樟子松人工幼林密度与个体生长指标的关系

以孟家岗的樟予松密度试验样地定期观测和集中调查材料为基础，对林分密度与林木个体生长和形质指标的关系进行了初步分析。结果表明：30a以下的幼林，林分密度与林分平均直径、林分平均高、冠长、冠幅、轮枝内枝数、枝直径、枝长和林分平均单株材积均存在明显的负相关关系，即林分密度越大，林分平均直径、林分平均高、冠长、冠幅、枝直径、枝长和林分平均单株材积越小，轮枝内枝数越少；林分密度越小，林分平均直径、林分平均高、冠长、冠幅、枝直径、枝长和林分平均单株材积越大，轮枝内枝数越多。但是林分密度与不同生长级林木平均直径、平均高、冠长、冠幅、轮枝内枝数、枝直径、枝长和平均单株材积的关系比较复杂。总的来看，密度对各个指标的影响程度因林木生长级的增大而减少，因林木生长级的降低而增大。密度对上层木的树高、冠长、冠幅、树冠上层枝直径和枝长等的影响比较小；而对林木直径和单株材积，即使是上层木，影响也比较大。

Relationship between Individual Growth Index and Stand Density of Young Pinus sylvestris var. mongolica Plantatios

A study was conducted to analyse the relationship between stand density and individual growth indexes of Pinus sylvestris var. mongolica with data from permanent sample plots for stand density experiment in Mengjiagang Forest Farm. Results showed that, for the young plantation under 30 years old, there was negative relationship between stand density and stand mean diameter, mean height, mean crown height, mean crown width, branch number in a whorl, branch diameter, branch length and mean individual volume. That is, with the increase of stand density, stand mean diameter, mean height, mean crown height, mean crown width, branch number in a whorl, branch diameter, branch length and mean individual volume decreased, and vice versa. While the relationship was complex between stand density and mean diameter, mean height, mean crown height, mean crown width, branch number in a whorl, branch diameter, branch length, and mean individual volume of individual trees in different growth classes. In general, the effect of stand density on each index increasesd with the decrease of growth class, and vise versa. Stand density had a weak impact on height, crown height, crown width, diameter and length of upper branches; but a strong impact on mean diameter and mean individual volume, even if the trees were in the first class.