水土保持林土壤改良效益评价研究

Benefit evaluation on soil improvement by the water and soil conservation forest

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 research of forest benefit evaluation is a hotspot and difficulty at present.We evaluated soil improvement benefit of water and soil conservation forest(WSGF).We tried to find a method that can be used for forest evaluation,and illustrated that comprehensive index of benefit evaluation on soil improvement of WSCF can be regarded as total objective layer of index system,and criterion layer consists of soil fertility,soil anti erodibility and anti sourability.The index layer is composed by soil enzyme activities,organic matter content,water stable aggregate content,mean weight diameter,disperse ratio,aggregate degree,soil rigidity,infiltrate coefficient and pH.To calculate the comprehensive index of benefit evaluation,the data of indexes practically measured should be translated into scalar quantity first.Then the comprehensive index could be calculated directly to hierarchy total array weights,or step by step according to hierarchy single array weights,which produced the same results.The comprehensive index should be emended to remove the influences of site factors and could be used to evaluate the benefits of different kinds of water and soil conservation forests.