杉木材性株内变异的研究Ⅰ.木材力学性质和木材密度

对１５株浙江产杉木株内不同高度和圆周不同方位上木材的抗弯强度、抗弯弹性模量、顺纹抗压强度和木材密度的差异，木材密度的径向变异模式和木材力学性质与木材密度的相关关系进行了测定和分析。主要结果是：抗弯强度和抗弯弹性模量在株内不同高度上差异特别显著；顺纹抗压强度和木材密度未表现出显著差异；在圆周不同方位上，三项力学性质和木材密度均为南北向高于东西向，差异不显著；木材密度径向变异模式在不同高度和不同方位上均为接近水平有一定波动的直线；三项力学性质与木材密度的相关关系在不同高度和不同方位上均特别显著，但不同力学性质与木材密度的相关系数有明显差异，不同高度上和圆周不同方位上，亦有差异。

VARIATION OF MECHANICAL PROPERTIES AND WOODDENSITY WITHIN TREES OF CHINESE-FIR

The differences in wood density, MOR,MOE and crushing strength, the radial variation patterns of wood density and th properties and wood density among different heights and four cardinal sides within 15Chinese-fir trees from Zhejiang province were determined and analysed.There weresignificant differences in MOR and MOE but no significant ones in wood density andcrushing strength among different heights . The mechanical properties and wood densityin northem and southem sides were higher than thos in eastem and westem sides,however, the differences were insignificant, The density profiles at different heightsand in different cardinal sides were horizontal straight lines with fluctuation within0.1g/cm.There were significant correlations between mechanical properties and wooddensity at different heights and different cardinal sides. The correlation coefficientswere greater in southem and eastem sides than in northem and westem side with larger variation in the correlations of MOR and MOE to wood density.