共查询到19条相似文献，搜索用时 218 毫秒
1.
对火炬松（ＰｉｎｕｓｔａｅｄａＬ．）速生材５个高度木材的基本密度、年轮宽度、生长率、晚材率和管胞弦壁纤丝角进行系统测量、统计和分析，结果表明，木材基本密度随树干高度的增加而降低．但各高度之间的差异不显著；生长率从髓心向外，南北方向都是随年轮数的增加而减小，在高度上是随树干高度的增加而增大．但其差异性均不显著．晚材率与木材基本密度呈线性正相关，与纤丝角呈线性负相关；木材基本密度与纤丝角呈负相关；纤丝角与生长率呈正相关．其相关显著性均随树干高度的增加而减弱．这些规律，为火炬松速生材的有效利用和林木生长调控提供了理论依据． 相似文献
2.
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显著,株间径向变异不显著。年轮密度各组成成分随高度增加而增加,其中年轮平均密度、早材密度、最小密度增加量较小,年轮最大密度、晚材密度增加量较大;相对而言,Ⅰ-69杨木材密度径向变异大于轴向变异。 相似文献
3.
4.
为了解邓恩桉的木材性质,本研究采用排水法和《GB/T 1930-2009》方法测定邓恩桉的生材含水率、年轮宽度以及木材密度。结果表明：全树生材含水率、年轮宽度、生材密度和基本密度均值分别为114.61%、4.73 mm、1.164 g·cm-3、0.522 g·cm-3。随着树高的增加,年轮宽度、木材密度呈-大-小-大‖趋势,生材含水率呈-小-大-小‖趋势;由髓心向外,木材密度逐渐减小,生材含水率逐渐增大,年轮宽度先增加后减小。4个材性指标在树干径向不同位置间差异极显著,在不同树高间差异不显著（除年轮宽度外）。基本密度与3个材性指标间存在极显著或显著相关。 相似文献
5.
造林密度对马尾松木材主要性质影响的研究 总被引：1，自引：0，他引：1
本文对贵州省龙里林场马尾松密度试验林 ,5种造林密度 ,15年生马尾松木材基本密度、生长轮宽度、晚材率和解剖特性进行研究。结果表明 :造林密度对马尾松生长轮宽度、晚材率和管胞列数影响较大 ,方差分析达到显著水平。造林密度大 ,则生长轮变窄 ,管胞列数减少 ,晚材率增加。造林密度对马尾松木材基本密度的影响不显著 ,但具明显的规律性 ,即随着造林密度加大木材基本密度增加 ,造林密度过大反而下降。造林密度对管胞形态的影响表现出因树龄而异 ,不同造林密度马尾松管胞形态总平均值变化不大 ,但管胞长度随树龄的增大而增加的趋势受到造林密度影响。较低的造林密度各生长轮管胞长度差异不显著。组织比量不受造林密度影响。 相似文献
6.
《广西林业科学》2020,(2)
为探究不同树龄尾巨桉无性系(Eucalyptus urophylla×E. grandis)人工林木材纤维形态特征的差异,以广西国有维都林场5年生和7年生尾巨桉无性系人工林木材为研究对象,采用解析木取样方法,对两个树龄尾巨桉无性系木材的纤维长度、宽度、腔径和双壁厚进行测定,分析其木材纤维特性。结果表明,5年生和7年生尾巨桉无性系木材纤维的平均长度分别为956.71和958.36μm,平均宽度分别为20.26和20.65μm,平均腔径分别为13.29和13.08μm,平均双壁厚分别为6.97和7.57μm,平均长宽比分别为47.32和46.48,平均壁腔比分别为0.54和0.59。由树干根部至梢部,木材纤维长度呈先增大后减小的趋势,宽度呈逐渐减小的趋势,双壁厚表现为5年生缓慢增大、7年生上下波动;自髓心向树皮,纤维长度、宽度和双壁厚均呈逐渐增加的趋势。方差分析表明,5年生尾巨桉无性系木材不同年轮间纤维长度、宽度和双壁厚差异均极显著;不同树干高度间纤维腔径差异极显著,其余差异均不显著。7年生尾巨桉无性系木材不同年轮间纤维双壁厚差异不显著,其余均差异极显著;不同树干高度间纤维长度、宽度、腔径和双壁厚差异均不显著。 相似文献
7.
8.
