基于能值的沂蒙山区农业生态系统发展评价及退耕还林损益分析

EVALUATION OF AGRO ECOSYSTEM DEVELOPMENT AND COST BENEFIT ANALYSIS OF RETURNING FARMLAND TO FOREST BASED ON THE EMERGY THEORY IN YIMENG MOUNTAIN

关键词:  能值分析 沂蒙山区 农业生态系统 可持续发展 退耕还林

Key words:  emergy analysis  agro ecosystem  sustainable development  returning farmland to forest  Yimeng mountain

摘要:

应用能值分析理论与方法、情景模拟方法，定量分析了临沂市2001～2010年农业生态经济系统的投入产出状况、运行效率和环境负荷，揭示临沂市农业生态系统的能值演替的基本趋势，揭示了系统内种植业、牧业、林业、渔业各组分的构成情况及其发展趋势，测算了临沂市2002～2010年的退耕还林效益。结果显示：临沂市2010年农业总投入能值为1.18E+22sej，总产出能值为688E 22sej，可持续发展指数为105；临沂市2001～2010年农业总投入能值呈下降趋势，农业总产出能值呈上升趋势，可持续发展指数呈上升趋势；退耕还林后与退耕前相比，每年能值净增量为105E 19sej/年。结果表明临沂市需要调整农业生态经济结构，增加水产业、畜牧业、林业所占比例；种植业生产应提高农业机械化水平，减少劳动力投入，减少化肥投入量，加大有机肥施用量，提高农业生产技术含量；将需要退耕的941万hm2坡耕地尽快还林，减少能值损失。

Abstract:

A series of calculations and indicators were established based on the theory and methodology of the energy and scenario simulation method by using the data of statistical books during the period of 2001 to 2010. This paper systematically evaluated the input-output condition, running efficiency and environmental load of the agricultural ecosystem in Yimeng Mountain area from 2001 to 2010, disclosed the energy succession trend of the agricultural ecosystem in this area and the structure of planting industry, livestock breeding, forestry and fishery within the system, and calculated the costs and benefits of returning farmland to forest in Linyin City from 2002 to 2010. The results showed that: 1) the total energy input to the agriculture system was 118E+22sej, the total energy yield of agriculture was 688E 22sej and the energy-based sustainable index was 105 in the year of 2010; 2) the total energy input of agriculture went down in the first five years, and then rose slowly in the last five years, but it showed downward trend overall; the total energy yield of agriculture system kept increasing in these years, except in the year of 2007; the energy-based sustainable index declined in the year of 2002, 2004, 2006 and 2010, but it still showed the overall upward trend, its change interval was only 023; 3) the net increase amount of the energy was 105E 19sej/a after returning farmland to forests. It concluded that 1) the economic structure of agricultural ecosystem in Linyi City should be adjusted by increasing the proportion of livestock breeding, forestry and fishery. 2) The level of agricultural mechanization should be raised, the labor input should be reduced, and the amount of organic manure should be increased, and meanwhile, the technical content of agricultural and the efficiency of fertilizer use should be enhanced. 3) The slope farmland of 941×104hm2 areas should be returned to forests as quickly as possible in order to reduce the loss of energy.