摘要
本文从微观水平到宏观水平对应拉木的特性进行了深入的观测和研究,并将之与正常木进行比较。本研究选择杨树(从法国采的Populus cv.I4551和从中国采的Populus deltoids cv.I-69/55)作为实验材料,因为杨树中很容易产生有胶质纤维的应拉木并伴有大的纵向生长应力;另外,杨树也是一个在全球都非常重要的速生人工林树种。
本研究中纵向生长拉应力被用作应拉木严重程度的指标,而生长应力水平又由生长应变来指示。根据不同研究目的,本文运用了两种方法来测定生长应变:
1.为了微观水平上的研究:应变片法,此方法可以直接给出生长应变值(GrowthStrain,简称GS);
2.为了宏观水平上的研究:单孔法,直接测出的值称作“生长应力指示值”(GrowthStress Indicator,简称GSI),基本和生长应变值成正比。
本文的研究内容和意义主要有如下几点:
●树木生长应力的产生机理一直是林业科研工作者热烈争论的疑点课题,本文进一步推进了这一的讨论并且尝试了在细胞壁和组织水平上揭示生长应力现象。这部分实验使用了与传统的常规切片不同的方法。在传统的未包埋试样上制得的常规切片上发现胶质纤维中的胶质层呈可疑的脱离和膨胀状态。为了能够观测到实木中胶质层的实际状态从而使得进一步的研究结果的真实可信,本文使用了包埋过的试样,用玻璃刀片和钻石刀片进行超薄切片。
●本文对不同严重程度的应拉木以的解剖特征、物理力学性质和化学组成做了全面的测定和深入的分析讨论,并与相应的正常木进行比较,建立了木材特性与生长应力水平之间的关系,为进一步了解和合理利用应拉木,特别是杨树应拉木提供了理论基础。
●由于干缩对木材的加工利用有着显著的影响,因此本文特别对不同严重程度的应拉木的横向干缩进行深入的研究并与正常木的干缩进行比较。通过对细胞壁水平、组织水平以及实木水平上干缩特征的研究,提出了胶质纤维和正常纤维的干缩模型。
●杨树的一个重要用途是用来旋切制成单板再进一步加工利用,而在由含有应拉木的杨木旋切的单板中,起毛和翘曲是两个主要问题。因此,本文对由不同程度的应拉木区域旋切的单板的起毛和翘曲进行了测定并和正常木区域的进行对比。
通过以上几个方面的研究,得出如下主要结论:
●进一步证实了Clair等(2005b;2005a)的报道,在传统的未包埋试样上制得的常规切片上发现的胶质层脱离和膨胀状态是一种在切片过程中造成的人为破坏结果,并不是它的实际状态。在立木和实木中,无论是在生材还是干燥后的木材中,胶质层是并没有脱离细胞壁的其他层,并且不是膨胀状态,它的实际厚度比在常规切片上观测到的要小。因此,要想研究胶质层的真实状态和性质,传统的常规切片方法是不合适的,建议使用本实验中所运用的方法,即使用包埋试样切片,并且要考虑要使用的切片到试样端头的距离。
●胶质纤维中胶质层与S_2层的粘着程度不如细胞壁中其它层(即胞间层、初生壁、S_1层和S_2层以及正常纤维中的S_3层)之间的粘着程度,但这种粘着程度足够强而不至于因干燥而分开,尽管胶质层有很大的轴向横向干缩率。这一发现也确定了胶质层对应拉木物理和力学性质有着重要的影响。
●根据在立木中测得的GS而划分的不同严重程度的应拉木中,通过对包埋试块端头切制的切片上胶质层膨胀率的测定,发现此膨胀率和GS呈正相关。由于端头处胶质层中的纵向拉应力在试块包埋前制备时已完全释放,因此胶质层纵向收缩,根据Poisson原理,胶质层横向膨胀。综合以上发现和推测,我们可以推导出在严重应拉木胶质纤维的胶质层中的纵向拉应力要比在轻微应拉木的胶质层中的纵向拉应力大。
●在倾斜的立木中,倾斜树干的上部有着最大的纵向生长应力,沿树干外围到倾斜树干下部,生长应力呈下降分布。相应的大多数木材性质有着相似或相反的规律,与GSI呈正相关或负相关。
●在用应变片法测定的试样中,在GS小于610με的试样中没有胶质纤维出现,在大于816με的试样中胶质纤维的面积比率达到50%或更大,这意味着胶质纤维出现的可能临界点在这两个值之间。另一个100%胶质纤维出现的可能临界点是在1540和1935με之间。
●在测定的有胶质纤维的应拉木试样中,单位面积的组织中胶质纤维越多而且其胶质层越厚,则相应的纵向生长应力(和GS成比例)越大。这意味着这些因素影响着生长应力的产生,其中胶质层在产生高生长应力中起着最重要的作用,胶质层的量对生长应力的水平有着决定性的影响。这一结论可以推测为由下面的假说来解释:应拉木中的纵向生长拉应力产生是由细胞壁中微纤丝的拉应力来决定的(Bamber 1978;Okuyama et al.1986;Bamber 1987;Clair et al.2006a),因为胶质层中的木质素含量甚微。
●正常木纤维的胞壁厚度明显小于应拉木的包括胶质层在内的细胞壁厚度,而又显著大于胶质纤维中除胶质层以外的其它层细胞壁的厚度。在应拉木中,生长应力随着胶质纤维中的胶质层厚度的增加而增加,而其它层厚度则减小。纤维长度和直径分别与生长应力水平呈正相关和负相关。生长应力水平与纤维和导管的组织比量分别呈正相关和负相关。
●根据厚度的相对减小率而计算得出的胶质层干缩率(也即径向干缩率)显著地大于其它层细胞壁的干缩率。胶质层以及总体细胞壁的干缩率与GS没有显著的相关关系,而除胶质层之外的其他层细胞壁的干缩率则与GS有着显著的负相关关系。
●胶质层与GS之间没有明显相关关系意味着从低GS到高GS的应拉木胶质纤维中的胶质层没有质的上的区别,这也证实了前面的推论,即胶质层量的上的差异决定着生长应变的变动,也即与之成比例的生长应力的变动。
●在干燥过程中,应拉木胶质纤维的胞腔增大而且其增大量与GS呈正相关,而正常木纤维的胞腔在本实验中则发现干燥后变小了。这一发现说明胶质层在干燥过程中是由里(胞腔一侧)向外(细胞外围)收缩的(也即它的内周长增大),因此它的干缩对细胞的整体干缩率几乎没有影响,因而其整体干缩率主要受其他层细胞壁干缩的控制,因为我们发现其他层细胞壁是由细胞外围向内干缩的(也即其外围周长变小)。
●无论是正常木还是应拉木,在组织和宏观水平上(分别基于切片和实木上的观测),弦向的干缩率都明显高于径向的,弦向和轴向干缩率分别与GS/GSI呈显著的负相关和正相关,而径向干缩率则与GS/GSI之间没有发现明显相关关系。
●木材的基本密度和纤维饱和点分别与GSI有着显著但微弱的正相关关系。随着GSI的增大,弹性模量和比弹性模量增大而顺纹抗压强度和比抗压强度则降低。从正常木到应拉木,木材的红色和黄色程度降低,颜色偏深的更接近b~*轴。
●与倾斜树干一周其他部位相比,在GSI最大的树干上侧,纤维素含量最高,而木质素含量则相反。
●由于有应拉木的存在,在位于倾斜树干上侧的旋切单板上有严重的起毛现象,并且这部分单板严重翘曲变形。而在倾斜树干下侧的单板上,这些现象基本可以忽略。整体上,单板的起毛率和翘曲程度与GSI呈正相关。
In this study,tension wood behaviours from microscopic to macroscopic levels were observed and measured compared to normal wood.Poplar(Populus cv.I4551 from France and Populus deltoids cv.I-69/55 from China) was chosen as plant material,because poplar is known to have a characteristic tension wood with G-layer and to produce a high longitudinal stress.Poplar is also a very important fast growth plantation tree in the world.
Longitudinal growth stress was regarded as indication of tension wood severity and growth strain(GS) was used to indicate the growth stress level.Two methods were used in this study to measure the GS according to the different purposes:
- for the microscopic study,the strain gauge method giving a direct estimate of the GS;
- for the macroscopic study,the single hole drilling method providing with a "growth stress indicator"(GSI) approximately proportional to the GS.
