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森林效益评价是目前林业研究的热点 ,也是难点问题。通过评价水土保持林土壤改良效益 ,对效益评价的方法和思路进行了探索。指出水土保持林土壤改良效益指标体系的总目标层为效益评价综合指数 ,准则层包括土壤肥力、抗蚀性能和抗冲性能 3个方面 ,指标层由水稳性团聚体含量、有机质含量、土壤酶活性、p H值、平均重量直径、团聚度、分散率、土壤硬度和渗透系数构成。在计算效益评价综合指数时 ,首先要对各项指标的实测数据进行处理 ,使之转化为无量纲的标度值 ;然后可根据层次单排序的权值分步进行计算 ,也可按照层次总排序的权值直接计算 ,获得效益评价综合指数。为消除立地因子的影响 ,要对效益评价综合指数进行校正 ,校正后的综合指数可以反映出不同水土保持林土壤改良效益的好坏。
The evaluation of forest benefits is a hot topic in forestry research and also a difficult issue. By evaluating soil improvement benefits of soil and water conservation forest, the methods and ideas of benefit evaluation were explored. It points out that the total target layer of soil improvement benefit index system of soil and water conservation forest is comprehensive index of benefit evaluation, and the criterion layer includes soil fertility, corrosion resistance and impact resistance. The index layer is composed of water-stable aggregates, organic matter content, Enzyme activity, p H value, average weight diameter, agglomeration, dispersion, soil hardness and permeability coefficient. When calculating the comprehensive index of benefit evaluation, the measured data of each index should be first processed to be converted into a dimensionless scale value. Then the calculation can be performed step by step according to the weight of the single rank order, The weights of the rankings are calculated directly and the comprehensive index of benefit evaluation is obtained. In order to eliminate the influence of site factors, the comprehensive index of benefit evaluation should be corrected. The corrected composite index can reflect the soil improvement benefits of different soil and water conservation forests.