Ecosystem Change Analysis of Agriculture and Animal Husbandary Regions in Last Ten Years:A Case Study in Taipusi,Inner Mongolia Distribution and Dispersal of Alien Sweet Clover along Roadside in An Agro-pastoral Ecotone of Northern China Exploring strategies about ecological improvement based on local responses in northern agro-pastoral ecotone Analysis of C4 plants in term of habitats and morphological functional types in agro-pastoral ecotone North to the Beijing, China Effects of Land Use Change on Environment in Agro-pastoral Ecotone Based on Ecosystem Services Value:A case study in Taipusi, Inner Mongolia IRM Approach to Analyze the Coupling of Pasture,Livestock and Crop Systems in the Agro-pastoral Ecotone