环洞庭湖区农业生态系统能值演变趋势的研究

Study on emergy evolution trend of agro-ecosystem in Dongting lake area

应用能值分析方法,对2000～2009年湖南省环洞庭湖区农业生态系统的能值总量、投入和产出结构以及各能值指标的变化趋势进行了分析。结果表明:研究期间,能值投入总量基本保持平稳,投入结构不断优化,其中工业辅助能值投入量由1.28E+22 sej增至1.68E+22 sej,增加了31.26%,可更新有机能值投入量由6.05E+21 sej下降为5.53E+21 sej;该系统能值产出总量和产出效率均有较大幅度提高,2009年总能值产出达到5.42E+22 sej,与2000年相比提高了40.04%,净能值产出率由2.05上升至2.43,但由于环境负载率有更大幅度的上升,由1.23上升到1.74;该系统可持续发展指数呈缓慢下降趋势,由1.67下降到1.40,且该数值一直维持在1<ESI<10的水平,表明环洞庭湖区农业生态系统属于富有活力和发展潜力的生态系统。发展生态农业,实现经济发展方式的转变是该系统面临的基本任务。

By using the energy analysis method, the trendencys of total energy value, input-output structure and changes of energy indicators in Hunan Dongting lake area＇ s agro-ecosystem from 2000 to 2009 were analyzed. The results indicate that during the study period, the system had maintained a stable total energy value input, and its input structure was continuously optimizing. The value of input industrial auxiliary energy increased from 1.28E＋22 sej to 1.68E＋22sej and added 31.26%, while the value of input renewable organic energy decreased from 6.05E＋21sej to 5.53E＋21 sej. The results also show that the system＇s total output energy value and output efficiency had risen greatly. The total output energy value in 2009 reached 5.42E ＋22 sej which was higher than that of 2000 by 40.04 % and the net output ratio of energy increased from 2.05 to 2.43. Furthermore, the system＇s environmental loading ratio had got an ever-increasing trend which changed from 1.23 to 1.74. The system＇s sustainable development index had got a slow down trend and decreased from 1.67 to 1.40. The index value which was always more than 1 and less than 10, indicated that agriculture of Dongting lake area is a system of vitality and has development potential. The development of ecological agriculture, realizing the transformation of economic development mode of the system is a fundamental task.