塞罕坝华北落叶松人工林水源涵养功能研究

Study on water conservation function of Larix principis-rupprechtii Mayr. plantation in Saihanba Forest Farm, Hebei Province

为了评价塞罕坝地区华北落叶松人工林水源涵养功能高低,对塞罕坝地区30 a生不同密度的华北落叶松人工林的枯落物持水量、土壤水分物理特性进行研究。并依据土壤总毛管蓄水量和枯落物有效拦蓄量的大小评价不同密度林分水源涵养功能,将土壤总毛管蓄水量和枯落物有效拦蓄量归一统计,定义为水源涵养指数,作为林分的水源涵养功能的评判。结果表明：（1）对于研究的9个密度下的华北落叶松林,枯落物最大持水量是自身重量的3~4倍,最大持水率为249.98%～302.48%,人工林密度越大,持水量能力越大。（2）土壤总孔隙度为41.7%～62.9%。土壤的最大蓄水量为3 046.14～3 403.49 t/hm2,密度越大,土壤蓄水能力越强,当密度大于1 350株/hm2时,增大趋势趋于平缓。（3）枯落物和土壤的综合水源涵养指数随密度的增大而增大,最大值为最小值的1.29倍,当密度大于1 350株/hm2时,趋于稳定,且在1 350～1 800株/hm2之间,发挥的水源涵养功能较强。

In order to evaluating water conservation functions of Larix principis-rupprechtii Mayr.in Saihanba Region,the litter waterholding capacity and soil moisture physical characteristics of 30-year-old L.principis-rupprechtii plantations with different planting density were investigated.The water conservation functions of the plantations with different planting density were evaluated according to the effective water storage capacity of total soil capillary（EWSTSC） and the effective litter water-holding storage capacity（ELWHSC）.By making a normalization processing statistics of EWSTSC and ELWHSC,it was defined as a water conservation index to be used to judge forest’s water conservation functions.The results show that（1） for the studied larch stands with nine densities,the maximum water holding capacity litter was three ~ four times of itself weight,the maximum water holding rate was 249.98% ~ 302.48%,and the greater the plantation density,the greater water-holding capacity was.（2） the total soil porosity was in the context of 41.7% to 62.9%,the maximum storage capacity of the soil were in 3046.14 ~ 3403.49 t/hm2,the greater the soil density was,the higher the soil water storage capacity was,and when the density was greater than 1350 trees/hm2,the increasing trend became flatten.（3） the litter and soil water conservation index raised with the increase of soil density,the maximum value was 1.29 times of the minimum one,when the density was greater than 1350 trees/hm2,the indexes stabilized,and when the densities were between 1350 ~ 1800 trees/hm2,the water conservation functions reached the maximum.