摘要
利用６株２７年生火炬松伐倒木解析材料，分析木材基本密度的株内变异规律。结果表明，各年轮基本密度及相应的自髓心的断面基本密度的径向变异表现为，在各断面高度随距髓心年轮数的增加而增大，到一定年轮数后增加趋缓；纵向变异则为自干基向上迅速下降，３～５ｍ高度以上保持相对稳定。相关分析表明各部位及相应的断面木材基本密度值ＢＤ与距髓心的年轮数Ｒ和其高度Ｈ位置有关，可用ＢＤ＝ａ＋ｂ／Ｒ＋ｃ／Ｈ来拟合两者的株内变化趋势。本研究样木的幼龄材与成熟材的过渡区为第１２年轮左右，幼年材与成熟材的基本密度相关随年轮数增加而趋显著及稳定。
Six loblolly pine trees of 27 a were cut down as analysis trees and sliced into 3 ring group wood samples for the determination of wood basic density,the within tree variations of basic density were studied in details.The results showed there existed radial variation and vertical variation of the ring wood basic density and the cross section wood basic density of certain number of rings from pith.The radial variation from pith to bark at any given height is that the basic density increases from pith outward for about the first 15 rings and then levels out,the vertical variation from trunk base to top is that the basic density is the highest near the base and decreases fast upward within 3～5 m butt and then stays essentially constant with increasing height.The regression analyses show the certain ring wood basic density and cross section wood basic density is the function of ring position from pith and sample height, BD=a+b/R+c/H .The age of transition from juvenile to mature wood is about 12 a,the wood basic density correlation of young timber stage and mature timber stage become notable and steady with the increase of age of young timber,the early selection for wood basic density would be done after the transition age of juvenile to mature wood.
出处
《林业科学研究》
CSCD
北大核心
1999年第1期97-102,共6页
Forest Research
基金
国家自然科学基金
关键词
火炬松
木材基本密度
株内变异
Pinus taeda
wood basic density
within tree variation
