The transitional region between cropland in semi\|humid regions and grassland (pasture) in semi\|arid regions, is an important ecological barrier, which prevents the desert from extending into the plains of eastern China. It is also a region with severe environmental problems such as desertification, vegetation degradation and soil salinization due to its natural fragility enhanced by human activities. These problems directly affect the environment of central and eastern China. In this paper we analyze the ...