This study advances the discussion on the origin of growth stresses generation and reveals the growth stresses at cell wall and tissue levels.The measurements were performed on embedded samples sectioned with glass knife and diamond knife,which allows to avoid the uncontrolled swelling and detachment of G-layer during sample preparation with conventional sectioning method.
From normal wood to different severities of tension wood,defined by measured growth strain,wood properties were measured including anatomical,physical,mechanical and chemical properties,as well as the properties of rotary cutting veneer including woolly area proportion and distortion,which are the two most important problems for poplar veneer utilizations.The relationships between these properties and growth stress level are established.
Due to its high importance for wood utilizations,the transverse drying shrinkage of tension wood was studied in particular compared to that of normal wood at cell wall,tissue and massive wood level.A shrinking model is proposed for tension wood and normal wood.
From this study,following conclusions can be drawn:
- This study further confirmed the observations of Clair et al.(2005b;2005a) that G-layer observed with the conventional method of sectioning is in a swollen state and detached from S_2 layer,due to cutting end-effect artefacts.In living trees or massive tension wood in both wet and dry conditions,G-layer is well adhered with S_2 layer and not swollen.Thus for studying the real state and properties of G-layer,conventional sectioning method is not appropriate and embedded sample method,taking into account the distance of the sectioning location to the border,is propositional.
- The adherence between G-layer and S_2 layer are not as strong as that among other layers,i.e.among compound middle lamella,primary layer,S_1,S_2 and S_3 layer in normal wood.But this adherence is strong enough not to be altered by the high transverse and longitudinal shrinkage of G-layer after drying of tension wood.It confirms the contribution of G-layer to the physical and mechanical behaviour of tension wood.
- For the severe tension wood compared to mild tension wood as defined by the GSI measured at macroscopic level,higher longitudinal tensile stress was deduced in G-layer.
- The highest growth stress values were located in the upper sides of the inclined trunks. Other growth stress values mostly distributed between those of upper and lower sides. Most of wood characteristics exhibited similar distributions around the inclined trunks, their correlation with GSI being either positive or negative.
- In the samples examined,no G-fibres were observed for a GS up to 610μεwhile their surface ratio amounted to 50%or more from 816με,suggesting a hypothetical threshold for G-fibres occurrence between these two GS values.Almost 100%of the fibres contained G-fibres above another hypothetical GS threshold between 1540 and 193.5με.
- In the samples examined,more G-fibres per unit of tissue area and thicker G-layer accompany higher longitudinal growth stress(proportional to GS) in tension wood with G-fibres.It suggests that these factors contribute to the growth stress generation and hereinto G-layer plays the most important role in high growth stress generation,which supposedly can be explained by the hypothesis that the tensile stress of microfibrils governs the longitudinal tensile stress in tension wood(Bamber 1978;Okuyama et al. 1986;Bamber 1987;Clair et al.2006a).
- The thickness of normal wood cell wall was notably lower than that of the tension wood cell wall including G-layer but markedly larger than that of the other layers excluding G-layer.In tension wood the thickness of G-layer and other layers increased and decreased,respectively,with the increase of growth stress.Negative and positive correlations were found for cell diameter and fibre length,respectively,against growth stress level.Fibre and vessel proportion increased and decreased,respectively,with the increase of growth stress.
