辽东山区天然次生林间伐强度研究

在辽东山区某试验林场内设置固定标准地,观察间伐强度对天然次生林的作用效果,从而确定最佳的间伐强度.经过分析,强度间伐和中度间伐强度下,林分保留株数死亡较少而对照区死亡较多.不同间伐强度下,活立木蓄积量增长率最高的为中度间伐区,可达到0.247 m3/a.林分的年凋落量以弱度间伐强度最大为2.93 t/hm2,中度间伐与对照相差10.55,枯枝落叶的贮量以弱度间伐区最大为17.68 t/hm2,中度间伐与对照相差25.故中度间伐可以促进林地养分循环.认为伐去450株/hm2而保留900～990株/hm2是适合当地天然次生林的间伐强度.

A Study on Thinning Density of Natural Secondary Forest in Liaoning East

Fixed samples were set at east Liaoning to the preferable thinning density for the natural secondary for- ests.The resuhs showed that the mortality rates of the remaining trees were lower at the mid-thinning and high- thinning intensity.The rate of increase of the living tree was largest,under the mid-thinning intensity among all thinning intensities,which could reach 0.247 m~3/a.The annual litteffall under ebb-thinning intensity was the highest,which could reach 2.93 t/hm~2.The annual litterfall under mid-thinning intensity was 10.55% less than that of control.The rate of reservation of annual litterfall was the highest,i.e.,17.68 t/hm~2 under ebb-thinning intensity,under mid-thinning intensity however,the rate was 25% less than that of control.It was concluded that mid-thinning intensity could promote nutrient cirulation in forest soil.The preferable thinning intensity for natual secondary forest was to cut 450 trees/hm~2 and to maintain 900-990 trees/hm~2.