西部地区农业生态系统健康评价

Agroecosystem health assessment in western China

农业生态系统健康是农业生态系统的综合特征,它具有活力、组织结构和恢复力,是实现生态农业建设目标的重要保障。根据西部地区农业生态系统的特点和农业生态系统健康的内涵,从活力、组织结构和恢复力3方面选取单位面积农业净产值、农民人均纯收入、NPP利用率、土地人口承载度、系统生产优势度、人口密度、农村劳动者受教育程度、植被覆盖度、水资源供需比、系统稳定性指数、绿色覆盖度、抗灾度、有效灌溉面积率、单位面积耕地化肥农药农膜负荷和农业支出比例等17个指标,构建了西部地区农业生态系统健康的评价指标体系。然后,应用综合评价法、层次分析法和G IS等多种方法与手段,在区域尺度上对西部地区的6个农业生态区进行农业生态系统健康评价。最终得到如下结果:处在“亚健康”状态的是四川盆地区和广西盆地区;处在“不健康”状态的是青藏高原区、云贵高原区和黄土高原区;处在“恶化”状态的是蒙新区。西部地区农业生态系统健康综合评价结果的排名次序为:广西盆地区>四川盆地区>云贵高原区>青藏高原区>黄土高原区>蒙新区。

Agroecosystem with many comprehensive characteristics can be assessed through the measurement of its vigor, structure and resilience. Agroecosystem is very important to realize the healthy development of eco-agriculture. Based on the meaning of ecosystem health and the characteristics of agroecosystem, an assessment index system for agroecosystem in western China was formed from the vigor, structure and resilience. The indexes included the NPP utilization rate, the land carrying capacity （ratio）, the agricultural net output value of per km^2, the farmer net income per capita, the predominance of system produce, the population density, the diathesis of rural labourer, the vegetation coverage （ratio）, the soil and water erosion rate, the land desertification rate, the water resources supply and demand ratio, the index of system stability, the greenness coverage （ratio）, the resist capacity, the effective irrigation rate, the fertilizer, pesticide and plastic film dispensation of per arable land km2 and the agricultural expenditure proportion. Then the paper used various methods and means such as comprehensive evaluation method, AHP （the analytic hierarchy process） and GIS （the geographic information system） to assess the healthy state of the six agricultural eco-zones in west China. At last we got the following results. Agroecosystem in Sichuan basin district and Guangxi basin district were “subhealthy”, Qingzang plateau district, Yungui plateau district and Huangtu plateau were “not healthy”, Mengxin district was “worst”. The order from the best to the worst, among the six agricultural eco-zones in west China, was Guangxi basin district, Sichuan basin district, Qingzang Plateau district, Yungui Plateau district, Huangtu Plateau, and Mengxin district.