木材材性株内径向变异模式初探

以微密度分析对１７个欧美杨无性系木材密度径向变异模式进行了初步研究。主要结果是：性系各株木材密度株内径向变异曲线概貌大体一致。但相同母本的不同无性系间以至无性系内株间存在一定的差异。因此，对变异模式的描述必然带有一定的不确定性，不同年龄上的年轮平均密度在无性系间差异显著。不同无性系的年轮平均密度变异曲线一程度的交叉。但无性系间的年－年相关显著，表明了在无性系间进行早期选择的可行性。年轮平均密度与年     

木材材性株内径向变异模式初探IV.17个欧美杨无性系木材密度径向变异模式的研究

以微密度分析对１７个欧美杨无性系木材密度径向变异模式进行了初步研究。主要结果是：各无性系各株木材密度株内径向变异曲线概貌大体一致。但相同母本的不同无性系间以至无性系内株间都存在一定的差异。因此，对变异模式的描述必然带有一定的不确定性。不同年龄上的年轮平均密度在无性系间差异显著。不同无性系的年轮平均密度变异曲线间存在一定程度的交叉。但无性系间的年－年相关显著，表明了在无性系间进行早期选择的可行性。年轮平均密度与年轮内最大、最小密度的关系，在年龄影响下和无性系影响下的两个变异过程中分析，结果有差别。年轮平均密度与年轮宽度的关系在年龄影响下的变异过程中分析，表现为不显著的负相关，而在无性系影响下的变异过程中分析，多数情况下相关显著。     

材性改良研究

用单色软Ｘ射线木材密度计研究了１１年生美洲黑杨×小叶杨新无性系年轮密度组成性状性遗传变异。结果表明，年轮密度组成各性状无性系间存在极显著差异；牢轮密度、早材密度、最小密度、最大密度及木材密度梯度等性状遗传力比较高（ｈ＾２＝０．４１－０．５８），而晚村密度、早晚材密度比及密度变异幅度等性状遗传力比较低（ｈ＾２＝０．１５－０．２５）；同时各性状遗传力因生长林龄不同而不同。     

材性改良研究V．美洲黑杨×小叶杨新无性系年轮密度组成性状遗传参数估算

用单色软Ｘ射线木材密度计研究了１１年生美洲黑杨×小叶杨新无性系年轮密度组成性状遗传变异。结果表明，年轮密度组成各性状无性系间存在极显著差异；年轮密度、早材密度、最小密度、最大密度及木材密度梯度等性状遗传力比较高（ｈ２＝０．４１—０．５８），而晚材密度、早晚材密度比及密度变异幅度等性状遗传力比较低（ｈ２＝０．１５—０．２５）；同时各性状遗传力因生长林龄不同而不同。     

马尾松优树无性系生长、干形和木材密度评价

利用浙江淳安国家马尾松(Pinus massoninna)种质库中22年生来自9个产地(或省区)180个优树无性系的保存林材料,研究马尾松优树无性系生长和材性在产地间和产地内的遗传变异规律,并对保存的优树无性系进行综合评价。结果表明,马尾松优树无性系生长、形质和木材基本密度皆存在显著的产地间和产地内变异,其中产地内无性系间的变异为产地间变异的1.87～2.38倍;与生长性状比较,木材基本密度在产地间所占的变异分量相对较大;除湖南产地优树无性系年轮宽度从髓心向树皮呈单峰变化外,其它8个产地优树无性系的年轮宽度皆随形成层年龄的增加而逐渐变窄;马尾松优树无性系的木材基本密度从髓心至树皮逐渐增大,到达一定年龄后渐趋稳定,但四川和广东两产地优树无性系木材密度的径向均匀性较低。早晚相关分析结果显示,除江西、广东和四川产地优树无性系木材基本密度的早期选择年龄晚于径向生长外,马尾松不同产地优树无性系的木材密度和径向生长皆可在5年生时开始早期选择。通过聚类可将180个优树无性系归为3大类和4个亚类,并综合评选出20个速生优质的优树无性系,其主要集中在第1类和第2类第2亚类。     

