放牧和垦殖是我国北方农牧交错带主要土地利用活动。该活动范围的扩大或缩小、活动强度的增大或减弱是引起交错带土地利用变化的直接因素 ,其结果是草地和耕地面积的量变和质变 ,也是该区土地利用变化最直观的体现。文章选取我国典型的农牧交错区——科尔沁沙地 ,以人类垦殖活动作为主线 ,以耕地面积变化作为切入点 ,对科尔沁沙地近 50年的土地利用变化进行了动态分析。结果表明 :随着建国以来四次大规模的垦荒 ,科尔沁土地利用格局产生了显著的变化 ,集中体现为耕地面积的大幅度增加和草地等其他用地面积的减少 ,具体表现则是沙地农耕北界的北跃和耕地重心的北移。文章进而分析了引起这一变化的主要人文因子。

Ke’erqin Deserts, in eastern Inner Mongolia, has relatively favorite water and heat conditions for agriculture. Based on analyses of human reclamation activities, area of cultivated land in one typical region, and spatial structures and inner differences in/among major counties, land use pattern changes during last 50 years in Ke`erqin Deserts is discussed. The result shows that, after four times large scale reclamation since the foundation of P. R. China, Land use pattern Changed vastly in Ke`erqin Deserts. The major feature of that change is northern ward movement of both northern agriculture cultivation frontier and farmland gravity in Ke`erqin Deserts. And the major driving force of that change is increases in population and direction of national development polices, rather than natural conditions of rainfall and temperature, which have little change compared with 50 years ago. Over reclamation without proper protecting measures has caused environmental worsening and soil desertification in Ke’erqin Deserts.