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1.
Radial variation of wood properties in Neolamarckia cadamba trees from an East Java community forest
《Southern Forests》2013,75(4):351-359
Radial variations in wood properties, cell morphologies and cell proportions were investigated for nine 4-year-old Neolamarckia cadamba trees planted in a community forest in East Java, Indonesia. The relationships between stem diameter and wood properties, cell morphologies or cell proportions were determined to ascertain the effects of stem diameter on these properties. In the radial variations, almost all of the wood properties, cell morphol- ogies and cell proportion in N. cadamba were changed at around 4 to 6 cm distance from the pith, except for fibre diameter, and the proportion of fibre and axial parenchyma. For trees with larger stem diameter, the vessel diameter was also found to increase. In addition, the ray parenchyma and cell wall proportions in trees with larger stem diameter were lower than those in trees with smaller stem diameter. However, the wood properties obtained from the larger stem diameter trees did not always show lower values. The wood properties in N. cadamba were correlated to fibre wall thickness and vessel diameter. 相似文献
2.
R. V. Rao S. Shashikala P. Sreevani V. Kothiyal C. R. Sarma P. Lal 《Wood Science and Technology》2002,36(3):271-285
Within tree variation in anatomical properties of four and half year old grown Eucalyptus tereticornis Sm. clones have been investigated and correlated with specific gravity. Vessel frequency, vessel diameter and fiber length
were found to vary significantly from bottom to top with no definite trend. Significant variation exists in all the clones
of different parameters. Fiber length was positively correlated with fiber diameter and double wall thickness. Tissue proportions
did not show any significant variation from bottom to top. However, highly significant differences have been found between
clones among four cell types except fibers. Specific gravity is positively correlated with ray percentage, fiber percentage
– vessel percentage ratio and negatively correlated with vessel percentage, while all other anatomical parameters including
height and girth have no effect.
Received 25 August 1998 相似文献
3.
Yi-Qiang Wu Kazuo Hayashi Yuan Liu Yingchun Cai Masatoshi Sugimori 《Journal of Wood Science》2006,52(3):187-194
To explore the influence of the basic density on collapse-type shrinkage properties and to quantify the relationships of the
main anatomical features with shrinkage and collapse properties, all above-mentioned parameters were determined and analyzed
for three species of collapse-susceptible eucalypts, Eucalyptus urophylla, Eucalyptus grandis, and E. urophylla × E. grandis, planted in South China. The correlation coefficients were also determined and the corresponding regression equations were
established with the anatomical parameters measured by using multiple linear regression. The results indicated that: (1) basic
density was strongly positively linearly related to both unit tangential shrinkage (r = 0.970) and unit radial shrinkage (r = 0.959), weakly positively related to total shrinkage (r = 0.656 and 0.640 for tangential and radial, respectively), and weakly negatively related to residual collapse (r = 0.632 and 0.616 for tangential and radial, respectively). (2) The main factors affecting unit shrinkage were cell wall
proportion (WP), microfibril angle (MFA), and double fiber cell wall thickness (DWT); factors playing an important role in
total shrinkage were WP, ray parenchyma proportion (RP), and MFA, while RP had the highest effect on residual collapse (r = 0.949 and 0.860 for tangential and radial, respectively). (3) All corresponding regression models obtained were very suitable
for the evaluation of relationships between the anatomical parameters and unit shrinkage, total shrinkage, and residual collapse,
as measured using a moisture content of 28% as the fiber saturation point for all specimens. 相似文献
4.
Katri Luostarinen Katja Hakkarainen Henri Kaksonen 《Scandinavian Journal of Forest Research》2017,32(8):789-797
Soil affects the anatomy of downy birch wood (Betula pubescens), which raises the question whether the growth of this species differs between mineral and peat soils. The aim of this study was to compare growth, density and structure of xylem of B. pubescens between trees grown in different soils. Both growth and density differed between trees grown in different soils. All measured anatomical characteristics, except double thickness of fibre walls, percentage vessel area and ray number, showed differences between the soil types: the cell dimensions were larger and numbers smaller in trees grown in mineral soil. In peat, high growth rates decreased the wall:lumen ratio of fibres in maturing wood, while no such correlation was observed in trees grown in mineral soil at any studied cambial age. In addition, axial parenchyma may have a different role in trees grown in different soils, as the rapid growth decreased and increased axial parenchyma in mineral and peat soil, respectively. The characteristics affecting wood strength were more similar between trees grown in different soils than those affecting water conductance. The observed differences between trees grown in different soils emphasise rapid growth particularly at young ages and shorter reasonable rotation period in mineral soil. 相似文献
5.