- The drying shrinkage,measured as a relative thickness decrease,was significantly higher for G-layer than other layers.There were no significant correlation between GS and G-layer or all layers shrinkage,but a negative one was observed with other layers shrinkage.
- The absence of relationship between G-layer drying shrinkage and GS tend to prove that G-layer would be nor qualitatively different from low GS to high GS and would confirms the ideas that just the quantity of G-layer would be the driving force of growth strain,i.e.growth stress.
- In G-fibre,lumen size increased during drying and this increase was positively related with GS,but in normal wood fibre lumen size decreased during drying in our observations.These findings suggest that G-layer shrank outwards(i.e.its internal perimeter increases),so that its shrinkage weakly affected the total cell shrinkage and the mesoscopic shrinkage was controlled by the other layers shrinkage which shrank inwards(i.e.its external perimeter decreases).
- At both tissue and macroscopic levels,based on the observations on sections and massive wood,respectively,tangential shrinkage was notably higher than radial one both in normal and tension wood.The shrinkages in tangential and longitudinal directions were negatively and positively,respectively,correlated with GS/GSI,while no clear relation was found between radial shrinkage and GS/GSI.
- GSI was significantly but weakly correlated positively with basic density and negatively with FSP.With the increase of GSI,MOE and specific MOE increased, compressive strength and specific compressive strength decreased.From normal wood to tension wood the colour of wood became less reddish and less yellow,and darker specimens tend to approach the b~* axis.
- The cellulose content rose to a maximum in the upper sides where highest GSI values were measured,and the opposite for the lignin content.
- Severe veneer distortion and woolly phenomena happened in the veneers located in the upper sides of inclined trunks.In the lower sides the distortion and woolly phenomena were negligible.Positive correlations were found for them with growth stress level.
引文
AFNOR(1985)French standard NF B 51007,approved in February 1942,No.85365.
Alm(?)ras T,Thibaut A,Gril J(2005)Effect of circumferential heterogeneity of wood maturation strain,modulus of elasticity and radial growth on the regulation of stem orientation in trees.Trees,Structure and function 19:457-467
Alm(?)ras T,Yoshida M,Okuyama T(2006)The generation of longitudinal maturation stress in wood is not dependent on diurnal changes in diameter of trunk.Journal of Wood Science 52:452-455
Aloni R(1988)Vascular differentiation within the plant.In:Roberts LW,Gahan PB,Aloni R(eds)Vascular differentiation and plant growth regulators.Springer-Verlag,Berlin,pp 39-59
Amidon TE(1981)Effect of the wood properties of hardwoods on kraft paper properties.Tappi 64:123-126
Amos GL,Bisset IJW,Dadswell HE(1950)Wood structure in relation to growth in Eucalyptus gigantea Hook.Australian journal of science research B3:393-413
Amusant N,Beauchene J,Fournier M,Janin G,Thevenon M-F(2004)Decay resistance in Dicorynia guianensis Amsh.:analysis of inter-tree and intra-tree variability and relations with wood colour.Annals of forest science 61:373-380
Araki N,Fujita M,Saiki H,Harada H(1982)Transition of the fiber wall structure from normal wood to tension wood in Robinia pseudoacacia L.and Populus euramericana Guinier.Mokuzai Gakkaishi 28:267-273
Archer RR(1986)Growth stresses and strains in trees.Springer Verlag.
Arganbright DG,Bensend DW,Manwiller FG(1970)Influence of gelatinous fibers on the shrinkage of silver maple.Wood Science 3:83-89
Baba K,Adachi K,Take T,Yokoyama T,Itoh T,Nakamura T(1995)Induction of tension wood in GA3-treated branches of the weeping type of Japanese cherry(Prunus spachiana)Plant Cell Physiology 36:983-988
Babiak M,Kudela J(1995)A contribution to the definition of the fiber saturation point. Wood science and technology 29:217-226
Badia MA,Mothe F,Constant T,Nepveu G(2005)Assessment of tension wood detection based on shiny appearance for three poplar cultivars.Annals of forest science 62:43-49
Baill(?)res H,Castan M,Monties B,Pollet B,Lapierre C(1997)Lignin structure in Buxus sempervirens reaction wood.Phytochemistry 44:35-39
Balodis V(1991)Planning of pulpwood production from plantations ACIAR Proceedings,pp 132-137
Bamber RK(1972)Tree growth stresses:V.Evidence of an origin in differentiation and lignification.Wood Sci.Technol.6:251-262.
