人工林马尾松木材性质的变异

本文研究了广西人工林马尾松木材性质的变异及幼龄材与成熟材的差异。结果表明 ,幼龄材与成熟材的分界年龄在 14　 16a ,解剖性质在径向上的变异规律为 :射线比量、树脂道比量、胞壁率、胞腔直径、胞壁厚、管胞长度、管胞宽度和晚材壁腔比是自髓心向外呈递增趋势 ,管胞比量和晚材率为递减趋势 ,早材壁腔比和早材腔径比则近似于一条直线。方差分析结果表明 :树脂道比量、胞壁率、胞壁厚、管胞长度和管胞宽度 ,幼龄材与成熟材差异达显著或极显著水平。 5项木材物理力学性质均为成熟材高于幼龄材 ,且均达差异显著水平。木材性质间的相关分析表明 :木材基本密度与管胞长度、管胞宽度、射线比量、树脂道比量、胞壁率呈显著的正相关关系 ,木材气干密度与抗弯强度、抗弯弹性模量、顺纹抗压强度也呈显著的正相关关系     

杂种落叶松F2代自由授粉家系纸浆材遗传变异及多性状联合选择

对17年生7个杂种落叶松自由授粉家系和3个对照子代测定林(共10个处理)的生长和材性性状进行遗传变异分析、相关分析、综合指数评价与选择.结果表明:生长与材性性状家系间、家系内均存在较大的变异,除单位面积管胞数量外,其他性状晚材的变异系数均大于早材;材积、管胞长宽比和树脂道比量变异系数较大(26.2%～85.3%).基本密度、早材微纤丝角、管胞比量变异系数较小(1.4%～8.1%).方差分析表明:处理间综纤维素含量,早、晚材微纤丝角,管胞长宽比,晚材径向直径、胞壁率、壁腔比,管胞比量差异显著;材积、管胞长、弦向直径、早材和晚材单位面积管胞数量差异极显著,家系遗传力为59.3%～92.7%,家系水平的材性改良潜力较大.材积与综纤维素含量成极显著正相关,与早材和晚材微纤丝角、弦向直径、晚材壁腔比和管胞比量成正相关,与管胞长宽比和晚材单位面积管胞数量成负相关;基本密度与材积成微弱的负相关,与综纤维素含量成显著的负相关,与管胞长宽比、早材微纤丝角、晚材单位面积管胞数量成正相关;综纤维素含量与管胞长宽比和晚材单位面积管胞数量成负相关;管胞长宽比与晚材壁腔比成极显著负相关;晚材微纤丝角与管胞比量成显著的正相关.对生长和材性进行综合评价,选出I3,I4,I93个比较理想的多性状指数方程.适合作纸浆林培育的家系为兴7×日77-2、日5×长77-3和日3×兴9.入选率30%时,各性状家系遗传增益分别为:材积34.7%,综纤维素含量7.5%,晚材壁腔比11.0%,晚材胞壁率6.2%,管胞长宽比4.5%,晚材微纤丝角3.2%,管胞比量0.3%.     

中山杉和落羽杉木材解剖性质研究

以12年生中山杉和落羽杉胸高处木材为研究对象,利用纤维测定仪测定其管胞长度、宽度,采用图像分析仪测定其管胞壁厚、壁腔比和各种组织比量,利用双因素方差分析方法分析树种因素、距髓心生长轮数对管胞形态和组织比量等特征的影响.中山杉木材的管胞长度、宽度、长宽比均值分别为2 737.84μm、44.84 μm和60.86,落羽杉木材的管胞长度、宽度、长宽比的均值分别为2 698.52 μm、43.44μm和61.51;中山杉木材的早材和晚材管胞弦向壁厚均值分别为5.91 μm和7.57 μm,落羽杉木材的早材和晚材管胞弦向壁厚均值分别为5.89 μm和6.54 μm;中山杉早材和晚材管胞壁腔比均值分别为0.15和0.35,落羽杉的早材和晚材壁腔比均值与中山杉的一致.双因素方差分析的结果表明:除了中山杉晚材的管胞壁厚显著大于落羽杉晚材的管胞壁厚之外,这两个树种其它管胞形态特征、各种组织比量的差异在0.05水平不显著,该结果表明这两种木材的解剖特征很接近;中山杉、落羽杉幼龄木材除了管胞旱材的壁腔比、薄壁细胞组织比量在不同生长轮之间的差异在0.05水平不显著之外,测试的其它特征在不同生长轮之间的差异在0.05水平具有显著性.中山杉、落羽杉木材的解剖特征的径向变异具有相同的规律:管胞长度、管胞宽度、弦向壁厚、管胞组织比量从髓心向树皮都有逐渐增加的趋势,而射线组织比量从髓心向树皮有逐渐降低的趋势,薄壁细胞比量较小,径向变异也较小、没有明显的规律.     

