obtained from tree rings: average growth, growth trend, and count of abrupt growth declines. For P. lambertiana, models with average growth, growth trend, and count of abrupt declines improved overall prediction (78.6% dead trees correctly classified, 83.7% live trees correctly classified) compared with a model with average recent growth alone (69.6% dead trees correctly classified, 67.3% live trees correctly classified). For A. concolor, counts of abrupt declines and longer time intervals improved overall classification (trees with DBH ???20 cm: 78.9% dead trees correctly classified and 76.7% live trees correctly classified vs. 64.9% dead trees correctly classified and 77.9% live trees correctly classified; trees with DBH <20 cm: 71.6% dead trees correctly classified and 71.0% live trees correctly classified vs. 67.2% dead trees correctly classified and 66.7% live trees correctly classified). In general, count of abrupt declines improved live-tree classification. External validation of A. concolor models showed that they functioned well at stands not used in model development, and the development of size-specific models demonstrated important differences in mortality risk between understory and canopy trees. Population-level mortality-risk models were developed for A. concolor and generated realistic mortality rates at two sites. Our results support the contention that a more comprehensive use of the growth record yields a more robust assessment of mortality risk. ?? 2007 NRC.

  11. Potential tree species for use in the restoration of unsanitary landfills.

    PubMed

    Kim, Kee Dae; Lee, Eun Ju

    2005-07-01

    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 tree species 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 tree species in the plots, and enumerated all saplings < or =1 m high. Because black locust, Robinia pseudoacacia, was the dominant tree species 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 species had the highest number of saplings among all tree species. 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 species 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 species for waste landfills. Eleven woody species were selected for screening: Acer palmatum, Albizzia julibrissin, Buxus microphylla var. koreana, Ginkgo

  12. Frost hardiness of tree species is independent of phenology and macroclimatic niche.

    PubMed

    Hofmann, M; Bruelheide, H

    2015-03-01

    The differences in timing in bud burst between species 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 species-specific and depends on the species' 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 tree species, 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 species with early bud burst and species distributed in eastern and northern areas were more frost tolerant than species with late bud burst and species distributed in western and southern areas. Frost hardiness was estimated by exposing twigs to 11 frost temperatures between -4 °C and -80 °C 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 species' macroclimatic niche. Furthermore, frost hardiness of freshly opened buds did not differ among species. Thus, the investigated species with early bud burst take higher risks of frost damage than the species with late bud bursts. These findings indicate that frost hardiness might not play the key role in limiting the geographic distribution ranges previously anticipated.

  13. The probability of monophyly of a sample of gene lineages on a species tree

    PubMed Central

    Mehta, Rohan S.; Bryant, David; Rosenberg, Noah A.

    2016-01-01

    Monophyletic groups—groups that consist of all of the descendants of a most recent common ancestor—arise naturally as a consequence of descent processes that result in meaningful distinctions between organisms. Aspects of monophyly are therefore central to fields that examine and use genealogical descent. In particular, studies in conservation genetics, phylogeography, population genetics, species delimitation, and systematics can all make use of mathematical predictions under evolutionary models about features of monophyly. One important calculation, the probability that a set of gene lineages is monophyletic under a two-species neutral coalescent model, has been used in many studies. Here, we extend this calculation for a species tree model that contains arbitrarily many species. We study the effects of species tree topology and branch lengths on the monophyly probability. These analyses reveal new behavior, including the maintenance of nontrivial monophyly probabilities for gene lineage samples that span multiple species and even for lineages that do not derive from a monophyletic species group. We illustrate the mathematical results using an example application to data from maize and teosinte. PMID:27432988

  14. The probability of monophyly of a sample of gene lineages on a species tree.

    PubMed

    Mehta, Rohan S; Bryant, David; Rosenberg, Noah A

    2016-07-19

    Monophyletic groups-groups that consist of all of the descendants of a most recent common ancestor-arise naturally as a consequence of descent processes that result in meaningful distinctions between organisms. Aspects of monophyly are therefore central to fields that examine and use genealogical descent. In particular, studies in conservation genetics, phylogeography, population genetics, species delimitation, and systematics can all make use of mathematical predictions under evolutionary models about features of monophyly. One important calculation, the probability that a set of gene lineages is monophyletic under a two-species neutral coalescent model, has been used in many studies. Here, we extend this calculation for a species tree model that contains arbitrarily many species. We study the effects of species tree topology and branch lengths on the monophyly probability. These analyses reveal new behavior, including the maintenance of nontrivial monophyly probabilities for gene lineage samples that span multiple species and even for lineages that do not derive from a monophyletic species group. We illustrate the mathematical results using an example application to data from maize and teosinte. PMID:27432988

  15. Tree species and soil nutrient profiles in old-growth forests of the Oregon Coast Range

    USGS Publications Warehouse

    Cross, Alison; Perakis, Steven S.

    2011-01-01

    Old-growth forests of the Pacific Northwest provide a unique opportunity to examine tree species – soil relationships in ecosystems that have developed without significant human disturbance. We characterized foliage, forest floor, and mineral soil nutrients associated with four canopy tree species (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 species-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 tree species 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.

  16. Leaf and whole-tree water use relations of Australian rainforest species

    NASA Astrophysics Data System (ADS)

    Ishida, Yoko; Laurance, Susan; Liddell, Michael; Lloyd, Jonathan

    2015-04-01

    Climate change induces drought events and may therefore cause significant impact on tropical rainforests, where most plants are reliant on high water availability - potentially affecting the distribution, composition and abundance of plant species. Using an experimental approach, we are studying the effects of a simulated drought on lowland rainforest plants at the Daintree Rainforest Observatory (DRO), in tropical northern Australia. Before to build up the rainout infrastructure, we installed sap flow meters (HRM) on 62 rainforest trees. Eight tree species were selected with diverse ecological strategies including wood density values ranging from 0.34 to 0.88 g/cm3 and could be replicated within a 1ha plot: Alstonia scholaris (Apocynaceae), Argyrondendron peralatum (Malvaceae), Elaeocarpus angustifolius (Elaeocarpaceae), Endiandra microneura (Lauraceae), Myristica globosa (Myristicaceae), Syzygium graveolens (Myrtaceae), Normanbya normanbyi (Arecaceae), and Castanospermum australe (Fabaceae). Our preliminary results from sap flow data obtained from October 2013 to December of 2014 showed differences in the amount of water used by our trees varied in response to species, size and climate. For example Syzygium graveolens has used a maximum of 60 litres/day while Argyrondendrum peralatum used 13 litres/day. Other potential causes for differential water-use between species and the implications of our research will be discussed. We will continue to monitor sap flow during the rainfall exclusion (2014 to 2016) to determine the effects of plant physiological traits on water use strategies.

  17. Exploring full-waveform LiDAR parameters for tree species classification

    NASA Astrophysics Data System (ADS)

    Heinzel, Johannes; Koch, Barbara

    2011-02-01

    Precise tree species classification with high density full-waveform LiDAR data is a key research topic for automated forest inventory. Most approaches constrain to geometric features and only a few consider intensity values. Since full-waveform data offers a much larger amount of deducible information this study explores a high number of parameter and feature combinations. Those variables having the highest impact on species differentiation are determined. To handle the large amount of airborne full-waveform data and to extract a comprehensive number of variable combinations an improved algorithm was developed. The full-waveform point parameters amplitude, width, range corrected intensity and total number of targets within a beam are transferred into raster covering a test site of 10 km 2. It was possible to isolate the three most important variables based on the intensity, the width and the total number of targets. Up to six tree species were classified with an overall accuracy of 57%, limiting to the four main species accuracy was improved to 78% and constraining just to conifers and broadleaved trees even 91% could be classified correctly.

  18. How environmental conditions affect canopy leaf-level photosynthesis in four deciduous tree species

    SciTech Connect

    Bassow, S.L.; Bazzaz, F.A.

    1998-12-01

    Species 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 tree species can differ in their sensitivity to environmental conditions, these changes in species 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 tree species: 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 tree canopies.

  19. Large ontogenetic declines in intra-crown leaf area index in two temperate deciduous tree species.

    PubMed

    Nock, C A; Caspersen, J P; Thomas, S C

    2008-03-01

    The widespread occurrence of age-related changes in leaf morphology and allocation suggests that the leaf area index of individual trees (intra-crown LAI) may decline late in ontogeny. We used direct, within-canopy measurements to quantify the LAI of canopy trees with exposed crowns of two temperate deciduous species. Intra-crown LAI declined from approximately 7 to 4 in Acer saccharum, and from approximately 9.5 to 6.5 in Betula alleghaniensis, as tree size increased (from 15 to 72 cm diameter at breast height [dbh]). For A. saccharum, age (which varied from 30 to 160 years) was a significantly better predictor of LAI decline than dbh. We also modeled the effect of ontogenetic declines in LAI on understory light availability and found that light transmission increases significantly as canopy trees grow and mature. Our results thus suggest that gradual declines in LAI with tree age may play an important and overlooked role in contributing to the heterogeneity of sub-canopy light regimes in mature forests. PMID:18459337

  20. Changes in vessel anatomy in response to mechanical loading in six species of tropical trees.

    PubMed

    Christensen-Dalsgaard, Karen K; Fournier, Meriem; Ennos, Anthony R; Barfod, Anders S

    2007-01-01

    It is well known that trees adapt their supportive tissues to changes in loading conditions, yet little is known about how the vascular anatomy is modified in this process. We investigated this by comparing more and less mechanically loaded sections in six species of tropical trees with two different rooting morphologies. We measured the strain, vessel size, frequency and area fraction and from this calculated the specific conductivity, then measured the conductivity, modulus of elasticity and yield stress. The smallest vessels and the lowest vessel frequency were found in the parts of the trees subjected to the greatest stresses or strains. The specific conductivity varied up to two orders of magnitude between mechanically loaded and mechanically unimportant parts of the root system. A trade-off between conductivity and stiffness or strength was revealed, which suggests that anatomical alterations occur in response to mechanical strain. By contrast, between-tree comparisons showed that average anatomical features for the whole tree seemed more closely related to their ecological strategy.

