辽东山区天然次生林间伐强度研究

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

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 m^3/a。林分的年凋落量以弱度间伐强度最大为2.93 t/hm^2,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/hm^2,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/hm^2而保留900～990株/hm^2是适合当地天然次生林的间伐强度。

Fixed samples were set at east Liaoning to the preferable thinning density for the natural secondary forests. The results 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 litterfall 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. , 17.6g 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.