Geographical pattern of the deviation between taxonomic, phylogenetic, and functional diversity and its implications for the conservation of Chinese orchids

Abstract

Orchidaceae stands as one of the “flagship” groups in global biodiversity conservation, attracting significant attention from researchers in China. Previous studies have focused on taxonomic diversity, neglecting the integration of phylogeny and functional aspects. Here, we have leveraged a large dataset of distributions, evolutionary relationships, and functional traits of orchids in China to analyze geographic patterns of species richness (SR), weighted endemism (WE), phylogenetic diversity (PD), phylogenetic endemism (PE), functional diversity (FD), and functional endemism (FE). Furthermore, we analyzed the deviations between PD (or FD) and SR (PDdev, and FDdev), as well as between PE (or FE) and WE (PEdev, and FEdev), taking into account climatic and environmental variables. We also delineated the priority protection and survey areas of orchid plants in China. Our results revealed that the geographic patterns of SR, WE, PD, PE, FD, and FE for orchids generally exhibited similar trends. However, there were notable inconsistencies in the geographical patterns of PDdev, FDdev, PEdev, and FEdev, which might be related to the different environmental responses of these four diversity deviation metrics. We have pinpointed six priority conservation areas for orchids in China, i.e., southeasterrn Xizang, western Yunnan, central Yunan, the Karst area at the border of Guizhou and Guangxi, the border of Guangdong and Guangxi, and Taiwan Island. In addition, we have also identified certain priority survey areas for orchids, encompassing southeastern Xizang and other crucial locales. These findings will guide future conservation and research efforts aimed at safeguarding the rich biodiversity of orchids in China.