不同降雨等级及林分间伐强度对红松人工林穿透雨特征的影响

Effects of Different Rainfall Grades and Stand Thinning Intensities on the Characteristics of Throughfall of Pinus koraiensis Plantations

为明确间伐对红松(Pinus koraiensis)人工林水源涵养功能的影响程度,以本溪县草河口镇70年生不同间伐强度(对照区、中度区、极强区)的红松人工林为试验对象,研究了不同降雨强度下,不同间伐强度对红松人工林穿透雨率、产生过程及产流时间的影响,结果表明:穿透雨率随间伐强度增加而显著增加(P<0.05),当林外降雨量等级大于大暴雨级别时,受空间异质性等影响,中度区及极强区林冠截留降雨的能力达到了饱和状态,林冠截留能力减弱。穿透雨产流起始时间与降雨强度无关,与瞬时降雨强度有关,不同间伐强度都能减少降雨过程中的峰值,并延迟5 min,穿透雨产流结束时间与降雨结束时的雨强及时长有关。

In order to clarify the effect of thinning on water conservation function of Pinus koraiensis plantation,the 70-year-old Pinus koraiensis plantation with different thinning intensities(control area,moderate area and extremely strong area)in Caohekou area of Benxi County was studied.The effect of different thinning intensities on the throughfall rate,production process and runoff yield time of Pinus koraiensis plantation was studied.Result shows that the throughfall rate increase significantly with thinning intensities(P<0.05).When the rainfall grade outside the forest is greater than that of heavy rainfall,it was affected by spatial heterogeneity and other factors.The ability of canopy to intercept rainfall reach saturation state in extremely strong areas,and the ability of canopy interception was weakened.The beginning time of runoff generation of throughfall is not related to rainfall intensity,but to instantaneous rainfall intensity.Different thinning intensities can reduce the peak value in the process of rainfall and delay it for five minutes.The end time of runoff generation of throughfall is related to the intensity and duration of rainfall at the end of rainfall.