  1. Large ontogenetic declines in intra-crown leaf area index in two temperate deciduous tree species.

    PubMed

    Nock, C A; Caspersen, J P; Thomas, S C

    2008-03-01

    The widespread occurrence of age-related changes in leaf morphology and allocation suggests that the leaf area index of individual trees (intra-crown LAI) may decline late in ontogeny. We used direct, within-canopy measurements to quantify the LAI of canopy trees with exposed crowns of two temperate deciduous species. Intra-crown LAI declined from approximately 7 to 4 in Acer saccharum, and from approximately 9.5 to 6.5 in Betula alleghaniensis, as tree size increased (from 15 to 72 cm diameter at breast height [dbh]). For A. saccharum, age (which varied from 30 to 160 years) was a significantly better predictor of LAI decline than dbh. We also modeled the effect of ontogenetic declines in LAI on understory light availability and found that light transmission increases significantly as canopy trees grow and mature. Our results thus suggest that gradual declines in LAI with tree age may play an important and overlooked role in contributing to the heterogeneity of sub-canopy light regimes in mature forests.

  2. Environmental control of daily stem growth patterns in five temperate broad-leaved tree species.

    PubMed

    Köcher, Paul; Horna, Viviana; Leuschner, Christoph

    2012-08-01

    Tree 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 tree species (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 species. 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 species with increment peaks corresponding to air humidity maxima, even though the mean daily radial growth rate differed fivefold among the species. The five -species 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 tree 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 tree growth to

  3. Environmental control of daily stem growth patterns in five temperate broad-leaved tree species.

    PubMed

    Köcher, Paul; Horna, Viviana; Leuschner, Christoph

    2012-08-01

    Tree 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 tree species (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 species. 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 species with increment peaks corresponding to air humidity maxima, even though the mean daily radial growth rate differed fivefold among the species. The five -species 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 tree 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 tree growth to

  4. Influence of shade tolerance and development stage on the allometry of ten temperate tree species.

    PubMed

    Franceschini, Tony; Schneider, Robert

    2014-11-01

    Allometry studies the change in scale between two dimensions of an organism. The metabolic theory of ecology predicts invariant allometric scaling exponents, while empirical studies evidenced inter- and intra-specific variations. This work aimed at identifying the sources of variations of the allometric exponents at both inter- and intra-specific levels using stem analysis from 9,363 trees for ten Eastern Canada species with a large shade-tolerance gradient. Specifically, the yearly allometric exponents, α(v,DBH) [volume (v) and diameter at breast height (DBH)], β(v,h) [v and height (h)], and γ(h,DBH) (h and DBH) were modelled as a function of tree age for each species. α(v,DBH), and γ(h,DBH) increased with tree age and then reached a plateau ranging from 2.45 to 3.12 for α(v,DBH), and 0.874-1.48 for γ(h,DBH). Pine species presented a local maximum. No effect of tree age on β(v,h) was found for conifers, while it increased until a plateau ranging from 3.71 to 5.16 for broadleaves. The influence of shade tolerance on the growth trajectories was then explored. In the juvenile stage, α(v,DBH), and γ(h,DBH) increased with shade tolerance while β(v,h) was shade-tolerance independent. In the mature stage, β(v,h) increased with shade tolerance, whereas γ(h,DBH) decreased and α(v,DBH) was shade-tolerance independent. The interaction between development stage and shade tolerance for allometric exponents demonstrates the importance of the changing functional requirements of trees for resource allocation at both the inter- and intra-specific level. These results indicate the need to also integrate specific functional traits, growth strategies and allocation, in allometric theoretical frameworks. PMID:25168006

  5. Experimental evidence of large changes in terrestrial chlorine cycling following altered tree species composition.

    PubMed

    Montelius, Malin; Thiry, Yves; Marang, Laura; Ranger, Jacques; Cornelis, Jean-Thomas; Svensson, Teresia; Bastviken, David

    2015-04-21

    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 tree species. Our results show that the abundance and residence times of Cl(-) and Clorg after 30 years were highly dependent on which tree species were planted on the nearby plots. Average Cl(-) and Clorg content in soil humus were higher, at experimental plots with coniferous trees than in those with deciduous trees. 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.

  6. Epigenetic Variability in the Genetically Uniform Forest Tree Species Pinus pinea L

    PubMed Central

    Sáez-Laguna, Enrique; Guevara, María-Ángeles; Díaz, Luis-Manuel; Sánchez-Gómez, David; Collada, Carmen; Aranda, Ismael; Cervera, María-Teresa

    2014-01-01

    There is an increasing interest in understanding the role of epigenetic variability in forest species 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 species characterized by very low levels of genetic variation and a remarkable degree of phenotypic plasticity. DNA methylation profiles of different vegetatively propagated trees 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 trees allowed identifying common polymorphic methylation sensitive MSAP markers among replicates of a given propagated tree. This set of MSAPs allowed discrimination of the 70% of the analyzed trees. PMID:25084460

  7. Epigenetic variability in the genetically uniform forest tree species Pinus pinea L.

    PubMed

    Sáez-Laguna, Enrique; Guevara, María-Ángeles; Díaz, Luis-Manuel; Sánchez-Gómez, David; Collada, Carmen; Aranda, Ismael; Cervera, María-Teresa

    2014-01-01

    There is an increasing interest in understanding the role of epigenetic variability in forest species 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 species characterized by very low levels of genetic variation and a remarkable degree of phenotypic plasticity. DNA methylation profiles of different vegetatively propagated trees 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 trees allowed identifying common polymorphic methylation sensitive MSAP markers among replicates of a given propagated tree. This set of MSAPs allowed discrimination of the 70% of the analyzed trees.

  8. Multipurpose Compact Spectrometric Unit

    SciTech Connect

    Bocarov, Viktor; Cermak, Pavel; Mamedov, Fadahat; Stekl, Ivan

    2009-11-09

    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 multipurpose device, which is planned to be used for measurements of Rn activities, energy of detected particles by CdTe pixel detector or for coincidence measurements.

  9. Multipurpose Compact Spectrometric Unit

    NASA Astrophysics Data System (ADS)

    Bočarov, Viktor; Čermák, Pavel; Mamedov, Fadahat; Štekl, Ivan

    2009-11-01

    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 multipurpose device, which is planned to be used for measurements of Rn activities, energy of detected particles by CdTe pixel detector or for coincidence measurements.

  10. Multipurpose satellite bus (MPS)

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The Naval Postgraduate School Advanced Design Project sponsored by the Universities Space Research Association Advanced Design Program is a multipurpose 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).

  11. Diurnal and seasonal carbon balance of four tropical tree species differing in successional status.

    PubMed

    Souza, G M; Ribeiro, R V; Sato, A M; Oliveira, M S

    2008-11-01

    This study addressed some questions about how a suitable leaf carbon balance can be attained for different functional groups of tropical tree species under contrasting forest light environments. The study was carried out in a fragment of semi-deciduous seasonal forest in Narandiba county, São Paulo Estate, Brazil. 10-month-old seedlings of four tropical tree species, Bauhinia forficata Link (Caesalpinioideae) and Guazuma ulmifolia Lam. (Sterculiaceae) as light-demanding pioneer species, and Hymenaea courbaril L. (Caesalpinioideae) and Esenbeckia leiocarpa Engl. (Rutaceae) as late successional species, were grown under gap and understorey conditions. Diurnal courses of net photosynthesis (Pn) and transpiration were recorded with an open system portable infrared gas analyzer in two different seasons. Dark respiration and photorespiration were also evaluated in the same leaves used for Pn measurements after dark adaptation. Our results showed that diurnal-integrated dark respiration (Rdi) of late successional species were similar to pioneer species. On the other hand, photorespiration rates were often higher in pioneer than in late successional species in the gap. However, the relative contribution of these parameters to leaf carbon balance was similar in all species in both environmental conditions. Considering diurnal-integrated values, gross photosynthesis (Pgi) was dramatically higher in gap than in understorey, regardless of species. In both evaluated months, there were no differences among species of different functional groups under shade conditions. The same was observed in May (dry season) under gap conditions. In such light environment, pioneers were distinguished from late successional species in November (wet season), showing that ecophysiological performance can have a straightforward relation to seasonality.

  12. Do the rich get richer? Varying effects of tree species identity and diversity on the richness of understory taxa

    USGS Publications Warehouse

    Champagne, Juilette; Paine, C. E. Timothy; Schoolmaster, Donald; Stejskal, Robert; Volařík, Daniel; Šebesta, Jan; Trnka, Filip; Koutecký, Tomáš; Švarc, Petr; Svátek, Martin; Hector, Andy; Matula, Radim

    2016-01-01

    Understory herbs and soil invertebrates play key roles in soil formation and nutrient cycling in forests. Studies suggest that diversity in the canopy and in the understory are positively associated, but these studies often confound the effects of tree species diversity with those of tree species identity and abiotic conditions. We combined extensive field sampling with structural equation modeling to evaluate the simultaneous effects of tree diversity on the species diversity of understory herbs, beetles, and earthworms. The diversity of earthworms and saproxylic beetles was directly and positively associated with tree diversity, presumably because species of both these taxa specialize on certain species of trees. Tree identity also strongly affected diversity in the understory, especially for herbs, likely as a result of interspecific differences in canopy light transmittance or litter decomposition rates. Our results suggest that changes in forest management will disproportionately affect certain understory taxa. For instance, changes in canopy diversity will affect the diversity of earthworms and saproxylic beetles more than changes in tree species composition, whereas the converse would be expected for understory herbs and detritivorous beetles. We conclude that the effects of tree diversity on understory taxa can vary from positive to negative and may affect biogeochemical cycling in temperate forests. Thus, maintaining high diversity in temperate forests can promote the diversity of multiple taxa in the understory.