人工林火炬松纸浆材基本密度变异规律的研究

对3个标准地火炬松平均木木材的基本密度进行了系统的测定、分析和研究。结果表明：基本密度自髓心向外呈增加趋势；基本密度自树干基部向上呈减小趋势，但变化不大；基本密度存在较大的株间变异，且在F（0.05)水平上差异显著；立地指数大的标准地，木材基本密度小，且差异性达显著水平。     

木荷天然林分个体类型及材性性状变异

在浙、闽2省选取成一定纬度和海拔梯度的6个木荷天然林分,开展树干形质、树皮形态、木材纹理扭曲度、木材颜色和基本密度等个体类型表型变异及产地纬度和海拔影响研究。结果表明:木荷天然林分个体树皮厚度、颜色、形状及木材颜色等类型多样,除木材纹理扭曲度外,树干形质、树皮形态和木材基本密度等在林分间存在显著表型差异,但在林分内个体间变异以木材纹理扭曲度最大,树干圆满度、通直度和木材基本密度最小。木材性状的径向变异研究发现:木材基本密度由髓心向树皮方向逐渐下降,而年轮则先变宽后变窄,15～25年轮为平稳生长期。较高纬度的天然林分其树干相对通直圆满、树皮较薄、木材颜色较浅,而其他性状则未呈现明显的规律性;随海拔升高,木荷天然林分具有树干圆满、树皮薄而光滑,但树干通直度低、年轮窄、木材基本密度小的变化趋势。基于中心产区2个不同海拔天然林分个体性状相关分析表明,性状相关因林分所处海拔不同而有较大差异。在高海拔林分中,树皮性状是材性和径生长较好的指示指标,树干圆满的个体树皮光滑且颜色较浅、木材基本密度较小,而树干越通直的个体,树皮颜色越深,径生长也越快;在低海拔林分中,树皮厚度对树皮的其他性状和木材密度也有较好的指示作用,树干通直...     

樟树人工林株间株内材性变异及其材性预测的研究

樟树人工林株内纤维长度径向变异由髓心向外递增，而后趋于稳定；木材基本密度髓心处稍大，由髓心向外先稍递减而后递增，再趋于稳定；纤维长度和基本密度性状与生长轮年龄关系模型可用来预测其性状值。樟树木材幼龄期约为7－9a，株内细幼龄材基本密度较成熟材小1．0％－9．9％，株内幼龄材与成熟材基本密度差异多不显著；其浸提物含量幼龄材与成熟材之间差异不显著。纤维长度株内变异系数大于株间，木材基本密度均值和浸提物含量二性状则是株间变大于株内变异。生长速度对樟树木材纤维长度、基本密度、浸提物含量等性状影响不显著。     

火炬松木材基本密度的株内变异

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,各年龄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     

刺楸木材基本密度的变异研究

本文以安徽琅琊山天然林内的三株刺楸木材为材料，详尽研究其基本密度的径向变异、轴向变异以及影响基本密度变化的主要因子，结果发现：发现为木材基本密度的径向变化趋势为自髓心向外以曲线形式降低，到一定年限后保持平缓或略有下降，用幂池数模拟，相关系烤在０．８以上；轴向变化趋势为自树干基部向上渐增大，到５．３米处达最大值，再向上到树冠基部又变小．方差分析表明株间变异大于株内变异；从解剖分予组织比量来看，基本密     

Longitudinal growth strains in five clones of Eucalyptus tereticornis Sm.

We studied the variability in longitudinal growth strains and wood basic density in five-year old trees from five clones (one tree per clone) of Eucalyptus tereticornis. Mean longitudinal growth strain in clones ranged from 466 to 876 μm. There was a significant difference between clones in growth strains and wood basic density. Clone 10 exhibited maximum growth strains and basic density, whereas clone 3 and clone 7 exhibited minimum growth strains and basic density, respectively. Within a tree, the growth strain variation with tree height was high but statistically insignificant while within tree variation in basic density was very small. There was no specific trend in variation in either strain or density within a tree. There was 5% 200% difference in growth strain on opposite sides of the logs. However two strains showed a strong positive correlation. There was a moderate positive association of wood basic density and mean growth strains in logs. The variation around the periphery emphasize the need to measure strain more than one, preferably on opposite sides at the same height, on a tree to know the mean strain level for the purpose of selection of clones.     