Rina D. Koyani Isha M. Bhatt Hiral R. Patel Ajit M. Vasava 《Wood material science & engineering》2016,11(1):46-56
Lignin biodegradation potential of Schizophyllum commune Fr. is studied by using sound wood blocks of Ailanthus excelsa, Azadirachta indica, Tectona grandis, Eucalyptus sp. and Leucaena leucocephala. Initially, in vitro wood decay test showed minor weight loss, but it became rapid after one month. After 120 days of incubation, weight loss was minimum in T. grandis (24.05%) whereas it was maximum in A. excelsa (34.44%). Treated test blocks were characterised by enlargement of pits on ray cell wall, formation of additional boreholes in rays, separation of fibres and cell wall thinning and formation of ‘U’-shape notches. Fungal hyphae moved through the xylem cell lumen, and intercellular spaces formed in response to separation of fibres. Hyphae traverse in adjacent cell through the cell wall pits or by making additional boreholes. In all the species studied, xylem fibres and parenchyma (axial and ray) cells were more susceptible while vessels were resistant to fungal attack. In advanced stage of decay, fibres and axial parenchyma lost their rigidity while vessel walls showed uneven thinning. In the tension wood, G-fibres remained unaffected initially but loosening and separation of gelatinous layer facilitated fungal action and showed similar pattern of cell wall deterioration. Among the wood of different species studied, Tectona was more resistant whereas Ailanthus was more susceptible to fungal attack. 相似文献
6.
Jyunichi Ohshima Kazuya Iizuka Futoshi Ishiguri Shinso Yokota Toshihiro Ona 《林业研究》2020,31(3):885-900
Eucalyptus camaldulensis Dehnh. and E. globulus Labill. are economically important species for wood and pulpwood materials. Representative heights for assessing whole-tree values of cell-type proportions(vessels, fibers, ray and axial parenchyma percentages) using increment cores were examined by analysis of within-tree variations. Pattern differences were evaluated between trees and species in both radial and axial directions by statistical data analysis(Moses test). In E. camaldulensis,within-tree variation of vessel percentage was generally higher in the upper and outer regions of the trunk. In contrast, E. globulus within-tree variation was unclear. In both species, although no clear pattern of fiber percentages was observed, within-tree variations of ray and axial parenchyma levels were higher in the lower and inner regions.Significant differences in patterns were observed in the axial variation between species for vessel percentages and in the radial variation between trees of E. camaldulensis for ray parenchyma percentages. The representative heights for assessing whole-tree cell-type proportions were 0.8 mabove the ground for E. camaldulensis and 2.8 m for E.globulus, regardless of differences in tree height and pattern of within-tree variation of cell-type proportions. 相似文献
7.
The kinetics of xylem formation in four-year-old plants of Swietenia mahagoni (L.) Jacq. and Khaya ivorensis A. Chev. were studied by means of high resolution laser measurements (accuracy: ±2 μm) in a spatial resolution of 18.7 to
94.1 μm and a temporal resolution of 1 to 60 s. The radial enlargement of the xylem cells was completed within 0.36 to 8.85
hours in Swietenia and within 0.52 to 12.03 hours in Khaya, while secondary wall formation and lignification lasted days to weeks. Cell enlargement of vessels and ray parenchyma was
significantly faster than radial enlargement of fibres and axial parenchyma. The processes of formation of the secondary cell
wall and the lignification were slower in fibres than in vessels and parenchyma cells. In Swietenia new secondary cell formation was induced in distinct growth periods almost simultaneously in the whole shoot, while in Khaya new cell formation was restricted to parts of the shoot. Growth stresses in the shoot were studied in terms of released strain.
Higher growth stresses were observed in the shoot of Khaya compared to Swietenia. The results indicate that the higher growth stresses in the xylem of Khaya compared to Swietenia originate in the different kinetics of cell development of different cell types in combination with the heterogenous sequence
of cell formation within the shoot.
Dedicated to Prof. Dr. Dr. h.c. mult. W. Liese on the occasion of his 80th birthday. 相似文献
8.
