基于能值的天山北坡经济带农牧系统可持续性评估

应用能值分析理论和方法,对新疆天山北坡经济带农牧业生态经济系统进行了分析和评价,通过一系列的能值指标定量分析了该地区的农牧业系统的能值流动。结果表明:环境资源对农牧业系统的贡献很大,环境资源能值占总能值利用的79.2%,高于全国农业系统平均值(13%);净能值产出率为4.81,高于我国平均值(0.27),说明该区域农牧系统生产有一定的竞争优势;农牧业产品的宏观经济价值大于市场价值,这是由于农牧业生产中有相当大一部分环境资源无偿投入所致;环境负载率指标为0.373,低于我国农业系统的环境负载率(2.8),环境压力较小;可持续发展指数为12.90,有较好的发展潜力,据此,提出了一系列促进区域农业可持续发展的产业结构调整措施。

Emergy evaluation on the sustainability of cropping-grazing system in economic belt on northern slope of Tianshan Mountains

By the methods of emergy analysis,this paper evaluated the eco-economic system of cropping-grazing in the economic belt on northern slope of Tianshan Mountains.A suit of emergy indices was adopted to quantitatively assess the emergy flows.The results showed that environmental resources made a great contribution to the cropping-grazing system.The emergy of environmental resources occupied 79.2% of the total,and the net emergy yield rate was 4.81,which were much higher than the mean values(13% and 0.27)of the whole nation and illustrated that the cropping-grazing system in this area possessed a certain competitive advantage in its production.The macroeconomic value of the cropping-grazing products was much higher than their market value,due to the large input of 'free'resources from the environment to the cropping-grazing production.The value of environmental loading rate was 0.373,which was far below the national average of 2.8 and indicated a less pressure on the environment.The emergy sustainability index was 12.90,showing a good development potential of this system.Some measures about the industrial structure adjustment were proposed for promoting the sustainable development of regional agriculture.