冀北山地桦木林土壤水分物理性质研究

Study on soil water physical properties of Betulaforests in northern mountain of Hebei province

以4种不同桦木组成比例的林分类型为研究对象,比较其土壤水分-物理性质,结果表明:土层深度与容重呈正相关,落桦混交林土壤容重最大(1.14g/cm^3),桦木混交林最小(1.00g/cm^3);土壤孔隙度整体规律基本一致,随土层深度增加而减小,土壤毛管孔隙度、非毛管孔隙度、土壤总孔隙度均是黑桦纯林最大,分别为45.0%、9.6%、53.6%;土壤持水量(除桦木混交林规律不明显外)整体规律基本一致,随土层深度的增加而减小,土壤毛管持水量均值桦木混交林最大(43.2%),土壤最大持水量均值黑桦纯林最大(49.3%);土壤入渗速率与时间呈幂函数关系,初渗速率和稳渗速率规律一致,均是桦木混交林最大、桦杨混交林最小。

This article took four different tree species compositions of Betula spp. forests as the research objects to compare the laws of soil moisture physical properties. The results showed that： （1） Depth of soil layer and bulk density were positively correlated. The biggest average soil bulk density was mixed Larix principis-rupperchtii and Betula platyphylla （1.14 g/cm3）, while the smallest was Betula mixed forest （1.00 g/cm3）. （2） The law of soil porosity was basically the same, which decreased with the in- crease of soil depth. The soil porosity, non-capillary porosity, and the total soil porosity of Betula dahuri- ca forest were all the highest, which were 45.0%, 9.6%, and 53.6% respectively. （3） Soil water holding capacity decreased with the increase of soil depth, except for Betula mixed forest. Betula mixed forest had the biggest soil capillary water-holding capacity （43.2%）, while the biggest soil maximum water-holding capacity was Betula dahurica forest （49.3%）. （4）The soil infiltration rate and infiltration time was power functional relationship. The initial infiltration rate and steady infiltration rate were consistent, the value of which were the biggest for Butula mixed forest, and the smallest for mixed Betula platyphylla and Populus davidiana forest.