玛曲县土地利用/覆盖变化对区域生态系统服务价值的影响

运用GIS和遥感技术分析了玛曲县1975、1990和2005年的土地利用/覆盖特征,在此基础上使用生态价值系数(C)计算出该县生态系统服务价值.结果表明,该区域1975~2005年间生态系统服务价值从129.713亿元减少到123.961亿元,共损失5.75亿元,且损失量和损失幅度呈持续增加趋势;该区域生态系统服务价值中,废物处理价值最高,气候调节价值次之,原材料价值最低,且30年间各服务类型的价值均呈减小趋势;玛曲县1975、1990和2005年人均生态系统服务价值分别为58.96,42.80,29.51万元,表明玛曲县由于人口的增长,环境压力呈持续增大趋势.草地和湿地退化是导致该区域生态系统服务价值减少的主要原因.CS检验说明本研究所选C值较为合理.

Impacts of land use and land cover change on ecosystem service values in Maqu County

Land use change caused by changes in climate and human activities in high-altitude, cold pasture areas with a fragile environment significantly affects ecosystem services and functions. Evaluating ecosystem services can also clarify the ecological and environmental changes caused by land use change. Our study investigated changes in ecosystem services in response to land use change, caused mainly by climate change and human activities. The aim was to provide guidance for sustainable management of a high, cold pasture areas. We chose Maqu County, a region in the eastern fringe of the Tibetan Plateau with large areas of grassland and wetland, as the study area. We used remote sensing to evaluate land use changes, then applied a fast method for evaluating ecological service values in 1975, 1990, and 2005. The value of ecosystem services totaled 129.713×108 yuan in 1975, 128.390×108 yuan in 1990, and 123.961×108 yuan in 2005, representing a decrease of 5.75×108 yuan from 1975 to 2005 and an accelerating rate of decrease, mainly due to the degradation of high-cover grassland and wetlands. The combined ecosystem service value of wetlands, high- and moderate-cover grasslands, and shrubland was about 92% of the total value. Waste treatment and climate regulation were the two largest service functions, contributing about 42% of the total service value. Future land use planning should emphasize the protection of high-cover grassland and wetlands, which have the highest ecosystem service values and which showed accelerated degradation during the study period.