  13. Tree species diversity interacts with elevated CO2 to induce a greater root system response.

    PubMed

    Smith, Andrew R; Lukac, Martin; Bambrick, Michael; Miglietta, Franco; Godbold, Douglas L

    2013-01-01

    As a consequence of land-use change and the burning of fossil fuels, atmospheric concentrations of CO2 are increasing and altering the dynamics of the carbon cycle in forest ecosystems. In a number of studies using single tree species, fine root biomass has been shown to be strongly increased by elevated CO2 . However, natural forests are often intimate mixtures of a number of co-occurring species. To investigate the interaction between tree mixture and elevated CO2 , Alnus glutinosa, Betula pendula and Fagus sylvatica were planted in areas of single species and a three species polyculture in a free-air CO2 enrichment study (BangorFACE). The trees were exposed to ambient or elevated CO2 (580 μmol mol(-1) ) for 4 years. Fine and coarse root biomass, together with fine root turnover and fine root morphological characteristics were measured. Fine root biomass and morphology responded differentially to the elevated CO2 at different soil depths in the three species when grown in monocultures. In polyculture, a greater response to elevated CO2 was observed in coarse roots to a depth of 20 cm, and fine root area index to a depth of 30 cm. Total fine root biomass was positively affected by elevated CO2 at the end of the experiment, but not by species diversity. Our data suggest that existing biogeochemical cycling models parameterized with data from species grown in monoculture may be underestimating the belowground response to global change. PMID:23504733

  14. Predicting species' range limits from functional traits for the tree flora of North America.

    PubMed

    Stahl, Ulrike; Reu, Björn; Wirth, Christian

    2014-09-23

    Using functional traits to explain species' range limits is a promising approach in functional biogeography. It replaces the idiosyncrasy of species-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 tree)--indicative of life history, mechanical, and physiological adaptations--explain the climate ranges of 250 North American tree species distributed from the boreal to the subtropics. Although the relationship between traits and the median climate across a species 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 species. Maximum height affects the species 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 tree species 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

  15. Sap Flux Scaled Transpiration in Ring-porous Tree Species: Assumptions, Pitfalls and Calibration

    NASA Astrophysics Data System (ADS)

    Bush, S. E.; Hultine, K. R.; Ehleringer, J. R.

    2008-12-01

    Thermal dissipation probes for measuring sap flow (Granier-type) at the whole tree and stand level are routinely used in forest ecology and site water balance studies. While the original empirical relationship used to calculate sap flow was reported as independent of wood anatomy (ring-porous, diffuse-porous, tracheid), it has been suggested that potentially large errors in sap flow calculations may occur when using the original calibration for ring-porous species, due to large radial trends in sap velocity and/or shallow sapwood depth. Despite these concerns, sap flux measurements have rarely been calibrated in ring-porous taxa. We used a simple technique to calibrate thermal dissipation sap flux measurements on ring-porous trees in the lab. Calibration measurements were conducted on five ring-porous species in the Salt Lake City, USA metropolitan area including Quercus gambelii (Gambel oak), Gleditsia triacanthos (Honey locust), Elaeagnus angustifolia (Russian olive), Sophora japonica (Japanese pagoda), and Celtis occidentalis (Common hackberry). Six stems per species of approximately 1 m in length were instrumented with heat dissipation probes to measure sap flux concurrently with gravimetric measurements of water flow through each stem. Safranin dye was pulled through the stems following flow rate measurements to determine sapwood area. As expected, nearly all the conducting sapwood area was limited to regions within the current year growth rings. Consequently, we found that the original Granier equation underestimated sap flux density for all species considered. Our results indicate that the use of thermal dissipation probes for measuring sap flow in ring-porous species should be independently calibrated, particularly when species- specific calibration data are not available. Ring-porous taxa are widely distributed and represent an important component of the regional water budgets of many temperate regions. Our results are important for evaluating plant water

  16. On the Use of Shortwave Infrared for Tree Species Discrimination in Tropical Semideciduous Forest

    NASA Astrophysics Data System (ADS)

    Ferreira, M. P.; Zortea, M.; Zanotta, D. C.; Féret, J. B.; Shimabukuro, Y. E.; Souza Filho, C. R.

    2015-08-01

    Tree species mapping in tropical forests provides valuable insights for forest managers. Keystone species can be located for collection of seeds for forest restoration, reducing fieldwork costs. However, mapping of tree species in tropical forests using remote sensing data is a challenge due to high floristic and spectral diversity. Little is known about the use of different spectral regions as most of studies performed so far used visible/near-infrared (390-1000 nm) features. In this paper we show the contribution of shortwave infrared (SWIR, 1045-2395 nm) for tree species discrimination in a tropical semideciduous forest. Using high-resolution hyperspectral data we also simulated WorldView-3 (WV-3) multispectral bands for classification purposes. Three machine learning methods were tested to discriminate species at the pixel-level: Linear Discriminant Analysis (LDA), Support Vector Machines with Linear (L-SVM) and Radial Basis Function (RBF-SVM) kernels, and Random Forest (RF). Experiments were performed using all and selected features from the VNIR individually and combined with SWIR. Feature selection was applied to evaluate the effects of dimensionality reduction and identify potential wavelengths that may optimize species discrimination. Using VNIR hyperspectral bands, RBF-SVM achieved the highest average accuracy (77.4%). Inclusion of the SWIR increased accuracy to 85% with LDA. The same pattern was also observed when WV-3 simulated channels were used to classify the species. The VNIR bands provided and accuracy of 64.2% for LDA, which was increased to 79.8 % using the new SWIR bands that are operationally available in this platform. Results show that incorporating SWIR bands increased significantly average accuracy for both the hyperspectral data and WorldView-3 simulated bands.

  17. Predicting species' range limits from functional traits for the tree flora of North America.

    PubMed

    Stahl, Ulrike; Reu, Björn; Wirth, Christian

    2014-09-23

    Using functional traits to explain species' range limits is a promising approach in functional biogeography. It replaces the idiosyncrasy of species-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 tree)--indicative of life history, mechanical, and physiological adaptations--explain the climate ranges of 250 North American tree species distributed from the boreal to the subtropics. Although the relationship between traits and the median climate across a species 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 species. Maximum height affects the species 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 tree species 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.

  18. Strong neutral spatial effects shape tree species distributions across life stages at multiple scales.

    PubMed

    Hu, Yue-Hua; Lan, Guo-Yu; Sha, Li-Qing; Cao, Min; Tang, Yong; Li, Yi-De; Xu, Da-Ping

    2012-01-01

    Traditionally, ecologists use lattice (regional summary) count data to simulate tree species distributions to explore species coexistence. However, no previous study has explicitly compared the difference between using lattice count and basal area data and analyzed species distributions at both individual species and community levels while simultaneously considering the combined scenarios of life stage and scale. In this study, we hypothesized that basal area data are more closely related to environmental variables than are count data because of strong environmental filtering effects. We also address the contribution of niche and the neutral (i.e., solely dependent on distance) factors to species distributions. Specifically, we separately modeled count data and basal area data while considering life stage and scale effects at the two levels with simultaneous autoregressive models and variation partitioning. A principal coordinates of neighbor matrix (PCNM) was used to model neutral spatial effects at the community level. The explained variations of species distribution data did not differ significantly between the two types of data at either the individual species level or the community level, indicating that the two types of data can be used nearly identically to model species distributions. Neutral spatial effects represented by spatial autoregressive parameters and the PCNM eigenfunctions drove species distributions on multiple scales, different life stages and individual species and community levels in this plot. We concluded that strong neutral spatial effects are the principal mechanisms underlying the species distributions and thus shape biodiversity spatial patterns. PMID:22666497

  19. Analyzing lead absorption by the sycamore tree species in the industrial park of Rasht, Iran.

    PubMed

    Hashemi, Seyed Armin; FallahChay, Mir Mozaffar; Tarighi, Fattaneh

    2015-07-01

    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 tree species in the industrial park of Rasht. For this purpose, a sample of 32 sycamore tree species 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).

  20. Foliar temperature-respiration response functions for broad-leaved tree species in the southern Appalachians.

    PubMed

    Bolstad; Mitchell; Vose

    1999-11-01

    We measured leaf respiration in 18 eastern deciduous forest tree species to determine if there were differences in temperature-respiration response functions among species or among canopy positions. Leaf respiration rates were measured in situ and on detached branches for Acer pensylvanicum L., A. rubrum L., Betula spp. (B. alleghaniensis Britt. and B. lenta L.), Carya glabra (Mill.) Sweet, Cornus florida L., Fraxinus spp. (primarily F. americana L.), Liriodendron tulipifera L., Magnolia fraseri Walt., Nyssa sylvatica Marsh., Oxydendrum arboreum L., Platanus occidentalis L., Quercus alba L., Q. coccinea Muenchh., Q. prinus L., Q. rubra L., Rhododendron maximum L., Robinia psuedoacacia L., and Tilia americana L. in the southern Appalachian Mountains, USA. Dark respiration was measured on fully expanded leaves at 10, 15, 20, 25, and 30 degrees C with an infrared gas analyzer equipped with a temperature-controlled cuvette. Temperature-respiration response functions were fit for each leaf. There were significant differences in response functions among species and by canopy position within species. These differences were observed when respiration was expressed on a mass, nitrogen, or area basis. Cumulative nighttime leaf respiration was calculated and averaged over ten randomly selected nights for each leaf. Differences in mean cumulative nighttime respiration were statistically significant among canopy positions and species. We conclude that effects of canopy position and species on temperature-respiration response functions may need to be considered when making estimates of whole-tree or canopy respiration.

