白龙江上游不同演替阶段森林土壤入渗和持水特征

土壤入渗和持水性能对森林生态水文有着重要影响。为了解白龙江上游不同演替阶段森林土壤入渗特征和持水性能，在室内采用双环刀法对该地区土壤进行研究，测量土壤容重、孔隙度、持水量、渗透速率、根系含量等指标。结果表明:1)不同演替阶段森林土壤的容重、持水量、孔隙度的变化比较明显，并随着土层深度的增加土壤容重与持水量、孔隙度呈反比关系；2)土壤入渗速率在不同土层上各有差异，但总体有初渗速率＞平均渗透速率＞稳定入渗速率的趋势。在0~10 cm土层灌丛的渗透性能好，10~40 cm红桦林渗透性能优于其他林分；3)Kostiakov模型对不同植被类型不同土层的土壤入渗拟合的精度相对较高，尤其是对灌丛的拟合，是描述本研究区灌丛地土壤入渗特征最好的模型；4)植物粗根与土壤入渗呈负相关关系，与毛管持水量呈正相关关系，细根和中根与土壤入渗呈正相关关系，中根与毛管持水量呈负相关关系。

Characteristics of Forest Soil Infiltration and Water Holding Capacity in Different Succession Stages in the Upper Reaches of the Bailong River

Soil infiltration and water holding capacity have important effects on forest ecology and hydrology.In order to understand the characteristics of forest soil infiltration and water holding performance at different stages of succession in the upper reaches of the Bailong River,a double-ring tool method was used to study the soil in this area,and the indexes such as soil bulk density,porosity,water holding capacity,infiltration rate and root content were measured.The results showed that 1) the changes of bulk density,water holding capacity and porosity of forest soil in different stages of succession were more obvious,and the relationship between soil bulk density and water holding capacity and porosity was inversely proportional with the increase of soil depth.2) Soil infiltration rate varied in different soil layers,but the overall trend was that the initial infiltration rate>average infiltration rate>stabilize the infiltration rate.The permeability of 0-10 cm shrub soil layer was good,and the permeability of 10-40 cm red birch soil layer was better than other stands.3) Kostiakov model had relatively high accuracy in soil infiltration fitting of different vegetation types and different soil layers,especially for shrub,which was the best model to describe soil infiltration characteristics of the shrub land in this study area.4) There was a negative correlation between the crude root and soil infiltration,and a positive correlation between the capillary water holding capacity,between the fine root and the medium root and the capillary water holding capacity.