Maximilian Wentzel Tim Koddenberg Holger Militz 《Wood material science & engineering》2020,15(4):223-228
ABSTRACT Eucalyptus nitens specimens were thermally modified under open and closed systems. The anatomical characteristics from selected modifications that presented similar mass losses were investigated by analyzing images taken from scanning electron microscopy, transmission light microscopy, and X-ray micro-computed tomography. Wood cell wall thickness, fiber, and lumen area were measured and compared to unmodified specimens, and the crack formation after modification was also analyzed. There was only a slight decrease in the measured characteristics when compared to unmodified specimens. The wood cell wall thickness was less affected than the fiber and lumen areas, and both modifications presented similar crack formations. Overall, there were no significant differences between open and closed system modifications in the anatomical structure. 相似文献
9.
Focussing on four types of parenchyma cell around pith regions of branches of Robinia pseudoacacia L. var. inermis, we examined the timing and role of cell death during heartwood formation. Large parenchyma cells that were located in the
inner part of the pith died within a year. By contrast, other parenchyma cells died within 4 years, with the timing of cell
death depending on the type of cell. Axial parenchyma cells of the xylem close to the pith died first. Then, small parenchyma
cells died in the perimedullary zone in the outer part of the pith. Finally, ray parenchyma cells in the xylem close to the
pith died. Variations in the autofluorescence of cell walls, which might have been due to deposition of heartwood substances,
were observed first in xylem ray parenchyma cells and small parenchyma cells in the perimedullary zone. Our results indicate
that the initiation of heartwood formation occurs within 4 years in pith regions of branches in Robinia pseudoacacia L. var. inermis. Moreover, it appears that not only xylem ray parenchyma cells but also small parenchyma cells in the perimedullary zone
might be involved in the synthesis of heartwood substances. 相似文献
10.
以8年生尾叶桉(Eucalyptus urophylla S.T.Blake)无性系林为试材,就材性指标在株内、株间和无性系之间变异进行了研究分析。结果表明:纤维长度、纤维宽度、纤维长宽比、管孔弦向直径、纤维双壁厚度和纤维壁腔比在树干水平方向上的不同部位具有极显著性差异,呈由内向外逐渐增大的规律;微纤丝角度、单位面积管孔数和纤维腔径比在树于水平方向上的不同部位亦具有极显著性差异,但呈由内向外逐渐减小的规律;而木材胞壁率、木纤维比量、导管比量、射线比量、轴向薄壁组织比量和木纤维胞腔直径在树干水平方向上没有显著性变异;主要材性指标在同一无性系内的植株之间无显著性差异,但在无性系之间的差异均达到显著或极显著性水平。 相似文献
11.
This study tries to clarify the conflicting results from previous studies on cell wall thickening in bamboo culms by applying light and transmission electron microscopy in combination with image analysis. It focused on both fibre and parenchyma wall thickness of both temperate (Phyllostachys spp.) and tropical (Gigantochloa levis and Dendrocalamus asper) bamboo species of different ages in the light of their suitability for the wood industry. The observations indicated a great heterogeneity in cell wall thickness and cell wall layering pattern of fibres within one culm. Nested design ANOVA’s revealed a rising trend in wall thickness of late maturing fibres and parenchyma cells during the first year but significant wall thickening during later years could not be demonstrated. The high variability within one culm and between culms of the same age from 1 year on is partly masking a clear increased cell wall thickening at higher age. Nevertheless, the highest mean values for fibre wall thickness were recorded in culms of 44 months old or older, suggesting that some kind of late cell wall maturing can take place within one culm. 相似文献
12.
《Wood material science & engineering》2013,8(3):95-104
Abstract Several key wood properties of four Australian hardwood species: Corymbia citriodora, Eucalyptus pilularis, Eucalyptus marginata and Eucalyptus obliqua, were characterized using state-of-the-art equipment at AgroParisTech, ENGREF, France. The wood properties were measured for input into microscopic (cellular level) and macroscopic (board level) vacuum-drying models currently under development. Morphological characterization was completed using a combination of environmental scanning electron microscopy and image analysis software. A clear difference in fibre porosity, size, wall thickness and orientation was evident between species. Viscoelastic properties were measured in the tangential and radial directions using dynamic mechanical analysis instrumentation. The glass transition temperature was markedly different for each species owing to anatomical and chemical variations. The radial direction showed higher stiffness, internal friction and glass transition temperature than the tangential direction. A highly sensitive microbalance and laser technology were used to measure loss of moisture content in conjunction with directional shrinkage on microsamples. Collapse shrinkage was clearly evident with this method for E. obliqua, but not with other species, consistent with industrial seasoning experience. To characterize the wood–water relations of E. obliqua, free of collapse, thinner sample sections (in the radial–tangential plane) are recommended. 相似文献
13.
