青海祁连山地区兽类分布格局及动物地理学分析

Distribution Pattern and Zoogeographical Analysis of Mammals in Qilian Mountain Areas, Qinghai, China

根据 2 0 0 1～ 2 0 0 2年对青海祁连山及周边地区的考察 ,结合历史资料对青海祁连山及临近地区的兽类分布格局及动物地理分布等问题进行了探讨。通过兽类分布信息对该地区进行聚类 ,用物种分布的相似性聚类结果分析该地区兽类区系特点。结果表明 :湟水河谷兽类区系特殊 ;祁连山中部与青海湖北岸山地的区系成分近似 ;祁连山西部与其它区域区系差异明显 ;柴达木盆地东部与祁连山中部相近 ,而与柴达木盆地中、西部相区别。本地区的兽类分布格局与植被关系密切 ,充分体现出青藏高原和黄土高原过渡的特点。本区特有种类比较缺乏 ,在不同生境交错带具有各种成分混杂和相互渗透的现象 ,既包含了东部黄土高原和东南湿润地区的区系成分 ,又不乏典型的青藏高原种类 ,同时还与蒙新区有一定的联系。从而体现出祁连山地区在兽类物种多样性及其动物地理方面的边缘效应作用。

The Qilian Mountain is located in the northeastern margin of Qinghai-Tibet Plateau. The authors had conducted two surveys on distributions of mammals in the Qilian Mountain and its adjacent area during the summer in 2001-2002. Altogether 72 species of mammals have been recorded in our investigational area, belongings to 7 orders, 20 families and 53 genera. Among them, 62 species which occupying 86.1% of the total number of the mammals are considered to be Palaearctic and 7 species to be Oriental mammals, besides, the others to be widely spread mammals. On the basis of comprehensive physical factors including altitude, landforms, climate, vegetation, hydrology, land-use, etc., the reasearch area was divided into 10 basic units (Operational Taxonomic Unit, OTU). Then the information of mammals in each unit was used to compute species composition similarity for the 10 units, using clustering methods. The clustering results indicated that the fauna on mammals in Huangshui Valley is quite different from all the other areas. The central area of Qilian Mountain is similar to the mountain area of Northern Qinghai Lake. The faunal differences between the Western Chaidamu Basin and the Mountain area of eastern Chaidamu Basin are obviously existent. The Mountain area of eastern Chaidamu Basin has a much closer relationship with the Central area of Qilian Mountain than that with the western and central area of Chaidamu Basin. Ecologically the existence of Qilian Mountain have caused obvious edge effects on mammal diversity and zoogeography. The species composition of mammals in this area not only have some similarity to Qinghai-Tibet Plateau, but also have a close relationship with Xinjiang area. For these reasons, the mammal diversity and zoogeography of the Qilian Mountain could be considered as a transitional area.