基于能值理论的福建省农业系统动态研究

运用能值理论和方法，对福建省农业系统1981～2004年的能值投入和产出以及能值使用强度、能值货币比率、净能值产出率等9个指标24年来的变化趋势进行了分析。结果表明，24年来能值总投入和总产出都有较大增长；能值使用强度、能值投资率、能值生产率、系统优势度、环境承载力不断上升，表明农业系统经济开发程度不断提高，生产效益已远超过全球平均水平，农产品具有明显价格竞争优势，农业系统结构有所优化，同时对环境资源的压力也有所增大；能值货币比率和能值可持续发展指数不断下降，系统稳定度略有下降，表明由于农业系统集约化程度增强及开发强度加大，系统可持续性和稳定性有所降低。将各能值指标与其他地区比较，福建省农业生产的资源环境条件较为优越，农业系统生产环境仍处于较为良好状态。

DYNAMIC STUDY ON AGRICULTURAL SYSTEM IN FUJIAN PROVINCE BASED ON EMERGY THEORY

Based on emergy theory,the emergy input and output of agricultural system were analyzed in Fujian Province during the period from 1981 to 2004.The nine emergy indices analyzed are emergy density(ED),emergy dollar ratio(EDR),emergy yield ratio(EYR),emergy production ratio(EPR),emergy investment ratio(EIR),environmental carrying capacity(ECC),emergy sustainable index(ESI),system dominant degree(SDD)and system stability degree(SSD).The total emergy input and total emergy output increased during the 24 year period;the ED,EIR,EPBR,SDD,ECC increased continuously,indicating that the economic exploitive degree of the agriculture system raised continuously and the productive benefit far exceeded the mean level in the world.The agricultural products in this region had obvious advantages in terms of price,and the structure of agricultural system was optimized;but this may also indicate a pressure on the environmental resources.EDR and ESI decreased continuously,SSD decreased a little,indicating that the sustainability and stability of the agricultural system decreased due to the increase of the exploitive intensity and the exploitive degree in the agricultural system.Comparing all the emergy indices with other regions,it is found that the agricultural producing environmental resource condition was a lot more superior in Fujian Province,and its producing environment is still in a good condition.