典型喀斯特原始森林降水分配特征

Research on rainfall redistribution in karst natural forest

采用2008—2013年茂兰喀斯特原始森林降水观测资料,对降水截留动态变化规律及分配比例进行了系统的研究。结果表明:2008—2013年平均林外降水总量1 532.91 mm,穿透雨量、树干茎流量、树冠截留量分别占林外降水总量的80.99%、2.84%、16.17%,这三者与降水量均呈现极显著的线性关系(P<0.01),穿透雨率、截留率与降水量呈现对数函数关系。喀斯特森林水文各分量有明显的干季、雨季之分。与我国其他地区相比,喀斯特森林林冠截留率处于较低水平,而有较高的穿透雨率,增加了喀斯特森林林内有效降水,对喀斯特森林植被生长有积极的意义。

The characteristics of rainfall redistribution of Karst forest was studied ,which based on six years rainfall observation data from 2008 to 2013, the results showed that the average total rainfall was 1 532.91mm during the period of observation, the through fall, stem flow and canopy interception accounted for 80.99%, 2.84%, 16.17% of the rainfall in open field respectively. The line equation describing the relation between hrough fall, stem flow, canopy interception and rainfall in open field were fitted. The relationship between through fall rate, canopy interception rate and total rainfall could be described significantly by a logarithmic function. The proportions of the through fall, stem flow and canopy interception had great differences between dry and rain seasons. Compared with other areas in China, the canopy interception rate of Karst forest was low, and the through fall rate was higher, which increased the karst forest effective rainfall, and had positive significance for the growth ofkarst forest vegetation.