北京栓皮栎林分的干形质量初步研究

探讨了划分林木干形质量的标准,将林木干形质量分为通直、轻度弯曲、二杈分枝、多杈分枝和重度弯曲5类干形。选择了胸径、树高、冠幅、冠长等6个因子,并研究了这6个调查因子随干形质量变化的关系。通过方差分析发现不同干形质量的林木胸径差异并不明显,而其它的调查因子却因干形不同而表现出显著差异。对表现显著的林分因子进行多重比较研究,发现通直干形生长得较高、有较小的冠径比;二杈分枝和多杈分枝林木的冠幅较大,且二杈分枝类型林木的高径比最小。可以得出结论:在近自然经营过程中,在选择以材质为目的的目标树时,首先考虑干形通直的林木。

Primary Study on Stem Quality of Cork Oak (Quercus variabilis Blume)Plantations

This paper defines the standard which divides tree stem quality into five levels:straight stem,slightly bending stem,bi-branching stem,multi-branching stem and seriously bending stem.ANOVA is used to study the difference in diameter at breast height(DBH),height,the ratio of tree height to DBH(Rhd),crown width,crown height,the ratio of crown width to DBH(Rcwd) among stem quality levels.Significant differences are found except diameter.Multiple comparisons for siginificant factors are carried out.In general,the trees with straight stems and slightly bending stems have bigger values of height,smaller Rcwds; the trees with bi-branching stems and multi-branching stems have bigger crown width,and the trees with bi-branching have biggest Rhds.We suggest that trees with straight stems be selected as timber target trees in close-to-nature forest management.