Hiroshi Matsunaga Rika Shiotari Junji Matsumura Kazuyuki Oda Yasuhiro Utsumi Koichi Yamamoto 《Journal of Wood Science》2006,52(2):95-100
This is the first report to ascertain potassium location in black heartwood of sugi (Cryptomeria japonica). The objective of this study was to understand the distribution of potassium in sugi black heartwood in connection with
anatomical morphology. Scanning electron microscopy with energy dispersive X-ray analysis (SEM-EDXA) was used to investigate
the distribution of inorganic elements, especially potassium. In black heartwood, potassium was detected in all tissues (tracheids,
ray parenchyma, and axial parenchyma), but its concentrations were different in each xylem tissue. Potassium was particularly
accumulated in the droplets in axial parenchyma cells. In addition, calcium was also detected in all tissues. Phosphorus sometimes
existed in the granules in ray parenchyma cells. From optical microscopy, the axial parenchyma cells were observed to be arranged
in a tangential direction on transverse section and the droplets in these cells were distributed in areas of high ash and
green moisture content. For red heartwood, potassium detected by SEM-EDXA was far lower in all tissues than in the black heartwood,
while the trend for calcium was the converse. Potassium in axial parenchyma cells was more abundant in black heartwood than
in typical pale red heartwood. 相似文献
14.
A. P. Wilkins 《Wood Science and Technology》1986,20(3):229-233
Summary The distribution of cell wall deformations in the fibre walls adjacent to rays has been examined in five 40 year old Eucalyptus pilularis trees. This distribution was found to be related to both height and distance from the pith within these trees. Growth stresses are thought to influence the formation of fibre cell wall deformations at the ray-fibre contact area except at the marginal ray cell. Deformations in the fibre cell wall, which were at a maximum frequency at the marginal ray cell ray-fibre contact area, are considered to be due to the inflection of the fibre wall around the ray cell.I would like to thank Dr. R. K. Bamber for helpful comments and Mr. T. Groenstein (Biometrician Forestry commission of N.S.W.) for assistance with the statistics. 相似文献
15.
16.
In previous models the distribution of radial tensile stresses in the tree trunk has been explained as a response to the
mechanisms of growth stress generation in the longitudinal and tangential directions. We investigated the contribution of
ray tissue to growth stress generation in the tree trunk by the origin of the radial stresses during differentiation of parenchyma
cells. Measurements on three konara oak trees (Quercus serrata Thunb.) were carried out comparing the radial residual strain of big oak rays with the radial residual strain of the axial
tissues (containing only uniseriate rays). The results indicated that the ray tissue generated tensile growth stress in the
radial direction of the trunk (the axial direction of the parenchyma cells). In contrast to previous assumptions, the growth
stresses seem to be variable in relation to the individual tissue types. The mechanical advantage of a radially prestraining
effect of the rays is discussed for the living tree.
Received: October 9, 2001 / Accepted: April 22, 2002
Acknowledgments This research was carried out during a 2-month short-term stay of the first author at Nagoya University. The financial and
organizational support by Monbusho Foundation is gratefully acknowledged.
Correspondence to:I. Burgert 相似文献
17.
Collapse-type shrinkage is one of highly refractory drying defects in low-medium density plantation-grown eucalypt wood used as solid wood products. Basic density (BD), microfibril angle (MFA), double fibre cell wall thickness (DWT), proportion of ray parenchyma (RP), unit cell wall shrinkage, total shrinkage and residual collapse, which are associated with collapse-type shrinkage characteristics, were investigated by using simple regression method for three species of collapse-susceptible Eucalyptus urophyll, E. grandis and E.urophyllaxE.grandis, planted at Dong-Men Forest Farm in Guangxi autonomous region, China. The results indicated that : unit cell wall shrinkage had a extremely strong positive correlation with BD, moderately strong positive correlation with DWT, and a weakly or moderately negative correlation with RP and MFA; total shrinkage was positively correlated with BD, DWT and RP and negatively related to MFA, but not able to be predicted ideally by any examined factors alone owing to lower R^2 value (R^2≤0.5712); residual collapse was negatively correlated with BD and DWT, linearly positively correlated with MFA, and had strongly positive linear correlation with RP. It is concluded that BD can be used as single factor (R^2≥0.9412) to predicate unit cell wall shrinkage and RP is the relatively sound indicator for predicting residual collapse 相似文献
18.
