乌鲁木齐河上游大西沟地区种子植物区系特征分析

ASPECTS ON FLORISTIC ANALYSIS OF THE SEED PLANTS FROM DAXIGOU REGION OF UPPER URUMQI RIVER

本文研究了乌鲁木齐河上游大西沟地区的种子植物区系特征。调查表明 ,该地区现有种子植物 40 6种 ,隶属 1 98属 ,46科。种子植物科的组成以世界分布型科为主 ;属的组成以北温带分布型为主 ;种的组成以温带亚洲分布为主。区系成分的分析结果说明 ,该地区植物区系是东天山植物区系的组成部分 ,具有典型的北温带植物区系特征。该地区植物区系具有山地植物区系和垂直变化的特点 ,大部分种类集中分布于山地中部。与周围地区的共有程度分析表明 ,尽管东亚分布型在植物区系组成中占有的份额很小 ,但是在植物区系的形成和起源上 ,与我国北方森林和草原区系有很大的历史渊源性 ,明显不同于中亚荒漠植物区系。

A comparative study on flora of the seed plants from the Daxigou region of th e upper Urumqi River is carried out. There are about 406 species, 198 genera, 46 families of the seed plants in this region. About the constitutive of the famil ies, the cosmopolitan distribution plays the most important role; about that of genera, the north temperate distribution is dominant; and about that of species, the temperate Asia distribution is the most. Analyzing the floristic elements o f the region, the Daxigou flora is a part of East Tianshan flora. It shows appa rently the typical characteristics of Temperate Zone. It is a mountain flora and has vert ical distribution. Most of the plants distribute in the middle of the mountain. Comparing the common genera and species of Daxigou flora with those in the adjac ent regions, there is a close affinity between the Daxigou flora and Bei-Qilian shan flora. The flora of the region is very different from Xinjiang desert regi on, and there is a rather weak affinity between them. It seems likely to be a common flora origins among the three regions: Daxigou region, Bei-Qilianshan region and Neimongol grassland region.