2005-2009年三江源自然保护区生态保护和建设工程生态成效综合评估

本文评价了三江源自然保护区生态系统宏观结构及涵养水源、保持水土、保护生物多样等主要生态服务功能,分析了自然保护区生态保护与建设工程的生态成效及其原因。结果显示,工程实施后,各自然保护区的土地覆被转类指数明显增加,生态系统宏观状况好转;保护区内草地生产力皆呈增加趋势,水域面积增加,食物供给能力提高,栖息地生境好转。森林类保护区的森林面积减少趋势得到遏制;湿地类保护区的湿地面积多呈增加趋势;草地类保护区的草地减少趋势缓解,荒漠化明显遏制,草地植被覆盖度有所增加;冰川类保护区多条冰川出现明显退缩导致冰川融水增多,有利于雪线以下草地净初级生产力的增加。

Integrated assessment on the effectiveness of ecological conservation in Sanjiangyuan National Nature Reserve

Sanjiangyuan, located in Qinghai Province, is known as the water tower of China. This paper assessed the ecological effectiveness of those projects in Sanjiangyuan, through comparisons of ecological macrostructure, soil erosion and conservation, and grassland production before and after the projects. The natural and human driving factors for effectiveness were also analyzed. The results showed that land cover change index increased obviously, which represented the ecosystem restoration in Sanjiangyuan National Nature Reserves. The increased grassland net primary production and expanded water area were helpful to supply enough food and water to wildlife. Moreover, the declining trends of forest area were restrained in forest related nature reserves. In wetland related nature reserves, wetland area was increased. In grassland related reserves, decreasing trends of grassland and enlarging desertification were also restrained, and wetland expansion and increasing vegetation cover were obvious. In glacier related reserves, retreating glacier and thawing permafrost results to increasing water were useful to vegetation growth; however, it is uncertain in the long term.