宁夏盐池地区3种林分枯落物层和土壤水文效应

Hydrological effects of forest litter and soil of three kinds of forest stands in Yanchi District,Ningxia of northwestern China

以宁夏盐池县2种人工林(新疆杨和樟子松)和1种天然林(花棒)林分为研究对象,以定量评价其枯落物和土壤的水文功能为目的,通过标准地调查、土壤物理性质及持水能力测定和入渗实验,对林地枯落物和土壤水分效应进行研究。结果表明:1)新疆杨林分枯落物储量最大,为7.86 thm2;樟子松林分最大持水量和有效持水量最高,为23.73和18.26 thm2,相当于2.37和1.83 mm的水深。2)樟子松林地土壤具有较好的水源涵养能力,土壤的最大持水量为349.12 thm2,相当于34.91 mm的水深,其有效持水量为85.75 thm2,是花棒的3.24倍,相当于8.58mm的水深。3)利用幂函数,无论是对枯落物吸水速度与浸泡时间还是对不同降雨条件下土壤入渗速率与入渗时间进行拟合,均有较高的拟合系数。4)利用Philip入渗方程对各林地1 m土壤深度入渗进行拟合,得到了不同林地土壤的入渗特性指标。

A study of hydrological effects of litter layer and soil layer was carried out in two artificial forest stands （Populus bolleana and Pinus sylvestris var. mongolica） and one natural forest stand （Hedysarum scoparium） in Yanchi County, Ningxia of northwestern China. Its hydrological function of litter and soil was evaluated quantitatively through investigating standard spots, determining soil physical characteristics and water-holding capacity, and experimenting on soil infiltration, determining litter and soil water-holding capacity. The results showed that： 1 ） the litter total storage capacity of P. sylvestris var. mongolica was the largest, up to 7.86 t/hm2 ; P. sylvestris var. mongolica stand had both the maximum water capacity and available water capacity, which were 23.73 and 18.26 t/hm2, equivalent to water depth of 2.37 and 1.83 mm separately. 2） The P. sylvestris var. mongolica stand had strong soil water-holding capacity and the maximum of which was 349.12 t/hm2 , equivalent to 34.91 mm water depth. The available soil water-holding capacity of P. sylvestris var. mongolica stand was 85.75 t/hm2, which was 3.24 times of H. scoparium stand, equivalent to 8.58 mm water depth. 3） Power function model can better reflect both water absorption speed of ground cover and its immersing time, and soil infiltrating rate and infiltrating time under different rainfall conditions, which had high correlation coefficient. 4） Using Philip infiltration model fitting the soil infiltration process（ 1 m deep soil） , soil infiltration characteristics of different forest stands were obtained.