两种生态系统服务价值评估方法比较研究——以四川省金堂县三星镇土地整治工程为例

乡镇土地整治是建设中国美丽乡村的重要途径,对当地生态环境带来正面和负面影响,如何准确评价其生态效益是国家开展土地整治和美丽乡村建设需要面临的重要科学问题。以中国西南部丘陵地区典型乡镇——四川省金堂县三星镇的土地整治工程为例,对比分析了生态系统服务价值当量修正法和单项服务评价法评估土地整治生态效益的异同,以期确定适合我国西南部丘陵地区乡镇土地整治生态效益评估的合理方法。研究结果表明:单项服务评价法的评估结果(生态系统服务价值约300万元)比当量修正法(生态系统服务价值约290万元)高3.5%。当量修正法评估的各项生态系统服务价值增量由高到低依次为:调节服务价值支持服务价值供给服务价值文化服务价值;单项服务评价法评估的生态系统服务价值增量大小排序为:调节服务价值支持服务价值文化服务价值供给服务价值。方法依据和参数的选取不同,导致评估结果具有显著差异,主要表现在单项服务评价法测算的维持养分循环价值、美学景观价值分别是当量修正法的46.90倍和6.94倍,当量修正法测算的水文调节价值是单项服务评价法的5.93倍。单项服务评价法针对各项生态系统服务特征,灵活地选取差异化评估方法,因而其评估结果更准确、真实地反映了生态效益价值。建议运用单项服务评价法评估我国西南部丘陵地区乡镇土地整治的生态效益。

Comparing two ecosystem service evaluation methods of the ecological benefits from a land consolidation project at a township level: a case study in Sanxing Town, Jintang County of Sichuan Province

Land consolidation project at a township level is one of key ways to build a beautiful countryside in China. However, an important scientific problem is how to evaluate the ecological benefits produced by the land consolidation at a township level. Two methods of ecosystem service valuation (ESV), namely equivalent correction and single ecosystem service, were used to evaluate the ecological benefits in a representative case study area-the Sanxing Town, Jintang County, Sichuan Province of China. In order to find a suitable evaluation method of the ecological benefits at a township level, a comparative analysis of differences of estimated results and reasons for the differences was conducted. It indicated that the value estimated by the single ecosystem service method (about 3.0×10⁶ Yuan) was 3.5% larger than that estimated by the equivalent correction method (about 2.9×10⁶ Yuan). Economic values of all kinds of ecosystem services, calculated by the equivalent correction method, decreased as follows:regulating service > support service > supply service > cultural service. While those calculated by the single ecosystem service method were in an increasing order:regulating service > support service > cultural service > supply service. Different bases and parameters for the two methods caused the significant differences in the evaluation results. Values of nutrient cycling maintenance service and aesthetic landscape service, estimated by the single ecosystem service method, were 46.90 and 6.94 times higher than those estimated by the equivalent correction method, respectively. Value of hydrologic regulation service, estimated by the equivalent correction method, was 5.93 times greater than that estimated by the single ecosystem service method. The single ecosystem service method more accurately and truly reflects values of ecological benefits than the equivalent correction method, since it uses different methods to flexibly evaluate any single ecosystem service according to its characteristics. Therefore, the single ecosystem service method is recommended for evaluation of ecological benefits produced by a land consolidation project in a hilly area of Southwest China at a township level.