Bamber RK(1978)The origin of growth stresses.Contributed paper IUFRO Conference,Wood quality and utilization of tropical species.Laguna,Philippines,pp 7
Bamber RK(1979)The origin of growth stresses.Forpride Digest 8:75-79
Bamber RK(1987)The origin of growth stresses:a rebuttal.IAWA bulletin n.s.,8:80-84
Bamber RK(2001)A general theory for the origin of growth stresses in reaction wood:how trees stay upright.IAWA Journal 22:205-212
Bao FC,Jiang ZH,Jiang XM,Lu XX,Luo XQ,Zhang SY(2001)Differences in wood properties between juvenile wood and mature wood in 10 species grown in China.Wood science and technology 35:363-375
Barefoot AC(1963)Selected wood characteristics of young yellow-poplar.Part Ⅱ:Shrinkage of normal and abnormal wood.Forest Products Journal 13:443-448
Barnett JR,Bonham VA(2004)Cellulose microfibril angle in the cell wall of wood fibres.Biological reviews 79:461-472
Barnett JR,Jeronimidis G(2003)Reaction wood.In:Barnett JR,Jeronimidis G(eds)Wood quality and its biological basis.Blackwell publishing,pp 119-136
Bendtsen BA,Senft J(1986)Mechanical and anatomical properties in individual growth rings of plantation-grown eastern cottonwood and loblolly pine.Wood and fiber science 18:23-38
Berry SL,Roderick ML(2005)Plant-water relations and the fibre saturation point.New Phytologist 168:25-37
Bhat KM,Priya PB,Rugmini P(2001)Characterisation of juvenile wood in teak.Wood science and technology 34:517-532
Bletchly FEJ(1978)A study of reaction wood in european beech(Fagus sylvatica L.):variations in chemical composition around the outermost forty-seven growth rings of a branch.Journal of The Institude of Wood Science 8:76-80
Bordonn(?) P-A(1989)Module dynamique et frottement int(?)rieur dans le bois.Mesures sur poutres flottantes en vibrations naturelles.Thesis.Institut National Polytechnique de Lorraine Nancy,pp 109 p.+ bibliogr.+ annexes
Bosshard HH(1956)Uber die anisotropic der holzschwindung.Holz als Roh-und Werkstoff 14:285
Boyd JD(1950)Tree growth stresses:Ⅲ.The origin of growth stress..Australian journal of scientific research,series B,Biological sciences 3:294-309
Boyd JD(1972)Tree growth stresses-Part Ⅴ:Evidence of an origin in differentiation and lignification.Wood science and technology 6:251-262
Boyd JD(1977)Relationship between fibre morphology and shrinkage of wood.Wood science and technology 11:3-22
Boyd JD(1985)The key factor in growth stress generation in trees:lignification or crystallisation.IAWA bulletin 6:139-150
Brancheriau L,Baill(?)res H(2002)Natural vibration analysis of clear wooden beams:a theoretical review.Wood science and technology 36:347-365
Browning BL(1967)Methods of wood chemistry.Interscience,John Wiley & Sons.
Burtin P,Jay-Allemand C,Charpentier J-P,Janin G(1998)Natural wood colouring process in Juglans sp.(J.nigra,J.regia and hybrid J.nigra 23×J.regia)depends on native phenolic compounds accumulated in the transition zone between sapwood and heartwood.Trees-Structure and function 12:258-264
Cassens DL,Serrano JR(2004)Growth stress in hardwood timber.In:Goebel PC,Hix DM,Long RP,Yaussy DA(eds)Proceedings,14th Central Hardwood Forest Conference;2004 March 16 19;Wooster,OH.Gen.Tech.Rep.NE-316.Newtown Square,PA:U.S.Department of Agriculture,Forest Service,Northeastern Research Station,pp106-115
Cave ID(1969)The longitudinal Young's modulus of Pinus radiata.Wood Sci.Technol.3:40-48
Chafe SC(1979a)Growth stress in trees.Australian forest research 9:203-223
Chafe SC(1979b)Wood hardness as a poor indicator of growth stress.Australian forest research 9:147-148
Chaffey N(2000)Microfibril orientation in wood cells:new angles on an old topic.Trends in plant science 5:360-362
Chantre G,Chaunis S(1992)(?)tude de la variabilit(?) des qualit(?)s papetieres de 25 clones de peuplier ages d'un an Ann.AFOCEL.,pp 219-249
Chen X(1998)The sustainable development of wood industry for the 21st century.In:Forestry TCAo(ed)Proceedings of the workshop on forestry toward the 21st century.China Agricultural Science & Technology Press,Beijing,pp pp.510-520
Chow KY(1946)A comparative study of the structure and composition of tension wood in beech(Fagus sylvatica L.).Forestry 20:62-77
Christensen GN,Kelsey KE(1959)Die Geschwindigkeit der Wasserdampfsorption durch Holz.Holz als Roh-und Werkstoff 17:178-188
#12
Clair B,Thibaut B(2001)Shrinkage of the Gelatinous Layer of Poplar and Beech Tension Wood.IAWA Journal 22:121-131
Clair B,Ruelle J,Thibaut B(2003a)Relationship between growth stresses,mechano-physical properties and proportion of fibres with gelatinous layer in chestnut(Castanea Sativa Mill).Holzforschung 57:189-195
Clair B,Jaouen G,Beauch(?)ne J,Fournier M(2003b)Mapping radial,tangential and longitudinal shrinkages and relation to tension wood in discs of the tropical tree Symphonia globulifera.Holzforschung 57:665-671
Clair B,Thibaut B,Sugiyama J(2005a)On the detachment of the gelatinous layer in tension wood fiber.Journal of Wood Science 51:218-221
Clair B,Gril J,Baba K,Thibaut B,Sugiyama J(2005b)Precautions for the structural analysis of the gelatinous layer in tension wood.IAWA Journal 26:189-195
Clair B,Alm(?)ras T,Yamamoto H,Okuyama T,Sugiyama J(2006a)Mechanical behavior of cellulose microfibrils in tension wood in relation with maturation stress generation.Biophysical Journal 91:in press
Clair B,Ruelle J,Beauch(?)ne J,Pr(?)vost M-F,Fournier Djimbi M(2006b)Tension wood and opposite wood in 21 tropical rain forest species.1.Occurrence and efficiency of the G-layer.IAWA Journal 27:329-338
Clair B,Gril J,Sugiyama J,Thibaut B(2004)Consequence of sectioning on the morphology of the gelatinous layer in tension wood.In:Stanzl-Tschegg SE,Gindl M,Sinn G(eds)Proceedings of the 2nd International symposium on wood machining.Properties of wood and wood composites related to machining,Vienna,Austria:July 5-7,2004.BOKU University of natural resources and applied life sciences,Vienne,Autriche,pp 255-261
Clarke SH(1937)The distribution,structure and properties of tension wood in beech (Fagus sylvatica L.).Journal of Forestry 11:85-91
#12
C(?)t(?) WA,Day AC(1964)Anatomy and ustrastructure of reaction wood.In:C(?)t(?) WAJ(ed)Cellular ultrastructure of woody plants.Proceedings of the advanced science seminar-Pinebrook conference center,Upper Saranac Lake,New York,September 1964.Syracuse University Press,Syracuse,N.Y.(U.S.A.),pp 391-418
C(?)t(?) WAJ,Day AC,Timell TE(1969)A contribution to the ultrastructure of tension wood fibers.Wood Science and Technology 3:257-271
Coutand C,Jeronimidis G,Chanson B,Loup C(2004)Comparison of mechanical properties of tension and opposite wood in Populus.Wood Science and Technology 38:11-24
Cronshaw J,Morey PR(1968)The effect of plant growth substances on the development of tension wood in horizontally inclined stems of Acer Rubrum seedlings.Protoplasma 65:379-391
Dadswell HE,Wardrop AB(1949)What is reaction wood.Australian Forestry 13:22
Dadswell HE,Wardrop AB(1955)The structure and properties of tension wood.Holzforschung 9:97-104
De Bell DS,Singleton R,Harrington CA,Gartner BL(2002)Wood density and fiber length in young populus stems:relation to clone,age,growth rate and pruning.Wood and Fiber Science 34:529-539
Desch HE(1981)Timber.Its structure,properties and utilisation,6th ed.rev.edn.Timber Press.
