摘要
青海湖地区作为祁连山系中段南麓的一个大型山间盆地,是一个独具特色的地区。这里的以草原为基带及其周围山地的高寒灌丛和高寒草甸垂直系列,有其自身的特点和发展趋势。随着整个青藏高原的强烈隆升,本区植被也具有一系列的明显变化。大片森林趋于消退,仅残存有少数适应高寒生境的树种;温性植被类型局限于海拔较低处,而高寒植被类型相对分布较广。分析表明,青海湖地区的整体植被景观有向寒旱生境方向发展的演变趋势。本区植被出现上述演变趋势的主要原因在于该地区生境因抬升而趋于寒旱的过程中,植物种对其生境变化表现出不同的忍耐性和适应性所致。
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 29661km^2. The lake area is 4304.5km^2 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.
基金
中国科学院西北高原生物研究所所长基金
关键词
青海湖
植被
分布格局
演变趋势
Qinghai Lake
Vegetation type
Distributional pattern
Successional trend
