摘要
采用完全随机区组设计,分析不同造林密度对托里桉大径材生长的影响,为培育实木用途的托里桉大径材人工林提供参考.结果表明:3种不同造林密度对22年生托里桉的胸径、树高、单株材积、大径级的株数比率和材积率影响极显著,对保存率、蓄积量和离散度影响显著.造林密度为1 000株·hm‒2时,托里桉的保存率、胸径、树高、单株材积、大径级蓄积、林分蓄积量和净利润均达到最大值,分别比密度为1 667株·hm‒2时增加了21.35%、18.79%、18.35%、55.89%、100.00%、14.94%、74.44%;其离散度为1.022,接近临界值1.造林密度为1 000株·hm‒2时,托里桉大径材人工林各项生长指标均为最优,22 年生时的保存株数为 846 株·hm‒2,蓄积量达276.80 m3·hm‒2,净利润达 276 617 元·hm‒2,生产力与经济效益较高.
Abstract
A completely randomized block design was used to analyze the effects of different afforestation densities on the growth of large-diameter timber of Corymbia torelliana,providing a reference for the cultivation of large-diameter timber plantations of C.torelliana for solid wood use.The results showed that three different afforestation densities had a highly significant impacted on the diameter at breast height(DBH),tree height,individual volume,number ratio and volume ratio of large-diameter classes of 22-year-old C.torelliana.They also significantly affected its survival rate,volume and dispersion.At a density of 1 000 plants·hm‒2,the survival rate,DBH,tree height,individual volume,large-diameter volume,stand volume,and net profit all reached their maximum values,with increases of 21.35%,18.79%,18.35%,55.89%,100.00%,14.94%,and 74.44%,respectively,compared to the 1 667 plants·hm‒2 density.The dispersion was 1.022,close to the critical value of 1.The best growth indicators for C.torelliana large-diameter timber plantations were observed at a density of 1 000 plants·hm‒2.At 22 years of age,the number of surviving trees was 846 plants·hm‒2,the stand volume reached 276.80 m3·hm‒2,and the net profit was 276 617 yuan·hm‒2,demonstrating high productivity and economic benefits.
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