两种样地西南桦人工林木材纤维形态及变异规律

Fiber Morphological Features and Variation Pattern of Betula alnoides in Two Sample Plots

从样地一和样地二分别选取9年生西南桦(Betula alnoides)人工林木材各3株。沿样木南北取向及树高方向分别对其纤维长度、纤维宽度、纤维壁厚、纤维腔径、纤维长宽比及壁腔比等纤维形态特征值进行系统的测定和分析。结果表明西南桦人工林木材纤维长度较长且分布范围广,纤维长宽比大,纤维壁腔比小于1,说明西南桦人工林木材适合纸浆造纸;在相同样地内,西南桦人工林木材纤维长度、纤维宽度、双壁厚径向变异规律相似,即髓心处较小,沿髓心向外先逐渐增大,波动后趋于稳定;不同样地条件下,样地二西南桦人工林木材纤维长度均值小于样地一,而纤维宽度、腔径、双壁厚、长宽比和壁腔比等均值较样地一大。两样地各纤维形态特征值径向变异、轴向变异规律相差不大。不同样地各纤维形态特征值均值的t检验结果表明,西南桦人工林木材纤维长度、纤维宽度、纤维腔径在0.05水平上差异显著,而纤维壁厚、长宽比和壁腔比差异不显著,说明不同营林措施对人工林木材材性有一定影响。研究结果对西南桦人工林材质改良和定向培育以及其人工林成熟材的使用等具有一定的参考。

From each of both sample plots,three trees of nine-year old Betula alnoides were chosen as the materials,and the morphological features of wood fiber were observed and measured form north to south and along tree height,respectively. B. alnoides is suitable for pulp and paper industry because its fiber length is long,distribution range is wide,the ratio of the fiber length to width is big and the ratio of cell wall thickness to lumen diameter is small. Within the same sample plot, the radial variation patterns of wood fiber length,wood fiber width and double-cell wall thickness are analogous： from pith to bark,first increase moderately,then tending to be stable after a few years undulate. Within the different sample plots, the averages of B. alnoide fiber width,lumen diameter,double-cell wall thickness,length-diameter ratio and cell wall thickness to lumen diameter ratio are bigger in Plot One,while much smaller in fiber length. By t test at 0. 05,the patterns of the longitudinal variation of fiber length,fiber width and fiber tangential diameter are different significantly,while the double-cell wall thickness,length-diameter ratio and cell wall thickness to lumen diameter ratio show big fluctuation with no regulation,and the managing methods have certain impact on fiber morphological characteristics. Therefore,the research results can provide some references not only for property modification and directional cultivation of juvenile wood but also for the usage of mature wood.