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三江源区作为青藏高原的一部分,在目前日益加剧的全球变暖和人类活动现状下,其内部的草地生态系统发生了明显的退化现象,这种退化过程极大的影响了下游地区的生态安全。本文从生态系统最基本的净初级生产力(NPP)出发,利用IPCC提供的生态系统脆弱性的概念,建立了三江源地区基于NPP的脆弱性空间分布格局,同时对其进行了脆弱性等级划分,发现脆弱度等级随平均高程的增加而增高,根据插值得到的降雨量和湿润指数的空间分布,发现中度以上脆弱度主要分布在500mm等降雨量线以西,重度以上脆弱度主要分布在400mm等降雨量线以西,极度脆弱区主要分布在350mm等降雨量线以西。可见该区的脆弱度与降雨量有很大关系。湿润指数-30等值线很好的标示了大部分中度以上脆弱度,因此可见在这一区域水热交互作用是影响植物生长的更重要的因子。
As part of the Qinghai-Tibet Plateau, the Three Rivers Source Region has undergone significant degradation of grassland ecosystems under the present intensified global warming and human activities. This degradation process has greatly affected the ecological security of the downstream regions. Based on the basic net primary productivity (NPP) of ecosystems and using the concept of ecosystem vulnerability provided by IPCC, this paper establishes a spatial distribution pattern of vulnerability based on NPP in the Three River Source Region. At the same time, According to the spatial distribution of rainfall and wetness index, it is found that the above-mentioned degree of vulnerability mainly distributes to the west of the rainfall line of 500mm and the above degree of vulnerability mainly distributes in 400mm and so on To the west of the rainfall line, the extremely vulnerable areas are mainly distributed to the west of the 350 mm rainfall line. It can be seen that the degree of vulnerability in this area has a lot to do with rainfall. The wetness index -30 isotherms are good indicators of most of the above degree of vulnerability, so we can see in this region hydrothermal interaction is more important factor affecting plant growth.