华北落叶松林不同坡位土壤含水量对降雨的响应OA北大核心CSTPCD

To clarify the differences soil moisture content in response to rainfall at diverse slopes of forested hillslope,a typical hillslope covered by Larix gmelinii var. principis-rupprechtii plantation in the semi-humid zone of Liupan Mountain was selected for this study. Meteorological factors such as rainfall and variations in soil moisture content in the rhizosphere at 0-60 cm and different slope positions(upper,middle,and lower slopes) were observed continuously from May to October of 2022,and the response of soil moisture content to varied rainfall events and their slope position differences within the growing season were analyzed. Our results showed differences in soil moisture content among slope positions,with the mean values showing a upper>middle>lower slope pattern,with the fluctuations in soil moisture content being the greatest in the middle slope. Moreover,rainfall recharge of soil moisture content varied by slope,with the recharge thresholds being lowest(1.9 mm) in the middle slope and highest(2.3 mm) in the lower slope. Slope differences were also observed in the response of soil moisture content to rainfall at various rhizosphere levels. The response duration of soil moisture content in the 0-20 cm soil layer was the shortest for all slopes under light rainfall conditions. However,the duration of soil moisture content response was shorter in the 40-60 cm soil layer than in the 20-40 cm soil layer at the top and middle of the slope under moderate and heavy rainfall events. These observations indicated that there might be a preferential flow of water in the soil at the middle and upper slopes. The results of this study are important for understanding soil moisture movement and its redistribution on slopes.