长江流域爬行动物物种多样性大尺度格局研究

本文研究了长江流域爬行动物物种多样性的大尺度格局。长江流域内共记录了爬行动物166种,隶属于3目18科68属,特有种和濒危物种分别有24种和54种。根据陆生爬行动物分布特点,依据山系和水系将长江流域分为19个区域,虽然物种数和G-F指数在各区域内变化不大(江源区较低),但特有种比例从上游到下游随海拔降低逐渐降低;利用Jaccard物种相似性系数对长江流域内19个区域进行聚类分析,可以将整个流域分成五部分:江源区,横断山区和云南高原区,四川盆地和秦巴山区,贵州高原、江南丘陵、两湖平原和长江三角洲,鄱阳湖平原、长江下游平原和淮阳山地(汉江—大别山),基本反映了流域内自然地理环境及我国大陆地势三级台阶变化的特点。

A large-scale pattern in species diversity of reptiles in the Yangtze River Basin

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.