北京市松山不同海拔油松林枯落物及土壤水文效应

以北京市松山4个海拔梯度(751,890,1 012和1 211m)的油松(Pinus tabuliformis Carr)天然林为对象,对其枯落物层及土壤层水文效应进行研究。结果表明:(1)枯落物总蓄积量、枯落物最大持水量和最大持水率均随海拔的升高先增大后减小;(2)枯落物的总储量为9.03~27.75t/hm2,最大持水量为26.66~90.54t/hm2,与浸泡时间呈明显的对数关系(R0.93);最大持水率为287.62%~296.73%,与浸泡时间呈明显的幂函数关系(R0.99);(3)土壤容重随海拔升高而减小,其变化范围为1.38~1.66g/cm3,总孔隙度随海拔升高先减小后增大;(4)土壤初渗速率相差较大,稳渗速率为1.95~7.06mm/min,入渗速率与入渗时间呈幂函数关系(R0.70)。综合分析得出,低海拔油松天然林水源涵养功能较强。

Hydrological Effects of Forest Litters and Soils of Pinus Tabuliformis Forest at Different Altitudes of Songshan Mountains in Beijing City

A preliminary study on hydrological effects of litter and soil layers in natural Pinus tabuliformis forest was carried out at four different altitudes(751, 890, 1 012 and 1 211 m) in the Songshan Mountains in Beijing City. Results showed that:(1) The total storage capacity, maximum water holding capacity and maximum water holding rate of litter increased firstly and then decreased with increasing altitude. (2) The total storage capacity of litter was about 9.03~27.75 t/hm². The maximum water holding capacity of litter was about 26.66~90.54 t/hm² and had a visible logarithmic correlation with immersion time(R>0.93). The maximum water holding rate of litter was about 287. 62%~296.73% and had a power relation with immersion time (R>0.99). (3) The soil bulk density decreased with increasing altitude in the range from 1.38 to 1.66 g/cm³. The total soil porosity decreased firstly and then increased with altitude. (4) The initial infiltration rates of soils were largely different and the steady infiltration rates varied from 1.95 to 7.06 mm/min. The infiltration rate had power function correlation with infiltration time(R>0.70). Generally, Pinus tabulaeformis forest at low altitude has a stronger water conservation function.