不同优化情境下的县南沟流域商品型生态农业系统耦合关系

在对县南沟流域退耕还林工程实施后商品型生态农业系统现状耦合态势分析的基础上，以该流域商品型生态农业系统优化方案为基础，利用耦合过程模型，预测了系统在链网构建阶段、农业经济系统与农业生态系统优化耦合阶段的耦合关系。结果表明:自退耕还林工程实施以来，县南沟流域商品型生态农业系统一直处于协调化发展阶段，且农业生态系统与农业经济系统的综合指数均不断增加。当农业生态系统达到自我调节临界点时，在现状发展态势下农业经济系统演变速度为 V_En（t）=0.0673El（t），商品型生态农业系统链网构建阶段农业经济系统演变速度为V_En（t）=0.0913El（t），农业经济系统与农业生态系统优化耦合阶段农业经济系统演变速度为 V_En（t）=0.0999El（t），系统链网的完善、资源的合理高效利用以及碳汇林业的发展解决了商品型生态农业系统健康、持续发展的问题，同时提高了系统功能。

Coupling Relationship of Ecological Agro-system with Commodity in Different Optimized Scenarios in Xiannangou Watershed

Based on the coupling trend analysis of ecological agricultural system with commodity(EASC) in Xiannangou watershed after sloping land conversion program (SLCP), and optimized project of EASC in this watershed, this paper predicted the coupling relationship in Xiannangou watershed at the phase of system in the chain network construction and the optimized coupling phase of agricultural economic system and agricultural ecosystem by using coupling process model. Results showed that EASC of Xiannangou watershed is at the phase of coordinated development after the implementation of SLCP. And the comprehensive index of agroecological system and agricultural economic system are both growing continually. When agroecological system reaches the self-adjusting tipping point, the agricultural economic system evolution speed of the status quo of the development trend & the phase of EASC in the chain network construction & the optimized coupling phase of agricultural economic system and agricultural ecosystem respectively follow the formulas of V_En(t) =0.0673El(t) & V_En(t) =0.0913El(t) and V_En(t) =0.0999El(t). The problems of EASC health and sustainable development are solved by the completed system in the chain network construction, the reasonable utilization of resources and the development of carbon sequestration forestry, which improves the system function at the same time.