Background: Improved understanding of the processes shaping the assembly of tropical tree communities is crucial for gaining insights into the evolution of forest communities and biological diversity. The climate is t...Background: Improved understanding of the processes shaping the assembly of tropical tree communities is crucial for gaining insights into the evolution of forest communities and biological diversity. The climate is thought to be the first order determinant of abundance and distribution patterns of tree species with contrasting traits such as evergreen and deciduous leaf phenology. However, the relative role of neutral, and niche-based processes in the evolution of these patterns remain poorly understood.Methods: Here, we perform an integrated analysis of the data on tree species abundance, functional traits and community phylogeny from a network of 96 forest plots, each 1 ha in size, distributed along a broad environmental gradient in the central Western Ghats, India. Then, we determine the relative importance of various process in assembly and structuring of tropical forest communities with evergreen and deciduous leaf phenology.Results: The deciduous leaf phenological trait has repeatedly evolved among multiple distantly related lineages. Tree communities in dry deciduous forests were phylogenetically clustered and showed a low range and variance of functional traits related to light harvesting, reproduction, and growth suggesting niche-based processes such as environmental filtering play a vital role in the assembly of tree communities in these forests. The external factors such as human-mediated disturbance also significantly, but to a lesser extent, influences the species and phylogenetic turnover.Conclusions: These findings revealed that the environmental filtering plays a significant role in assembly of tree communities in the biologically diverse tropical forests in the Western Ghats biodiversity hotspot.展开更多
Aims We aimed at disentangling the effects of spatial distance,current and past environmental dissimilarity,and their combinations on tree community taxonomic and phylogenetic turnover by addressing the following ques...Aims We aimed at disentangling the effects of spatial distance,current and past environmental dissimilarity,and their combinations on tree community taxonomic and phylogenetic turnover by addressing the following questions:(i)Is tree community taxonomic and phylogenetic turnover related to the indirect effects of spatial distance via environmental dissimilarity?(ii)Does tree community taxonomic and phylogenetic turnover respond to paleoclimate(Last Glacial Maximum and Mid-Holocene)?Methods The study was carried out in 14 Atlantic rainforest sites in Brazil(20.4 ha sampled)containing 615 tree species from 83 plant families.We obtained plot-level geographic coordinates and soil variables and site-level bioclimatic variables in the current,Mid-Holocene and Last Glacial Maximum.We used structural equation models with a distance-based approach to(i)test the direct effects of spatial distance and environmental dissimilarity and(ii)test the indirect effects of spatial distance via environmental dissimilarity on taxonomic(Bray–Curtis distance)and phylogenetic turnover(Comdist and Comdistnt distances).Important Findings Our results suggest a weak indirect effect of spatial distance via environmental dissimilarity on taxonomic and phylogenetic turnover.Tree community turnover was driven by the direct effects of neutral,niche-based and historical processes.Thus,we inferred that the paleoclimate(historical processes)promoted the selection of the clades that gave rise to the current flora,while spatial distances(neutral processes)limited the dispersal range of species from the regional pool and environmental conditions(niche-based processes)locally selected the taxa that are able to persist.展开更多
基金supported by the following:NSERC-Canada grant to SD,SKN received scholarship from Concordia University,Canada and International Internship from Fonds Nature et technologies(FQRNT)which is gratefully
文摘Background: Improved understanding of the processes shaping the assembly of tropical tree communities is crucial for gaining insights into the evolution of forest communities and biological diversity. The climate is thought to be the first order determinant of abundance and distribution patterns of tree species with contrasting traits such as evergreen and deciduous leaf phenology. However, the relative role of neutral, and niche-based processes in the evolution of these patterns remain poorly understood.Methods: Here, we perform an integrated analysis of the data on tree species abundance, functional traits and community phylogeny from a network of 96 forest plots, each 1 ha in size, distributed along a broad environmental gradient in the central Western Ghats, India. Then, we determine the relative importance of various process in assembly and structuring of tropical forest communities with evergreen and deciduous leaf phenology.Results: The deciduous leaf phenological trait has repeatedly evolved among multiple distantly related lineages. Tree communities in dry deciduous forests were phylogenetically clustered and showed a low range and variance of functional traits related to light harvesting, reproduction, and growth suggesting niche-based processes such as environmental filtering play a vital role in the assembly of tree communities in these forests. The external factors such as human-mediated disturbance also significantly, but to a lesser extent, influences the species and phylogenetic turnover.Conclusions: These findings revealed that the environmental filtering plays a significant role in assembly of tree communities in the biologically diverse tropical forests in the Western Ghats biodiversity hotspot.
基金The work was supported by CAPES(Coordenacao de Aperfeiqoamento Pessoal de Nivel Superior/Coordination for the Improvement of Higher Education Personnel),FAPEMIG(Fundacao de Amparo a Pesquisa de Minas Gerais/Foundation for Supporting Research of the State of Minas Gerais)CNPq(Conselho Nacional de Desenvolvimento Cientffico e Tecnologico/National Council for Scientific and Technological Development)and to the Federal University of Lavras.
文摘Aims We aimed at disentangling the effects of spatial distance,current and past environmental dissimilarity,and their combinations on tree community taxonomic and phylogenetic turnover by addressing the following questions:(i)Is tree community taxonomic and phylogenetic turnover related to the indirect effects of spatial distance via environmental dissimilarity?(ii)Does tree community taxonomic and phylogenetic turnover respond to paleoclimate(Last Glacial Maximum and Mid-Holocene)?Methods The study was carried out in 14 Atlantic rainforest sites in Brazil(20.4 ha sampled)containing 615 tree species from 83 plant families.We obtained plot-level geographic coordinates and soil variables and site-level bioclimatic variables in the current,Mid-Holocene and Last Glacial Maximum.We used structural equation models with a distance-based approach to(i)test the direct effects of spatial distance and environmental dissimilarity and(ii)test the indirect effects of spatial distance via environmental dissimilarity on taxonomic(Bray–Curtis distance)and phylogenetic turnover(Comdist and Comdistnt distances).Important Findings Our results suggest a weak indirect effect of spatial distance via environmental dissimilarity on taxonomic and phylogenetic turnover.Tree community turnover was driven by the direct effects of neutral,niche-based and historical processes.Thus,we inferred that the paleoclimate(historical processes)promoted the selection of the clades that gave rise to the current flora,while spatial distances(neutral processes)limited the dispersal range of species from the regional pool and environmental conditions(niche-based processes)locally selected the taxa that are able to persist.