三倍体毛白杨新无性系木材干缩性的遗传分析

利用 9a生三倍体毛白杨测定林的 9个无性系为试材 ,着重研究了木材干缩率的遗传学问题。结果表明 :木材干缩率在无性系间的差异都达到了极显著水平 ,并受到强度遗传控制 ;木材干缩在株内纵向的变异模式是随树高增加而降低 ;全干体积 ,径向、弦向干缩率和气干体积 ,径向、弦向干缩率无性系重复力分别为 0 89,0 95 ,0 84 ,0 6 7,0 84和 0 6 8。     

三倍体毛白杨新无性系木材气干密度和力学性质性状的遗传控制及对单板材育种的意义

该文利用 9个 9年生三倍体毛白杨无性系木材试样 ,研究了木材气干密度组成及力学性质的遗传变异规律 .结果表明 ,木材气干密度组成及力学性质在无性系间存在显著或极显著差异 ,并受到中等强度的遗传控制 ;气干密度的径向和纵向变异与多数研究结果一致 ;力学性质除抗弯弹性模量和端面硬度外其株内变异趋势也基本符合木材学理论 .在力学性质指标中 ,抗弯弹性模量和弦面硬度是遗传性很强的性状 ,其无性系重复力分别为 0 90和 0 80 ,抗弯强度、顺纹抗压强度和硬度的无性系重复力稍低 .遗传相关表明对单板材可通过木材密度与干形等形质指标进行优良无性系选择     

木材材性株内径向变异模式初探──Ⅲ.种植密度对湿地松、火炬松木材密度径向变异模式的影响

对两个地区不同种植密度的湿地松、火炬松进行了微密度分析，研究了种植密度对木材密度径向变异模式的影响。主要结果是：种植密度对湿地松和火炬松各密度特征值径向变异模式的影响，主要表现在变异曲线平均水平高低的变动，而对变异曲线形状的影响并不显著。种植密度对湿地松和火炬松各年轮宽特征值径向变异模式的影响，主要表现在年轮宽度RW和早材宽度EW变异曲线平均水平高低的变动和RW、EW与晚材宽度LW变异曲线形状的变动。种植密度对年轮密度RD的影响从年轮内宽度和年轮密度变异曲线平均水平高低两个方面起作用，出现较复杂的情况，并非所有情况下都是单调的正相关。     

杨树新无性系木材性质的变异研究

The wood basic density, cellulose content and fiber form were investigated for all sample trees at breast height (1.3m) in seven poplar clones, and at 0 (butt), 5.6, 9.6, 13.6, 17.6, 19.6 and 21.6 m for clone Nanlin-95 and Nanlin-895, respectively,for providing information on variation patterns of wood density, fiber characteristics and holocellulose content within trees and among clones. The results showed that significant variations about wood density, cellulose content, fiber diameter and the ratio of fiber length to diameter existed among poplar clones examined. Variance analysis indicated that there were significant differences in wood basic density, fiber length, fiber diameter and cellulose content among the growth rings, which had an increasing tendency along the direction from pith to bark. The significant differences also existed in wood basic density, fiber length and fiber diameter at different tree height. The mean wood basic density had a general increase trend with increasing height of trees and the lowest was found at the base, while fiber length and fiber diameter had a general decline pattern with increasing height of trees and the biggest value was observed at the height of 5.6 m. Regression analysis indicated that the relationship between examined wood properties and growth ring number (cambial age), and the relationship between examined wood properties and tree height can be described by polynomial functions.     

