翠柏木材管胞形态和结晶度的株内变异

Variation of Wood Tracheid Character and Crystallinity of Calocedrus macrolepis

对云南产珍稀树种翠柏木材株内不同高度和圆周不同方位上木材管胞长度、宽度和结晶度的径向变异模式进行了测定和分析,并对各管胞形态特征与结晶度的相关关系进行分析且建立数学模型。结果表明:1)管胞长度和宽度的株内变异形式大致相似,管胞形态与树龄呈显著相关,表现为随着树龄的增加逐渐增加,至20a后趋于稳定,翠柏木材的成熟期界定为20a;方差分析表明在圆周不同方位上管胞长度和宽度差异不显著,管胞特征在不同高度上表现出显著差异,随着树高的增加而逐渐减小。2)结晶度的株内径向变异规律与管胞形态的相似,且与树龄间呈显著相关,表现为随着树龄的增加而增加后逐渐趋于稳定;不同高度上木材结晶度变化规律表现为随着树高的增加而逐渐下降,不同方位上木材结晶度变化规律表现为南>东>北>西。3)利用对数模型拟合各管胞形态特征与结晶度,相关系数均在0.9以上,从而建立了管胞形态与结晶度间的回归模型。可见翠柏是一种较好的纤维用材树种,为翠柏木材的优质定向培育以及利用结晶度进行管胞形态预测提供了理论基础和技术支持。

Calocedrus macrolepis is a rare tree species occurring in Yunnan, China. In order to understand the timber properties of the tree, a comprehensive determination and analysis were conducted on the mor- phological features, such as radical variation of wood tracheid length, width and crystallinity in each growth ring of C. macrolepis in different tree heights and directions, and on the correlation between these factors. The results were reported as follows. 1） The tracheid length and width increased with the increase of growth ring which was stabile after 20 years of growth. So the maturation stage of C. macrolepis was 20 a. The variance analysis indicated that the tracheid length and width in different directions was not sig- nificantly different, however, significant differences were found in different tree heights, and also de- creased with the tree height. 2） The radical variation tendency of crystallinity was similar to the tracheid morphological features, and significantly correlated with the tree age. The crystallinity decreased with the increase of tree height, and in different directions, it was in the order of south〉east〉 north 〉 west. 3） Correlated analysis of crystaltinity and tracheid morphological features indicated that the crystallinity was positively and significantly correlated with tracheid length and width with the correlation coefficient up to 0.9. Based on these, the prediction model of the cryatallinity and wood traeheid parameters was estab- lished. To sum up, C. macrolepis exhibited high potential as a commercial tree species with excellent tim-ber quality. The conclusion would provide theoretic guidance to the use of C. macrolepis and theoretic ba- sis to the tracheid morphological feature prediction by crystallinity.