大辽河流域水源涵养林枯落物持水特性研究

为探求大辽河流域水源涵养林枯落物的持水特性,以大辽河流域红松、落叶松、蒙古栎、杨桦、山杨、杂木林、胡桃楸灌木林和荒草地为研究对象,通过野外观测和浸水法,建立了枯落物持水量、吸水速率和浸泡时间的相互关系。结果表明:(1)不同林分枯落物总厚度和现存量为蒙古栎最大,分别为4.83cm和30.70t/hm²;灌木林最小,分别为0.65cm和3.32t/hm²。(2)最大持水量为3.97~36.02t/hm²,最大拦蓄量为3.34~34.06t/hm²,有效拦蓄量为0.85~20.39t/hm²,均表现为蒙古栎林最大,而灌木林和草地最小。(3)浸水实验结果表明,枯落物持水量与浸泡时间之间存在对数关系,枯落物吸水速率与浸泡时间之间存在幂函数关系,不同森林类型枯落物持水量和吸水速率随时间的动态变化规律基本相似。

Water-holding Capacity of Litter of Forest for Water Conservation in Great Liaohe River Basin

Pinus koraiensis,Larix keampfari,Quercus mongolica,polar-birch,Populus davidiana,weed trees,Shrubbery of Juglans mandshurica and the grass land in Great Liaohe River basin were investigated and studied to explore the hydrological characteristic of litter layer of water conservation forest and the relations between water-holding capacity,water absorption rate and soaking time of litters were established through field investigate and soak experiment.The results indicated that:(1)Among all the types of litters, the total thickness and existing litter amount of Quercus mongolica were the largest,4.83cm and 30.70t/hm² respectively,and the shrubbery was the least with 0.65cm and 3.32t/hm² respectively.(2)The maximum water holding capacity ranged from 3.97t/hm² to 36.02t/hm²,the mixed water retaining capacity from 3.34t/hm² to 34.06t/hm²,and the most effective water reaining capacity from 0.85t/hm² to 20.39t/hm² with the highest value in the Quercus mongolicaforest and the lowest in grassland.(3)Soak experiments demonstrated that water holding capacity and soaking time had remarkable logarithmic correlation, while the absorption rate and soaking time was of a power function.The dynamic changes of the water-holding capacity and the water-absorption rate were generally similar for litters of different forest types.