湖南农业生态系统能值结构功能效率分析

Analysis of Emergy Structure, Function and Efficiency of Agro-ecosystem in Hunan Province

为了探究湖南农业生态系统的能值投入产出结构功能与效率,揭示该区域人与自然资源和环境的相互关系,以能值理论为研究方法,以湖南农业2009年投入产出数据为依据,对湖南农业生态系统的能值结构、功能和效率进行实证分析。结果表明:(1)系统结构特点:湖南农业仍具有传统农业的生产特点,对劳动力、畜力的依赖性较大。工业辅助能值中,化肥对系统的贡献率最高,农业机械化水平低。工业辅助能值可更新比偏低,农业绿色能源的开发潜力和前景较大。系统产品定价偏低,忽视了自然资源和环境对农业生产的贡献,也反映出湖南农业产业链条相对短,产品附加值较低的特性。系统内部种植业和畜牧业的能值产出占绝对优势比例且其市场定价相对于林业和渔业偏低。(2)功能:该系统环境负载率虽不高,但是人口承受力超载。系统可持续发展指数为5.96,表明该系统富有活力和发展潜力,也意味着该系统经济并非常不发达、自然资源和环境的压力不是很大。(3)效率:该系统2009年的能值投入产出率略低于全国水平,表现出较明显的粗放型经济特点。因此,控制人口过快增长,转移剩余劳动力,进一步调整农业产业结构和产品结构,加强农业技术开发和利用,延长产业链,提高农业机械化和现代化水平是当前湖南农业的基本政策取向。

In order to explore the function and efficiency of emergy input-output of Hunan＇ s agro-ecosystem, and reveal the regional interrelationship among human, natural resources and environment, the author adopted emergy theory as the research method, and did empirical analysis on the emergy structure, function and efficiency of Hunan＇ s agro-ecosystem by utilizing the input-output data of Hunan agriculture in 2009. The results showed that： （1） Hunan agriculture had characteristics of traditional agricultural production, depended comparatively highly on the labor force and animal power. The contribution of chemical fertilizer on the system was the highest in industrial auxiliary emergy, and the agricultural mechanization level was still low. The proportion of renewable industrial auxiliary energy was also low, so the development potential and prospects of agricultural green energy were comparatively large. The products obtained low prices, which not only neglected the contribution of natural resources and environment, but also reflected the characteristics of short industrial chain and low added value of Hunan agriculture. The emergy output of planting industry and animal industry owned dominated proportion in the agro-ecosystem, while the product prices were lower than those of forestry industry and fishery industry. （2） The results showed characteristics of the system＇ s function. Though the system did not own a high environmental loading ratio, its carrying capacity of populatio~ was overloading. The system＇ s sustainable development index was 5.96 which not only showed its vitality and development potential, but also showed the undeveloped economy and not high pressure of natural resources and environment. （3） The results also showed characteristics of the system＇s efficiency. The emergy input-output of system was slightly lower than the national level in 2009, which showed relatively apparent extensive development characteristics. Therefore, it＇ s necessary to control the rapid population growth, transfer the rural surplus labor force, further adjust the agricultural structure and product structure, strengthen the development and utilization of agricultural technology, extend the industrial chain and enhance the agricultural mechanization and modernization level, which were the basic policy directions of Hunan Province.