Biology, Chemistry and Structure of Tension Wood

Author(s):  
Judith Felten ◽  
Björn Sundberg
Keyword(s):  
Author(s):  
K. W. Robinson

Tension wood (TW) is an abnormal tissue of hardwood trees; although it has been isolated from most parts of the tree, it is frequently found on the upper side of branches and leaning stems. TW has been classically associated with geotropic alignment, but more recently it has been associated with fast growth. Paper made from TW is generally lower in strength properties. Consequently, the paper industries' growing dependence on fast growing, short- rotation trees will result in higher amounts of TW in the final product and a corresponding reduction in strength.Relatively few studies have dealt with the role of TW in the structure of paper. It was suggested that the lower strength properties of TW were due to a combination of factors, namely, its unique morphology, compression failures in the cell wall, and lower hemicellulose content. Central to the unique morphology of the TW fiber is the thick gelatinous layer (G-layer) composed almost entirely of pure cellulose.


1955 ◽  
Vol 3 (2) ◽  
pp. 177 ◽  
Author(s):  
AB Wardrop ◽  
HE Dadswell

The cell wall organization, the cell wall texture, and the degree of lignification of tension wood fibres have been investigated in a wide variety of temperate and tropical species. Following earlier work describing the cell wall structure of tension wood fibres, two additional types of cell wall organization have been observed. In one of these, the inner thick "gelatinous" layer which is typical of tension wood fibres exists in addition to the normal three-layered structure of the secondary wall; in the other only the outer layer of the secondary wall and the thick gelatinous layer are present. In all the tension wood examined the micellar orientation in the inner gelatinous layer has been shown to be nearly axial and the cellulose of this layer found to be in a highly crystalline state. A general argument is presented as to the meaning of differences in the degree, of crystallinity of cellulose. The high degree of crystallinity of cellulose in tension wood as compared with normal wood is attributed to a greater degree of lateral order in the crystalline regions of tension wood, whereas the paracrystalline phase is similar in both cases. The degree of lignification in tension wood fibres has been shown to be extremely variable. However, where the degree of tension wood development is marked as revealed by the thickness of the gelatinous layer the lack of lignification is also most marked. Severity of tension wood formation and lack of lignification have also been correlated with the incidence of irreversible collapse in tension wood. Such collapse can occur even when no whole fibres are present, e.g. in thin cross sections. Microscopic examination of collapsed samples of tension wood has led to the conclusion that the appearance of collapse in specimens containing tendon wood can often be attributed in part to excessive shrinkage associated with the development of fissures between cells, although true collapse does also occur. Possible explanations of the irreversible shrinkage and collapse of tension wood fibres are advanced.


2016 ◽  
Vol 40 (6) ◽  
pp. 1099-1107
Author(s):  
Letícia Maria Alves Ramos ◽  
João Vicente de Figueiredo Latorraca ◽  
Thayanne Caroline Castor Neto ◽  
Letícia Souza Martins ◽  
Elias Taylor Durgante Severo

ABSTRACT Tension wood is an important anatomical structure for its participation in the orientation of the trunk and the architecture of the branches as a function of structural reinforcement. However, its presence in large amounts significantly affects the technological properties of wood, just as in the rubber tree. Nevertheless, there is still demand for information about the origin, distribution and structural features in this species. Thus, this study aims to characterize the cellular structures in tension and opposite wood in Hevea brasiliensis (rubber tree), as well as its radial and longitudinal distribution. Discs at the base and the middle of the commercial logs were collected from three trees in a commercial plantation located in Tabapoã - SP. Tangential diameter of vessels, fiber length (gelatinous and non-gelatinous fibers), microfibril angle and proportionality of cellular elements (vessels, axial parenchyma, ray, gelatinous fibers and non-gelatinous fibers) were measured, and influence of gelatinous fiber presence in vessel diameter was observed. Gelatinous fibers were observed in the two types of wood and in the two trunk heights. Both types of wood were distinguished by gelatinous fiber length and the proportion of axial parenchyma. The tension wood in mid-trunk was the most different, with long gelatinous fibers and less abundant, larger vessel diameter and vessel proportion. Moreover, smaller vessel diameter was observed in the regions with a high proportion of gelatinous fibers, suggesting that the plant invests more support than in liquid transport.


2003 ◽  
pp. 211-221
Author(s):  
Borislav Soskic ◽  
Aleksandar Lovric ◽  
Boda Vukovojac

The density, shrinkage and swelling of Paulownia elongata and P. fortuneii wood were researched. The study material was provided by Boda Vukovojac, B. Sc., who established the Paulownia plantation and sample plots on the territory of the Municipality Bela Crkva. The study results show the differences between the analyzed properties of these two species. The study results were also compared with the results of the similar species of wood. The data shows that the study wood can be used in wood products that are not subject to great loads during exploitation. Further study should investigate the liability of these wood species to form tension wood and deformations in the conditions of variable hygroscopic moisture.


2018 ◽  
Vol 52 (4) ◽  
pp. 1049-1060
Author(s):  
K. C. Sujan ◽  
Hiroyuki Yamamoto ◽  
Miyuki Ueda Matsuo ◽  
Masato Yoshida ◽  
Keiichi Asaka

Trees ◽  
2014 ◽  
Vol 28 (3) ◽  
pp. 687-697 ◽  
Author(s):  
C. Coutand ◽  
G. Pot ◽  
E. Badel
Keyword(s):  

IAWA Journal ◽  
2001 ◽  
Vol 22 (4) ◽  
pp. 401-413 ◽  
Author(s):  
P. B. Tomlinson

Gnetum gnemon exhibits Rouxʼs model of tree architecture, with clear differentiation of orthotropic from plagiotropic axes. All axes have similar anatomy and react to displacement in the same way. Secondary xylem of displaced stems shows little eccentricity of development and no reaction anatomy. In contrast, there is considerable eccentricity in extra-xylary tissue involving both primary and secondary production of apparent tension-wood fibres (gelatinous fibres) of three main kinds. Narrow primary fibres occur concentrically in all axes in the outer cortex as a normal developmental feature. In displaced axes gelatinous fibres are developed abundantly and eccentrically on the topographically upper side, from pre-existing and previously undetermined primary cortical cells. They are wide with lamellate cell walls. In addition narrow secondary phloem fibres are also differentiated abundantly and eccentrically on the upper side of displaced axes. These gelatinous fibres are narrow and without obviously lamellate cell walls. Eccentric gelatinous fibres thus occupy a position that suggests they have the function of tension wood fibres as found in angiosperms. This may be the first report in a gymnosperm of fibres with tension capability. Gnetum gne-mon thus exhibits reaction tissues of unique types, which are neither gymnospermous nor angiospermous. Reaction tissues seem important in maintaining the distinctive architecture of the tree.


2015 ◽  
Vol 14 (8) ◽  
pp. 3188-3203 ◽  
Author(s):  
Mélanie Mauriat ◽  
Jean-Charles Leplé ◽  
Stéphane Claverol ◽  
Jérôme Bartholomé ◽  
Luc Negroni ◽  
...  

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