  1. Atmospheric change alters foliar quality of host trees and performance of two outbreak insect species.

    PubMed

    Couture, John J; Meehan, Timothy D; Lindroth, Richard L

    2012-03-01

    This study examined the independent and interactive effects of elevated carbon dioxide (CO(2)) and ozone (O(3)) on the foliar quality of two deciduous trees species and the performance of two outbreak herbivore species. Trembling aspen (Populus tremuloides) and paper birch (Betula papyrifera) were grown at the Aspen FACE research site in northern Wisconsin, USA, under four combinations of ambient and elevated CO(2) and O(3). We measured the effects of elevated CO(2) and O(3) on aspen and birch phytochemistry and on gypsy moth (Lymantria dispar) and forest tent caterpillar (Malacosoma disstria) performance. Elevated CO(2) nominally affected foliar quality for both tree species. Elevated O(3) negatively affected aspen foliar quality, but only marginally influenced birch foliar quality. Elevated CO(2) slightly improved herbivore performance, while elevated O(3) decreased herbivore performance, and both responses were stronger on aspen than birch. Interestingly, elevated CO(2) largely offset decreased herbivore performance under elevated O(3). Nitrogen, lignin, and C:N were identified as having strong influences on herbivore performance when larvae were fed aspen, but no significant relationships were observed for insects fed birch. Our results support the notion that herbivore performance can be affected by atmospheric change through altered foliar quality, but how herbivores will respond will depend on interactions among CO(2), O(3), and tree species. An emergent finding from this study is that tree age and longevity of exposure to pollutants may influence the effects of elevated CO(2) and O(3) on plant-herbivore interactions, highlighting the need to continue long-term atmospheric change research.

  2. Structural and Chemical Characterization of Hardwood from Tree Species with Applications as Bioenergy Feedstocks

    PubMed Central

    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.

    2012-01-01

    Eucalypt species are a group of flowering trees 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 tree species. 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 tree species for use as biorefinery feedstocks. PMID:23300786

  3. A comparative framework of the Erythrina velutina tree species in reforested land and native populations.

    PubMed

    Souza, E M S; Pereira, G S; Silva-Mann, R; Álvares-Carvalho, S V; Ferreira, R A

    2016-01-01

    Erythrina velutina Willd. (Fabaceae: Papillionoideae) is a pioneer species found in tropical and subtropical regions of the world that has medicinal properties and that is used in reforestation projects. This species is rare in some areas of northeastern Brazil. This study aimed to characterize and compare genetic structures of natural and restored populations of E. velutina, with a focus on the selection of tree seeds. A total of 108 individuals from five natural populations and one restored population were analyzed using ISSR markers, resulting in 407 polymorphic fragments. A high rate of polymorphism was observed in the restored population. The highest genetic variability was identified within populations (82%). Genetic bottleneck tests were significant for the Carmópolis/Rosário do Catete and Laranjeiras natural populations along with the Laranjeiras restored population. Genetic distances significantly correlated with spatial distance. Only the restored population retained unique alleles. Similarly, increased genetic distance was observed in individuals of the restored populations compared to the other populations. Observed genetic variation in both natural and restored populations of E. velutina was moderate, thus enabling selection of divergent trees from those trees supplying seeds. Environmental protection and management of these areas is necessary for the maintenance of these individuals and subsequent reproduction. We recommend suggestions for E. velutina conservation, since the restoration model adopted in this study did not promote the development of the specimens until the reproductive stage in a fashion that aims to augment the soil seed bank supply, as is suggested for pioneer species. PMID:27323200

  4. Structural and Chemical Characterization of Hardwood from Tree Species with Applications as Bioenergy Feedstocks

    SciTech Connect

    Çetinkol, Özgül Persil; Smith-Moritz, Andreia M.; Cheng, Gang; Lao, Jeemeng; George, Anthe; Hong, Kunlun; Henry, Robert; Simmons, Blake A.; Heazlewood, Joshua L.; Holmes, Bradley M.; Zabotina, Olga A.

    2012-12-28

    Eucalypt species are a group of flowering trees 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 tree species. 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 tree species for use as biorefinery feedstocks.

  5. Do ectomycorrhizal and arbuscular mycorrhizal temperate tree species systematically differ in root order-related fine root morphology and biomass?

    PubMed Central

    Kubisch, Petra; Hertel, Dietrich; Leuschner, Christoph

    2015-01-01

    While most temperate broad-leaved tree species form ectomycorrhizal (EM) symbioses, a few species have arbuscular mycorrhizas (AM). It is not known whether EM and AM tree species differ systematically with respect to fine root morphology, fine root system size and root functioning. In a species-rich temperate mixed forest, we studied the fine root morphology and biomass of three EM and three AM tree species from the genera Acer, Carpinus, Fagus, Fraxinus, and Tilia searching for principal differences between EM and AM trees. We further assessed the evidence of convergence or divergence in root traits among the six co-occurring species. 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, tree species and soil depth for root morphology was determined. Root order was more influential than tree species while soil depth had only a small effect on root morphology All six species showed similar decreases in specific root length and specific root area from the 1st to the 4th root order, while the species 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 species (except for specific root area that was larger in AM species), indicating that mycorrhiza type is not a key factor influencing fine root morphology in these species. The order-based root analysis detected species differences more clearly than the simple analysis of bulked fine root mass. Despite convergence in important root traits among AM and EM species, even congeneric species may differ in certain fine root morphological traits. This suggests that, in general, species identity has a larger influence on fine root morphology than mycorrhiza type. PMID:25717334

  6. Chemical composition and fuel wood characteristics of fast growing tree species in India

    NASA Astrophysics Data System (ADS)

    Chauhan, S. K.; Soni, R.

    2012-04-01

    India is one of the growing economy in the world and energy is a critical input to sustain the growth of development. Country aims at security and efficiency of energy. Though fossil fuel will continue to play a dominant role in energy scenario but country is committed to global environmental well being thus stressing on environment friendly technologies. Concerns of energy security in this changing climatic situation have led to increasing support for the development of new renewable source of energy. Government though is determined to facilitate bio-energy and many projects have been established but initial after-affects more specifically on the domestic fuelwood are evident. Even the biomass power generating units are facing biomass crisis and accordingly the prices are going up. The CDM projects are supporting the viability of these units resultantly the Indian basket has a large number of biomass projects (144 out of total 506 with 28 per cent CERs). The use for fuelwood as a primary source of energy for domestic purpose by the poor people (approx. 80 per cent) and establishment of bio-energy plants may lead to deforestation to a great extent and only solution to this dilemma is to shift the wood harvest from the natural forests to energy plantations. However, there is conspicuous lack of knowledge with regards to the fuelwood characteristics of fast growing tree species for their selection for energy plantations. The calorific value of the species is important criteria for selection for fuel but it is affected by the proportions of biochemical constituents present in them. The aim of the present work was to study the biomass production, calorific value and chemical composition of different short rotation tree species. The study was done from the perspective of using the fast growing tree species for energy production at short rotation and the study concluded that short rotation tree species like Gmelina arborea, Eucalyptus tereticornis, Pongamia pinnata

  7. Identification of endangered or threatened Costa Rican tree species by wood anatomy and fluorescence activity.

    PubMed

    Moya, Róger; Wiemann, Michael C; Olivares, Carlos

    2013-09-01

    A total of 45 native Costa Rican tree species are threatened or in danger of extinction, but the Convention on International Trade Endangered Species (CITES) includes only eight of these in its Appendices. However, the identification of other species based on their wood anatomy is limited. The present study objective was to describe and to compare wood anatomy and fluorescence activity in some endangered or threatened species of Costa Rica. A total of 45 (22 endangered and 23 threatened with extinction) wood samples of these species, from the xylaria of the Instituto Tecnológico de Costa Rica and the Forest Products Laboratory in Madison, Wisconsin, were examined. Surface fluorescence was positive in eight species, water extract fluorescence was positive in six species and ethanol extract fluorescence was positive in 24 species. Almost all species were diffuse porous except for occasional (Cedrela odorata, C. fissilis, Cordia gerascanthus) or regular (C. salvadorensis and C. tonduzii) semi-ring porosity. A dendritic vessel arrangement was found in Sideroxylon capari, and pores were solitary in Guaiacum sanctum and Vantanea barbourii. Vessel element length was shortest in Guaiacum sanctum and longest in Humiriastrum guianensis, Minquartia guianensis and Vantanea barbourii. Finally, anatomical information and fluorescence activity were utilized to construct an identification key of species, in which fluorescence is a feature used in identification.

  8. The effects of drought and shade on the performance, morphology and physiology of Ghanaian tree species.

    PubMed

    Amissah, Lucy; Mohren, Godefridus M J; Kyereh, Boateng; Poorter, Lourens

    2015-01-01

    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 tree 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 tree species 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 species shade- and drought tolerances are not in trade-off, but largely uncoupled. When individual species responses were analysed, then for most of the traits only one to three species showed significant interactive effects between drought and shade. The uncoupled response of most species to drought and shade should provide ample opportunity for niche differentiation and species coexistence under a range of water and light conditions. Overall our greenhouse results suggest that, in the absence of root

  9. Interspecific variation in xylem vulnerability to cavitation among tropical tree and shrub species.

    PubMed

    Lopez, Omar R; Kursar, Thomas A; Cochard, Hervé; Tyree, Melvin T

    2005-12-01

    In tropical moist forests, seasonal drought limits plant survival, productivity and diversity. Drought-tolerance mechanisms of tropical species should reflect the maximum seasonal water deficits experienced in a particular habitat. We investigated stem xylem vulnerability to cavitation in nine tropical species with different life histories and habitat associations. Stem xylem vulnerability was scored as the xylem water potential causing 50 and 75% loss of hydraulic conductivity (P50 and P75, respectively). Four shade-tolerant shrubs ranged from moderately resistant (P50=-1.9 MPa for Ouratea lucens Kunth. Engl.) to highly resistant to cavitation (P50=-4.1 MPa for Psychotria horizontalis Sw.), with shallow-rooted species being the most resistant. Among the tree species, those characteristic of waterlogged soils, Carapa guianensis Aubl., Prioria copaifera Griseb. and Ficus citrifolia Mill., were the most vulnerable to cavitation (P50=-0.8 to -1.6 MPa). The wet-season, deciduous tree, Cordia alliodora (Ruiz and Pav.) Oken., had resistant xylem (P50=-3.2 MPa), whereas the dry-season, deciduous tree, Bursera simaruba (L.) Sarg. was among the most vulnerable to cavitation (P50=-0.8 MPa) of the species studied. For eight out of the nine study species, previously reported minimum seasonal leaf water potentials measured in the field during periods of drought correlated with our P50 and P75 values. Rooting depth, deciduousness, soil type and growth habit might also contribute to desiccation tolerance. Our results support the functional dependence of drought tolerance on xylem resistance to cavitation.