Summary The cross-sectional view of pitting between various cell types inPinus banksiana Lamb. was studied at the ultrastructural level. Cell types inPinus banksiana include longitudinal tracheids, ray tracheids, ray parenchyma cells, buffer cells and epithelial cells. Two common characteristic features of bordered pit-pairs between longitudinal tracheids are an initial pit border and a thickened torus at the center of the pit membrane. The shape and size of the pit border and torus of bordered pit-pairs between two compression wood cells, and between the last-formed latewood longitudinal tracheid and first-formed earlywood longitudinal tracheid were different from those in the earlywood and latewood longitudinal tracheids. The pit border on the ray tracheid side varied in size and shape due to wall dentation. No initial pit border was found on the pit border of the ray tracheid side. The shape of bordered pit-pairs between two ray tracheids varied considerably due to irregularity of the dentate cell wall. The size of bordered pit-pairs in longitudinal tracheids was between 16 m to 20 m, which was twice the diameter of bordered pit-pairs in ray tracheids. Bordered pitpairs at the end wall of two ray tracheids appeared to be the smallest at 5 m, Pit aspiration occurred in the bordered pit-pairs with or without a torus. In the heartwood zone, some half-borders pit-pairs between tracheary and ray parenchyma cells showed an additional secondary wall on the ray parenchyma cell side. Plasmodesmata were found in the half-bordered pit-pairs as well in the simple pit-pairs. Blind pits were observed between a ray tracheid and a longitudinal tracheid. Bordered pit-pairs between two buffer cells were also observed. The possible functions of buffer cells were discussed.Use of transmission electron microscope provided by the Science Instrumentation Lab, Lakehead University and the technical assistance provided by Mr. A. MacKenzie, Director of Science Instrumentation Lab are gratefully appreciated 相似文献
19.
The formation of reaction and barrier zones was studied in the xylem of Eucalyptus globulus and Eucalyptus nitens tree stems after wounding and artificial inoculation with two white rot fungi. The study had two objectives: to describe host responses in Eucalyptus spp. by light microscopy and to determine whether they would differ in a fungal treatment (wounding and inoculation by one of two fungal isolates) when compared to a control treatment (wounding only). Eucalyptus globulus and E. nitens developed similar reaction and barrier zones. The E. globulus barrier zone was characterized by kino vein formation. In both hosts, the reaction zone was primarily influenced by content and distribution of living tracheids and parenchyma cells within the sapwood. By contrast, the anatomy of the barrier zone showed similarities to the basic xylem structure of each host, except for some cell types that were newly formed (sclereids, kino veins) or increased in number (parenchyma cells, tracheids). Other cell types were reduced in number or completely absent. Host response in terms of barrier zone width appeared to be greater in the fungal than control treatment. Both wood decay fungi appeared to induce a wider barrier zone in both species than that associated with non‐specific damage caused exclusively by wounding. However, the small number of replicates available for this study was possibly insufficient to provide statistical evidence for different barrier zone width between fungal and control treatments. 相似文献
20.
《Scandinavian Journal of Forest Research》2012,27(7):577-584
ABSTRACTThe connection between chemical composition and anatomy of wood is poorly studied. Abiotic and biotic growth conditions affect the synthesis of structural compounds and the anatomy of wood at the same time as they affect growth. In this study, the wood chemical composition, and connections between wood chemistry and anatomy were studied in downy birch (Betula pubescens Ehrh.) grown on four growth sites possessing mineral and peat soils. Lignin, holocellulose, extractive and ash contents, and effective heating value were analysed and compared with libriform fibre double wall thickness and lumen diameter, vessel size and number, and ray and axial parenchyma numbers. Measured lignin and extractive contents were exceptionally high and holocellulose content low. Correlations between wood anatomy and effective heating value were partly different on different soils. Correlations between holocellulose and anatomy were the opposite of the correlations between other chemical compounds and anatomy. The significant correlations between chemical composition and anatomy were commonly opposite in trees grown on peat than in trees grown on mineral soil. Particularly, vessel characteristics and fibre wall thickness correlated significantly with wood chemistry in trees grown on mineral soil. The connections between wood anatomy and chemistry proved to be soil-dependent. 相似文献