长江流域兽类物种多样性的分布格局

共记录了长江流域内兽类280种,隶属于11目36科135属,特有种和受威胁物种分别有14种和154种。根据兽类分布特点,依据山系和水系将长江流域分为19个区域,除了江源区外,物种丰富度、G-F多样性指数和特有种比例,从上游到下游区域总体趋势是随海拔降低逐渐降低,形成以四川盆地和沅江为分界线的3个数量级;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,发现整个流域分成4部分:江源区;横断山区、川西高原、云南高原、四川盆地和秦巴山区;贵州高原、江南丘陵、鄱阳湖平原和长江三角洲;淮阳山地、两湖平原和长江下游平原,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 Mammals in the Yangtze River Basin

280 species and subspecies were documented on mammal biodiversity in the Yangtze River Basin. They belong to 11 orders, 36 families and 135 genera, of which, 14 species are endemic and 154 threatened, respectively. Based on the distribution characteristics of mammals, the Yangtze River Basin were divided into 19 regions by deep rivers and high mountains. Except the headwater of the basin, species richness, G-F diversity index and the proportion of endemic species decreased gradually from the headwater to the estuary of the basin with a gradient of the elevation, and formed three value scales by Sichuan Basin and Yuanjiang River. Based on the species distribution in 19 regions (Jaccard similarity), cluster analysis was used to analyze the similarity of mammals. The 19 regions were clustered into four groups: (1) the headwater of basin, (2) Hengduanshan Mountain region, Yunnan Plateau, Sichuan Basin and Qinling-Dabashan Mountains, (3) Guizhou Plateau, Jiangnan hills, the plains in Poyang Lake and the delta of the Yangtze River basin, (4) Huaiyang mountains, Dongting Lake plain and Jianghan plain (or the Two-Lake plains), and the Lower reaches of the Yangtze River Basin. This grouping results responds to the environmental characteristics of the total basin and three large topographic platforms of the Chinese mainland.