共查询到20条相似文献，搜索用时 250 毫秒
1.
无性系杉木木材物理性质研究 总被引：1，自引：0，他引：1
对金洞林场杉木无性系19年生(不含苗龄)的木材物理性质研究,结果表明:杉木优良无性系木材的基本密度、径向干缩率、弦向干缩率、体积干缩率分别是0.279 g.cm-3、2.90%、5.10%和7.85%;整个无性系的基本密度、径向干缩率、弦向干缩率、体积干缩率分别是0.301 g.cm-3、3.28%、5.26%和8.27%;而对照CK的基本密度、径向干缩木材基率、弦向干缩率、体积干缩率分别是0.275 g.cm-3、2.80%、5.10%和8.00%.研究证明:杉木优良无性系不但木材产量高,而且木材质量也并不比当地实生苗差.选用杉木优良无性系造林,不但能增加木材产量,而且材质也不会因速生而变劣. 相似文献
2.
以6个杨树无性系木材为研究对象,对杨树的密度及干缩性能进行了分析研究,为杨树木材的加工利用提供依据。结果表明:6个杨树无性系木材基本密度为0.33～0.43 g/cm3,气干密度为0.39～0.51 g/cm3,全干密度为0.37～0.49 g/cm3,密度在不同无性系间差异极显著。50号杨、中林46杨、南杨木材密度沿径向呈逐渐增加的变化趋势,而108杨、N179杨和桑巨杨木材密度呈现先降低后逐渐增加的趋势。杨树无性系木材气干和全干干缩差异均值分别为2.53和2.22,不同无性系间气干干缩率(径向、弦向、体积、干缩差异)和全干干缩率(径向、弦向、体积、干缩差异)差异均极显著。50号杨、N179杨和桑巨杨木材干缩差异沿髓心向外呈现先增加后减小的趋势,中林46杨呈现逐渐增加的趋势,108杨和南杨则是呈现先减小后增加的趋势。相关性分析表明:木材密度与不同状态下干缩差异呈极显著负相关;木材基本密度除与弦向和体积气干干缩率不相关,与其他干缩指标均呈极显著正相关;不同干缩指标之间呈极显著正相关。 相似文献
3.
杉木人工林幼龄材与成熟材木材干缩性能指标的比较 总被引：3，自引：0，他引：3
测定了建始长岭岗林场 32年生杉木人工林的干缩性能指标 ,并分析了各指标在立地与木材径向部位上的差异 ,结果表明 :来自两样地的木材干缩性能指标均无明显差异 ;木材在径向部位上按 16年为界划分的成熟材与幼龄材相比较 ,全干状态和气干状态下的径向干缩率均具有极显著差异 (α =0 0 1) ,全干和气干体积干缩率、全干和气干差异干缩、全干弦向干缩率等指标的差异达显著水平 (α =0 0 5 ) ,气干弦向干缩率在径向部位上差异不显著。 相似文献
4.
《林业工程学报》2019,(6)
为了提高进口辐射松木材加工利用效率,扩展其使用范围,参照国家标准对新西兰辐射松木材的气干密度、干缩性、湿胀性径向变异进行了研究。结果表明:辐射松木材近树皮、中部和近髓心的气干密度分别为0.502,0.480和0.452 g/cm~3,自树皮至髓心气干密度呈现出逐渐减小的趋势,并且在0.05水平达到了显著差异,平均气干密度为0.478 g/cm~3,属于低密度木材;辐射松木材在气干状态下,其径向、弦向及体积干缩率自近树皮至近髓心呈现出逐渐减小的趋势,并且弦向和径向干缩率在0.05水平上达到了显著差异,体积干缩率在0.01水平上达到了极显著差异;辐射松木材在全干至气干状态下,其径向、弦向及体积湿胀率自近树皮至近髓心呈现出逐渐减小的趋势,并且径向湿胀率在0.05水平达到了显著差异,弦向和体积湿胀率在0.01水平达到了极显著差异。在同一环境条件下,辐射松径向的干缩率和湿胀率均小于弦向。研究结果为进口辐射松木材的加工利用及径向不同部位木材尺寸稳定性能评价提供了重要的数据支撑。 相似文献
5.