人工兴安落叶松次生木质部的解剖学研究

运用木材解剖图像分析系统和显微照相的方法对人工兴安落叶松次生木质部的解剖结构进行研究,结果表明:落叶松具正常树脂道和受伤树脂道两种类型,前者常见于晚材。落叶松生长轮内的早晚材在干和枝内急变,在根内缓变。早材管胞呈六边形至多边形,胞壁常见单列具缘纹孔,偶见对列具缘纹孔;晚材管胞多呈矩形,胞壁鲜见具缘纹孔,通常为单列具缘纹孔。落叶松木射线同时具有单列木射线和纺锤形木射线两种类型,纺锤形木射线中仅含一枚纵行树脂道。纵行管胞与木射线交叉形成的纹孔场为云杉型。从根到干再到枝,管胞逐渐细化,管胞长度逐渐减小,木射线分布由密到疏。     

酸雨及大气污染对马尾松木材材性影响的研究：Ⅱ.木材构造

对广西壮族自治区生长在严重酸雨危害（ＳＩＩ）、轻度酸雨危害（ＳＩ）和未受酸雨危害（Ｓ０）三个地方的马尾松（ＰｉｎｕｓｍａｓｓｏｎｉａｎａＬａｍｂ．）木材构造进行了研究，结果如下：边材宽度、管胞长度、径向直径、径壁厚度及弦壁厚度，５ＩＩ＜ＳＩ＜Ｓ０；年轮宽度、管胞径向腔径、弦向直径、弦向腔径及管胞比量，ＳＩＩ＜Ｓ０＜ＳＩ：晚材率、管胞胞壁率及树脂道比量，ＳＩＩ＞ＳＩ＞Ｓ０；木射线比量，ＳＩＩ＞Ｓ０＞ＳＩ；纤丝角，ＳＩＩ＝Ｓ０＜ＳＩ。经方差分析，边材宽度、年轮宽度及管胞径向直径三者差异显著；而其它各项差异均不显著。     

广西融水特色红心杉木优树材质性状变异规律研究

[目的]通过测定和分析广西融水种源红心杉木优树材质性状指标,以了解该地区红心杉木材性状变异规律。[方法]以广西融水种源60株20年生的红心杉木优树为研究材料,测定单株材积、红心率、基本密度、组织比量、管胞性状、微纤丝角等10个材质性状指标,分析各材性性状指标分布和变异规律及性状间的相关关系。[结果]表明:红心率、基本密度、木射线比量、管胞比量、管胞长、管胞宽、管胞长宽比等性状数据分布服从正态分布。融水两个地区红心杉优树轴向薄壁细胞比量的变异系数分别为35.08%和44.97%,变异较大。管胞比量变异系数分别为3.28%和3.56%,变异较小。红心率、木射线比量、管胞长、管胞宽、微纤丝角等性状差异极显著(P0.01),轴向薄壁细胞比量差异显著(P0.05)。10个材质性状间存在12对表型显著相关。[结论]测定的10个性状均是连续性数量性状。早、晚材的管胞长度、管胞宽度和管胞长宽比等性状数据呈从心材至边材逐渐增加的规律。作为重要经济性状的红心率与木射线比量呈极显著正相关(P0.01),单株材积与轴向薄壁细胞比量呈显著正相关(P0.05),而单株材积与基本密度的相关性不显著,这使红心杉木生长量与材性相结合的遗传改良成为可能。     

油麦吊云杉木材解剖性质与材性分析

以油麦吊云杉(Picea brachytyla?(Franch.)?Pritz.?var.?complanata?(Mast.)?Cheng?ex?Rehd.)解析木圆盘为研究对象,通过木材解剖测定其年轮宽度、管胞长度与宽度、管胞腔径/双壁厚度形态特征和木材含水率、干缩性质与密度等材性性状的径向变异规律.结果表明,油麦...     