东北主要树种心材与边材的生长特征 总被引：4，自引：2，他引：2
以东北东部山区温带森林的7个主要组成树种--红松、兴安落叶松、春榆、水曲柳、胡桃楸、黄菠萝和蒙古栎为研究对象,比较分析各树种心材和边材的生长特征.结果表明:树种显著地(P<0.001)影响边材年轮数和边材宽度,红松、水曲柳、兴安落叶松、胡桃楸、春榆和黄菠萝的平均边材年轮数分别为9.6、9.5、7.9、6.8、5.0和3.9年,其平均边材宽度分别为1.96、1.27、2.55、1.06、0.72和0.46 cm.被测针叶树边材宽度明显大于阔叶树.心材年轮数与形成层年龄、心材半径和边材宽度与树干去皮半径均存在着极显著的正相关关系(P<0.000 1),而边材年轮数随形成层年龄的变化规律因树种而异.心材形成速率和心材起始树龄因树种而异,分别波动在0.677～1.041 a-1和4.3～8.5年.随树干高度增大心材半径和木质部半径递减,边材宽度则在树干基部异常大,1～2 m向上保持相对稳定.心材年轮数随树高递减,但边材年轮数的变化因树种而异,红松边材年轮数递减,落叶松先增后减,水曲柳先减后增,春榆、胡桃楸和黄菠萝的变化很小.各树种心材和边材特征的显著差异,可以反映出其生长状况、水分利用对策、物质生产等方面的差异. 相似文献
9.
美洲黑杨不同径级木材纤维、导管形态及其基本密度的差异 总被引：1，自引：0，他引：1
通过对美洲黑杨林分内不同径阶木材解剖特性和基本密度的差异分析,结果表明:(1)株内径向年轮宽度先增加,第3轮达最大宽度,之后逐渐减小,10轮后年轮宽度仅2.3mm。纤维、导管形态中的长度、宽度及长宽比径向表现为递增模式,前5轮迅速增加,5轮之后缓慢增加,8轮之后趋于稳定;壁厚径向上总的趋势稍微增加,壁腔比因宽度增大而表现出稍微降低,呈起伏状。树木基本密度径向趋势是随着树龄增加而增大,浸提物含量径向为递减模式;(2)林分内不同径阶个体间同一年轮宽度和木材基本密度随着径阶增加而增大,两者径阶间的差异达到显著性水平。不同径级同一轮纤维形态、导管形态特征株间差异均不显著。这反映了杨树林分内生长量与木材基本密度间为正相关,与纤维形态、导管形态特征值之间没有相关性。基本密度随着径阶增加而增大,可能与木材组织比量中的纤维比例增加有关。 相似文献
10.
欧美杨107杨苗人工倾斜树干应拉木形成特征及其解剖特性 总被引：1，自引：0，他引：1
以60株1年生的欧美杨107杨幼苗为研究对象,在生长季节开展人工倾斜树干试验,将幼苗分成5组(每组12株)后倾斜成不同的角度(0°,15°,30°,45°和60°),苗木生长4个月后在次生木质部取样,观测横切面宏观和微观特征,分应拉区和对应区对其解剖特性进行测定分析。结果表明:1)随着倾斜角度的增加,横截面轮廓由圆形向椭圆形转变,年轮偏宽及起毛区域比例也随着角度增加而增大,方差分析表明不同倾斜角度对年轮偏宽及起毛区域比例影响显著;2)应拉木横切面双染色后随倾斜角度的增加导管数目减少,直径增加,胶质层厚度和区域增大,细胞腔表面由平整变为袖套状起伏,其形状由规则变为不规则;3)纤维长度、宽度和双壁厚随角度增加呈波动变化,应拉区比对应区纤维长度短,双壁厚厚,纤维宽度不同区域无明显变化模式,方差分析表明倾斜角度对纤维长度、宽度和双壁厚影响不显著,不同单株和区域对其影响显著;4)组织比量随倾斜角度的增加,应拉区胶质纤维比量增加明显,其他比量变化不明显,方差分析表明倾斜角度对应拉木组织比量影响不显著,不同单株和区域对其影响显著。 相似文献
11.
