通过对贡嘎山亚高山峨眉冷杉与冬瓜杨演替林连续两年林下降水与树干径流的实验观测, 分析研究了演替林林下降水、树干径流、林冠截留的变化特征, 并验证了Gash(1995)模型模拟该区林冠截留的适用性. 结果显示, 2008年和2009年贡嘎山亚高山演替林林下降水分别占降水量的76.4%和77.0%, 树干径流量较小, 可以忽略不计, 林冠截留量分别为23.6%和23.O%. Gash(1995)模型中蒸散发参数采用Penman-Monteith公式计算, 饱和冠层储水量采用Preira法, 模型对整个湿季的林冠截留模拟效果较好, 2008年模拟值与实测值分别为125.6mm和126.1mm, 2009年均为150.1mm, 说明Gash(1995)模型在该区具有较好的适用性

Gross rainfall, throughfall and stemflow were measured during the growing seasons of two tree species of Abies afbri and Populus purdomii in 2008 and 2009 in a subalpine succession forest on the Gongga Mountain. Throughfall (the net precipitation under the two tree species), steamflow and canopy interception are analyzed. In addition, the applicability of the Gash model (1995) is examined using the measurement. The model requires only a limited amount input and uses the Penman-Monteith equation for evapotranspiration estimation. The capacity of the canopy storage is calculated using the Preira method in the model. The results show that the throughfall can account for 76.4% and 77.0% of gross rainfall in 2008 and 2009, respectively, while the stemflow is too small to contribute the gross rainfall, and the remaining is intercepted by canopies. The amount of gross rainfall is found to be the main influential factor on the interception process compared to the rainfall duration and intensity. Simulations of canopy interceptions agree well with the observed values for the two growing seasons. For example, the values of simulated and observed interceptions are respectively 125.6 mm and 126. 1 mm for the growing season of 2008, which illustrates that the applicability of the Gash model in this region