中文摘要：

优化农业生态系统结构是改善区域生态环境、维护生态安全的重要途径。利用研究区统计年鉴数据,运用能值理论、方法,对准格尔旗农业生态系统的能值投入、产出结构和运行效率进行定量评估,评价环境资源对农业生态系统的影响与贡献,为农业生态系统结构优化提供理论依据。研究表明：（1）环境资源,尤其是可更新资源的能值投入对准格尔旗农业生态系统生产力的贡献最大。遵循适度规模原则,优化能值投入结构,提高环境资源利用效率,加强水土保持,同时发展集水型生态农业,推广现代农牧业是提高准格尔旗农业生态系统生产力的根本出路;（2）畜牧业是准格尔旗农业生态系统的支柱。发展草基畜牧业,构建可持续的生态经济范式,实施＂农牧互促＂方案,提高农牧业系统耦合度及其整体生产力,是发展准格尔旗农业生态系统生产力的战略方向;（3）准格尔旗农业生态系统对当地环境资源的依赖程度增加。增强系统同化作用,加大农业科技辅助能值投入,降低干旱灾害风险,提高农业生产力,是改善准格尔旗生态环境质量,促进区域可持续发展的重要举措。

英文摘要：

Optimizing the agro- ecosystem structure is an important way to improve the regional eco -environ- ment and to maintain ecological safety. Statistical Yearbook was used to evaluate quantitatively emergy input - output structure and operating efficiency of agro - ecosystem in Zhunger County by emergy theory, the impact and contribution of environmental resources to agro - ecosystem were assessed, and a theoretical basis for optimizing the agro- ecosystem structure was provided. The study showed that： （1） Emergy input of environmental re- sources, especially renewable resources had maximum contribution to agro -ecosystem productivity. Following the principle of appropriate scale, optimizing the emergy input structure, improving the use efficiency of environ- mental resources, intensifying soil conservation, while developing water - harvesting ecological agriculture, pro- moting modern agriculture and animal husbandry are the fundamental way to improve agro - ecosystem productivi- ty in Zhunger County; （2） Livestock was the pillar of agro - ecosystem. So developing grass - based animal hus- bandry, building a sustainable eco - economic paradigm, the implementing mutually of the agricultural and pas- toral, and improving their coupling degree and overall productivity are the strategic direction for the development of agro - ecosystem productivity in Zhunger County ; （3） Agro - ecosystem was more dependent on local environ- mental resources in Zhunger County. Enhancing the assimilation of system, increasing auxiliary emergy input of agricultural science and technology, and reducing the risk of drought disasters, increasing agricultural productivi- ty would be important initiatives to improve the eco - environment quality, and to promote regional sustainable development in Zhunger County. Key words ： agro - ecosystems ; emergy input ; emergy output ; emergy indices ; the farming - pastoral ecotone of northern China.