乐昌含笑人工林和天然林木材物理性质的比较 总被引：2，自引：0，他引：2
针对目前对乐昌含笑木材物理性质研究很少的现实 ,通过对乐昌含笑人工林和天然林木材物理性质的测定和分析 ,探讨乐昌含笑人工林和天然林木材物理性质及其差异和利用途径。结果表明 :乐昌含笑天然林木材生材密度 0 76 6g/cm3 ,基本密度为 0 4 2 0g/cm3 。乐昌含笑人工林木材生材密度 0 70 6g/cm3 ,基本密度为 0 382g/cm3 ,均小于乐昌含笑天然林木材 ;乐昌含笑天然林木材径向干缩系数、弦向、体积干缩系数和差异干缩分别为0 0 89、0 2 0 6、0 30 0和 2 32 ,乐昌含笑人工林木材径向干缩系数、弦向和体积干缩系数分别为 0 0 77、0 2 0 9和 0 2 97,说明乐昌含笑人工林木材的尺寸稳定性小于乐昌含笑天然林木材。乐昌含笑天然林木材作为家具及室内装饰用材具有轻质、易加工、变形小等优点。 相似文献
6.
对香椿木材的物理力学性质及抽提物含量进行了系统研究。结果表明:香椿木材为轻质木材,气干密度0.45 g/cm3;气干材径向、弦向、体积干缩率分别为1.53%、3.21%、4.85%;全干材径向、弦向、体积干缩率分别为3.33%、6.56%、10.46%;饱水径向、弦向、体积湿胀率分别为3.45%、7.01%、11.67%;香椿木材顺纹抗压强度25.64 MPa,抗弯强度75.01 MPa,抗弯弹性模量6331.24 MPa,端面、径面、弦面的硬度分别为2.90 k N、1.91 k N、2.08 k N;香椿木材的热水抽提物含量为5%、苯醇抽提物含量为4.47%、1%No OH抽提物含量为20%。 相似文献
7.
抽提处理对尾巨按木材干缩性的影响 总被引：1，自引：0，他引：1
为了抑制桉木干缩,采用全因子试验方法研究抽提工艺对尾巨桉木材干缩性的影响.试验结果表明:碱抽提对尾巨桉木材线性干缩率(径向、弦向)、体积干缩率的影响规律不一,但第6、8,9组方案的碱抽提试样的差异干缩率趋近于1;冷水抽提对尾巨桉木材线性干缩率(径向、弦向)、体积干缩率的影响规律比热水抽提明显,热水抽提材的差异干缩波动幅度比冷水抽提材大,效果较好的工艺组合也明显少;第3,4、7、8、11、12组方案的冷水抽提试样的差异干缩趋近于1,而仅第12组方案的热水抽提试样的差异干缩趋近于1.因此,碱抽提和水抽提可以降低尾巨桉木材干缩性的各向异性. 相似文献
8.
油茶木材物理力学性质分析 总被引：1，自引：0，他引：1
《广西林业科学》2021,50(3)
为给油茶(Camellia oleifera)木材的综合利用提供理论参考,以37年生油茶木材为研究对象,对其主要物理力学性质进行测定,并将其与气干密度相近的木材进行对比分析。结果表明,油茶木材的基本、气干和全干密度分别为0.669、0.870和0.839 g/cm3。弦向、径向和体积气干干缩率分别为9.30%、4.80%和14.10%,差异干缩为1.94;弦向、径向和体积全干干缩率分别为13.30%、7.20%和20.20%,差异干缩为1.85;弦向、径向和体积干缩系数分别为0.339%、0.226%和0.667%。端面、弦面和径面硬度分别为11 100、9 470和9 280 N;木材抗弯强度、抗弯弹性模量、顺纹抗压强度和冲击韧性分别为118.0 MPa、8 910 MPa、49.2 MPa和208 kJ/m2;品质系数为2 499.2×105Pa。油茶木材干缩均匀性中等,尺寸稳定性中等;有较高的密度和品质系数以及中等的抗弯和顺纹抗压强度,虽然短小,但可采用指接或拼接等方式加以利用;柔韧性非常好,在弯曲成型方面有显著优势,适用于制作弯曲构件或弯曲木家具,可采用木材弯曲成型技术对其进行加工。 相似文献
9.