  10. The Effects of Drought and Shade on the Performance, Morphology and Physiology of Ghanaian Tree Species

    PubMed Central

    Amissah, Lucy; Mohren, Godefridus M. J.; Kyereh, Boateng; Poorter, Lourens

    2015-01-01

    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 tree 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 tree species 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 species shade- and drought tolerances are not in trade-off, but largely uncoupled. When individual species responses were analysed, then for most of the traits only one to three species showed significant interactive effects between drought and shade. The uncoupled response of most species to drought and shade should provide ample opportunity for niche differentiation and species coexistence under a range of water and light conditions. Overall our greenhouse results suggest that, in the absence of root

  11. Detecting CO2 Fertilization in Tree Ring Records: Evidence from Natural Populations of Boreal Forest Species

    NASA Astrophysics Data System (ADS)

    Nelson, E. A.; Thomas, S. C.

    2008-12-01

    Global increases of atmospheric CO2 concentration are predicted to enhance tree 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 tree ring increments in south-east Yukon, west-central Manitoba and northern Ontario, sampling the dominant tree species at each site: lodgepole pine (Pinus contorta), white spruce (Picea glauca) and black spruce (Picea mariana), respectively. Over 50 tree 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 trees 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 trees. 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.

  12. Fruit production in three masting tree species does not rely on stored carbon reserves.

    PubMed

    Hoch, Günter; Siegwolf, Rolf T W; Keel, Sonja G; Körner, Christian; Han, Qingmin

    2013-03-01

    Fruiting is typically considered to massively burden the seasonal carbon budget of trees. The cost of reproduction has therefore been suggested as a proximate factor explaining observed mast-fruiting patterns. Here, we used a large-scale, continuous (13)C labeling of mature, deciduous trees in a temperate Swiss forest to investigate to what extent fruit formation in three species with masting reproduction behavior (Carpinus betulus, Fagus sylvatica, Quercus petraea) relies on the import of stored carbon reserves. Using a free-air CO2 enrichment system, we exposed trees to (13)C-depleted CO2 during 8 consecutive years. By the end of this experiment, carbon reserve pools had significantly lower δ(13)C values compared to control trees. δ(13)C analysis of new biomass during the first season after termination of the CO2 enrichment allowed us to distinguish the sources of built-in carbon (old carbon reserves vs. current assimilates). Flowers and expanding leaves carried a significant (13)C label from old carbon stores. In contrast, fruits and vegetative infructescence tissues were exclusively produced from current, unlabeled photoassimilates in all three species, including F. sylvatica, which had a strong masting season. Analyses of δ(13)C in purified starch from xylem of fruit-bearing shoots revealed a complete turn-over of starch during the season, likely due to its usage for bud break. This study is the first to directly demonstrate that fruiting is independent from old carbon reserves in masting trees, with significant implications for mechanistic models that explain mast seeding.

  13. Novel multipurpose timer for laboratories

    NASA Technical Reports Server (NTRS)

    Eisler, W. J.; Klein, P. D.

    1969-01-01

    Multipurpose 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.

  14. Crown Plasticity and Competition for Canopy Space: A New Spatially Implicit Model Parameterized for 250 North American Tree Species

    PubMed Central

    Purves, Drew W.; Lichstein, Jeremy W.; Pacala, Stephen W.

    2007-01-01

    Background Canopy structure, which can be defined as the sum of the sizes, shapes and relative placements of the tree crowns in a forest stand, is central to all aspects of forest ecology. But there is no accepted method for deriving canopy structure from the sizes, species and biomechanical properties of the individual trees in a stand. Any such method must capture the fact that trees are highly plastic in their growth, forming tessellating crown shapes that fill all or most of the canopy space. Methodology/Principal Findings We introduce a new, simple and rapidly-implemented model–the Ideal Tree Distribution, ITD–with tree form (height allometry and crown shape), growth plasticity, and space-filling, at its core. The ITD predicts the canopy status (in or out of canopy), crown depth, and total and exposed crown area of the trees in a stand, given their species, sizes and potential crown shapes. We use maximum likelihood methods, in conjunction with data from over 100,000 trees taken from forests across the coterminous US, to estimate ITD model parameters for 250 North American tree species. With only two free parameters per species–one aggregate parameter to describe crown shape, and one parameter to set the so-called depth bias–the model captures between-species patterns in average canopy status, crown radius, and crown depth, and within-species means of these metrics vs stem diameter. The model also predicts much of the variation in these metrics for a tree of a given species and size, resulting solely from deterministic responses to variation in stand structure. Conclusions/Significance This new model, with parameters for US tree species, opens up new possibilities for understanding and modeling forest dynamics at local and regional scales, and may provide a new way to interpret remote sensing data of forest canopies, including LIDAR and aerial photography. PMID:17849000

  15. The Role of Native Tree Species on Leaf Breakdown Dynamics of the Invasive Tree of Heaven ( Ailanthus altissima) in an Urban Stream

    NASA Astrophysics Data System (ADS)

    Swan, C.; Healey, B.

    2005-05-01

    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 species. For example, Tree 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 tree species, excluding native species 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 tree leaves and those of TOH in an urban stream, (2) study the detritivore feeding rate of the same leaf species, and (3) determine if increasing native species 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 tree species employed. Furthermore, mixing TOH with native tree species, 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 species. Subsequent analysis of the structural integrity of all leaf species 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 species. Instead

  16. Heterogeneity in soil water and light environments and dispersal limitation: what facilitates tree species coexistence in a temperate forest?

    PubMed

    Masaki, T; Hata, S; Ide, Y

    2015-03-01

    In the present study, we analysed the habitat association of tree species in an old-growth temperate forest across all life stages to test theories on the coexistence of tree species in forest communities. An inventory for trees 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 tree species, and the spatial correlations within and among species were analysed. The light level had no statistically significant effect on distribution of saplings and seedlings of any species. In contrast, most species 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 species. However, no effective niche partitioning among the species was apparent even at the adult stage. Furthermore, results of spatial analyses suggest that dispersal limitation was not sufficient to mitigate competition between species. 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 species within this forest than expected in tropical forests. The tree species assembly in this temperate forest might be controlled through a neutral process at the spatial scale tested in this study.

  17. An analysis of the daily radial activity of 7 boreal tree species, northwestern Quebec.

    PubMed

    Tardif, J; Flannigan, M; Bergeron, Y

    2001-01-01

    In the 'Des Vieux Arbres' ecological reserve situated within northwestern Quebec, 40 band dendrometers were installed on 7 of the major boreal tree species. The late Spring-early Summer daily radial activity registered in 1997 was related to daily weather variables. For each tree species, the daily mean i) cumulative radial increment and ii) radial activity indexed series obtained by first-difference standardization were analyzed. The results indicate the existence of strong similarities among the 7 species. All showed strong synchronous fluctuations in radius during late winter and early spring. This period ended with a short but sharp increase in radial increments that marked the passage of water into the stem. This initial swelling, less obvious in Pinus species was followed by a prolonged period of little change in radial activity. Meteorological data indicated that air temperature was positively related to stem swelling during the late winter-early spring period. Both air and soil temperatures became negatively related to radial expansion once the passage of water has occurred in the stem. Starting in early June, all species registered a sustained increase in radial increments possibly associated with active cell division. After this, radial expansion was negatively related to air temperature and positively to rainfall. PMID:11339696

  18. Environmental isolation and characterisation of Cryptococcus species from living trees in Havana city, Cuba.

    PubMed

    Illnait-Zaragozí, M T; Martínez-Machín, G F; Fernández-Andreu, C M; Perurena-Lancha, M R; Theelen, B; Boekhout, T; Meis, J F; Klaassen, C H

    2012-05-01

    Cryptococcus isolates from Cuban patients were identified as C. neoformans var. grubii. Although this species has since long been associated with bird droppings, a recent genotyping study provided strong evidence for additional origins of exposure. We sampled different species of trees in Havana, Cuba to identify other potential sources of exposure to this fungus. A total of 662 samples were collected from 331 trees and cacti from Havana, Cuba. Initial selection of the isolates was carried out by conventional techniques. Isolates were further characterised using a combination of AFLP analysis and DNA sequence analysis. Identification by conventional methods yielded 121 C. neoformans and 61 C. gattii isolates. Molecular analyses showed that none of these isolates was C. gattii and only one isolate proved to be C. neoformans var. grubii. A total of 27 different other species were identified. The most prevalent species was C. heveanensis (33%). Sixty-five unidentifiable isolates segregated into ten potentially novel species. Conventional cultivation methods have a low specificity for C. neoformans complex and molecular analyses need to be applied to confirm identification of isolates from environmental sources. Environmental niches responsible for most of human cryptococcal infections in Cuba remain to be identified.

  19. Recovery performance in xylem hydraulic conductivity is correlated with cavitation resistance for temperate deciduous tree species.