木质部解剖构造特征对高产脂思茅松选育的影响研究

为了更准确地确定高产脂思茅松优良种源的选择指标,本研究对高产脂和低产脂的思茅松木质部进行解剖构造观察,并进一步探讨胸径与产脂量之间的关系。结果显示：高产脂思茅松的单个轴向树脂道面积、轴向树脂道密度、径向树脂道密度、径向树脂道直径均显著高于低产脂。高产脂木质部木射线分布密度和高度也高于低产脂思茅松。当思茅松受到外界机械刺激后,高产脂新生轴向树脂道的增长数量明显多于低产脂,同时,该生长轮中的晚材率也高于低产脂思茅松。在实验样地划分的5个小区中,只有第2小区思茅松的胸径与产脂量呈正相关性关系,其余4个小区均不存在相关性。结果表明：木质部单个轴向树脂道面积、轴向树脂道密度、径向树脂道密度、径向树脂道直径、木射线密度和木射线高度均可作为高产脂种质选育的有效参考指标;受到外界刺激后新生树脂道数量和晚材率的变化也可以作为高产脂种质选育的重要参考指标。     

人工林马尾松晚材率、年轮宽度和组织比量变异研究

对22年生人工林马尾松木材年轮宽度、晚材率和组织比量进行系统的测量、统计和分析，结果表明，年轮宽度随树龄增加先增加后减小，而随树干高度的增加先减小后增加。晚材率随着树龄增加呈波动增大，而随树干高度的增加呈逐渐减小趋势。木射线比量和树脂道比量随树龄增加呈波动增大，但总体变幅不大，而前者随树干高度的增加呈波动减小，后者先减小再增大。管胞比量随树龄增加呈波动减小，而随树干高度的增加先增加，达到一定值后减小，然后再增加。方差分析表明，年轮宽度、晚材率、组织比量在各年轮间、各高度间差异显著或极显著。     

矮生杉木解剖构造研究

借助光学显微镜和计算机显微图像分析系统,对矮生杉木的解剖性质进行了研究,其主要特征:①矮生杉木生长轮明显,早晚材缓变;管胞壁上的具缘纹孔单列;轴向薄壁组织量多,星散状排列;木射线高有3～12个细胞,多数为3～7个细胞;射线薄壁细胞与早材管胞间的交叉场为杉木型,多2～4个.②矮生杉木第2年轮单位面积的管胞数量平均值为4 047个/mm2,径向层数平均值为118层/轮.③矮生杉木管胞长度平均值为1 560.5μm,管胞宽度平均值为20.06μm,管胞双壁厚平均值为3.602μm,管胞壁腔比平均值为0.21,管胞长宽比平均值为69.90,腔径比平均值为0.830.     

Anatomical and FTIR analyses of phloem and xylem of <Emphasis Type="Italic">Tetracentron sinense</Emphasis>

The fast growth of Tetracentron sinense is a potential valuable timber resource, but whether its anatomy and chemical components are suitable for timber is unknown. We used light microscopy and SEM to examine the anatomical structure and FITR to measure the chemical components of the phloem and xylem of this tree. Radial variations in growth ring width and tracheid dimensions were also evaluated. The sieve tube, phloem parenchyma cell and sclereids clusters were the main cells in phloem, and the tracheid was the fundamental cell in xylem. An unusual tracheid type, fiber-tracheids or vessel-liked elements was visible. Wood rays nonstoried, uniseriate and multiseriate, including heterogeneous II, occasionally I, and usually 3–6 cells wide. The mean growth-ring width was 2.53 ± 0.46 mm, and the percentage of late wood was over 60%. For radial variation, growth-ring width increased at an early growth stage, and reached the largest increment during years 11–15, then decreased. The maximum growth-ring width was 5.313 mm. During late growth (60–85 years), trees also maintained a high radial growth increment. Radial variation in the percentage of late wood was uniform, about 50–70%, throughout the growth years. Growth patterns in the length and width of early and late wood were similar as the trees aged. From the FTIR results, the chemical components differed significantly between xylem and phloem, hemicellulose in particular was higher in the xylem than in the phloem, where it was apparently absent. All of these suggest that the composition of phloem in T. sinense is very similar to that of hardwood, and it has higher growth ratio and uniform wood properties.     