Dinwoodie JM(1966)Growth stresses in timber.A review of literature.Forestry 39:162-170
Du S,Yamamoto F(2007)An overview of the biology of reaction wood forma.Journal of Integrative Plant Biology 49:131-143
Evans II JW,Senft JF,Green DW(2000)Juvenile wood effect in red alder:analysis of physical and mechanical data to delineate juvenile and mature wood zones.Forest products journal 50:75-87
Fang C-H,Liu S-Q,Zhu L-H,Jin S-X,Wu W-Q(2002)Comparative study on the effect of fertilization on wood anatomical features of Poplar Ⅰ-69(in Chinese).Journal of Anhui Agricultural University 29:398-402
Fei B(1995)Variation in the microfibrillar angle of Paliurus Hemsleyanus Rehd.wood.Journal of Anhui Agricultural University 22:262-265
Fisher JB,Stevenson JW(1981)Occurence of reaction wood in branches of Dicotyledons and its role in tree architecture.Botanical Gazette 142:82-95
Food and Agriculture Organization of the United Nations(2007)http://www.fao.org/.
Forest Products Laboratory(1999)Wood handbook:wood as an engineering material.U.S.Department of Agriculture,Forest Service,Forest Products Laboratory.
Fournier M,Chanson B,Thibaut B,Guitard D(1994)Mesure des deformations r(?)siduelles de croissance (?) la surface des arbres,en relation avec leur morphologic Observation sur diff(?)rentes esp(?)ces.Annales des Sciences Foresti(?)res 51:249-266
Fujita M,Saiki H,Harada H(1974)Electron microscopy of microtubules and cellulose microfibrils in secondary wall formation of poplar tension wood fibers.Mokuzai Gakkaishi 20:147-156
Furuya N,Takahashi S,Miyazaki M(1970)The chemical compositions of gelatinous layer from the tension wood of Populus euro-americana.Mokuzai Gakkaishi 16:26-30
Grzeskowiak V,Sassus F,Fournier M(1996)Coloration macroscopique,Retraits longitudinaux de maturation et de s(?)chage du bois de tension du Peuplier(Populus x euramericana cv.I.214.).Ann.Sci.For.53:1083-1097
Guitard D,Amri FE(1987)Mod(?)les pr(?)visionnels de comportement (?)lastique tridimensionnel pour les bois feuillus et les bois r(?)sineux.Annales des Sciences Foresti(?)res 4:335-358
Haines DW,Leban JM,Bormann FH(1996)Determination of Young's modulus for spruce,fir and isotropic materials by the resonance flexure method with comparisons to static flexure and other dynbamic methods.Wood science and technology 30:253-263
Haygreen JG,Bowyer JL(1982)Forest products and wood science.An introduction.The Iowa State University Press.
Hernandez RE,Koueaa A,Beaudoin M,Fortin Y(1998)Selected mechanical properties of fast-growing Poplar hybrid clones.Wood and fiber science 30:138-147
Horgan CO,Knowles JK(1983)Recent developments concerning Saint-Venant's principle,in:J.W.Hutchinson and T.Y.Wu(Eds.),Advances in Applied Mechanics.
Hudson DJ(1966)Fitting segmented curves whose join points have to be estimated.J.Am.Stat.Assoc.61:1097-1129
Isebrands JG,Bensend DW(1972)Incidence and structure of gelatinous fibers within rapid-growing eastern cottonwood.Wood and Fiber Science 4:61-71
Jacobs MR(1939)Further studies on fibre tension.Bulletin Comonwealth forestry bureau 24:36 p.
Jacobs MR(1945)The growth stresses of woody stems.Commonwealth Forestry Bureau.
Jacobs MR(1965)Stresses and strains in tree trunks as they grow in length and width.In:s.n(ed)Meeting of section 41(Forest products)of the International Union of Forest Research Organisations.Melbourne,October 1965,pp 15 p.
