摘要
对 5 9年生尾叶桉纸浆林生长分析表明 :(1)密度与树高、胸径呈反比。 3种密度的树高、胸径大小均为密度B >C >D。两配置树高、胸径也以配置B >A。 (2 )密度对单株材积的影响与对胸径影响的规律一致。 5 9年生时单株材积生长量以密度B最高 ,达到 0 0 85 33m3·株 - 1,是最低单株材积密度D的 2 0 4倍。两配置单株材积以配置B >A。 (3) 4 7年生时单位面积蓄积量大小为密度B >C>D ,密度B达到 94 185m3·hm- 2 ,是最低D处理蓄积量的 1 15倍 ;5 9年生时蓄积量最大者为密度C ,达到 12 7 6 0m3·hm- 2 ,是最低蓄积密度D的 1 17倍。随着时间的变化 ,密度控制尤为重要。 4 7、5 9年生时单位面积蓄积均以配置B >A ,配置B分别比配置A高 2 4 82 %、2 3 5 3%。 (4)对胸径D和冠幅CW 值用方程进行回归拟合 ,结果以乘幂CW=a×Db 拟合最好。方程表达式为CW=0 4 72 4×D0 6 715。 (5 )编制的经营密度表反映出 ,随着胸径D的递增 ,基本经营密度N0 逐渐下降 ;当D≥ 18cm时 ,N0
The dynamic change of tree height growth, DBH growth and volume growth in the stands of different Eucalyptus urophylla planting densities, the relationship between DBH growth and crown growth and the basic management density for E. urophylla timbers have been studied for 5.9 years in Laibin County of Guangxi Zhuang Municipality, China. The results indicate that density is negatively correlated with height growth, DBH growth and volume growth. (1)The height, DBH, the volume growth per stem of three planting densities is in the order of density 1 667>2 222>3 333 stem·hm -2 . After 3.7 years the height in different seedlings scheme is in the order of (2 m×3 m)>(1 m×6 m). The highest volume growth per stem is 1 667 stem·hm -2 , and 2.04 times that of 3 333 stem·hm -2 . (2)The order of volume growth per unit area of three planting densities is density 1 667>2 222>3 333 stem·hm -2 at 4.7 years but density 2 222>1 667>3 333 stem·hm -2 at 5.9 years. It means that the largest density does not reach the largest volume growth per unit area, that of the largest density 2 222 stem·hm -2 is 127.60 m 3·hm -2 , and 1.17 times that of 3 333 stem·hm -2 . (3)The relationship between DBH and crown could be described by using power equation C W=a× D b. The express equation is C W=0.472 4× D 0.671 5 . (4)The basic management density is negatively correlated with DBH. By means of the correlation analysis, the basic management density for E. urophylla plantations is developed, and the suitable planting density for E. urophylla pulp timber is also determined.
出处
《林业科学研究》
CSCD
北大核心
2002年第2期175-181,共7页
Forest Research
基金
世界银行贷款NAP和FRDPP项目<桉树速生丰产林培育技术的研究与推广>(1996~ 2 0 0 0年 )内容之一
关键词
尾叶桉
纸浆林
造林
密度控制
Eucalyptus urophylla
pulp timber
planting density
productivity
