Geographic patterns of taxonomic and phylogenetic ß-diversity of aquatic angiosperms in China.

ABSTRACT

China covers a vast territory harbouring a large number of aquatic plants. Although there are many studies on the ß-diversity of total, herbaceous or woody plants in China and elsewhere, few studies have focused on aquatic plants. Here, we analyse a comprehensive data set of 889 aquatic angiosperm species in China, and explore the geographic patterns and climatic correlates of total taxonomic and phylogenetic ß-diversity as well as their turnover and nestedness components. Our results show that geographic patterns of taxonomic and phylogenetic ß-diversity are highly congruent for aquatic angiosperms, and taxonomic ß-diversity is consistently higher than phylogenetic ß-diversity. The ratio between the nestedness component and total ß-diversity is high in northwestern China and low in southeastern China. The geographic patterns of taxonomic and phylogenetic ß-diversity of aquatic angiosperms in China are obviously affected by geographic and climatic distances, respectively. In conclusion, the geographic patterns of taxonomic and phylogenetic ß-diversity of aquatic angiosperms are consistent across China. Climatic and geographic distances jointly affect the geographic patterns of ß-diversity of aquatic angiosperms. Overall, our work provides insight into understanding the large-scale patterns of aquatic angiosperm ß-diversity, and is a critical addition to previous studies on the macroecological patterns of terrestrial organisms.