摘要
采用不同林龄长白落叶松人工林的60株优势木数据建立林分饱和密度模型,编制了经营密度表,再利用26块密度近似于合理经营密度的不同生长阶段样地的平均胸径增长量、径阶分布和总蓄积量的分析,评价以经营密度表指导抚育间伐的过程及效果。结果表明:随平均胸径的增大林分密度不断减少,方程N=3 847.345 1e-0.082D适用于预估林分密度,编制的经营密度表反映了0.6~0.8郁闭度下长白落叶松各个生长阶段的最适林分密度。26块模拟样地的间伐前密度为2 883株/hm2,经历3次间伐后的林分平均密度分别为2 000、1 400和1 000株/hm2,最终成熟林的平均林分密度为600株/hm2,树冠竞争因子为416.33,总蓄积量为242.12 m3/hm2,大径材比率达59.26%。
Based on 60 different aged dominant tree data in Larix olgensis Herry.plantations,saturated density model was built,and then complied the reasonable density table by diameter series.According to the table,we chose 26 plots which had similar values with reasonable densities of different age stages as test samples.Investigation and statistical results of mean values of diameter increment,diameter distribution and volume in the 26 plots were used to analyze and access the process and effect of thinning.Results showed that stand density declines with the increment of diameter,and an exponential functions of N=3 847.345 1e-0.082D was available for estimating reasonable density.The reasonable density table showed the optimum densities of age series between 0.6-0.8 cover closure.Average stand density before thinning of 26 sampling plot was 2 883 trees/hm2,and average stand densities after 3 times thinning were respectively 2 000,1 400,and 1 000 trees/hm2.In mature forest,the density was 600 trees/hm2,crown competition factor(CCF) was 416.33,the whole volume was 242.12 m3/hm2,and the ratio of big-diameter log was 59.26 %.
出处
《南京林业大学学报(自然科学版)》
CAS
CSCD
北大核心
2012年第6期69-75,共7页
Journal of Nanjing Forestry University:Natural Sciences Edition
基金
国家林业公益性行业科研专项项目(200904003-1)
国家林业局“948”项目(2008-4-48)
关键词
长白落叶松
人工林
合理密度
间伐
直径分布
蓄积量
Larix olgensis Herry.
plantation
reasonable density
thinning
diameter distribution
volume