宁夏盐池县土地利用变化对生态系统服务价值的影响

以宁夏盐池县1989、1995、1999、2003、2006和2009年6期TM影像为基础，运用GIS方法提取各年土地利用数据，分析盐池县土地利用动态变化；采用中国陆地生态系统的服务价值测算方法，分析土地利用变化引起的生态系统服务价值变化。结果表明，1989-2009年间盐池县土地利用变化显著，林地和建设用地面积持续增加，草地面积先减少后增加，耕地和未利用地面积先增加后减少，水域面积小幅波动变化；研究期内盐池县生态系统服务价值总体呈增加趋势，林地面积的增加起到主导作用；盐池县生态系统服务价值构成中，草地居于主导地位，贡献率在49.8%-60.4%之间，林地的贡献比例持续增加，致使盐池县生态系统服务价值结构格局发生良性转变；各土地利用类型生态系统服务价值敏感性指数都小于1，表明盐池县生态系统服务价值对生态服务功能价值系数缺乏弹性，研究结果可信。

Impacts of Land Use Change on Ecosystem Service Value in Yanchi County of Ningxia

Based on TM image data in 1989, 1995, 1999, 2003, 2006 and 2009 of Yanchi County of Ningxia, the land use date of Yanchi County in each year were extracted supported by RS and GIS technology, and used to analyze the dynamic change of land use. The land use data were studied for estimating the change of ecosystem services value caused by the land use change of Yanchi County, using the evaluation method of China terrestrial ecosystem services value. The results showed that the changes of land use were obvious during 1989 to 2009. The area of woodland and construction land had an increasing tendency; grassland area changed from decreasing to increasing, which was in contrary to farmland and un-used land areas （from increasing to decreasing）; water area fluctuated slightly. The ecosystem services value of Yanchi County had an increasing tendency during 1989 to 1995, because the increasing woodland area had took the major role in raising the total ecosystem services value. The grassland accounted for a large proportion of the total ecosystem service value of Yanchi County, with its contribution rate from 49.8% to 60.4%. And the composition of the ecosystem services value of Yanchi County happened benign change for the increasing contribution rate of woodland. The ecosystem services value sensitivity index of each land use type was less than 1, indicating that the ecosystem services value of Yanchi County lacks flexibility on its service value index, and the research results are reliable.