基于能值理论的生态资本价值——以阜康市天山北坡中段森林区生态系统为例

Study on the value of ecological capital based on the emery theory:A case study on the forest ecosystem in the middle part of the north slope of the Tianshan Mountain

能值理论是美国生态学家H.T.Odum依据系统生态学的基本原理和方法提出的,它通过对生态系统能量-价值过程的分析,为生态经济学的研究提供了新的理论和方法。以能值理论为基础,以位于阜康市的天山中段北坡森林区生态系统为研究对象,对系统生态资本的能值流量、资本存量进行了初步的研究,同时,对生态系统服务价值和系统的生态安全也进行了延伸研究。研究结果表明,这里每年的能值流量达6.36×1020sej,相当于货币流2.61亿美元;其中输入能流2.01×1020sej,占系统总能流的31.58%;系统滞留能流1.85×1020sej,占29.01%;输出能流2.51×1020sej,占39.41%。这说明生态系统对能量具有放大作用,进入生态系统的能量虽然在量上没有变化,但却发生了质的变化,低质的能量变成了高质的能量,而且生态系统越复杂,这种转换效率越高。生态资本存量达9.97亿美元,主要存在于土壤中,占资本总量的90.69%,其次是淡水。这说明水、土是生态系统之本,植被之价值不在于其本身,而在于其保持水土的功能。在延伸研究中,生态系统服务价值为1.19亿美元,其中涵养水源4780万美元,占总价值量的40.25%,保持土壤5580万美元,占46.99%。研究还表明目前研究区生态系统处于较为安全的状态,但面临的挑战很大。

The emergy theory was founded by H.T.Odum, an American ecologist. The emergy theory is based on the theory and methods of the System Ecology. The theory holds that the maintenance and evolution of an ecosystem depends on energy. However, when the energy transfers from lower levels to higher ones, there will be a great loss in the process. So, forming 1J higher quality energy will need a large amount of lower quality energy. In other words, different forms of energy have different attributions. By dealing with the energy-value-process of ecosystem, the theory provides us with a new approach to the economic ecology. This paper attempts to develop a new method to study the function and value of ecological capital by focusing on the forest ecosystem in the middle part of the northern slope of the Tianshan Mountain in Fukang ,Xinjiang Autonomous Region based on the Emergy Theory. This paper deals with four aspects of ecological capital: emergy flows, ecological capital deposit, ecosystem service value, and ecological safety. Emergy flows are new quantities of ecological capital every year. Ecological capital deposit is the total capital quantity of an ecosystem. Ecosystem service value includes not only emergy flows, but also some dummy emergy flows. Ecological safety is related to the input and output of system emergy. If energy input into ecosystem was more than its output, the ecosystem would be safe; on the other hand, if emergy input into ecosystem is less than the output, the ecosystem would be unsafe. Although the quantity of the energy which passes through the system does not change, the quality may be enhanced. In other words, due to the processes in the ecosystem, lower quality energy may become higher quality one. Following the improvement of the complexity of the ecosystem, this translation ratio is higher and higher. This study shows that the emergy flows of the study region are about 6.36×10~20 sej/a, or about US$~261 000 000. The capital deposit reaches about 2.43×10~22 sej,or about US$997 000 000, which is mainly in soil which accounting for about 91% of the total. The second is water. This shows that the soil and water holding are the main function of the ecosystem. There are still two problems involved: (1) the value of the forest ecosystem services, and (2) the safety of the ecosystem. The value of the forest ecosystem services reaches about US$145 000 000. The main is water holding, US$~47 800 000, which accounts for 40.25% of the total, and soil conservation, US$55 800 000, which accounts for 46.99% of the total. This study also shows that the ecosystem is safe at present, but it may be threatened when faced with tourism exploitation.