土桥沟流域不同林分枯落物的水文特性

Hydrologic Characteristics of Litter under Different Forest Types in Tuqiaogou Watershed

通过对土桥沟流域5种主要林分类型的枯落物蓄积量及其持水性能的研究,分析了不同林分类型枯落物的蓄积量、持水量、吸水速率等特性.结果表明:各林分枯落物蓄积量油松>刺槐>油松刺槐混交林>白榆>侧柏,蓄积量3.00～7.28 t·hm-2.枯落物层最大持水量油松>油松刺槐混交林>刺槐>白榆>侧柏,最大持水率侧柏为256.67%,油松刺槐混交林为244.42%,白榆为224.00%,刺槐为214.05%,油松为177.43%.枯落物未分解层和半分解层在前0.25 h吸水速率最大,在前2 h内吸水速率降低幅度最大,以后逐渐减弱,浸水24 h时吸水速率趋近于零.

The litter preservation and its water-holding capacity in five main forest types at Tuqiaogou watershed were studied.The litter preservation,water holding capacity and water absorption speed,ect.were determined.The result showed that the litter amount in different forests followed the sequence of Pinus tabulaeformis>Robinia pseudoacacia>P.tabulaeformis and R.pseudoacacia>Ulmus pumila>Platycladus orientalis,the quantity ranging from 3.00 to 7.28 t/hm2.The maximum water holding capacity of litter in different forests was in the order of P.tabulaeformis>P.tabulaeformis and R.pseudoacacia>R.pseudoacacia>U.pumila>P.orientalis.The maximum rate of water retention of P.orientalis was 256.67%,P.tabulaeformis and R.pseudoacacia mixture 244.42%,U.pumila 224.00%,R.pseudoacacia 214.05% and P.tabulaeformis 177.43%.For litter undecomped or semi-decomposed,the water absorption speed was very fast in the beginning 0.25 hours;within first 2 hours water absorption speed droped quickly and would approach to 0 after immersion for 24 hours.