青藏高原动物地理区的地位和东部界线问题

STUDIES ON THE POSITION OF THE QINGHAI-XIZANG PLATEAU REGION IN ZOOGEOGRAPHIC DIVISIONS AND ITS EASTERN DEMARCATION LINE

本文从历史时空的角度分析了青藏高原地区发生的鱼类区系的变化过程，和高原鱼类区系演化的相对独立性，认为这一鱼类区系的分化直接反映了高原隆升事件，并应当在动物地理区划上得到客观反映，即将青藏高原作为一个独立的区划单元。由于青藏高原的隆升和造成古北区、东洋区分化的第三纪末、第四纪初的全球性气候变冷在时间上相近、波及的范围都巨大，共同促成了欧亚大陆古北区、东洋区和青藏高原区特有类群的分化，作为对这些地史事件反映的青藏高原区、古北区和东洋区，在动物地理区划上应该具有相同的地位．另外，依据高原鱼类的分布范围和青藏高原对非高原鱼类的阻碍作用，讨论了青藏高原的界限及其划分问题。

In this paper, from a historically temporal and spatial piont of view, we analysed the process and the uniqueness of the ichthyo-fauna differentiation in Qinghai-Xizang plateau from Tertiary to present, and suggested that the ichthyo-fauna differentiation due to the uplift of the Qinghai-Xizang plateau might have been reflected in zoogeographic divisions (i. e.the Qinghai-xizang plateau should be considered as an independent unit). The formation of a certain zoogeographical division unit is surely related to a definite event in a given geological period, and the division of Holarctic Region and the Oriental Region is related to the temperature decrease that occurred in the middle stage of Tertiary period. The formation of the Qinghai-Xizang plateau region is surely related to the uplift of the Qinghai-Xizang plateau. The upheavae of the plateau and the global temperature decrease occurred almost at the same period and might have made certain influences. These hictorical events jointly urged the differentiation of the Eurasia ichthyo-fauna, which led to the division among the Holarctic Region, the Oriental Region and the Qinghai-Xizang Plateau Region. As a Region reflection of those events that happened at the same period, the Holarctic Region, the Oriental Region and the Qinghai-Xizang Plateau Region must have equal positions in zoogeographic divisions. The natural distribution boundary of plateau fishes (i.e.the subfamily Schizothroacinae and the genus Triplophysa) formed the demarcation line of the Qinghai-Xizang plateau region. In the eastern part of the plateau region, concerning the cutting of the same river into two parts, the range of the plateau region was also limited in area where Eastern Asiatic or river-plain fishes can not reach.