Tracheid length in relation to seedling height in conifers

Summary Changes in tracheid length during the development of primary and secondary xylem are analysed in relation to the division and elongation of cambial initials, in first year seedlings ofPinus sylvestris andPicea sitchensis. During primary and early secondary growth tracheid length varies with leaf internode length, but this relationship soon becomes obscured during later secondary growth. Correlations between seedling height and tracheid length thus depend on variation in tracheid length with radial xylem increment before and after terminal bud production. Since the relation between shoot and tracheid length is a complex one, the clonseness of the correlation varies with environmental treatment, but overall, a doubling of shoot length increased tracheid length by about 10%.I am grateful to ProfessorS. D. Richardson andDr. G. K. Elliott for many helpful suggestions. This work was financed by a grant from the Natural Environment Research Council. Plants were grown from seed kindly supplied by the Forestry Commission Research Division (Scotland and North England).     

Study on tracheid variation ofPicea koraiensis (nakai) in natural stand and plantation

Tracheid characteristics ofPicea koraiensis from natural stand in Liangshui area and plantation in Mao'ershan area were studied. The results of variance analysis showed that the tracheid length, diameter, and thickness of tracheid wall were significant differences between the growth rings. All those characteristics tend to increase from heart-center to bark. In natural stand, it has positive correlation between the characteristics. In plantation, the tracheid length has positive correlation with the trachied diameter, while both the trachied length and the trachied diameter has negative correlation with the thickness of trachied wall. The tracheid length and diameter have no significant difference in growth between natural stand and plantations. The thickness of tracheid wall from the plantation is a little thicker than that from the natural stand before 15 years. Foundation item: This paper was part of State 9th Five-Year Plan project of “Early Mensuration ofPicea koraiensis (nakai)”. Biography: REN Xu-qin (1973-), female, graduate student in Northeast Forestry University, Harbin 150040, P. R. China. Responsible editor: Song Funan     

Effect of flooding of soil on growth,stem anatomy,and ethylene production of cryptomeria japonica seedlings

Flooding of soil for 55 days altered the rate of growth and stem anatomy of 9‐month‐old Cryptomeria japonica seedlings. Although flooding did not affect height growth it reduced the rate of dry weight increment of seedlings while increasing stem diameter. The reduction in dry weight increment of seedlings resulted largely from decay of roots and, to a lesser extent, from inhibition of growth of roots and needles. The increased diameter growth of flooded seedlings resulted largely from an increase in bark thickness associated with increased phloem production and greater amount of intercellular space. Flooding reduced xylem increment in submerged stems but increased it above the water level because of larger tracheids rather than more tracheids per radial file. Flooding also increased lumen diameters of tracheids, decreased tracheid wall thickness (as a proportion of tracheid diameter), and stimulated formation of axial parenchyma cells in the xylem. Cryptomeria japonica seedlings adapted to flooding by forming adventitious roots, primarily on the original root system and submerged portion of the stem. Such new roots originated in the xylem ray parenchyma. Flooding stimulated ACC synthesis in roots and ethylene production in stems. The role of ethylene in alteration of stem anatomy is discussed.     

How timing of stem girdling affects needle xylem structure in Scots pine

While needles represent a proportionally large fraction of whole-plant hydraulic resistance, no studies to date have investigated how source–sink disturbances affect needle xylem structure. In this study, we evaluated structural changes in xylem in current-year needles of Scots pine 227 and 411 days after stem girdling (hereafter referred to as DAG). Maximum and minimum tracheid lumen diameters and therefore also the size of tracheid lumen areas increased in needles 227 DAG compared to control needles. In contrast, tracheid dimensions were similar in needles 411 DAG as in the control needles, but smaller xylem area and lower number of tracheids resulted in the lower theoretical needle hydraulic conductivity of those needles. Several needle xylem parameters were intercorrelated in both control and girdled trees. These observed changes provide a new understanding of the processes that occur following a source–sink disturbance. Considering anatomical parameters such as the number of tracheids, tracheid dimension, or needle xylem area, which are rarely described in physiological studies, could be helpful, for example, in understanding to tree hydraulic systems or for modeling gas exchange. Finally, empirical equations were developed to calculate needle theoretical hydraulic conductivity and the number of tracheids in needles using an easily measurable parameter of needle xylem area.     