Nakai Takashi 《中国林业科技(英文版)》2003,(2)
A comprehensive analysis on the variation pattern of early- and latewood tracheid morphological parameters along tree (Cunninghamia lanceolata Hook.) height, including length and width, wall thickness, tissue proportion, cell wall percentage, width of growth rings, and on the relationship among them are conducted. The results indicate an initially rapid and then gentle increase of tracheid length and width, thickness of the radial wall and tangential wall of tracheid, area percentage of tracheid from pith to outward, while S2 microfibril angle (Mfa) of tracheid, and rays percentage gradually decrease and then tend to be stable. The variation of all anatomical parameters but earlywood cell wall thickness shows no significance along tree height. The radial variation pattern of width of growth rings is characterized with initially slight decrease followed immediately by a rapid and then much more gentle increase from pith to outward. The delimitation age between juvenile and mature wood is 14-16 years. Com 相似文献
12.
不同林龄尾巨桉林木碳贮量研究 总被引：1，自引：0，他引：1
以雷州半岛6个林龄尾巨桉林分为研究对象,分析了不同林龄尾巨桉林分的单株生物量和林分碳贮量变化特征。结果表明：随着林龄的增长,尾巨桉林分的平均树高、平均胸径和单木生物量均有所增加,但各个器官所占比例的变化趋势不同：树干和树叶所占比例增加,树枝、树皮和树根所占比例降低。1—7年生尾巨桉林分碳贮量在1822．56—33925．75kg·hm2,随着林龄增长,尾巨桉林分的碳贮量呈逐渐增多的趋势。树干有机碳贮量所占比例迅速增大,树枝、树皮和树根的逐渐减小,树叶所占比例先增大后减小。 相似文献
13.
Jean-Pierre Lasserre Euan G. Mason Michael S. Watt John R. Moore 《Forest Ecology and Management》2009
Pinus radiata D. Don trees from six clones, grown at initial spacings of 2500 stems ha−1 and 833 stems ha−1 were destructively harvested. For these trees wood properties were measured on radial slices sampled at a height of 1.4 m above the ground. Relative to wide spacing, close initial stand spacing significantly reduced microfibril angle (MFA) and ring width and significantly increased dynamic modulus of elasticity (MOE), fibre length, latewood percentage and cell wall thickness. Density and fibre width were not significantly different between spacing treatments. Examination of the influence of genetic population on wood properties indicated that genotype significantly influenced MFA, MOE and ring width. The key wood properties MFA, MOE and fibre length were regressed against tree diameter, height and stem slenderness. All three wood properties were most strongly correlated with stem slenderness. Multiple regression models developed for MFA, MOE and ring width accounted for respectively 62%, 81% and 58% of the variation in these variables. The following changes occurred in sampled properties with increasing ring number: MFA and ring width declined markedly; MOE and fibre length increased markedly; latewood percentage and cell wall thickness increased slightly; and density and fibre width did not show any radial trend. 相似文献
14.
Joe Yao 《Wood Science and Technology》1970,4(3):163-175
Summary Forty lobiolly pine trees were studied for the purpose of finding a possible reason for the growth rate-specific gravity controversy. In addition, properties such as specific gravity of earlywood and latewood, latewood percentage, and their relations with growth rate and specific gravity of wood were investigated.The results show that, in general, significant relationship do exist between specific gravity and number of rings per inch for growth rates ranging from approximately 3...8 rings per inch. Specific gravity was generally unrelated with slower growth rates, i.e., more than 8 rings per inch.Specific gravity of specimens having the same number of rings per inch varied according to height-decreasing with increasing height. Latewood percentage was related to number of rings per inch in a similar manner as specific gravity. Within a tree, latewood percentage of wood having the same number of rings per inch decreased with increasing height.Negative relationships between earlywood specific gravity and number of rings per inch were found to be significant for the 30 percent height and for all heights when combined. However, there was no significant relationship between latewood specific gravity and number of rings per inch. Average laterwood specific gravity decreased with height. Earlywood specific gravity only decreased from 5.3...30 percent height levels and then showed an increase. In general, wood properties such as specific gravity and latewood percentage of wood, specific gravity of earlywood and latewood, varied more from breast height to approximately the 30 percent height, than between equal distances above the 30 percent height level. 相似文献
15.
The ring characteristics and screw withdrawal resistance (SWR) of naturally regenerated Taiwan yellow cypress (Chamaecyparis obtusa var. formosana) trees were explored. Significant differences in average ring width (RW), earlywood width, latewood width, ring density (RD),
earlywood density (ED), latewood density (LD), highest density (Dmax), lowest density (Dmin), latewood percentage (LWP), and SWR were observed between trees, rings (SWR excluded), and tree height positions. The RW
components in the radial direction increased from the pith outward to about the 3rd to 5th ring and then decreased to about
the 25th ring; it was almost constantly sustained toward the bark side. The RD in the radial direction slowly decreased from
the pith outward to the bark side. Average ring width and ring density were significantly affected by the various tree growth
rates, radial ring numbers, and tree height positions. ED, LD, Dmax, Dmin, and LWP were the most important factors determining the overall RD. RW did not correlate with tree RD. SWR is correlated
with ED, RD, Dmin, LWP, and intra-ring density variation (IDV). Thus, the SWR can be used to predict wood density and in nondestructive evaluation
of a living tree. 相似文献
16.
