Benefit evaluation on soil improvement by the water and soil conservation forest
水土保持林土壤改良效益评价研究

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.