白石水库流域森林生态系统枯落物层和土壤层水文效应研究

Hydrological effects of litter layer and soil layer in forest ecosystem of Baishi Reservoir Basin

文章以白石水库流域3种典型林分类型为例,对其生态系统不同土壤层、枯落物层的水文特征利用浸泡法、环刀法进行定量分析。结果表明:枯落物蓄积量表现为落叶松<油松林<刺槐,总体处于23.21-39.22t/hm^2,且针叶林未分解层枯落物大于半分解层;枯落物层有效拦蓄量为41.65-90.63t/hm^2,最大持水量为50.90-109.41thm^2,均表现为落叶松<油松林<刺槐,枯落物层持水功能较好的为刺槐天然次生林;枯落物未分解与半分解层的浸水饱和时间为10h、8h,且二者存在显著的对数关系(R^2>0.91),枯落物达到最大吸水速率时间为1h,约4h明显减缓,浸泡时间与吸水速率间呈幂函数关系(R^2>0.93);3种植被类型的总孔隙度为27.85-30.17,土壤容重均值为1.09-1.24g/cm^3,有效持水量为21.67-29.57t/hm^2,土壤层持水能力表现为落叶松<油松林<刺槐,入渗时间与速率之间呈幂函数关系(R^2>0.90)。综合不同植被类型水文功能,白石水库流域刺槐天然次生林的水源涵养能力最强,在水土保持和生态环境治理应加强恢复和保护天然次生林。

Taking three typical forest types in Baishi reservoir basin as an example,this paper makes quantitative analysis on the hydrological characteristics of different soil layers and litter layers in its ecosystem by means of immersion method and ring knife method.The results show that the litter volume is larch,Pinus tabulaeformis and Robinia pseudoacacia,which is 23.21-39.22t/hm^2 in total,and the litter volume in the undifferentiated layer of coniferous forest is larger than that in the semi decomposed layer;the effective litter volume is 41.65-90.63t/hm^2,and the maximum water holding capacity is 50.90-109.41t/hm^2,which is larch,Pinus tabulaeformis and Robinia pseudoacacia,and the natural secondary forest of Robinia pseudoacacia has better water holding function in litter layer;the litter volume is 41.65-90.63t/hm^2,and the maximum water holding capacity is 50.90-109.41t/hm^2.The saturated time of the undifferentiated and semi decomposed layer is 10h and 8h,and there is a significant logarithmic relationship between them(R^2>0.91).The time of the litter reaching the maximum water absorption rate is 1H,which slows down obviously around 4H.The relationship between the soaking time and the water absorption rate is a power function(R^2>0.93).The total porosity of the three vegetation types is 27.85-30.17,the average soil bulk density is 1.09-1.24g/cm^3,and the effective water capacity is 21.The water holding capacity of soil layer is larch,Pinus tabulaeformis and Robinia pseudoacacia,and the relationship between infiltration time and infiltration rate is power function(R^2>0.90).According to the hydrological functions of different vegetation types,Robinia pseudoacacia natural secondary forest in Baishi reservoir basin has the strongest water conservation capacity,and the restoration and protection of natural secondary forest should be strengthened in soil and water conservation and ecological environment management.