三水市农业生态系统经济能值投入产出分析

Input-output emergy analysis of agricultural ecosystem in Sanshui city, Guangdong

进行生态学与经济学系统分析方法的交叉探索,将能值这一全新的生态经济度量尺度引入经济学投入产出分析表,对广东省珠江三角洲三水市农业生态系统经济能值的直接消耗系统和完全消耗系统分析,弥补经济学分析中自然环境投入价值缺失的同时,为复合系统能值分析中各系统间互作分析的量化评价探索了新的途径。分析结果表明:三水市农业生态系统中种植业、渔业、畜牧业和林业之间存在经济能值的依存关系,有着直接的相互作用。种植业、渔业和畜牧业子系统间的经济能值交流网络较为发达。在种植业、渔业、畜牧业和林业中,渔业对种植业的完全消耗系数最大,达到3.461×10-2,畜牧业对种植业的完全消耗系数也最大,达到了8.423×10-2;种植业对渔业的完全消耗系数最大,达到了7.685×10-2。林业与种植业、渔业、畜牧业互相的完全消耗系数都比较小,林业和其它三个子系统的经济能值交流较弱。种植业子系统是整个三水市农业生态系统的基础,渔业和畜牧业在种植业的基础上发展,对物质和能量的再利用起了重要作用。林业子系统是三水市农业生态系统内部物质能量交流网络的薄弱环节。三水市农业生态系统的内部结构有待进一步调整,以加强各子系统间的互作,提高物质与能量的使用效率。

This paper is an integration study of ecology and economy evaluation methods. Emergy, a newest ecological economic unit, was introduced into economic input-output table analysis to study the direct and fully emergy consume index of Sanshui agricultural ecosystem. Emergy, instead of money as the common unit of value, took the value of environment input into same consideration with economic flux which could not be evaluated in pure economic analysis. The integration between emergy and input/output table brought a light on the quantitatively analysis of the interactions among different systems. The result showed that there are direct interactions among planting subsystem, fishery subsystem, grazer subsystem and forestry subsystem through emergy flow. The emergy interactions among planting subsystem, fishery subsystem and graziery subsystem are especially strong. The fully consume indices of fishery subsystem and graziery subsystem on planting subsystem reached to 3.461×10-2 and 8.423×10-2 respectively, while that of planting subsystem on fishery subsystem arrived at 7.685×10-2 at the same time. Comparing with other subsystems, forestry subsystem has weak interactions with other subsystems. Planting subsystem is the basal element of the agricultural ecosystem. Fishery and graziery were developed with its energy and material support. Planting subsystem was the key element in the reuse of different materials in the agricultural ecosystem. On the contrary, forestry subsystem is the weak point on material and energy interactions in the agricultural ecosystem. The structure of Sanshui agricultural ecosystem should be further improved to strength interactions among the subsystems, and thus, to improve the efficiency of material and energy use of the agricultural ecosystem.