北京山区4种典型林分枯落物持水特性的定量分析

Quantitative analysis of water holding capacity of 4 typical forest litters in Beijing mountainous area

以北京山区4种典型林分为研究对象,测定各林分枯落物的蓄积量,并采用室内浸泡法对枯落物持水过程进行分析,结果表明:(1)林分枯落物厚度及蓄积量均表现为栓皮栎林>侧柏林>油松林>刺槐林,其中半分解层蓄积量占80%以上;(2)最大持水量变化范围为9~77 t/hm^2,有效持水量变化范围为6~53 t/hm^2;(3)枯落物持水过程表现为"迅速吸水-缓慢吸水-逐渐饱和",相同持水时间下,4种林分的未分解层枯落物持水量大小为刺槐>栓皮栎>侧柏、油松,半分解层枯落物持水量大小为栓皮栎>油松>侧柏>刺槐;(4)枯落物吸水速率随浸水时间的增加而减小,两者呈一定的幂函数关系(V=ktn)。

Four typical forests were selected to investigate the stock volume and water-holding capacity of litter layers,the results showed that ：（1） the order of total storage capacity of four litters showed as Quercus variabilis 〉Platycladus orientalis 〉Pinus tabuliformis〉 Robinia pseudoacacia,and the volume of half decomposition accounted for more than 80%;（2） the maximum capacity of litter layer ranged from 9 t/hm2 to 77 t/hm2,and the effective capacity ranged from 6 t/hm^2 to 53 t/hm^2;（3） the water holding of litters showed a process of ＂rapid absorptionslow absorption-gradual saturated＂;under the same soaking time,the water holding capacity of undecomposed litters showed as R. pseudoacacia 〉Q. variabilis〉 P. orientalis,P. tabuliformis,and the water holding capacity of half decomposed litters showed as Q. variabilis P. tabuliformis〉 P. orientalis〉 R. pseudoacacia;（4） the absorption rate decreased by immersion time,and they showed a power function relationship（V=ktn）.