为探讨长江三峡库区次生植被的森林水文作用,对重庆四面山暖性针叶林的林冠截留影响因素及林冠截留效应进行了研究。结果表明:①该地区暖性针叶林林冠截留主要受气象因素和林分郁闭度的影响,各气象因子对林冠截留影响程度顺序依次为降雨量〉降雨强度〉气温〉空气湿度〉风速,其中,降雨量是影响林冠截留的主导因素;林分郁闭度越大,林冠截留量和林冠截留率越大,截留能力越强。②1号标准地林冠截留量与降雨量呈一元线性关系,2、3、4、5号标准地林冠截留量与降雨量呈幂函数关系,其达到饱和截留量时的降雨量依次为55.4、37.0、102.4、102.4mm。各标准地林冠截留量与降雨量的相关系数依次为0.977、0.670、0.617、0.790、0.817,且在O.01水平(单侧)上显著相关。在未达到饱和截留量之前,林冠截留量随降雨量的增加而增加,并逐渐趋向于饱和截留量;当林冠截留量接近或达到饱和截留量后,林冠截留量的增加会很少或者不再增加。
An experiment was conducted to study the effect of canopy interception of warm needle-leaved forest in Simian Mountain of Chongqing and its influencing factors in order to understand the water conservation function of secondary vegetations in the Three Gorges Reservoir Region of Yangtze River. Results show that the main factors influencing canopy interception of warm needle-leaved forest in this region are meteorological factors and canopy density. Rainfall has the most obvious impact on the canopy interception, followed by rainfall intensity, temperature, humidity and wind speed. With increasing canopy density, canopy interception amount and canopy interception rate increase and the capacity of canopy interception also becomes stronger. The relationship between the canopy interception amount of the sample plot No. 1 and the rainfall amount could be described by a unitary linear equation, while that between the canopy interception amounts of the sample plots No. 2-No. 5 and the rainfall amount could be expressed by a power function, and the rainfall amounts for each sample plot to reach the conditions when the canopy was saturated were 55.4, 37.0, 102.4, and 102.4 mm. The correlation coefficients between the canopy interception amounts of the five plots and the rainfall amount were 0. 977, 0.670, 0. 617, 0. 790, 0.817 respectively, indicating a significant relationship at the 0.01 level ( one side). Before reaching the saturated canopy interception, canopy interception amount increased with rainfall amount and gradually became saturated; when the canopy interception amount was close to or reached the saturation level, the interception amount slightly increased or no longer increased.