作 者 ：蔡则谟
期 刊 ：林业科学 1994年 30卷 6期 页码：548-555
Keywords:Teak, Fibre length, Specific gravity, Standard physical and mechanical property,
摘 要 ：11—13龄柚木20株,17—19龄7株,取自海南岛尖峰岭,用以研究木材比重及纤维长度的某些特性及测定标准物理力学性质。以胸高圆盘加权平均数为单元,比重0.466—0.588,平均0.516:纤维长度0.878—1.230mm,平均1.063mm。生长轮宽度与比重及纤维长度之间表现弱的负相关。第1轮和第9轮的材性存在显著的相关关系。材性在标地间的差异不显著,标地内株间的差异很显著。径向变异:髓心附近几轮的纤维长度和比重均增长很快,第8轮以后,前者增长缓慢,后者多起伏。轴向变异:1.心部系列(髓心向外6生长轮)第1轮纤维长度的轴向变异很小,其外几轮的纤维长度缓慢向上减轻或有起伏;基部各生长轮的比重很大,向上急剧减小至1.3m高度,此后各生长轮的变化不一致。2.边部系列(树皮向内6生长轮)纤维长度和比重均很快向上减小。讨论了影响纤维长度轴向变异的主要因素。提出标准物理力学性质的试验结果。
Abstract:Twenty 11-13-year-old trees and seven 17-19-year-old trees of Tectona grandis L. f. were taken from Hainan Island to study some characteristics of wood specific gravity and fibre length, and to test the standard physical and mechanical properties.With the weighted mean of the breast height disc as the unit, specific gravity varied from 0.466 to 0.588, averaging 0.516, and fibre length varied from 0.878 to 1.230 mm, averaging 1.063 mm. A slight negative relationship was observed between ring width and specific gravity (r=-0.029), also and fibre length (r=-0.108). There were significant correlations between the 1st ring and the ninth ring for both properties.Variations in the two properties among sample plots were insignificant while those between trees within sample plot were highly significant.Radial variation Fibre length increased rapidly outward from the pith in the few rings; after the eighth ring the rate of increase slowed down. Specific gravity showed similar increasing trend to that of fibre length at first and more fluctuations after the eighth ring.Axial variation This analysis was based on seven trees, from each of which discs at 0.2, 1.3, 3.6, 5.6 and 7.6m height levels of the trunk were removed, then every growth ring in the southern and northern radii from each of these discs were further sampled. 1. Core sequence (six growth rings from the pith outward) In the ring nearest the pith, fibre length varied very little up the tree, and in the outer rings, either it decreased gradually or showed some fluctuations. Specific gravity in the six rings at the base were the greatest, then decreased rapidly to the 1.3m height, after which they varied differently up the trunk. 2. Sheath sequence (six growth rings from the bark inward) Fibre length and specific gravity in the six rings all decreased rapidly from the base upward. The main factors affecting the two sequences of axial variation in fibre length were discussed.The result of the standard physical and mechanical properties tested was presented.
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