【摘要】 根据东北山地沙地区和京津周围沙地平原区退耕还林工程区的自然、经济和社会条件,在对退耕还林工程25个省(区、市)1897个县(市、区、旗),以县级单位为单元进行系统区划,建立了4个大区-12个区-39个亚区-116个小区4级区划体系的基础上,按照退耕还林生态经济社会效益紧密结合、可持续发展的基本原则,根据大量试验地观测结果和长期生产实践的科学分析,并参考大量前人研究成果,分别研究了各区的退耕还林模式,经过系统集成、创新提炼,形成了较为完整的退耕还林区域模式体系。共计9个亚区31个小区模式。更多还原

【Abstract】 In this paper,based on setting up 4 grade divisions:4 major regions-12 regions-39 subregions-116 minor regions in 1897 counties of 25 provinces according to the basis of close combination of ecological,economical and social benefits and sustainable development in RFA,and on the basis of measurement resutts from test plots and productive practice,through system synthesis and refering the former study results,was formed a complete regional system of return of farmland to afforestation, 9 subregions,31 minor regions.更多还原