对安庆段长江滩地I-72杨的密度和干缩性进行了研究。结果表明:I-72杨的气干密度、全干密度和基本密度分别为0.454 g/cm3、0.415 g/cm3和0.364 g/cm3;I-72杨木材密度的径向变异为自髓心向外,最初递减,然后再向外层递增;轴向变异为沿树干向上逐渐增加;I-72杨的径向、弦向和体积全干缩率分别为3.917%、8.093%和12.138%,体积干缩系数为0.169,差异干缩为2.107;I-72杨5.3 m高度处的径向、弦向和体积全干缩率测量值均大于1.3 m高度处的测量值。 相似文献
10.
11.
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 相似文献
12.
13.
马尾松种子园无性系结实量、种实性状及遗传参数的分析 总被引：8，自引：0，他引：8
马尾松(Pinusmassoniana)是我国南方重要的用材树种。80年代初在马尾松主产区建立了一批初级无性系种子园,并开展了种子园有关营建技术的研究。反映种子园无性系繁育能力的种实性状包括了球果及种子性状,是林木种子园经营管理者所关注的重要内容,它涉及到种子园的产量和种子品质等问题。国外对火炬树(P .teada)、阿勒皮红松(P .abasica)、斑克松(P .banksiana)、白云杉(Piceaglaua)、北美黄杉(Pseudosugamenziesii)等树种(Matthewsetal.,1986 ;Matzirisetal.,1998;Todhunteretal.,1981;Horh ,1984 ;Clairetal .,1991) ,研究了花粉产量… 相似文献
14.
15.
以102个17年生杉木无性系为试材,对木材的干缩性与吸水性进行测定分析发现,木材干缩性、吸水性在杉木无性系间差异极显著;干缩性变异幅度为3.1%～20.0%,表型变异系数达59.8%;吸水性变异幅度在214.5%～338.1%间,表型变异系数为13.2%。木材干缩性与吸水性均具有明显的无性系方差分量,表明杉木木材干缩性与吸水性受遗传控制。进一步研究显示,杉木无性系木材干缩性遗传变异系数为38.6%,重复力为0.390,均属中低水平;吸水性遗传变异系数值虽较低,但重复力相对较高(0.664),属中上水平;在不同入选率(10%、20%、30%)下,木材干缩性与吸水性随入选率的降低其遗传增益值(绝对值)不断提高。研究还发现,杉木木材干缩性与木材基本密度、心材比间为极显著遗传负相关,与木材吸水性间则表现为极显著遗传正相关;木材吸水性在遗传水平上与胸径、材积、心材比间呈极显著正相关,而与木材基本密度间为极显著负相关。 相似文献
16.
The microfibril angle (MFA) of seven poplar clones was determined using X-ray diffraction technique. MFA was measured for
every growth ring at breast height (1.3 m) for all sample trees, and at 0 (butt), 5.6, 9.6, 13.6, 17.6, 19.6 and 21.6 m for
clone I-69, Nanlin-95 and Nanlin-895. A total of 900 samples (chips) were assessed. Significant variation was observed among
poplar clones and growth rings. Mean clonal MFAs at the breast height ranged from 15.2° to 21.0°. MFA at breast height varied
from 7.8° to 28° between growth rings and showed a consistent pith-to-bark trend of declining angles. Disc-average microfibril
angle in poplar clones declines rapidly from 0 to 5.6 m height, after which, it is near constant within tree height. Significant
variation was also observed in disc-average MFA among tree heights. Correlation analysis showed that the correlation between
MFAs from rings 5 to 11 at breast height was significant, while whole-tree values of each growth ring were significantly correlated
with the corresponding MFA at breast height. The results of this study provide some basis for genetic selection of poplar
trees based on wood-quality criteria and for devising appropriate sampling strategies for MFA measurement. 相似文献
17.
