冀西北不同林分类型土壤贮水与入渗特征

Characteristics of soil water storage and infiltration in different forest types in northwest Hebei Province

为改善冀西北森林水土保持和水源涵养的能力,在河北省张家口市涿鹿县林场选择油松、华北落叶松、山杨、白桦4种林分类型,以撂荒地作为对照,进行了土壤入渗和贮水特征的研究。结果表明,土壤饱和贮水量排序为:白桦林(373.24 mm)>油松林(352.72 mm)>山杨林(325.20 mm)>华北落叶松林(306.28 mm)>撂荒地(286.30 mm)。土壤容重均值排序为:白桦林(0.90 g/cm^(3))<油松林(0.95 g/cm^(3))<山杨林(0.99 g/cm^(3))<华北落叶松林(1.00 g/cm^(3))<撂荒地(1.27 g/cm^(3))。土壤入渗速率与入渗时间呈现明显幂函数关系,林分的土壤渗透性能均高于撂荒地,其中白桦林稳渗速率最大(5.21 mm/min),水土保持能力最好。土壤容重与土壤孔隙度、贮水量呈负相关关系。森林对非毛管孔隙(滞留贮水)的改善作用要大于毛管孔隙(吸持贮水)的改善作用。

In order to improve the ability of water and soil conservation and water conservation of forests in northwest Hebei Province,the characteristics of soil infiltration and water storage were studied in the Zhuolu Forest Farm of Zhangjiakou City,Hebei Province.Compared with abandoned land,four forest types were selected:Pinus tabulaeformis,Larix principis-rupprechtii,Populus davidilana and Betula platyphylla.The results showed that forest vegetation greatly improved soil water storage capacity,and soil saturated water storage was ranked as follows:Betula platyphylla forest(373.24 mm)>Pinus tabulaeformis forest(352.72 mm)>Populus davidilana forest(325.20 mm)>Larix principis-rupprechtii forest(306.28 mm)>abandoned land(286.30 mm).The order of soil bulk density was as follows:Betula platyphylla forest(0.90 g/cm^(3))<Pinus tabulaeformis forest(0.95 g/cm^(3))<Populus davidilana forest(0.99 g/cm^(3))<Larix principis-rupprechtii forest(1.00 g/cm^(3))<abandoned land(1.27 g/cm^(3)).The relationship between soil infiltration rate and infiltration time was a power function.The soil permeability of stands was higher than that of abandoned land.The Betula platyphylla forest had the highest steady infiltration rate(5.21 mm/min)and the best soil and water conservation ability.Soil bulk density was negatively correlated with soil porosity and water storage.The effect of forest on the improvement of non-capillary pore(retention water storage)was greater than that of capillary pore(absorption water storage).