树洞周边愈伤木与正常木的化学组成及物理力学特性的比较

Comparisons of Chemical Composition and Physico-mechanical Properties between Callus Wood and Normal Wood around Tree Hole

以黄山松、悬铃木的愈伤木及其附近的正常木为研究对象,采用X射线法测定了结晶度,同时比较分析了其主要化学成分(纤维素和木质素质量分数)、物理力学性质(基本密度、顺纹抗压强度)及部分解剖性质的差异,研究了顺纹抗压强度与主要化学成分、基本密度和结晶度之间的相关性。结果表明:黄山松和悬铃木愈伤木的结晶度、纤维素和木质素质量分数、基本密度、顺纹抗压强度均比正常木的大,差异显著,而且纤维/管胞细胞壁厚、直径大、纤维短,总体表明愈伤木的材性指标比正常木高;黄山松和悬铃木愈伤木与正常木的部分指标相差不是十分明显,但愈伤木在整个结构中起增强作用,表明这一增强机制是由愈伤木的构造贡献的。

With the callus wood and the＇surrounding normal wood of Pinus taiwanensis and Platanus acerifolia, we tested the cel lulose crystallinity of the callus woods and the surrounding normal woods by X-ray diffraction spectrum and studied the difference of the main chemical compositions （ cellulose and lignin content）, physico-mechanical properties （ basic density and axial compression strength） and the anatomy properties. We also analyzed the correlations between the axial compres sion strength and the main chemical compositions, basic density and cellulose crystallinity. The cellulose crystallinity, cel lulose and lignin content, basic density and axial compression strength of the callus woods are higher than those of the sur- rounding normal woods with significant difference and the fibre/tracheid cell wall of callus woods is thicker. The larger di ameter and the shorter length indicate that the wood property index of callus wood is higher than normal wood. The differ ence between the indexes of the callus woods and the surrounding normal woods is not so significant, but the callus wood plays potential role in the whole structure. Therefore, the reinforcement mechanism is contributed by the callus wood struc-ture.