人工林米老排木材化学成分及其在树干高度上的变异

Study of Mytilania laosensis Plantation: Contents of Wood Chemical Components and Their Variation along Tree Stem

采用我国木材化学成分分析国家标准,对人工林米老排木材化学成分进行了测定和研究分析.结果表明:人工林米老排木材冷水抽提物含量和热水抽提物含量分别为2.67%和3.12%,1%NaOH抽提物含量为17.08%,纤维素含量为47.49%,综纤维素含量为80.42%,木素含量为28.80%,pH值为5.44;木材冷水抽提物和综纤维素含量在树干的不同高度上略有差异,但方差分析检验,差异不显著,热水抽提物、1%NaOH抽提物、纤维素和木素含量在树干的不同高度上差异显著,达到1%显著性水平;由树基往上,热水抽提物含量略呈两端高、中间低的趋势,冷水抽提物、1%NaOH抽提物和木素的含量逐渐降低,综纤维素含量和木材pH值逐渐升高;纤维素含量在树干上的分布规律为中间高、两端低,而且从树干中部往上的降低幅度较大.

According to the Chinese standard for wood chemical component analysis, contents of the chemical components of Mytilania Laosensis wood have been determined. The results show that the contents of cold-water extractives, hot-water extractives and 1% NaOH extractives are respectively 2.67%, 3.12% and 17.08%; that the contents of cellulose, holocellulose and lignin are respectively 47.49%, 80.42% and 28.80%; and that the pH value of wood is 5.44. The results also show that at different heights along the tree stem, the difference of the contents between cold-water extractives and holocellulose is not significant in a statistic sense but the contents of hot-water extractives, 1% NaOH extractives, cellulose and lignin vary significantly along the tree stem, the difference arriving at 1% significance level. Going upwards from the bottom of the tree stem, contents of hot-water extractives are low in the middle section but go up towards the two ends; contents of cold-water extractive, 1% NaOH extractives and lignin tend to decrease; and contents of holocellulose and pH value tend to increase while the content of cellulose is high in the middle section and goes down towards the two ends, especially the upper end.