摘要
本文研究了油松木材管胞纤丝角度的变异和纤丝角度与解剖、抗拉、抗弯强度间的相互关系。管胞次生壁S_2层的纤丝角径向变化由髓心向外,开始递减很快,13年后纤丝角度大小相对稳定。纤丝角轴向变异由基部开始向下逐渐减小,3.3m高处纤丝角度最小,然后向上增大,基部纤丝角度最大。单一生长轮内早材开始的纤丝角度小,然后缓慢增加,达最大值后逐渐减小,晚材的边缘稍增大,最大纤丝角位于早材部位,年轮外层近晚材80%处纤丝角度最小。纤丝角度与管胞长度间呈高度直线负相关,用方程y=a+b·θ模拟优于y=a+b·cosθ。纤丝角度与管胞宽度、长宽比、胞壁厚度等因子呈密切的线性负相关。纤丝角度对顺纹抗拉强度、抗弯强度等影响显著。
Five trees of Pinus tabulaeformis were collected from a stand of Zhongtiao Mountains in Shanxi province. Microfibrillar angle within the S_2 layer of the secondary wall in tracheid decreases rapidly from pith outwards, and then levels off after 13 years old. Along the trunk, microfibrillar angle tends to be great at the base, decreases to minimum at 3.3 m height, then increases again near the trunk tip. Within a single growth ring, microfibrillar angle is small at the begining of spring-wood, increases slowly to maximum, then decreases to late wood. At the outside of 80% position of late wood, the microfibrillar angle is minimum. There is a significant negative linear correlation between tracheid length (Y) and microfibrillar angle (θ), and the equation Y=a+b·θ is superior to Y=a+b·cos θ. The microfibrillar angle is inversely proportional to the trachcid width, the length-width radio of tracheid, the cell wall thickness, etc. The effects of microfibrillar angle on the tensile and bending strength are singnificant.
基金
安徽农学院与山西中条山森林经营管理局合作项目
关键词
油松
管胞
微纤丝角
力学
Pinus tabulaeformis
Tracheid
Microfibrillar angle
Varation
Anatomy
Tensile and bending strength
Correlation.