Genetic variation analysis and comprehensive evaluation of wood property traits of 20-year-old Chinese fir clone

This work focuses on the genetic variation of Chinese fir clones in the radial direction. Four 20-year-old Chinese fir clones were selected in Kaihua Forest Farm, Zhejiang, China, and the differences and genetic characteristics were studied. Clonal repeatability, genotype coefficient of variable, and phenotypical coefficient of variable were calculated to light on the genetic variation on the radial direction. Results showed significant differences (P?<?0.05) between the clones and annual rings of the same clone. The clonal repeatability of the ten wood properties is ranged from 0.5 to 0.8, wherein the fiber length, elastic modulus, and total dry density are higher than 0.7. For all the measured traits, the phenotypic variation of clones is greater than that of the genetic variation. Overall, the measured wood traits, especially the mechanical and physical properties, are strongly controlled by heredity, which means they are potentially helpful for genetic improvement of wood properties and optimal breeding. Furthermore, the clonal repeatability of the measured traits varies between annual rings, and the physical and mechanical properties are relatively stable. The principal component analysis results reveal that the clone of Kai 13 has the highest score.

     

An application of mixed-effects model to evaluate the effects of initial spacing on radial variation in wood density in Japanese larch (Larix kaempferi)

The effects of initial tree spacing on wood density at breast height were examined for 22-year-old Japanese larch (Larix kaempferi). The experiment involved the use of three plots with different initial tree spacing densities (300, 500, and 1000 trees/ha). For five trees selected from each plot, the total tree height, diameter at breast height, height to the base of the live crown, and crown diameter were measured. Ring width and wood density for individual growth rings were determined by X-ray densitometry. A mixed-effects model was applied for fitting the radial variation in wood density in relation to initial spacing. Models having various mean and covariance structures were tested in devising an appropriate wood density model. The model, consisting of the mean structure with quadratic age effects and heterogeneous first-order autoregressive covariance, was able to describe the radial variation in wood density. Closer spacing of trees (1000 trees/ha) resulted in a faster increase in wood density from the pith outward than for more widely spaced trees, indicating that initial tree spacing may influence the age of transition from juvenile to mature wood.     

I-69杨年轮宽度和密度变异规律

以I-69杨木材为试样,运用树木年轮图像分析系统和树木年轮分析系统获取年轮宽度和年轮密度数据,并对组成成分径向变异和轴向变异规律进行了分析.结果表明:I-69杨木材密度的径向变异规律随树龄增加而增大,最大密度波动较大,最小密度随树龄增加总体趋势下降,早材密度、晚材密度随树龄增加而增加;年轮组成成分各项指标株内径向变异极...     

Variability of wood properties in two wild cherry clonal trials

There has been an increase in wild cherry cultivation over recent decades, revealing a need for improvements in planting material to be used for the production of high quality timber. To date, trial tests have been carried out mainly on growth and tree architectural traits, while no investigations have focused on wood properties. The present study investigated the variability of the growth traits and the physical and mechanical properties of wild cherry wood, both within the tree, within and among clones and between sites. The aims of the study are to provide useful information on the genetics of wood traits in valuable hardwoods and to discuss how within-tree variation can affect early selection of genotypes. The results suggest that site was the most important source of variation in growth traits and in the proportion of heartwood, although differences among clones were highly significant. The number of sapwood rings was very homogeneous both between sites and among clones. Concerning the wood traits, most variation was detected within the tree, rather than within or among clones or between sites. Within tree variability seems to be mainly due to heartwood/sapwood presence. However, since there is a high correlation between heartwood and sapwood properties, a quite efficient selection made on the basis of sapwood should provide an efficient means of selecting heartwood traits.     

36个美洲黑杨无性系基本材性遗传变异的研究*

山东省长清县３６个８年生美洲黑杨无性的木材基本密度、纤维长度，树高和胸径在无性系间的变异达极显著水平，用选优法选出５个密度较高，纤维较生，生长较快的优良无性系，它们的引种号分别是１３号，３号，３４号，２２号和８号，除２２号起源于加拿大外，其余均起源于美国，木材基本密度，纤维长度，树高和胸径的广义遗传力分别为０．３２、０．４０、０．４３和０．７１，材性和生长性受中等或较强遗传控制。树木生长速度分别与