    PubMed

    Ogasa, Mayumi; Miki, Naoko H; Murakami, Yuki; Yoshikawa, Ken

    2013-04-01

    Woody species hydraulically vulnerable to xylem cavitation may experience daily xylem embolism. How such species cope with the possibility of accumulated embolism is unclear. In this study, we examined seven temperate woody species to assess the hypothesis that low cavitation resistance (high vulnerability to cavitation) is compensated by high recovery performance via vessel refilling. We also evaluated leaf functional and xylem structural traits. The xylem recovery index (XRI), defined as the ratio of xylem hydraulic conductivity in plants rewatered after soil drought to that in plants under moist conditions, varied among species. The xylem water potential causing 50% loss of hydraulic conductivity (Ψ50) varied among the species studied, whereas only a slight difference was detected with respect to midday xylem water potential (Ψmin), indicating smaller hydraulic safety margins (Ψmin - Ψ50) for species more vulnerable to cavitation. Cavitation resistance (|Ψ50|) was negatively correlated with XRI across species, with cavitation-vulnerable species showing a higher performance in xylem recovery. Wood density was positively correlated with cavitation resistance and was negatively correlated with XRI. These novel results reveal that coordination exists between cavitation resistance and xylem recovery performance, in association with wood functional traits such as denser wood for cavitation-resistant xylem and less-dense but water-storable wood for refillable xylem. These findings provide insights into long-term maintenance of water transport in tree species growing under variable environmental conditions.

  20. A test of the hydraulic vulnerability segmentation hypothesis in angiosperm and conifer tree species.

    PubMed

    Johnson, Daniel M; Wortemann, Remi; McCulloh, Katherine A; Jordan-Meille, Lionel; Ward, Eric; Warren, Jeffrey M; Palmroth, Sari; Domec, Jean-Christophe

    2016-08-01

    Water transport from soils to the atmosphere is critical for plant growth and survival. However, we have a limited understanding about many portions of the whole-tree hydraulic pathway, because the vast majority of published information is on terminal branches. Our understanding of mature tree trunk hydraulic physiology, in particular, is limited. The hydraulic vulnerability segmentation hypothesis (HVSH) stipulates that distal portions of the plant (leaves, branches and roots) should be more vulnerable to embolism than trunks, which are nonredundant organs that require a massive carbon investment. In the current study, we compared vulnerability to loss of hydraulic function, leaf and xylem water potentials and the resulting hydraulic safety margins (in relation to the water potential causing 50% loss of hydraulic conductivity) in leaves, branches, trunks and roots of four angiosperms and four conifer tree species. Across all species, our results supported strongly the HVSH as leaves and roots were less resistant to embolism than branches or trunks. However, branches were consistently more resistant to embolism than any other portion of the plant, including trunks. Also, calculated whole-tree vulnerability to hydraulic dysfunction was much greater than vulnerability in branches. This was due to hydraulic dysfunction in roots and leaves at less negative water potentials than those causing branch or trunk dysfunction. Leaves and roots had narrow or negative hydraulic safety margins, but trunks and branches maintained positive safety margins. By using branch-based hydraulic information as a proxy for entire plants, much research has potentially overestimated embolism resistance, and possibly drought tolerance, for many species. This study highlights the necessity to reconsider past conclusions made about plant resistance to drought based on branch xylem only. This study also highlights the necessity for more research of whole-plant hydraulic physiology to better

  1. Light-exposed shoots of seven coexisting deciduous species show common photosynthetic responses to tree height.

    PubMed

    Miyata, Rie; Kohyama, Takashi S

    2016-10-01

    Functional traits of light-exposed leaves have been reported to show tree height-dependent change. However, it remains unknown how plastic response of leaf traits to tree height is linked with shoot-level carbon gain. To answer this question, we examined the photosynthetic properties of fully lit current-year shoots in crown tops with various heights for seven deciduous broad-leaved species dominated in a cool-temperate forest in northern Japan. We measured leaf mass, stomatal conductance, nitrogen content, light-saturated net photosynthetic rate (all per leaf lamina area), foliar stable carbon isotope ratio, and shoot mass allocation to leaf laminae. We employed hierarchical Bayesian models to simultaneously quantify inter-trait relationships for all species. We found that leaf and shoot traits were co-varied in association with height, and that there was no quantitative inter-specific difference in leaf- and shoot-level plastic responses to height. Nitrogen content increased and stomatal conductance decreased with height. Reflecting these antagonistic responses to height, photosynthetic rate was almost unchanged with height. Photosynthetic rate divided by stomatal conductance as a proxy of photosynthetic water use efficiency sufficiently explained the variation of foliar carbon isotope ratio. The increase in mass allocation to leaves in a shoot compensated for the height-dependent decline in photosynthetic rate per leaf lamina mass. Consequently, photosynthetic gain at the scale of current-year shoot mass was kept unchanged with tree height. We suggest that the convergent responses of shoot functional traits across species reflect common requirements for trees coexisting in a forest.

  2. A test of the hydraulic vulnerability segmentation hypothesis in angiosperm and conifer tree species.

    PubMed

    Johnson, Daniel M; Wortemann, Remi; McCulloh, Katherine A; Jordan-Meille, Lionel; Ward, Eric; Warren, Jeffrey M; Palmroth, Sari; Domec, Jean-Christophe

    2016-08-01

    Water transport from soils to the atmosphere is critical for plant growth and survival. However, we have a limited understanding about many portions of the whole-tree hydraulic pathway, because the vast majority of published information is on terminal branches. Our understanding of mature tree trunk hydraulic physiology, in particular, is limited. The hydraulic vulnerability segmentation hypothesis (HVSH) stipulates that distal portions of the plant (leaves, branches and roots) should be more vulnerable to embolism than trunks, which are nonredundant organs that require a massive carbon investment. In the current study, we compared vulnerability to loss of hydraulic function, leaf and xylem water potentials and the resulting hydraulic safety margins (in relation to the water potential causing 50% loss of hydraulic conductivity) in leaves, branches, trunks and roots of four angiosperms and four conifer tree species. Across all species, our results supported strongly the HVSH as leaves and roots were less resistant to embolism than branches or trunks. However, branches were consistently more resistant to embolism than any other portion of the plant, including trunks. Also, calculated whole-tree vulnerability to hydraulic dysfunction was much greater than vulnerability in branches. This was due to hydraulic dysfunction in roots and leaves at less negative water potentials than those causing branch or trunk dysfunction. Leaves and roots had narrow or negative hydraulic safety margins, but trunks and branches maintained positive safety margins. By using branch-based hydraulic information as a proxy for entire plants, much research has potentially overestimated embolism resistance, and possibly drought tolerance, for many species. This study highlights the necessity to reconsider past conclusions made about plant resistance to drought based on branch xylem only. This study also highlights the necessity for more research of whole-plant hydraulic physiology to better

  3. A test of the hydraulic vulnerability segmentation hypothesis in angiosperm and conifer tree species

    DOE PAGES

    Johnson, Daniel M.; Wortemann, Remi; McCulloh, Katherine A.; Jordan-Meille, Lionel; Ward, Eric; Warren, Jeffrey M.; Palmroth, Sari; Domec, Jean -Christophe

    2016-05-04

    Water transport from soils to the atmosphere is critical for plant growth and survival. However, we have a limited understanding about many portions of the whole-tree hydraulic pathway, because the vast majority of published information is on terminal branches. Our understanding of mature tree trunk hydraulic physiology, in particular, is limited. The hydraulic vulnerability segmentation hypothesis (HVSH) stipulates that distal portions of the plant (leaves, branches and roots) should be more vulnerable to embolism than trunks, which are non-redundant organs that require a massive carbon investment. In the current study, we compared vulnerability to loss of hydraulic function, leaf andmore » xylem water potentials and the resulting hydraulic safety margins (in relation to the water potential causing 50% loss of hydraulic conductivity) in leaves, branches, trunks and roots of four angiosperms and four conifer tree species. Across all species, our results supported strongly the HVSH as leaves and roots were less resistant to embolism than branches or trunks. However, branches were consistently more resistant to embolism than any other portion of the plant, including trunks. Also, calculated whole-tree vulnerability to hydraulic dysfunction was much greater than vulnerability in branches. This was due to hydraulic dysfunction in roots and leaves at less negative water potentials than those causing branch or trunk dysfunction. Leaves and roots had narrow or negative hydraulic safety margins, but trunks and branches maintained positive safety margins. By using branch-based hydraulic information as a proxy for entire plants, much research has potentially overestimated embolism resistance, and possibly drought tolerance, for many species. This study highlights the necessity to reconsider past conclusions made about plant resistance to drought based on branch xylem only. As a result, this study also highlights the necessity for more research of whole-plant hydraulic

  4. Photoperiod and temperature responses of bud swelling and bud burst in four temperate forest tree species.

    PubMed

    Basler, David; Körner, Christian

    2014-04-01

    Spring phenology of temperate forest trees is optimized to maximize the length of the growing season while minimizing the risk of freezing damage. The release from winter dormancy is environmentally mediated by species-specific responses to temperature and photoperiod. We investigated the response of early spring phenology to temperature and photoperiod at different stages of dormancy release in cuttings from four temperate tree species in controlled environments. By tracking bud development, we were able to identify the onset of bud swelling and bud growth in Acer pseudoplatanus L., Fagus sylvatica L., Quercus petraea (Mattuschka) Liebl. and Picea abies (L.) H. Karst. At a given early stage of dormancy release, the onset and duration of the bud swelling prior to bud burst are driven by concurrent temperature and photoperiod, while the maximum growth rate is temperature dependent only, except for Fagus, where long photoperiods also increased bud growth rates. Similarly, the later bud burst was controlled by temperature and photoperiod (in the photoperiod sensitive species Fagus, Quercus and Picea). We conclude that photoperiod is involved in the release of dormancy during the ecodormancy phase and may influence bud burst in trees that have experienced sufficient chilling. This study explored and documented the early bud swelling period that precedes and defines later phenological stages such as canopy greening in conventional phenological works. It is the early bud growth resumption that needs to be understood in order to arrive at a causal interpretation and modelling of tree phenology at a large scale. Classic spring phenology events mark visible endpoints of a cascade of processes as evidenced here. PMID:24713858

  5. Photoperiod and temperature responses of bud swelling and bud burst in four temperate forest tree species.

    PubMed

    Basler, David; Körner, Christian

    2014-04-01

    Spring phenology of temperate forest trees is optimized to maximize the length of the growing season while minimizing the risk of freezing damage. The release from winter dormancy is environmentally mediated by species-specific responses to temperature and photoperiod. We investigated the response of early spring phenology to temperature and photoperiod at different stages of dormancy release in cuttings from four temperate tree species in controlled environments. By tracking bud development, we were able to identify the onset of bud swelling and bud growth in Acer pseudoplatanus L., Fagus sylvatica L., Quercus petraea (Mattuschka) Liebl. and Picea abies (L.) H. Karst. At a given early stage of dormancy release, the onset and duration of the bud swelling prior to bud burst are driven by concurrent temperature and photoperiod, while the maximum growth rate is temperature dependent only, except for Fagus, where long photoperiods also increased bud growth rates. Similarly, the later bud burst was controlled by temperature and photoperiod (in the photoperiod sensitive species Fagus, Quercus and Picea). We conclude that photoperiod is involved in the release of dormancy during the ecodormancy phase and may influence bud burst in trees that have experienced sufficient chilling. This study explored and documented the early bud swelling period that precedes and defines later phenological stages such as canopy greening in conventional phenological works. It is the early bud growth resumption that needs to be understood in order to arrive at a causal interpretation and modelling of tree phenology at a large scale. Classic spring phenology events mark visible endpoints of a cascade of processes as evidenced here.