Altered light conditions following thinning affect xylem structure and potential hydraulic conductivity of Norway spruce shoots

Trees must respond to many environmental factors during their development, and light is one of the main stimuli regulating tree growth. Thinning of forest stands by selective tree removal is a common tool in forest management that increases light intensity. However, morphological and anatomical adaptations of individual shoots to the new environmental conditions created by thinning are still poorly understood. In this study, we evaluated shoot morphology (shoot length, needle number, projected leaf area) and anatomy (tracheid lumen area, tracheid number, tracheid dimensions, xylem area, potential hydraulic conductivity) in three Norway spruce (Picea abies/L./Karst.) families exposed to different thinning regimes. We compared shoot characteristics of upper-canopy (i.e. sun-exposed) and lower-canopy (i.e. shaded) current-year shoots in a control plot and a plot thinned to 50 % stand density the previous year. One tree per family was chosen in each treatment, and five shoots were taken per canopy position. We found that upper-canopy shoots in both plots had higher values than lower-canopy shoots for all studied parameters, except lumen roundness and tracheid frequency (i.e. tracheid number per xylem area). Thinning had little effect on shoot morphology and anatomy 1 year after thinning, except for small but significant changes in tracheid dimensions. Needles were more sensitive to altered light conditions, as projected leaf area of shoot, needle number and leaf hydraulic conductivity changed after thinning. Differences between upper- and lower-canopy shoots did not seem to be influenced by thinning and were almost the same in both plots. Our results suggest that lower-canopy shoots require several years to modify their morphology and anatomy to new light conditions following thinning. The slow light adaptation of the lower canopy may be of practical importance in forest management: thinned stands may be predisposed to drought stress because newly exposed shoots experience increased illumination and transpiration after thinning.     

Cavitation in dehydrating xylem of Picea abies: energy properties of ultrasonic emissions reflect tracheid dimensions

Ultrasonic emission (UE) testing is used to analyse the vulnerability of xylem to embolism, but the number of UEs often does not sufficiently reflect effects on hydraulic conductivity. We monitored the absolute energy of UE signals in dehydrating xylem samples hypothesizing that (i) conduit diameter is correlated with UE energy and (ii) monitoring of UE energy may enhance the utility of this technique for analysis of xylem vulnerability. Split xylem samples were prepared from trunk wood of Picea abies, and four categories of samples, derived from mature (I: earlywood, II: 30-50% latewood, III: >50% latewood) or juvenile wood (IV: earlywood) were used. Ultrasonic emissions during dehydration were registered and anatomical parameters (tracheid lumen area, number per area) were analysed from cross-sections. Attenuation of UE energy was measured on a dehydrating wood beam by repeated lead breaks. Vulnerability to drought-induced embolism was analysed on dehydrating branches by hydraulic, UE number or UE energy measurements. In split samples, the cumulative number of UEs increased linearly with the number of tracheids per cross-section, and UE energy was positively correlated with the mean lumen area. Ultrasonic emission energies of earlywood samples (I and IV), which showed normally distributed tracheid lumen areas, increased during dehydration, whereas samples with latewood (II and III) exhibited a right-skewed distribution of lumina and UE energies. Ultrasonic emission energy was hardly influenced by moisture content until ～40% moisture loss, and decreased exponentially thereafter. Dehydrating branches showed a 50% loss of conductivity at -3.6 MPa in hydraulic measurements and at -3.9 and -3.5 MPa in UE analysis based on cumulative number or energy of signals, respectively. Ultrasonic emission energy emitted by cavitating conduits is determined by the xylem water potential and by the size of element. Energy patterns during dehydration are thus influenced by the vulnerability to cavitation, conduit size distribution as well as attenuation properties. Measurements of UE energy may be used as an alternative to the number of UEs in vulnerability analysis.     

红皮云杉人工林和天然林管胞性状的变异研究(英文)

本文分别对凉水地区的红皮云杉天然林和帽耳山地区的红皮云杉人工林的管胞性状进行了研究,方差分析结果表明：管胞长度、管胞直径和管胞壁厚度在各年轮间都存在显著差异。管胞的性状从隋心到树皮都呈现出增加的趋势;天然林中,管胞各性状间存在显著的正相关;人工林中,管胞长度和管胞直径呈明显的正相关,但管胞长度和管胞直径分别与管胞壁厚度存在显著的负相关关系。天然林和人工林相比,管胞长度和管胞直径都没有太大差异,只是在15年生以前,人工林的管胞壁厚度稍大于天然林。