北京山区侧柏人工林水源涵养功能对抚育间伐的响应

通过对不同抚育强度下侧柏人工林的土壤及枯落物持水特性的研究,结果表明:抚育间伐5年后,弱度、中度、强度抚育样地土壤容重0-10cm处分别比对照样地降低9.5%,13.0%,18.9%,10-20cm处弱度、中度和强度抚育样地分别比对照降低0.3%,6.5%和9.8%;0-10cm处总孔隙度分别增加9.6%,13.1%,19.1%,10-20cm处分别增加-0.3%,6.3%,9.5%;水源涵养量分别增加5.5%,25.1%,32.1%;土壤总贮水量分别增加14.3%,4.6%,9.7%。与对照样地相比,各抚育样地枯落物蓄积量分别增加92.2%,268.3%,19.0%,最大持水率分别增加10.6%,28.4%,28.7%,持水量分别增加116.8%,379.3%,55.8%。方差分析显示,中度抚育和强度抚育效果与对照样地差异显著,说明抚育可改善土壤物理性质,减小土壤容重,增加土壤孔隙度,从而提高土壤水源涵养功能。因此从水源涵养的角度来说,在阳坡薄土条件下侧柏人工林更适宜采用中度和强度抚育措施。

Effects of Thinning on Water Conservation of Platycladus orientalis Plantation in Beijing Mountain Area

The research subject of this paper is to study the soil characteristics and hydrological effects of litter of Platycladus orientalis plantation with heavy,medium and light intensity thinning respectively,the results showed: Compared with nonthinning,the soil bulk density decreased 9.5%,13.0%,18.9% respectively at soil depth of 0-10 cm and decreased 0.3%,6.5% and 9.8% respectively at soil depth of 10-20 cm;the soil total porosity increased 9.6%,13.1%,19.1% respectively at soil depth of 0-10 cm and increased-0.3%,6.3%,9.5% respectively at soil depth of 10-20 cm;water conservation increased 5.5%,25.1%,32.1% respectively;the total water holding capacity increased 14.3%,4.6%,9.7% respectively after different intensity thinning after 5 years.Contrasted with the control,the litter amount increased 92.2%,268.3%,19.0% respectively,maximal litter water retention rate increased 10.6%,28.4%,28.7%,litter water retention increased 116.8%,379.3%,55.8% respectively.Variance analysis shows that there are notable differences between the treatments of medium,heavy intensity thinning and the control which indicated that thinning measure can improve the soil physical properties,reduce soil bulk density,increase the soil total porosity and improve soil water conservation.Therefore,the medium and heavy intensity thinning measure is more favorable for Platycladus orientalis plantation according to the water conservation.