小陇山林区日本落叶松人工林林冠截留特征

Characteristics of Canopy Interception of Larix kaempferi in Xiaolongshan Forest

2011年4月—10月7个月在秦岭西段小陇山林区对25年生日本落叶松人工林共33次降水事件的林冠截留特征定位观测,期间,林外大气降水总量为951.30mm,林冠截留率、树干茎流率、穿透率分别为16.63%、0.86%和82.51%;不同雨量级分析,穿透降水量和穿透降水率、树干茎流量和树干茎流率、林冠截留量均随着总降水量的增加呈递增趋势,而林冠截留率则随着大气降雨量和林内净降水量的增加呈递减趋势。比较相近雨量下的不同降雨强度林冠截流变化,降雨强度越大林冠截留量和截留率越小,表明持续时间较短强度大降雨,林冠截留量少,截留率亦小;强度小历时较长的降雨,截留量和截留率都大。当林外降水量>0.5mm时才观测到林内穿透雨。树干茎流的变化幅度不大。

Based on the orientational observations from April to October 2011, canopy interception characteristics of 25 a Larix kaempferi plantation were studied in Xiaolong Mountain forest region. The results showed that in the total precipitation of 951.30 mm from 33 times observation, the canopy interception, the stemflow and the throughfall accounted for 16.63%, 0.86% and 82.51% of total precipitation, respectively. Based on analysis of different rainfall classes, the higher the rainfall class, the greater the throughfall and the stemflow and the interception, the greater the throughfall ratio and stemflow ratio, and the lower the interception ratio. Under similar rainfall conditions, the higher the rainfall intensity, the lower the interception and interception ratio. It indicated that the interception and interception ratio in rainfall of short duration and high intensity were lower than that in rainfall of long duration and low intensity. Throughfall was observed when precipitation〉0.5 mm. The rangeability of stemflow was tiny.