  6. Light-exposed shoots of seven coexisting deciduous species show common photosynthetic responses to tree height.

    PubMed

    Miyata, Rie; Kohyama, Takashi S

    2016-10-01

    Functional traits of light-exposed leaves have been reported to show tree height-dependent change. However, it remains unknown how plastic response of leaf traits to tree height is linked with shoot-level carbon gain. To answer this question, we examined the photosynthetic properties of fully lit current-year shoots in crown tops with various heights for seven deciduous broad-leaved species dominated in a cool-temperate forest in northern Japan. We measured leaf mass, stomatal conductance, nitrogen content, light-saturated net photosynthetic rate (all per leaf lamina area), foliar stable carbon isotope ratio, and shoot mass allocation to leaf laminae. We employed hierarchical Bayesian models to simultaneously quantify inter-trait relationships for all species. We found that leaf and shoot traits were co-varied in association with height, and that there was no quantitative inter-specific difference in leaf- and shoot-level plastic responses to height. Nitrogen content increased and stomatal conductance decreased with height. Reflecting these antagonistic responses to height, photosynthetic rate was almost unchanged with height. Photosynthetic rate divided by stomatal conductance as a proxy of photosynthetic water use efficiency sufficiently explained the variation of foliar carbon isotope ratio. The increase in mass allocation to leaves in a shoot compensated for the height-dependent decline in photosynthetic rate per leaf lamina mass. Consequently, photosynthetic gain at the scale of current-year shoot mass was kept unchanged with tree height. We suggest that the convergent responses of shoot functional traits across species reflect common requirements for trees coexisting in a forest. PMID:27262582

  7. The effect of soil-borne pathogens depends on the abundance of host tree species.

    PubMed

    Liu, Yu; Fang, Suqin; Chesson, Peter; He, Fangliang

    2015-01-01

    The overarching issue for understanding biodiversity maintenance is how fitness advantages accrue to a species as it becomes rare, as this is the defining feature of stable coexistence mechanisms. Without these fitness advantages, average fitness differences between species will lead to exclusion. However, empirical evidence is lacking, especially for forests, due to the difficulty of manipulating density on a large-enough scale. Here we took advantage of naturally occurring contrasts in abundance between sites of a subtropical tree species, Ormosia glaberrima, to demonstrate how low-density fitness advantages accrue by the Janzen-Connell mechanism. The results showed that soil pathogens suppressed seedling recruitment of O. glaberrima when it is abundant but had little effect on the seedlings when it is at low density due to the lack of pathogens. The difference in seedling survival between abundant and low-density sites demonstrates strong dependence of pathogenic effect on the abundance of host species. PMID:26632594

  8. The effect of soil-borne pathogens depends on the abundance of host tree species

    PubMed Central

    Liu, Yu; Fang, Suqin; Chesson, Peter; He, Fangliang

    2015-01-01

    The overarching issue for understanding biodiversity maintenance is how fitness advantages accrue to a species as it becomes rare, as this is the defining feature of stable coexistence mechanisms. Without these fitness advantages, average fitness differences between species will lead to exclusion. However, empirical evidence is lacking, especially for forests, due to the difficulty of manipulating density on a large-enough scale. Here we took advantage of naturally occurring contrasts in abundance between sites of a subtropical tree species, Ormosia glaberrima, to demonstrate how low-density fitness advantages accrue by the Janzen–Connell mechanism. The results showed that soil pathogens suppressed seedling recruitment of O. glaberrima when it is abundant but had little effect on the seedlings when it is at low density due to the lack of pathogens. The difference in seedling survival between abundant and low-density sites demonstrates strong dependence of pathogenic effect on the abundance of host species. PMID:26632594

  9. The effects of flooding and sedimentation on seed germination of two bottomland hardwood tree species

    USGS Publications Warehouse

    Pierce, A.R.; King, S.L.

    2007-01-01

    Flooding and sedimentation are two of the dominant disturbances that influence tree species 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 tree species: 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 species. 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 tree species composition in floodplain systems, and that tolerance levels to such stressors vary by species. ?? 2007, The Society of Wetland Scientists.

  10. Environmental correlates for tree occurrences, species distribution and richness on a high-elevation tropical island.

    PubMed

    Birnbaum, Philippe; Ibanez, Thomas; Pouteau, Robin; Vandrot, Hervé; Hequet, Vanessa; Blanchard, Elodie; Jaffré, Tanguy

    2015-07-10

    High-elevation tropical islands are ideally suited for examining the factors that determine species distribution, given the complex topographies and climatic gradients that create a wide variety of habitats within relatively small areas. New Caledonia, a megadiverse Pacific archipelago, has long focussed the attention of botanists working on the spatial and environmental ranges of specific groups, but few studies have embraced the entire tree flora of the archipelago. In this study we analyse the distribution of 702 native species of rainforest trees of New Caledonia, belonging to 195 genera and 80 families, along elevation and rainfall gradients on ultramafic (UM) and non-ultramafic (non-UM) substrates. We compiled four complementary data sources: (i) herbarium specimens, (ii) plots, (iii) photographs and (iv) observations, totalling 38 936 unique occurrences distributed across the main island. Compiled into a regular 1-min grid (1.852 × 1.852 km), this dataset covered ∼22 % of the island. The studied rainforest species exhibited high environmental tolerance; 56 % of them were not affiliated to a substrate type and they exhibited wide elevation (average 891 ± 332 m) and rainfall (average 2.2 ± 0.8 m year(-1)) ranges. Conversely their spatial distribution was highly aggregated, which suggests dispersal limitation. The observed species richness was driven mainly by the density of occurrences. However, at the highest elevations or rainfalls, and particularly on UM, the observed richness tends to be lower, independently of the sampling effort. The study highlights the imbalance of the dataset in favour of higher values of rainfall and of elevation. Projected onto a map, under-represented areas are a guide as to where future sampling efforts are most required to complete our understanding of rainforest tree species distribution.

  11. Environmental correlates for tree occurrences, species distribution and richness on a high-elevation tropical island

    PubMed Central

    Birnbaum, Philippe; Ibanez, Thomas; Pouteau, Robin; Vandrot, Hervé; Hequet, Vanessa; Blanchard, Elodie; Jaffré, Tanguy

    2015-01-01

    High-elevation tropical islands are ideally suited for examining the factors that determine species distribution, given the complex topographies and climatic gradients that create a wide variety of habitats within relatively small areas. New Caledonia, a megadiverse Pacific archipelago, has long focussed the attention of botanists working on the spatial and environmental ranges of specific groups, but few studies have embraced the entire tree flora of the archipelago. In this study we analyse the distribution of 702 native species of rainforest trees of New Caledonia, belonging to 195 genera and 80 families, along elevation and rainfall gradients on ultramafic (UM) and non-ultramafic (non-UM) substrates. We compiled four complementary data sources: (i) herbarium specimens, (ii) plots, (iii) photographs and (iv) observations, totalling 38 936 unique occurrences distributed across the main island. Compiled into a regular 1-min grid (1.852 × 1.852 km), this dataset covered ∼22 % of the island. The studied rainforest species exhibited high environmental tolerance; 56 % of them were not affiliated to a substrate type and they exhibited wide elevation (average 891 ± 332 m) and rainfall (average 2.2 ± 0.8 m year−1) ranges. Conversely their spatial distribution was highly aggregated, which suggests dispersal limitation. The observed species richness was driven mainly by the density of occurrences. However, at the highest elevations or rainfalls, and particularly on UM, the observed richness tends to be lower, independently of the sampling effort. The study highlights the imbalance of the dataset in favour of higher values of rainfall and of elevation. Projected onto a map, under-represented areas are a guide as to where future sampling efforts are most required to complete our understanding of rainforest tree species distribution. PMID:26162898

  12. Community structure, diversity and total biomass of tree species at Kapur dominated forests in Peninsular Malaysia

    NASA Astrophysics Data System (ADS)

    Norafida, N. A. Nik; Nizam, M. S.; Juliana, W. A. Wan

    2013-11-01

    A study was conducted to determine the species composition, diversity and biomass of Kapur (Dryobalanops aromatica Gaertn.f.) dominated forests in Peninsular Malaysia. Three forests were selected in different geographical zones, namely Bukit Bauk Virgin Jungle Reserve (BBVJR), Terengganu, Lesong Forest Reserve (LFR), Pahang and Gunung Belumut Recreational Forest (GBRF), Johor. Thirty plots of 0.1 ha (50 m × 20 m) were established with a total sampling area of 1.0 ha at each forest site. All trees with ≥5 cm diameter at breast height (dbh) were tagged, measured and voucher specimens were collected. Floristic composition in the study plot at BBVJR recorded 55 families, 147 genera and 336 species. In LFR, there were 52 families, 138 genera and 288 species, whereas in GBRF there were 52 families, 132 genera and 271 species. D. aromatica was the most important species in all study plots with the Importance Value Index (IVi) of 17.81%, 23.01% and 16.25% in BBVJR, LFR and GBRF, respectively. Similar trend at family level showed the Dipterocarpaceae was the most important family in each of the areas with the family Importance Value Index (FIVi) of 27.95% (BBVJR), 26.09% (LFR) and 27.16% (GBRF). Shannon diversity index (H'f) and Shannon evenness index (J'f) of trees at BBVJR was 5.02 and 0.86; LFR was 4.63 and 0.82; and GBRF was 4.82 and 0.86, respectively. Sorensen's community similarity coefficient (CCs) showed that tree communities between BBVJR, LFR and GBRF had low similarities with values of 0.3 to 0.4. The highest total biomass estimated was in LFR with a value of 739.44 t/ha, followed by BBVJR at 701.34 t/ha and GBRF at 606.29 t/ha.

