天然林闽楠木材纤维形态径向变异研究

以50年生天然林闽楠(Phoebe bournei)为研究对象,借助数码光学显微镜和图像测量分析软件对闽楠木材纤维形态进行测量和分析,研究了闽楠木材纤维形态的径向变异规律。结果表明,闽楠木材纤维长度、宽度、腔径、双壁厚、壁腔比、长宽比平均值分别为1079、21.93、14.56、7.31μm和0.55、49。纤维长度和长宽比的径向变异规律较为明显,随树龄的增长呈“递增-稳定”的变异规律;纤维双壁厚和壁腔比随树龄的增长径向变异规律总体上呈波动性递增的趋势;纤维宽度、腔径随树龄的增长变异规律不明显。经方差分析,纤维长度和长宽比随树龄变异在0.01水平差异显著,纤维双壁厚随树龄变异在0.05水平差异显著,纤维宽度、腔径和壁腔比随树龄差异不显著。采用有序聚类最优分割法,划分出天然林闽楠幼龄材和成熟材的界限为21~23a。

Radial Variations of Fiber Morphology for Phoebe bournei Wood from Natural Forest

The fiber morphology of Phoebe bournei wood naturally grown for 50 years was measured and analyzed by using digital optical microscopy and image measurement and analysis software,aiming at studying the radial variation of the wood fiber morphology.The average measurement data were as follows: length 1 079 μm ,width 21.93 μm,lumen diameter 14.56 μm,wall thickness 7.31 μm,thickness-diameter ratio 0.55 ,and length to width ratio 49.The results showed that the rule by which the fiber length and the length to width ratio radially vary was more notable.That is,the fiber length and the length to width ratio radially vary incrementally and stably with the tree age.The fiber wall thickness and the thickness-diameter ratio radially varied with the tree age incrementally but irregularly.And the radial variation of the fiber width and the lumen diameter was not notable.As shown by the analysis of variance,the fiber length and the length-width ratio varied significantly with the tree age at the level of 0.01,and the wall thickness varied significantly with the tree age at the level of 0.05,while the variations of the width,lumen diameter and thickness-diameter ratio with tree age were not significant.Using the optimum method of classification,it was found that the boundary line between juvenile wood and mature wood of P.bournei ranged from 21 to 23 years.