A large-scale pattern in species diversity of reptiles in the Yangtze River Basin
长江流域爬行动物物种多样性大尺度格局研究

We synthesized information on reptile biodiversity in the Yangtze River Basin. We documented 166 species that had been recorded and described from the basin. There are 3 orders,18 families and 68 gen- era. Of these,24 species are endemic and 54 endangered. Since the distribution patterns of terrestrial reptiles are determined by the deep rivers and high mountains to a great extent,we divided the Yangtze River Basin into 19 sub-regions. Except the headwater of the basin,the other 18 sub-regions show similar values in spe- cies richness and G-F index. However,the proportion of endemic species decreased gradually from the headwater to the estuary of the basin with the gradient of elevation. Based on the species distribution in 19 sub-regions (Jaccard similarity),cluster analysis was used to analyze the similarity of reptiles in the 19 sub-regions. The 19 sub-regions were clustered into five groups:(1) The headwaters of the basin,(2) Heng- duan Mountains and Yunnan Plateau,(3) Sichuan Basin and Qinling-Dabashan Mountains,(4) Guizhou Pla- teau,Jiangnan hills,the Two-Lake Plain and the delta of the Yangtze River Basin,(5) Poyang Lake Plain,lower reaches of the basin,and Huaiyang Mountains (from Hanjiang River to Dabieshan Mountain). This grouping reflects the environmental characteristics of the total basin and the three large topographic plat- forms of the Chinese mainland.