Distribution pattern and zoogeographical division of mammals on the Qinghai-Tibet Plateau

The Qinghai-Tibet Plateau is located in southwestern China. 250 species of mammals belonging to 10 orders and 30 families have been recorded by the authors on the plateau. On the basis of comprehensive physical factors, the whole plateau was divided into 24 basic units identified as Operational Taxonomic Units (OTU) for clustering. The information on mammals in each was used to compute composition similarity for the 24 OTU using Ward's methods. Our study indicated that Palaearctic species were mainly distributed in Qiangtang and the northern plateau while the Oriental species were mainly distributed in southern Tibet and the Hengduan Mountains. The Palaearctic species in Qiangtang and the northern plateau comprised 88.6% of those on the whole plateau while the Oriental species in southern Tibet and the Hengduan Mountains comprised 97.7%. Based on clustering analysis and the landform on the plateau etc., the zoogeographic distributions can be classified into fourth-level divisions. First,the zoogeographic distribution of the Qinghai-Tibet Plateau can be divided into two first-level divisions with the linkage distance between 0.6219 and 1.0738. Second, the zoogeographic distribution of the whole plateau can be divided into four second-level divisions with the linkage distances between 0.5034 and 0.6219. Third, the zoogeographic distribution of the whole plateau can be divided into seven third-level divisions with the linkage distances between 0.2236 and 0.2684. Fourth,the zoogeographic distribution of the whole plateau can be divided into sixteen fourth-level divisions with the linkage distances between 0.0930 and 0.1245. Finally, according to the mammalian distribution and the evolution of the plateau, we discussed how the distribution pattern of the mammals in the Qinghai-Tibet Plateau formed. It is suggested that the formation of the distribution pattern is closely related to the uplift of the plateau.