我国人工林生态系统的水成本核算

健康的生态系统能够提供水土保持、防风固沙、涵养水源、调节气候、减少环境污染、增加游憩地与文化保护等良好的生态服务价值。然而,生态环境修复与建设不仅需要巨大的经费投入,也需要占用大量的自然资源。为了正确理解人工造林活动的成本问题,论文用7种蒸散发模型首次对我国1949年以来人工造林和自然植被恢复的耗水量及人工造林耗水量的机会成本进行计算,初步了解人工修复活动对水资源供给的影响。结果显示,1952—2011年我国人工造林累计耗水量比自然修复多767×10⁸ m³,水机会成本累计536×10⁸元。为了维护生态平衡,生态修复（尤其是人工修复）和经济活动都应关注水资源的成本问题,通过不同措施的成本效益比较,最大限度地降低生态修复成本,这是修复生态学需要面对的重要科学问题之一。

Water Costs of Afforestation and Natural-restoration in China

It’s well known that a healthy ecosystem has potentials in conservation of water and soil, prevention of wind erosion, refining regional water environment, regulating climatic, reducing pollution, increasing recreation and cultural protection, and other ecosystem services. However, ecological environment restoration and construction not only demands a huge amount of investment, but also takes up large quantities of water and soil resource. In order to properly figure out the costs of afforestation programs, for the first time, in this paper we used seven evapotranspiration models to calculate the water consumption of afforestation and natural vegetation and the water cost of afforestation since 1949. We found that the water consumption of afforestation was more than that of natural vegetation by 767×10⁸ m³, and the accumulative opportunity cost of water was 536×10⁸ yuan. To maintain the ecological balance, any ecological restoration, especially artificial restoration, and socio-economic activities should spare no efforts to pay attention on water cost. It is an essential issue encountered by restoration ecology to minimize the cost of restoration and improve the net value of ecosystem service by comparing cost-effectiveness of different measures.