双台河口湿地生态系统物质生产服务价值评价去重复性计算研究

Study on Double Counting in Shuangtai Estuary Wetland Ecosystem Material Production Service Valuation Base on Emergy Algebra

重复性计算在生态系统服务评价研究中是一个突出的问题,严重影响评价结果的准确性,如果不能正确地去除湿地生态系统服务价值评价中重复计算的部分,会使评价结果的可信度降低。文章在传统能值理论的能值转换率基础上,根据能值流程图,提出了能值转换系数的概念,对双台河口湿地生态系统物质生产服务价值进行了评价,以期找到合理的方法将评价过程中产生的重复性计算剔除,使得评价结果更加准确。通过对稳定系统中"分离(split)"、"反馈(feedback)"、"共产物(co-product)"3个基本机制的"预先分析"以看出,未经能值流程图预先分析的能值转换系数结果与经预先分析的结果相比,存在12%~38%的误差,预先分析后的结果更加准确。在此基础上,对双台河口湿地生态系统物质生产服务价值及重复性计算进行了评价。研究结果显示,双台河口湿地生态系统物质生产服务功能年能值价值为34.54×10^(19) sej·a^(-1),在评价过程中产生的重复性计算量为5.95×10^(19) sej·a^(-1),评价过程中重复性计算剔除率为15%,表明在对双台河口湿地物质生产服务进行价值评价时,产生的重复性计算问题不可忽视。通过对湿地生态系统服务流程图的描绘,可以有效剔除评价过程中产生的重复性计算,更加精确地量化湿地生态系统服务的价值。同时,该方法不仅适用于湿地生态系统,对其它生态系统服务价值的评价也有一定借鉴意义。

Ecosystem services valuation has made certain progress, but double counting still occurs. If this double counting problemcannot be removed appropriately, the credibility of the evaluation results will be reduced. Based on the transformity of traditionalenergy value theory, according to the energy value flow chart, the concept of energy conversion coefficient is put forward to evaluatethe material production services of Shuangtai estuary wetland ecosystem and the double counting error. By establishing the flowchart of emergy, this paper analyzed the three basic mechanisms―‘split, feedback, and co-product’ in the wetland ecosystem servicesto avoid the double counting error, we compared the calculated results with precondition to the results without precondition, and theerror range was from 12% to 38%. On that basis, the value of the material production service in the Shuangtai estuary wetland wasevaluated. The results showed that the value of the material production service in the Shuangtai estuary wetland is 34.54×1019 sej·a-1,during the process of the evaluation, the amount of double counting is 5.95×1019 sej·a-1, the double counting rate of the evaluationprocess is 15%, which indicates that the double counting problem cannot be ignored. Our results indicated that associating withemergy and the preconditioning analysis of the system can remove the double counting effectively and make the evaluation resultsmore accurate. Meanwhile, this method is not only suitable for the wetland ecosystem, but also has certain reference significance forother ecosystem service value evaluation.