北京密云水库油松人工林对降水分配的影响

2004～2006年,对北京密云水库库西33年生的油松人工林的林冠截留、穿透降水和树干茎流进行了观测。观测结果表明,油松林冠截留率为31.67%,随着降水量的增大截留率迅速减小,并趋向于截留极限,油松林冠截留量与降水量呈幂函数关系。透流率为67.65%,穿透降水量与大气降水量之间呈极显著的正相关关系。干流率为0.68%,树干茎流量占降水量的比例极小,偏相关分析表明,树干茎流量与大气降水量、平均降雨强度及30 min最大雨强密切相关。

Influence on Precipitation Distribution of Pinus tabuleaefomis Forest in Miyun Reservoir

From 2004 to 2006, a Pinus tabulaeformis plantation which was 33 years old was observed to study canopy interception, throughfall and stenflow in western reservoir of Miyun of Beijing. The results showed that the average ratio of interception, throughfall and stenflow were 31.67%, 67. 65% and 0. 68%, respectively. The rates of interception dropped off rapidly and inclined to the terminal value with the increasing amount of precipitation. The relationship between the amount of canopy interception and precipitation was power function. There was a prominent and positive correlation between throughfall amount and precipitation amount. Stemflow contributions to total fluxes of rainfall are particularly small. Stemflow was close correlation with precipitation amount, average rain density and the maximal rain density in thirty minutes by partial correlation.