生态系统服务价值评估研究进展——国外学者观点

生态系统服务的价值评估是目前生态学研究热点和存在较多争议的领域之一。争论的焦点主要集中在生态系统服务货币化评估的必要性和有效性。通过对大量文献的检索，较为系统地总结了国外学者的观点，特别是引起诸多争论的主要原因：一是由于生态系统本身的复杂性，各项服务之间存在着相互依赖的关系，使生态系统服务的分类本身就缺乏严格的标准，同时存在着时间和空间上复杂的尺度转换问题，从而使生态系统服务的价值评估容易出现重复计算；二是由于经济学方法本身存在着一定的局限性，对于不同的评估对象和评估目标往往需要选取不同的评估方法，每一种生态系统服务通常可以有几种不同的评估方法，评估结果在很大的程度上依赖于选择的不同方法．从而使得到的结果间缺乏可比性；三是由于生态系统不同于经济系统。有时用经济学方法对生态系统进行评估时往往很难反映出自然系统的价值，特别是当人类对生态系统服务的偏好随着时间和新信息的出现而发生变化时，可能会出现更大的差异。今后的研究应当着力于上述困难的解决，以便使生态系统的评估结果更加客观可信，为生态补偿机制建立和生态系统管理等提供有力支撑。

Review of foreign opinions on evaluation of ecosystem services

Since the early 1960s, especially after the publication of Costanza's famous article in Nature in 1997, evaluation of ecosystem services has been one of the hottest and most debated issues in the field of ecology and ecological economics. Different opinions were expressed regarding the necessity and validity of evaluation using economic methods. The main difficulties for economic evaluation were discussed. Firstly, the complexity of ecosystem, including interdependence and transition of spatial-temporal scaling of various ecological functions lead to repeated calculation and difficult in extrapolating evaluation results. Secondly, the economic methods have their own limitation and weakness. For instance, different methods have been chosen in accordance with evaluation objects and purposes, and evaluation results rely very much on the methods selected.These cause non-comparability between the results. Lastly, economic methods could not always reflect real values of natural ecosystems when preferences of human to ecosystem services change with time and appearance of new information. It is recommended that future studies should focus on the above issues so as to ensure an objective and reliable assessment result, and provide a strong support for establishing ecological compensation mechanisms and improving ecosystem management.