摘要
Aims Studies integrating phylogenetic history and large-scale community assembly are few,and many questions remain unanswered.Here,we use a global coastal dune plant data set to uncover the important factors in community assembly across scales from the local filtering processes to the global long-term diversification and dispersal dynamics.Coastal dune plant communities occur worldwide under a wide range of climatic and geologic conditions as well as in all biogeographic regions.However,global patterns in the phylogenetic composition of coastal dune plant communities have not previously been studied.Methods The data set comprised vegetation data from 18463 plots in New Zealand,South Africa,South America,North America and Europe.The phylogenetic tree comprised 2241 plant species from 149 families.We calculated phylogenetic clustering(Net Relatedness Index,NRI,and Nearest Taxon Index,NTI)of regional dune floras to estimate the amount of in situ diversification relative to the global dune species pool and evaluated the relative importance of land and climate barriers for these diversification patterns by geographic analyses of phylogenetic similarity.We then tested whether dune plant communities exhibit similar patterns of phylogenetic structure within regions.Finally,we calculated NRI for local communities relative to the regional species pool and tested for an association with functional traits(plant height and seed mass)thought to vary along sea–inland gradients.Important Findings Regional species pools were phylogenetically clustered relative to the global pool,indicating regional diversification.NTI showed stronger clustering than NRI pointing to the importance of especially recent diversifications within regions.The species pools grouped phylogenetically into two clusters on either side of the tropics suggesting greater dispersal rates within hemispheres than between hemispheres.Local NRI plot values confirmed that most communities were also phylogenetically clustered within regions.NRI values decreased with
基金
A.K.B.was supported by the Faculty of Science and Technology,Aarhus University(2008-218/5-24)
Augustinus’Foundation(11-0677)
Oticon(11-0565)
Niels Bohr Foundation and Aarhus Universitets Forsknings Fond(AUFFF2011-FLS330)
J.-C.S.was supported by the European Research Council(ERC-2012-StG-310886-HISTFUNC)
Additionally,we also consider this article a contribution of Center for Informatics Research on Complexity in Ecology(CIRCE)
funded by Aarhus University and Aarhus University Research Foundation under the AU IDEAS program.
