Abstract: Inner Mongolia pastoral area is the ecological buffer area in northern China with ecological fragility. Its land development was severe in recent years. The evaluation of land use change and ecosystem services was carried out in order to provide scientific support for planning and management of land resources in pastoral areas. Taking Inner Mongolia Pastoral Area as the research area,the evolution characteristics of ecosystem services including carbon fixation and soil conservation were analyzed by land use transfer matrix and change dynamic degree from 2000 to 2015. The results showed that:Grassland and unused land were the main land use types. During this period,the area of building land,forest,cropland and saline alkali land increased,while the area of waters,sand,grassland and unused land decreased. The conversions of land use types were mainly from grassland to cropland,building land,forest,and from sand and water area to grassland. Global carbon fixation and soil conservation both increased. Carbon fixation and soil conservation services provided by grassland were accounted for the largest proportion,followed by sand and cropland. In the future ecological management,the appropriate use of grassland,cropland should be considered. On the basis of protecting grassland and forest,the grassland should be expanded,the sand area should be controlled and restored,and the land use structure should be optimized properly.

Key words: Land-use change, Ecosystem services, Carbon fixation, Soil conservation, Inner Mongolia pastoral area

摘要： 内蒙古牧区是我国北方生态安全屏障，生态脆弱，近年来开发强度大，土地利用变化明显。本文以内蒙古牧区为研究区，利用遥感地理信息系统和模型模拟的方法，通过2000—2015年土地利用转移矩阵和变化动态分析，了解生态系统服务碳固定、土壤保持演变特征，开展土地利用变化及碳固定、土壤保持评价，为牧区土地资源管理提供科学支撑。结果表明：内蒙古牧区主要的土地利用类型为草地和未利用地；16年间，该地区建筑用地、林地、耕地、盐碱地面积增加，水域、沙漠、草地、未利用地面积减少；土地利用变化从草地向耕地、建筑用地、林地转移，从沙漠、水域向草地转移；全域碳固定和土壤保持均呈增加态势；各土地利用类型提供的碳固定和土壤保持服务，草地占比最大，其次为沙漠和耕地。该区域应注重保护草地、林地，扩大草地面积，治理沙漠区域，优化土地利用结构，提高生态系统服务。

关键词: 土地利用变化, 生态系统服务, 碳固定, 土壤保持, 内蒙古牧区