Janin G,Ory JM,Bucur V(1990)Les fibres du bois de reaction.A.T.I.P.44:268-375
Jourez B,Riboux A,Leclercq A(2001a)Anatomical characteristics of tension wood and opposite wood in young inclined stems of poplar(populus euramericana cv "ghoy").IAWA J.22:133-157
Jourez B,Riboux A,Leclercq A(2001b)Comparison of basic density and longitudinal shrinkage in tension wood and opposite wood in young stems of Populus euramericana cv.Ghoy when subjected to a gravitational stimulus.Canadian journal of forest research 31:1676-1683
Kaeiser M,Boyce SG(1965)The relation of gelatinous fibers to wood structure in eastern cottonwood(Populus deltoides Marsh.).Amer.J.Bot.52:711-715
Kelsey KE(1963)A critical review of the relationship between the shrinkage and structure of wood.Commonwealth scientific and industrial research organization Australia.
Kennedy RW(1957)Fibre lenght of fast and slow grown black cottonwood.For.Chron.33:46-55
Keylwerth R(1951)Die anisotrope Elastizitat des Holzes und der Lagenholzer[Anisotropy of elasticity of wood and wood-based materials].VDJ- Forschungsheft 430,Düsseldorf[in German].
Klason P(1908)Bidrag till narmare k(a|¨)nnedom on granvedens kemiska sammans(a|¨)ttning.Arkiv f(o|¨)r Kemi,Mineralogi och Geologi 3:1-20
Klumpers J,Janin G(1992)Influence of age and annual ring width on the wood colour of oaks.Holz als Roh]und Werkstoff 50:167-171
Kollmann FFP,C(?)t(?) WA,Jr.(1968)Principles of wood science and technology.Vol.1.Solid wood.Springer-Verlag.
Koponen S,Toratti T,Kanerva P(1989)Modelling longitudinal elastic and shrinkage properties of wood.Wood science and technology 23:55-63
Koubaa A,Hernandez R,Beaudoin M,Poliquin J(1998)Interclonal,intraclonal,and within-tree variation in fiber length of poplar hybrid clones.Wood Fiber Sci.30:40-47
Kroll RE,Ritter DC,Au KC(1992)Anatomical and physical properties of Balsam poplar (Populus balsamifera L.)in Minnesota.Wood and fiber Science 24:13-24
Kübler H(1987)Growth stresses in trees and related wood properties.Forest products abstracts 10:62-119
Kuo CM,Timell TE(1969)Isolation and characterization of a galactan from tension wood of American Beech {Fagus grandifolia Ehrl.).Svensk Papperstidn 72:703-716
Lenz O(1954)Le bois de quelques peupliers de culture en Suisse.Ann.Inst.Fed.Rech.For.30
Liu S,Loup C,Gril J,Dumonceaud O,Thibaut A,Thibaut B(2005)Studies on European beech(Fagus sylvatica L.).Part 1:Variations of wood colour parameters.Annals of forest science 62:625-632
Lowell EC,Krahmer RL(1993)Effects of lean in red alder trees on wood shrinkage and density.Wood and Fiber Science 25:2-7
Maeglin RR(1987)Juvenile wood,tension wood,and growth stress effects on processing hardwoods.In:Applying the latest research to hardwood problems:Proceedings of the 15th annual hardwood symposium of the Hardwood Research Council;1987 May 10-12;Memphis,TN.Memphis,TN:Hardwood Research Council;1987:100-108
Maisonneuve O(1971)Sur le principe de Saint-Venant.Thesis.Universit(?) de Poitiers Poitiers,pp 119 p.+ annexes
Mathew F(2003)Structural studies on Tension wood of Hevea brasiliensis(Para Rubber)with special reference to clonal variability.Thesis.Mahatma Gandhi University Kotayam,Kerala(Inde).pp 177 p.
Matyas C,PESZLEN I(1997)Effect of age on selected wood quality traits of poplar clones.Silvae Genetica 46:64-72
Meylan BA(1972)The Influence of microfibril angle on the longitudinal shrinkage-moisture content relationship.Wood Science and Technology 6:293-301
Morey PR,Cronshaw J(1968)Developmental changes in the secondary xylem of Acer Rubrum induced by various auxins and 2,3,5-tri-iodobenzoic acid.Protoplasma 65:287-313
Munch E(1938)Statics and dynamics of the cell wall's spiral structure,especially in compression wood and tension wood.Flora 32:357-424
National Technical Monitoring Bureau(1991)National standard GB 1927～1943-91:Testing methods for physical and mechanical properties of wood.Beijing:China Standard Press.
National Technical Monitoring Bureau(2004)National standard GB/T 9846.1～9846.8-2004:Plywood.Beijing:China Standard Press.
