Study on the situation of soil organic carbon storage in ecotone between ag riculture and anim al husbandry-A case study from Inner Mongolia Relationship of Interdependence and Contradictory between Ecological Restoration and Economic Development in theEcotone between Agriculture and Animal Husbandry in North China Strategies and approaches of ecological and economical construction in the ecotone between agriculture and animal husbandry of North China Effect of grazing on grassland under protective plantation in the ecotone between agriculture and animal husbandry of Songnen plain Spatial transference of grazing space in the ecotone between agriculture and animal husbandry in the Songnen Plain Spatial recognition of ecological importance and analysis of terrain gradients characteristic of unused lands in Guyuan County