摘要
用回归分析的方法研究竞争指标与林木胸径生长量的相关关系 ,其结果表明 ,与胸径生长量的相关性 ,对象木相对直径 (SD )最强 ,直径比 (DR )、带距离权重的断面积比 (BR )第二强 ,带距离权重的直径比 (WDR)、断面积比 (WBR)第三强 ,距离均值 (MD )、距离平方均值 (RS)、竞争木相对直径 (CD)很弱 ,说明在一般人工林内 ,林木间距和竞争木大小对对象木胸径生长量的影响不明显 ,对象木自身的大小是引起其生长量差异的主要因子。用模型优选方法构建的单木模型 ,主要适用于黔中地区中上等立地条件。
On the basis of 18 fixed sample plot materials,8 competition index were used,the interrelated relation between competition and growth of breast-height diameter was analysed with method of regression analysis.The results of analysis made clear that the related coefficient between breast-height diameter growth and every competition index,corresponding index successively is subject tree diameter(SD),diameter ratio (DR),basal area ratio (BR),weighted diameter ratio with distance (WDR),weighted basal area ratio with distance (WBR),mean of distance (MD),mean of distance square (MDS),competitor diameter (CD).It illusrates that the relationship between diameter growth and distance,size of competitor is very weak.The size of subject tree is main factor affecting its growth,so it is main key element composing competition index.These models apply to Pinus massoniana plantation in middle part of Guizhou province in which site condition is middle or superior ,stand density is normal.
出处
《林业科技》
北大核心
2001年第3期1-4,共4页
Forestry Science & Technology