Ne(?)esan(?) V(1955)Die Beziehung zwischen dem Reaktionsholz der Laub-und Nadelh(o|¨)lzer.Biologia(Bratislava)10:647-659
Ne(?)esan(?) V(1958)Effect of β-indoleacetic acid on the formation of reaction wood.Phyton 11:117-127
Nepveu G,Keller R,Teissier du Cros E(1978)S(?)lection juv(?)nile pour la qualit(?) du bois chez certains peupliers noirs.Ann.Sci.For.35:69-92
Nicholson JE(1971)A rapid method for estimating longitudinal growth stresses in logs.Wood science and technology 5:40-48
Nishino Y,Janin G,Chanson B,D(?)tienne P,Gril J,Thibaut B(1998)Colorimetry of wood specimens from French Guiana.Journal of wood science 44:3-8
Norberg PH,Meier H(1966)Physical and chemical properties of the gelatinous layer in tension wood fibre of aspen(Populus tremula L.).Holzforschung 20:174-178
Okumura S,Harada H,Saiki H(1977)Thickness variation of the G-layer along a mature and a differentiating tension wood fiber in Populus euramericana.Wood science and technology 11:23-32
Okuyama T,Kawai A,Kikata Y,Yamamoto H(1986)The growth stresses in reaction wood Proc.IUFRO-18 Word Congress Div.5,Ljubljana,Yugoslavia,pp 249-260
Okuyama T,Kanagawa Y,Hattori Y(1987)Reduction of residual stresses in logs by direct heating method.Mokuzai Gakkaishi 33:837-843
Okuyama T,Yamamoto H,Murase Y(1988)Quality improvement in small log of Sugi by direct heating method.Wood industry(Jap.)43:14-18
Okuyama T,Yamamoto H,Iguchi M,Yoshida M(1990a)Generation process of growth stresses in cell walls Ⅱ.Growth stresses in tension wood.Mokuzai Gakkaishi 36:797-803
Okuyama T,Yamamoto H,Kobayashi I(1990b)Quality improvement in small log of Sugi by direct heating method(2).Wood industry(Jap.)45:63-67
Okuyama T,Yamamoto H,Yoshida M,Hattori Y,Archer RR(1994)Growth stresses in tension wood:role of microfibrils and lignification.Ann.Sci.For.51:291-300
Okuyama T,Yoshida M,Yamamoto H(1995)An estimation of turgor pressure change as one of the factors of growth stress generation in cell walls.Mokuzai Gakkaishi 41:1070-1078
Okuyama T,Takeda H,Yamamoto H,Yoshida M(1998)Relation between growth stress and lignin concentration in the cell wall:ultraviolet microscopic spectral analysis.Journal of wood science 44:83-89
Okuyama T(1993)Growth stresses in tree.J.Jpn.Wood Res.Soc.39:747-756
Okuyama T(1997)Assessment of growth stresses and peripheral strain in standing trees.In:s.n(ed)Conferencia IUFRO sobre silvicultura e melhorament de Eucaliptos,pp 14 p.
Ollinmaa P(1959)Reaktiopuututkimusksia.Summary:Study on reaction wood.Acta For.Fennica 72:1-54
Onaka F(1949)Studies on compression and tension wood.Wood research,Bulletin of the Wood research Institute,Kyoto University,Japan 24:1-88
Panshin AJ,de Zeeuw C(1980)Textbook of Wood Technology,4th edn.Mc Graw-Hill Book Co.,New York.
Parham RA,Robinson KW,Isebrands JG(1977)Effects of tension wood on Kraft paper from a short-rotation hardwood {Populus “Tristis No.1”).Wood Sci.Technol.11:291-303
Peszlen I(1994)Influence of age on selected anatomical properties of Populus clones.IAWA Journal 15:311-321
Pilate G,Chabbert B,Cathala B,Yoshinaga A,Lepl(?) J-C,Laurans F,Lapierre C,Ruel K (2004)Lignification and tension wood.Comptes rendus biologies 327:889-901
Polge H(1984)Essai de caract(?)risation de la veine verte du Merisier.Ann.Sci.For.41:45-58
Rasband WS(1997-2006)ImageJ.U.S.National Institutes of Health,Bethesda,Maryland,USA,http://rsb.info.nih.gov/ij/
Ritter DC,Kroll RE,Gertjejansen RO(1993)Zones of gelatinous fibers in Populus balsamifera L.Wood and fiber science 25:198-208
Roos KD,Shottafer JE,Shepard RK(1990)The relationship between selected mechanical properties and age in quaking aspen.Forest Products Journal 40:54-56
Ruan X,Wang W,Pan B(1993)Study of microfibril angles in reaction wood.Scientia Silvae Sinicae 29:531-536
Ruelle J,Clair B,Beauchene J,Prevost MF,Fournier M(2006)Tension wood and opposite wood in 21 tropical rain Forest species.2.Comparison of some anatomical and ultrastructural criteria.IAWA Journal 27:in press
Ruelle J(2006)Analyse de la diversit(?) du bois de tension de 3 especes d'angiospermes de for(?)t tropicale humide de Guyane Francaise.Thesis.Forest and wood science Universite Antilles Guyane.Cayenne,pp 210
Sachsse H(1961)Anteil und Verteilungsart von Richtgewebe im Holz der Rotbuche.Holz als Roh-und Werkstoff 19:253-259
Saiki H,Ono K(1971)Cell wall organization of gelatinous fibers in tension wood.Bull.Kyoto Univ.For.42:210-220
Salmen L,Ruvo Ad(1985)A model for the prediction of fiber elasticity.Wood and fiber science 17:336-350
Sasaki Y,Okuyama T,Kikata Y(1978)The evolution process of the growth stress in the tree.The surface stresses on the tree.Mokuzai Gakkaishi 24:140-157
#12
Scurfield G,Wardrop AB(1962)The nature of reaction wood.Ⅵ.The reaction anatomy of seedlings of woody perennials.Aust.J.Bot.10:93-105
Scurfield G,Wardrop AB(1963)The nature of reaction wood.Ⅶ.Lignification in reaction wood.Aust.J.Bot.11:107-116
Siau JF(1984)Transport processes in wood.Springer Verlag.
Simpson LA,Barton AFM(1991)Determination of the fibre saturation point in whole wood using differential scanning calorimetry.Wood science and technology 25:301-308
Skaar C(1988)Wood-water relations.Springer Verlag.
Stamm AJ(1971)Review of nine methods for determining the fiber saturation points of wood and wood products.Wood Science 4:114-128
Sugiyama K,Okuyama T,Yamamoto H,Yoshida M(1993)Generation process of growth stresses in cell walls:Relation between longitudinal released strain and chemical compostion.Wood Sci.Technol.27:257-262
Thibaut B,Gril J(2003)Growth stresses.In:Barnett JR,Jeronimidis G(eds)Wood quality and its biological basis.Blackwell publishing,pp 136-156
Timell TE(1969)The chemical composition of tension wood.Svensk Papperstidn 72:173-181
Timell TE(1980)Karl Gustav Sanio and the first scientific description of compression wood.IAWA Bulletin 1:147-153
Timell TE(1986)Compression wood in Gymnosperms.Vols 1-3.Springer Verlag.
