Abstract: The Black Soil Type grassland degradation occurred broadly in Three River Source Region,located in the hinterland of Qinghai-Tibet Plateau,due to the long-term impacts of climatic warm up and overgrazing.The bottleneck to the natural recovery of the Black Soil Type degraded grassland was analyzed by the investigations of soil,environment,and soil seed bank in the center of Three River Source Region and the succession of cultivated grassland in this region was tracked.The results of community succession investigation show that the perennial cultivated grassland could improve the soil micro-environments and provide the zonalic conditions for the plant invasion;meanwhile,it shortened the local vegetation recovery process of the degraded grassland by the connection of vegetation succession and natural invasion.The results of this study would provide the credible theories and methods to the natural recovery of Black Soil Type grassland degradation and the melioration of the ecological environment in Three River Source Region.

Key words: Three River Source Region, Degraded grassland, Cultivated grassland, Vegetation recovery

摘要： 三江源区位于青藏高原腹地,长期在气候变暖和超载放牧的双重压力下,草地大片退化,形成大面积"黑土滩"型退化草地,引起源区生态环境的恶化。本研究以三江源区"黑土滩"型退化草地的土壤、环境和种子库为研究对象,分析了三江源区"黑土滩"型退化草地自然恢复的瓶颈;采用以空间代替时间的群落研究方法,对在"黑土滩"型退化草地上建植多年的人工草地演替过程进行了跟踪研究。结果发现:在"黑土滩"型退化草地上建立多年生人工草地,能够改善土壤微环境,为地带性植被的入侵创造适宜条件,实行人工草地植被演替与地带性植被自然入侵的连接,可以大大缩短"黑土滩"型高寒退化草地地带性植被的恢复进程。本研究为"黑土滩"型退化草地的恢复,改善三江源区生态环境,提供可靠的理论依据与措施。

关键词: 三江源区, 退化草地, 人工草地, 植被恢复