To investigate the relations between growth and the wood properties of Japanese larch (Larix kaempferi), six sample trees of varied ages and radial growth were felled and the ring width, ring density, percentage of latewood, and some other factors were determined. There were significant differences in ring density and percentage of latewood between sample trees with vigorous growth and those with poor growth. In corewood the ring density decreased with increasing ring width for all sample trees, whereas in outerwood this trend did not appear. Moreover, the latewood width increased with the increment of ring width only in outerwood, whereas there was almost no change in the corewood. The variation in patterns of ring width, ring density, and percentage of latewood in the radial direction and the relation with height was also studied.Part of this report was presented at the 47th annual meeting of the Japan Wood Research Society, Kochi, April 1997 相似文献
17.
A. E. Akachuku 《Wood Science and Technology》1985,19(1):1-12
Summary Wood samples of Gmelina arborea were collected from four different localities (sites) in Nigeria. The proportion of vessels was determined by a modification of Ladell's (1959) randomized dot technique. The site and plot effects on vessel proportion were not significant. The tree effect was very highly significant with a variance component of up to 25.4 per cent. The tree mean values of vessel proportion ranged from 9 to 21.3 per cent. There was no close correlation between tree mean values of vessel proportion and tree growth parameters (tree height, diameter at breast height and crown diameter). The effect of stem height was not significant. The effects of radii (the variation around the stem's circumference) and age were very highly significant with variance components of up to 21 and 11.7 per cent respectively. The differences in the values of vessel proportion for earlywood and latewood were very highly significant; the variance component was 22.9 per cent. Earlywood had a lower proportion of vessels than latewood (12 and 16 per cent respectively). Vessel proportion was not correlated with ring width. The effects of factor interactions were not practically important. 相似文献
18.
实验观测了青皮竹(Bambusa textilis McClure)和慈竹(B.emeiensis)不同发育期(竹笋、幼竹和成年竹)的解剖特征,包括组织比量、基本组织、维管束及纤维形态的变化。结果表明,随着发育成熟,2个竹种的基本组织比量都呈现下降趋势,而输导组织和纤维组织则呈现不同程度的增长趋势。基本组织的减小量基本上等于纤维组织和输导组织的增加量。在同一发育期慈竹的维管束密度大于青皮竹。纤维长度随着竹龄的增加而变长和增宽,在同一发育期,纤维细胞的直径中部大于基部和顶部。竹子发育期间,纤维直径、双壁厚、长宽比及腔径比都随竹龄增加而增大,壁腔比则呈现下降趋势。2种竹材维管束的径向宽度均大于其弦向宽度。 相似文献
19.
Important wood, pulp and fibre properties were investigated on small wood samples from two Rumanian, one German and one Norwegian provenance of Norway spruce (Picea abies) grown in Sørkedalen, Norway. Several samples were collected from inside each single tree, both in radial and transversal direction in the stem. Data were collected from a total of 59 trees, each 28 years of age. All investigated properties showed close relationship to ring number (RN) (cambium age). For basic density and fibre wall thickness (FWT), a fast decline was first observed when moving from pith to bark and a minimum value was found around RN 5–8. The declining trend was then followed by an increase. Kraft pulp yield, fibre length and fibre width (FW) also increased with RN, but the increase was most pronounced close to the pith. The pulp yield (PY) more or less stabilised outside of RN 5–6. FW showed a decrease outside of RN 10–12, but this was probably due to the remarkable simultaneous drop in ring width for the investigated trees. FW decreased, while basic density and fibre length increased with increasing height in the tree. PY and FWT were not affected by height in tree. Diameter at breast height (DBH) was the most important variable indicating differences between trees in the investigated material. Basic density, fibre length and FWT decreased, while FW increased with increasing DBH. Height to crown had a positive effect on basic density, but had no influence on any of the remaining properties. Differences between provenances were found for basic density, fibre length and FW. The analyses showed that it is possible to describe the variation inside and between trees satisfactorily for a range of important wood and fibre properties. 相似文献