抚育间伐对北京山区油松幼龄人工林水源涵养功能的影响

通过对不同抚育强度下油松人工幼龄林的土壤及枯落物特性的研究,结果表明:5年后,弱度、中度、强度抚育样地土壤容重0-10cm处分别降低2.2%,4.1%,10.3%,10-20cm处分别降低3.2%,4.5%,15.3%,总孔隙度0-10cm处分别增加3.0%,5.8%,10.2%,10-20 cm处分别增加3.1%,7.2%,17.8%;水源涵养量分别增加12.2%,48.7%,44.4%;土壤总贮水量分别增加3.1%,6.5%,13.8%.与对照相比,各抚育样地枯落物蓄积量分别增加19.0%,91.7%,60.2%,最大持水率分别增加4.5%.23.3%,16.5%,持水量分别增加24.3%,135.5%,86.9%.方差分析显示,强度抚育和中度抚育效果差异显著,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.因此在阴坡厚土条件下,从水源涵养的角度来说,油松人工幼龄林更适宜采用强度和中度抚育措施.

Effects of Thinning on Water Conservation of Young Pinus tabulaeformis Plantation in Beijing Mountain Area

The research subj eet of this paper is to study the soil characteristics and hydrological effects of litter of young Pinus tabulaeforrnis plantation with heavy,medium and light intensity thinning respectively,the results showed:5 years later,compared with non-thinning,the soil bulk density decreased 2.2%,4.1%,10.3%respectively at soil depth of 0-10cm and decreased 3.2%,4.5%,15.3%respectively at soil depth of 10-20 cm;the soil total porosity increased 3.0%,5.8%,6,10.2%respectively at soil depth of 0-10 cm and increased 3.1%,7.2%,6,17.8%respectively at soil depth of 10-20 cm;water conservation increased 12.2%,48.7%,44.4%respectively;the total water-holding capacity increased 3.1%,6.5%,13.8%respectively after different intensity thinning.Contrasted with the control,the litter amount increased 19.0 %,91.7 %,,60.2%respectively,maximal litter water retention rate increased 4.5%,23.3%,16.5%,litter water retention increased 24.3%,135.5%,86.9%respectively.Variance analysis shows that there are notable differences between the treatments of heavy,medium 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 heavy and medium intensity thinning measure is more favorable for young Pinus tabulaeforrnis plantation according to the water conservation.