喀斯特森林恢复演替过程中枯落物和土壤水文特征研究

Hydrological characteristics of litters and soil in restoration and succession of Karst forest

采用空间代替时间的方法,研究了茂兰退化喀斯特森林恢复演替过程中3个不同演替阶段（灌木、次生林和原生乔木林）的枯落物和土壤水文特征.结果表明：枯落物总储量在4.31～5.38 t/hm2之间,最大持水量在8.84～15.22 t/hm2之间,有效拦蓄能力在4.25～8.28 t/hm2之间;枯落物总储量、最大持水量和有效拦蓄能力均随演替进程逐渐增大.在枯落物持水过程中,前2h内各演替阶段枯落物不同分解层持水作用较强;枯落物持水量与浸泡时间呈明显对数关系,枯落物吸水速率与浸泡时间呈明显幂函数关系.土壤容重也随演替进程而增大,变化范围为1.07～1.22g/cm3;各演替阶段内土壤容重随土层加深逐渐增大.土壤饱和持水量随演替进程呈增大趋势,然而灌木土壤的有效持水量高于其他两个演替阶段,表明灌木在持水性能方面也发挥巨大作用。

Based on the method of taking space instead of time, hydrological characteristics of litters layer and soil layer in three succession stages of natural restoration of Karst forest vegetation in the Maolan National Nature Reserve of Guizhou were studied. We chose shrubs, secondary forests and primary forests to represent the prior-（PS）, middle- （MS） and later-succession （LS）, respectively. The results showed that the total storage, maximum water holding capacity and modified interception capacity of litters increased through succession. The corresponding values of mentioned above were 4.31-5.38 t/hm2, 8.84-15.22 t/hm2 and 4.25-8.28 t/hm2, respectively. During the process in water holding of litter layer, the water holding capacity and absorption speed in the first 2 hours was superior to the rest of time. Water holding capacity and immersed time had visible logarithmic relationship, whereas absorption rate and immersed time was power function relationship. The average of soil bulk density at 0-30 cm depth also increased through succession, which was 1.07-1.22 g/cm3. In addition, the soil bulk density increased with the soil depth increasing in each succession stage. The total soil porosity and soil water holding capacity increased along the process of succession. Compared with MS and LS, the effective retaining water storage of soil in shrubs didn＇t drop behind the other two types of Karst forests, which suggested that shrubs might also played an important role in forest eco-hydrological functions.