Contrasting patterns of phylogenetic diversity across climatic zones of Western Ghats:A biodiversity hotspot in peninsular India  

作　　者：Divya B. Ramesh B.R. K.Praveen Karanth 

机构地区：[1]Karanth Lab,TE-11,Center for Ecological Sciences,Indian Institute of Science(IISc),Bangalore 560012,India [2]French Institute of Pondicherry,11 Saint Louis Street,P.O.Box 33,Pondicherry 605001,India

出　　处：《Journal of Systematics and Evolution》2021年第2期240-250,共11页植物分类学报（英文版）

摘　　要：This study attempts to understand the biogeographic history of the western Ghats forests by investigating decoupling between phylogenetic and taxonomic diversity.We specifically test whether the deciduous forests have been recently established,whether the southern region was a refuge,and whether the deciduous and evergreen forest species have disparate evolutionary histories.We used speciescomposition data from 23 forest types along the Western Chats for all woody angiosperms above 10-cm diameter at breast height.Forests were broadly grouped as either evergreen or deciduous.Mean phylogenetic distances corrected for species richness and mean phylogenetic beta diversity corrected for shared species were assessed using z-scores from null distributions.Null distributions were generated by randomizing the species relationships on the phylogeny.We found that all evergreen forests showed a greater phylogenetic diversity as compared with null expectations.Deciduous forests showed the inverse pattern.Within the evergreen belt,there was a decreasing phylogenetic diversity from south to north,as predicted by the southern refuge hypothesis.The phylogenetic beta diversity across evergreen-deciduous forests was lesser than the null expectation,whereas it was much higher across forests within the evergreen belt.This study provides the first phylogenetic evidence for the antiquity of evergreen forests aswell as the southern refuge hypothesis in the Western Ghats.The deciduous forests species have shared evolutionary histories with the evergreen forest species,suggesting multiple shifts between evergreen and deciduous states through the lineages.Conversely,the evergreen species exhibited a disparate evolutionary history across these forests,possibly owing to sharper ecological or climatic gradients.

关 键 词：ANGIOSPERMS ARIDIFICATION beta diversity BIOGEOGRAPHY phylogenetic beta diversity phylogenetic diversity. 

分 类 号：Q943[生物学—植物学]