樟子松固沙林土壤水分动态对降雨入渗的响应

[目的]分析樟子松固沙林土壤水分动态对降雨入渗过程的响应,为深入研究沙地人工林土壤水分管理提供科学依据。[方法]采用Watchdog土壤水分自动监测系统测定了浑善达克沙地2个生长周期内沙地樟子松林和流动沙丘0—120cm土层水份含量的动态,并选择3种降雨事件探讨樟子松林土壤水分对降雨入渗的响应过程。[结果]在降雨量19.4mm时,樟子松林地降雨入渗到达20cm所需要时间为4h,而流动沙丘为5h;降雨量30.2mm时,樟子松林地降雨入渗到达40cm所需要时间为13h,而流动沙丘为9h;降雨量47.1mm时,樟子松林地降雨入渗到达80cm所需要时间为27h,而流动沙丘为24h。降雨19.4~47.1mm时樟子松林地降雨入渗深度可达80cm,而流动沙丘在降雨19.4mm时降雨入渗深度则超过80cm,降雨30.2mm或47.1mm时,降雨入渗深度则超过120cm。[结论]不同降雨事件对樟子松林不同土层降水入渗进程和降水入渗深度有明显影响。

Response of Soil Water Dynamics in Scotch Pine Sand-fixation Forest to Rainfall Infiltration

[Objective] The response of soil water dynamics in Scotch pine sand-fixation forest to rainfall infiltration was analyzed to provide basis for further studying sand soil water management.[Methods] Watchdog soil moisture automatic monitoring system were used to record soil water content of 0-120 cm soil layers in Scotch pine(Pinus sylvestnis) sand-fixation forest in Hunshandake sandland, form June 20 to October 31 year 2014, and form May 1 to September 30 year 2015, respectively. And at the same time, we selected the 3 kinds of rainfall events to study soil moisture content variation with respect to rainfall infiltration under different influence processes in different depth soil layers of Scotch pine sand-fixation forest.[Results] In 19.4 mm rainfall event, it took 4 h for the rainfall infiltration reached to 20 cm soil layers in Scotch pine sand-fixation forest, it took 5 h in moving sanddunes; in 30.2 mm rainfall event, 13 h and 9 h elapsed when the rainfall infiltrations reached to 40 cm soil layers in Scotch pine sand-fixation forest and in moving sanddunes; in 47.1 mm rainfall events, 27 h and 24 h elapsed when the rainfall infiltrations reached to 80 cm soil layers in Scotch pine sand-fixation forest and in moving sanddunes. Depth of rainfall infiltration in Scotch pine sand-fixation forest reached to 80 cm soil layers in 19.4~30.2 mm rainfall events comparatively, depth of rainfall infiltration in moving sanddunes was more than 80 cm soil layers even in 19.4 mm rainfall events, it was more than 120 cm soil layers in 30.2 mm or 47.1 mm rainfall events.[Conclusion] Different rainfall events significantly affected on rainfall infiltration process and depth of rainfall infiltration in Scotch pine forest.