沿坝地区3种典型林分类型枯落物层与土壤层水源涵养能力综合评价

Comprehensive Evaluation of Water Conservation Capacity in Litter and Soil Layer of Three Typical Forest Types Along the Highland Area

为了研究沿坝地区3种典型林分的枯落物层与土壤层的水源涵养能力,利用熵权法对林分的枯落物层和土壤层的相关因子进行了综合评价。结果表明:(1)枯落物层最大持水量:针阔混交林>油松林>落叶松纯林;有效拦蓄量:针阔混交林>油松林>落叶松纯林。(2)持水量与浸水时间的回归方程为Q=alnt+b(R^2>0.97),持水速率与浸水时间的回归方程为V=Kt^n(R^2>0.94)。(3)3种林分类型土壤总孔隙度的排序为:针阔混交林>油松纯林>落叶松纯林;土壤持水能力大小排序为:针阔混交林>落叶松纯林>油松纯林;3种林分土壤层的初渗速率差距比较大,大小排序为:针阔混交林>落叶松纯林>油松纯林;林分的稳渗速率大小排序为:针阔混交林>落叶松纯林>油松纯林;入渗速率与入渗时间回归方程为:f=at^(-b)(R>0.96)。(4)利用熵权法计算得出的权重大小排序为:枯落物最大持水量>枯落物有效拦蓄量=土壤持水力>初渗速率>土壤毛管孔隙度>土壤容重>枯落物蓄积量=土壤非毛管孔隙度,3种林分类型综合评分排序为:针阔混交林>油松纯林>落叶松纯林。针阔混交林为最优的水源涵养林,其在保持水土、涵养水源方面功能最强。

In order to study the water conservation ability of the litter layer and soil layer of 3 typical stands along the highland area,the entropy weight method was used to evaluate the relative factors of the litter and soil layers.The results showed that:(1)the maximum water holding capacity of the litter layer decreased in the order:Coniferous and broad-leaved forest>Pinus tabuliformis forest>Larix gmelinii pure forest;the effective retention amount decreased in the order:Coniferous and broad-leaved forest>Pinus tabuliformis forest>Larix gmelinii pure forest;(2)the regression equation of water holding capacity and soaking time was presented as Q=a ln t+b(R 2>0.97),and the regression equation of water holding rate and soaking time was presented as V=Kt n(R 2>0.94);(3)the total soil porosity of 3 types of forest types decreased in the order:Coniferous and broad-leaved mixed forest>Pinus tabuliformis forest>Larix gmelinii pure forest;the soil water holding capacity decreased in the order:Coniferous and broad-leaved mixed forest>Larix gmelinii pure forest>Pinus tabuliformis forest;the initial infiltration rate of soil layer of 3 kinds of stand was larger,the size decreased in the order:Coniferous broad-leaved mixed forest>Larix gmelinii pure forest>Pinus tabuliformis forest;the stable infiltration rate of the stand decreased in the oder:Coniferous and broad-leaved mixed forest>Larix gmelinii pure forest>Pinus tabuliformis forest;the regression equation of infiltration rate and infiltration time was presented as f=at-b(R>0.96);(4)the weights calculated by the entropy weight method followed the sequence:the maximum water holding capacity of the litter>the effective blocking amount of the litter=soil water holding capacity>initial infiltration rate>soil capillary porosity>soil bulk weight>litter volume=soil non capillary porosity,and comprehensive scoring of 3 types of forest type decreased in the order:Coniferous and broad-leaved mixed forest>Pinus tabuliformis forest>Larix gmelinii pure forest.Coniferous and broad-leaved mixed forest is the best water conservation forest,which has the strongest function of soil and water conservation.