  13. Chemical taxonomy of tree peony species from China based on root cortex metabolic fingerprinting.

    PubMed

    He, Chunnian; Peng, Bing; Dan, Yang; Peng, Yong; Xiao, Peigen

    2014-11-01

    The section Moutan of the genus Paeonia consists of eight species 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 species belonging to section Moutan. However, although previous studies have analyzed the metabolites found in these species, the metabolic similarities that can be used for the chemotaxonomic distinction of section Moutan species are not yet clear. In this study, HPLC-DAD-based metabolic fingerprinting was applied to the classification of eight species: 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 tree 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 species 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 species between these two subsections. According to their metabolic fingerprinting characteristics, P. ostii and P. suffruticosa can be considered one species, and this result is consistent with the viewpoint of medicinal plant scientists but different from that of classical morphological processing. Significantly large

  14. The All-Species Living Tree project: a 16S rRNA-based phylogenetic tree of all sequenced type strains.

    PubMed

    Yarza, Pablo; Richter, Michael; Peplies, Jörg; Euzeby, Jean; Amann, Rudolf; Schleifer, Karl-Heinz; Ludwig, Wolfgang; Glöckner, Frank Oliver; Rosselló-Móra, Ramon

    2008-09-01

    The signing authors together with the journal Systematic and Applied Microbiology (SAM) have started an ambitious project that has been conceived to provide a useful tool especially for the scientific microbial taxonomist community. The aim of what we have called "The All-Species Living Tree" is to reconstruct a single 16S rRNA tree harboring all sequenced type strains of the hitherto classified species of Archaea and Bacteria. This tree is to be regularly updated by adding the species with validly published names that appear monthly in the Validation and Notification lists of the International Journal of Systematic and Evolutionary Microbiology. For this purpose, the SAM executive editors, together with the responsible teams of the ARB, SILVA, and LPSN projects (www.arb-home.de, www.arb-silva.de, and www.bacterio.cict.fr, respectively), have prepared a 16S rRNA database containing over 6700 sequences, each of which represents a single type strain of a classified species up to 31 December 2007. The selection of sequences had to be undertaken manually due to a high error rate in the names and information fields provided for the publicly deposited entries. In addition, from among the often occurring multiple entries for a single type strain, the best-quality sequence was selected for the project. The living tree database that SAM now provides contains corrected entries and the best-quality sequences with a manually checked alignment. The tree reconstruction has been performed by using the maximum likelihood algorithm RAxML. The tree provided in the first release is a result of the calculation of a single dataset containing 9975 single entries, 6728 corresponding to type strain gene sequences, as well as 3247 additional high-fquality sequences to give robustness to the reconstruction. Trees are dynamic structures that change on the basis of the quality and availability of the data used for their calculation. Therefore, the addition of new type strain sequences in

  15. Beech vs. Pine - how different tree species manage their water demands

    NASA Astrophysics Data System (ADS)

    Heidbüchel, Ingo; Dreibrodt, Janek; Simard, Sonia; Güntner, Andreas; Blume, Theresa

    2016-04-01

    In north-eastern Germany large parts of the landscape are covered by pine trees. Although beech used to be one of the typical species for the region, today it makes up only a small fraction of the forested area. In order to reinstate a more natural forest composition an effort is made to decrease the coniferous forest in the next 30 years from 70% to 40% while increasing the deciduous forest from 20% to 40%. This will have consequences for the forest water balance that we would like to understand better. In an attempt to capture the complete tree water balance for both species we monitored all relevant hydrologic fluxes in four stands of pure beech and pine (both young and old stands) as well as in eight mixed stands (as part of the TERENO observatory). Extensive measurements of throughfall and stemflow were conducted with 35 rain trough systems, 50 stemflow collectors and tipping buckets. Soil moisture was monitored in 70 depth profiles with a total of 450 sensors ranging from 10 cm down to 200 cm. In combination with soil water potential measurements at 5 depths root water uptake from different depths and hydraulic redistribution between depths could be determined. Sapflux sensors recorded tree water use for 16 trees and groundwater level was monitored at 16 locations. We found that soil moisture conditions under beech were more variable than under pine, especially in the upper 100 cm. This was due to the higher influx of water from stemflow on the one hand and to the more intensive/effective use of soil water by the beech on the other hand. Our sap flux measurements show that beech was able to sustain steady rates of sapflux even under extremely dry soil conditions. While annual average sapflow was twice as high for pines compared to beeches, pine trees were less effective in taking up water from the soil and reduced sap flow considerably during dry phases. We still found the upper 100 cm of soil under pine to be generally wetter than under beech and considered

  16. Leaf Phenological Characters of Main Tree Species in Urban Forest of Shenyang

    PubMed Central

    Xu, Sheng; Xu, Wenduo; Chen, Wei; He, Xingyuan; Huang, Yanqing; Wen, Hua

    2014-01-01

    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 tree species 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 tree species. Moreover, the relationships between temperature and leafing phenology, defoliating phenology, and leaf lifespan were analyzed. Findings The timing of leafing differed greatly among species. The early leafing species 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 species varied significantly, the early defoliation species 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 species would have a longer life span and consequently have

  17. Co-occurring species differ in tree-ring delta(18)O trends.

    PubMed

    Marshall, John D; Monserud, Robert A

    2006-08-01

    The stable oxygen isotope ratio (delta(18)O) of tree-ring cellulose is jointly determined by the delta(18)O of xylem water, the delta(18)O of atmospheric water vapor, the humidity of the atmosphere and perhaps by species-specific differences in leaf structure and function. Atmospheric humidity and the delta(18)O of water vapor vary seasonally and annually, but if the canopy atmosphere is well mixed, atmospheric characteristics should be uniform among co-occurring trees. In contrast, xylem water delta(18)O is determined by the delta(18)O of water being drawn from the soil, which varies with depth. If co-occurring trees draw water from different soil depths, this soil-water delta(18)O signal would be manifest as differences in delta(18)O among the trees. We examined the variation in tree ring delta(18)O, over eight decades during the 20th Century, among three species co-occurring in natural forest stands of the northern Rocky Mountains in the USA. We sampled 10 Douglas-firs (Pseudotsuga menziesii (Mirb.) Franco var. glauca), 10 ponderosa pines (Pinus ponderosa Laws.) and seven western white pines (Pinus monticola Dougl.). As expected, variation in atmospheric conditions was recorded in the delta(18)O of the cellulose produced in a given year, but observed climatic correlations with delta(18)O were weak. Significant correlations with June climate data included: daily maximum temperature (r = 0.29), daily minimum temperature (r = -0.25), mean temperature (r = 0.20), mean daily precipitation (r = -0.54), vapor pressure deficit (r = 0.32) and solar radiation (r = 0.44). Lagged effects were observed in Douglas-fir and western white pine. In these species, the delta(18)O of a given annual ring was correlated with the delta(18)O of the previous ring. Ponderosa pine showed no significant autocorrelation. Although the species means were correlated among years (r = 0.67 to 0.76), ponderosa pine was consistently enriched in delta(18)O relative to the other species; differences

  18. [Dynamic changes of dominant tree species in broad-leaved Korean pine forest at different succession stages in Changbai Mountains].

    PubMed

    Guo, Li-ping; Ji, Lan-zhu; Wang, Zhen; Wang, Zhi-xuan

    2011-04-01

    Taking the broad-leaved Korean pine forest stands at four different succession stages after clear-cutting in Changbai Mountains as test objects, this paper studied the change characteristics of community composition and dominant species. The tree species richness, Shannon diversity index, and Simpson dominance index at different succession stages had less change, but the evenness and abundance changed greatly. As succession progressed, the community composition changed constantly, i.e., species number decreased, while the basal area sum and the maximum importance value of dominant tree species increased, suggesting that the dominance of dominant species was continuously improved with succession. In the succession process of broad-leaved Korean pine forest in Changbai Mountains, Betula platyphylla, Populus davidiana, Phellodendron amurense, Ulmus japonica, and other intolerant or semi-intolerant tree species decreased, while Tilia amurensis, Fraxinus mandshurica, Pinus koraiensis, Acer mono, and other shade-tolerant species increased. PMID:21774305

  19. [Dynamic changes of dominant tree species in broad-leaved Korean pine forest at different succession stages in Changbai Mountains].

    PubMed

    Guo, Li-ping; Ji, Lan-zhu; Wang, Zhen; Wang, Zhi-xuan

    2011-04-01

    Taking the broad-leaved Korean pine forest stands at four different succession stages after clear-cutting in Changbai Mountains as test objects, this paper studied the change characteristics of community composition and dominant species. The tree species richness, Shannon diversity index, and Simpson dominance index at different succession stages had less change, but the evenness and abundance changed greatly. As succession progressed, the community composition changed constantly, i.e., species number decreased, while the basal area sum and the maximum importance value of dominant tree species increased, suggesting that the dominance of dominant species was continuously improved with succession. In the succession process of broad-leaved Korean pine forest in Changbai Mountains, Betula platyphylla, Populus davidiana, Phellodendron amurense, Ul