Abstract:

Qinghai Lake is the largest inland one in China. It is situated in the northeastern part of Qinghai-Xizant (Tibetan) Plateau. The area of Qinghai Lake region is 29661km2. The lake area is 4304.5km2 measured in 1986.

The vegetation types distributed in Qinghai Lake region mainly include desert vegetation, temperate steppe, alpine shrub, alpine meadow, alpine steppe and alpine subnival vegetation. In this region, the dominant vegetation types are of alpine ones, and the temperate types are only distributed in the area near the lake.

Based on our investigation and analysis, some characteristics of vegetation succession in this area are showed as follows:

(1) The forest is a stage of regression. Only two tree species(Sabina przewalskii and Picea crassifolia)are distributed as relic species in this area.

(2) The alpine vegetation types are relatively developing, but the temperate vegetation are not.

(3) The vegetation around Qinghai Lake has its individual characteristics and special successional trend, In general, vegetational landscape in Qinghai Lake region has been tending to become one which has a strong adaptation to extremely high and harsh habitats.

According to the study on succession of aquatic environment and palaeoclimatology and ancient sporopollen analysis. The climate of this area tended to become colder and drier although the fluctuation did exist during the process of change. Under the increasing pressure caused by this climatic change, the plant species which adapted the change got developed, and the development of individual species which did not adapt to this change was suppressed and inhibited, This is the reason why vegetation around Qinghai Lake tended to success towards the type adapting extremely high and harsh habitats.