关键词: 塔里木河下游, 荒漠生态系统, 脆弱性, 驱动力, 退化机制

Abstract: Over the past decades, zero-flow caused the reduction of groundwater level and the degradation of vegetation, meanwhile, sandy desertification spread seriously in the lower reaches of the Tarim River. Based on the overall review of intrinsic characteristics, natural environment, and their interaction in the special desert ecosystem, this paper firstly discussed some important issues contributed to the desert ecosystem degradation-such as bio-community instability, natural environmental fragility, ecosystem functional limitedness; then analyzed the anthropogenic disturbance regimes happened in the ecosystem in past decades. Its inborn characteristic displayed that the desert eco-system was sensitive to disturbance and has only low resistance to the disturbance and limited resilience of restoration after degradation. The degradation of desert ecosystem was resulted from integration of high natural fragility, intensive human-induced disturbance regime, and their interaction. Since 1950s, the man-induced disturbance regimes have played as an important driving force was responsible for the degradation of the desert ecosystem degradation. The result of human-induced disturbance would be emphasized under rigorous environment in arid area. The restoration of degradation of desert eco-system in the lower reaches of the Tarim River was put forward finally. Since May 2000, the project of ecological transporting water, the result showed that the respond of ground-water was significant. In the vicinities along the river channel, vegetation restoration was evident, but the seedlings were scarce. Vegetation restoration must be follow the ecological feature of vegetation and conform to the theory of vegetal occurrence of inland river in arid zone.

Key words: lower reaches of Tarim River, desert ecosystem, fragility, disturbance, degradation mechanism