采集白皮松3个新变异类型(盆仙白皮松、瑞王白皮松、9号树)、北京良种基地母树、北京市挂牌古树等共48个样品,应用SSR技术,对上述样品分别进行鉴定和多样性评价。结果表明:同一个变异类型的无性系与其原变异枝之间在所有位点上均不存在差异,说明其无性系及其原变异枝属于相同的基因型,"瑞王白皮松"和其母株(古树152)非变异枝间在SSR—Y5位点上存在差异,"瑞王白皮松"与"盆仙白皮松"在SSR—Y2位点上存在差异。"9号树"在Y2、Y5 2个位点上与"盆仙白皮松"、"瑞王白皮松"不同,而与其母树群体莽山良种基地的母树相同。可以通过上述位点的检测来鉴定3个不同的变异类型。"盆仙白皮松"、"瑞王白皮松"和"9号树"、古树群组、莽山群组间的遗传距离分别为0.021 1、0.011 4、0.081 3、0.063 8。"瑞王白皮松"与"盆仙白皮松"间、"瑞王白皮松"与古树间存在遗传上的差异。参试样品的有效等位基因数(Ne)、Shannon’s信息指数(I)、观测杂合度(Ho)、期望杂合度(He)、Nei’s多样性指数(Nei’s)的平均值分别为1.230、0.302、0.221、0.189、0.197。多样性水平略高于白皮松人工群体而与白皮松天然群体接近,说明参试样品具有较高的遗传多样性水平,具有选择利用的遗传基础较好。 相似文献
18.
Teak(Tectona grandis Linn. f.), one of the mostvalued tree species in the world, is slow-growing with a long period until it can be harvested;therefore, ensuring that only high-quality seedlings or clones are selected for planting is critical. The main objective was to determine performance and repeatability of selected clones in terms of growth and survival rates in different micro-environments. A 2-year clonal trial using 41 clones and a local seedling of teak as a control were grown at 4 microsites differing in spacing, soil fertility and alley crops to assess tree height, diameter and survival rate that was evaluated in Purwakarta, West Java, Indonesia using a randomized complete block design with four replicates of each clone at each microsite. Teak growth was influenced by clone(p < 0.01), microsite(p < 0.05) and clone 9 micrositeinteraction(p<0.01). The interaction clone 9 microsite resulted in several potential superior clones that differed in terms of growth rates at each microsite. On the basis of diameter only, superior clones(nos. 14, 18, 24, 30 and 37)were identified. Repeatability estimated was Rc2= 0.84 for diameter and Rc2= 0.77 for height. Growth performance of teak trees varied among microsites. Repeatability values for diameter and height characters were high. The effect of variable growth on each clone was influenced by genetic factors, environmental factors and the interaction of genetics 9 environment. Microsite significantly affected growth of teak clones. Clone 9 microsite interaction significantly affected growth of clones and led to the growth of superior clones at each microsite. 相似文献
19.
Eitaro Fukatsu Yoko Fukuda Makoto Takahashi Ryogo Nakada 《Journal of Wood Science》2008,54(3):247-251
Variations in carbon content in wood among 102 clones, selected from almost the entire natural distribution area, were investigated
in Larix kaempferi. The average carbon content was 50.50%, 50.94%, and 50.80% in sapwood, heartwood, and whole wood, respectively. The difference
in carbon content between clones was significant. The clonal repeatabilities were 0.46, 0.38, and 0.44 in heartwood, sapwood
and whole wood, respectively. The coefficients of variation in the clonal mean carbon content were only 0.43%, 0.42%, and
0.41% in heartwood, sapwood, and whole wood, respectively. This small genetic variation and resulting small relative genetic
gain of carbon content indicate that the genetic improvement of carbon content by selection has a small effect on the genetic
improvement of carbon sequestration capacity by selection in L. kaempferi. 相似文献
20.
Chu Demiao Yao Tao Zhou Liang Yan Hanwei Yu Min Liu Yamei You Yunfei Bahmani Mohsen Lu Changqing Ding Zhenhao Liu Shengquan 《European Journal of Forest Research》2022,141(1):59-69
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.
相似文献