Toupin RA(1965)Saint-Venant's principle.Archive for rational mechanics and analysis 18:83-96
Tr(?)nard Y,Gu(?)neau P(1975)Relations entre contraintes de croissance longitudinales et bois de tension dans le h(?)tre(Fagus sylvatica L.).Holzforschung 29:217-223
Wada M,Okano T,Sugiyama J,Horii F(1995)Characterization of tension and normally lignified wood cellulose in Populus maximowiczii.Cellulose 2:223-233
Wardrop AB,Dadswell HE(1948)The nature of reaction wood Ⅰ-The structure and properties of tension wood fibres.Australian journal of scientific research,series B,Biological sciences 1:3-16
Wardrop AB,Dadswell HE(1955)The nature of reaction wood.Ⅳ.Variations in cell wall organization of tension wood fibres.Australian journal of botany 3:177-189
Wardrop AB(1956)The nature of reaction wood.Ⅴ.The distribution and formation of tension wood in some species of Eucalyptus.Australian journal of botany 4:152-166
Wardrop AB(1965)The formation and function of reaction wood.In:C(?)t(?) WAJ(ed)Cellular ultrastructure of woody plants.Proceedings of the advanced science seminar-Pinebrook conference center,Upper Saranac Lake,New York,September 1964.Syracuse University Press,Syracuse,N.Y.(U.S.A.),pp 371-390
Wardrop AB(1964)The reaction anatomy of arborescent angiosperms.In:Zimmermann MH(ed)The formation of wood in forest tree.Academic Press,New York,pp405-456
Washusen R,Ilic J(2001)Relationship between transverse shrinkage and tension wood from three provenances of Eucalyptus globulus Labill.Holz als Roh und Werkstoff 59:85-93
Washusen R,Ades P,Evans R,Ilic J,Vinden P(2001)Relationships between density,shrinkage,extractives content and microfibril angle in tension wood from three provenancesof 10-year-old Eucalyptus globulus Labill.Holzforschung 55:176-182
Washusen R,Ilic J,Waugh G(2003)The relationship between longitudinal growth strain and the occurrence of gelatinous fibers in 10 and 11-year-old Eucalyptus globulus Labill.Holz als Roh-und Werkstoff 61:299-303
Wershing HT,Bailey IW(1942)Seedlings as experimental material in the study of “redwood” in conifers.Journal of Forestry,40:411-414 40:411-414
Yamamoto H,Okuyama T(1988)Analysis of the generation process of growth stresses in cell walls.Mokuzai Gakkaishi 34:788-793
Yamamoto H,Okuyama T,Yoshida M,Sugiyama K(1991)Generation process of growth stresses in cell walls Ⅲ.Growth stresses in compression wood.Mokuzai Gakkaishi 37:94-100
Yamamoto H,Okuyama T,Sugiyama K,Yoshida M(1992)Generation process of growth stresses in cell walls Ⅳ.Action of the cellulose microfibrils upon the generation of tensile stresses.Mokuzai Gakkaishi 38:107-113
Yamamoto H,Okuyama T,Yoshida M(1993)Generation process of growth stresses in cell walls V.Model of tensile stress generation in gelatinous fibers.Mokuzai Gakkaishi 39:118-125
Yamamoto H,Okuyama T,Yoshida M(1995)Generation process of growth stresses in cell walls Ⅵ.Analysis of growth stress generation by using a cell model having three layers(S1,S2,and I+P).Mokuzai Gakkaishi 41:1-8
Yamamoto H(1998)Generation mechanism of growth stresses in wood cell walls:roles of lignin deposition and cellulose microfibril during cell wall maturation.Wood science and technology 32:171-182
Yamamoto H,Abe K,Arakawa Y,Okuyama T,Gril J(2005)Role of the gelatinous layer (G-layer)on the origin of the physical properties of the tension wood of Acer sieboldianum.Journal of wood science 51:222-233
Yoshida M,Nakamura T,Yamamoto H,Okuyama T(1999)Negative gravitropism and growth stress in GA3-treated branches of Primus spaciana Kitamura f.spachiana cv.Plenarosea.Journal of wood science 45:368-372
Yoshida M,Okuda T,Okuyama T(2000)Tension wood and growth stress induced by artificial inclination in Liriodendron tulipifera Linn,and Prunus spachiana Kitamura f.ascendens Kitamura.Annals of forest science 57:739-746
Yoshida M,Okuyama T(2002)Techniques for measuring growth stress on the xylem surface using strain and dial gauges.Holzforschung 56:461-467
Yoshida M,Ohta H,Yamamoto H,Okuyama T(2002a)Tensile growth stress and lignin distribution in the cell walls of yellow poplar,Liriodendron tulipifera Linn.Trees-Structure and function 16:457-464
Yoshida M,Ohta H,Okuyama T(2002b)Tensile growth stress and lignin distribution in the cell walls of black locust(Robinia pseudoacacia).Journal of Wood Science 48:99-105
Yoshizawa N,Inami A,Miyake S,Ishiguri F,Yokota S(2000)Anatomy and lignin distribution of reaction wood in two Magnolia species.Wood science and technology 34:183-196
Zha C(2005)The inheritance and variation of wood properties in plantation poplar.Thesis.Forest Products Department Anhui Agricultural University.Hefei.pp 136
Zhang SY(1995)Effect of growth rate on wood specific gravity and selected mechanical properties in individual species from distinct wood categories.Wood science and technology 29:451-465
Zimmermann MH(1964)The formation of wood in forest trees.Academic Press,New York,pp 562
Zobel BJ(1980)Inherent differences affecting wood quality in fast-grown plantations IUFRO Congf.Div.5.,Oxford,England,pp p169-188
Zobel BJ,Buijtenen JPv(1989)Wood variation.Springer-Verlag.