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

2001 ◽  
Vol 31 (10) ◽  
pp. 1676-1683 ◽  
Author(s):  
B Jourez ◽  
A Riboux ◽  
A Leclercq

In a greenhouse, under controlled conditions, young shoots, taken from poplar cuttings (Populus euramericana (Dole) Guinier cv. Ghoy), were artificially bent to quantify the modifications of physical properties induced by a gravitational stimulus. At the end of the growing season, basic density and longitudinal shrinkage were measured on very small samples taken from pure tension wood tissue observed on the upper face of the inclined axis and compared with opposite wood tissue, free of gelatinous fibers, developed on the opposite lower face. In a second step, shoots bent at two different lean intensities were analyzed. In young poplar wood, gravitational stimulus was found to have a significant effect on physical properties. Relations between basic density and longitudinal shrinkage are different depending on the types of wood considered. Shrinkage appears more sensitive to lean intensity in the range considered here.

IAWA Journal ◽  
2001 ◽  
Vol 22 (2) ◽  
pp. 133-157 ◽  
Author(s):  
B. Jourez ◽  
A. Riboux ◽  
A. Leclercq

Young shoots from poplar cuttings (Populus euramericana cv ʻGhoyʼ) were artificially inclined to 30° from vertical to quantify the anatomical modifications induced by this gravitational stimulus. At the end of the growing season, the tension wood tissue (from the upper face of the inclined axis) was compared to the opposite wood tissue (from the lower face), with radial position taken into account. On isolated elements after maceration, fibres and vessels were significantly longer in tension wood tissue. In the cross section, the gelatinous fibres had a smaller radial diameter than normal fibres in opposite wood. Vessel frequency and porosity were significantly lower in tension wood than in opposite wood. Solitary vessels in tension wood were less circular in cross section than in opposite wood, but their surface area did not differ. Rays were more numerous in tension wood than in opposite wood but their height did not differ between the two tissue types. Finally, there was a negative correlation between the proportion of vessel lumina (lowest in tension wood) and the proportion of fibre lumina including the G layer. The very controlled nature of this experiment (greenhouse, young clonal material, detailed anatomical observations within one growth ring) and the image analysis technology (allowing a large number of observations) enabled us to draw conclusions that may not have been seen in less-controlled experiments and /or those with smaller sample sizes.


2011 ◽  
Vol 41 (5) ◽  
pp. 930-937 ◽  
Author(s):  
Shakti S. Chauhan ◽  
John C.F. Walker

This paper presents a new approach to assess wood quality in 1-year-old Eucalyptus regnans F. Muell. Twenty-two seedlings were grown tilted to induce tension wood and acoustic velocity, basic density, longitudinal shrinkage, and volumetric shrinkage of both opposite wood and tension wood were assessed subsequently. Longitudinal growth strains were also estimated in the leaning stems by sawing along the length through the pith and measuring the bending of the two halves. The derived longitudinal growth strain, which varied from 708 to 2319 µε, was uncorrelated with stem and wood characteristics. Wood characteristics differed significantly between upper-side wood (predominantly tension wood) and lower-side wood (opposite wood). Tension wood was characterized by a higher acoustic velocity (high stiffness), basic density, and volumetric shrinkage compared with opposite wood. Tension wood also exhibited significant collapse and dimensional distortion such as twisting. Longitudinal shrinkage exhibited a significant negative relationship with acoustic velocity in opposite wood and a positive relationship with the basic density in tension wood. This new approach has potential in early selection of breeding material with superior normal wood properties from 1-year-old material by isolating the influence of tension wood. This approach can also be useful in understanding the variability in propensity of tension wood production in breeding populations.


PERENNIAL ◽  
2006 ◽  
Vol 2 (1) ◽  
pp. 16
Author(s):  
Andi Detti Yunianti

Since there have been a big difference between wood production and industrial need, wood diversification plays an important role in handling wood deficiencies. Wood raw material diversification could developed and increased throughout the use of whole parts of the tree including branch. The current study was aimed at understanding stem and branch physical properties (basic density, air-dry specific gravity, air-dry moisture content and shrinkage) of macadamia wood as quality indicators for efficient utilization in the future. For the purpose of the study, parts of stem and branch of the tree were taken from a macadamia tree. Test specimens of stem were cut 50 cm from the ground while that of branch were selected from the largest diameter at 10 cm distance from the main stem of the tree. All samples were tested for their physical properties according to ISO standards, 1975. Results showed that the basic density, air dry specific gravity and longitudinal shrinkage of the branchwood of macadamia were higher than those of the stem. The air-dry moisture content, radial and tangential shrinkage were low on the branchwood. Keywords : Wood Physical Properties, Branchwood , Macadamia Wood


2010 ◽  
Vol 1 (1) ◽  
pp. 6-11
Author(s):  
Thiago Campos Monteiro ◽  
Renato da Silva Vieira ◽  
José Tarcísio Lima ◽  
Edy Eime Pereira Baraúna ◽  
Duam Matosinhos de Carvalho ◽  
...  

The reaction wood is formed in an attempt to remain upright tree in response to the action of forces such as winds, irregular crown or slope of the land that tend to incline it. In hardwoods, as in Eucalyptus, this type of wood is called tension wood and occurs in the region of the stem facing the face of force application. Indicative of the presence of this type of wood is the high shrinkage and basic density compared to normal wood. Once the basic density and shrinkage are parameters for determining the quality of the wood, this study aimed to evaluate the variation of basic density and shrinkage of opposite and tension wood along the radius in four species of Eucalyptus sp. Four tree species Eucalyptus camaldulensis, Eucalyptus maculata, Eucalyptus pilularis and Eucalyptus urophylla, with 32 years of age, were taken from an experimental planting of the Federal University of Lavras. Specimens were made to represent the diametrical variation of the opposite of tension wood in disks cut at the dbh. The results indicate that the properties of radial, tangential and volumetric shrinkage, coefficient of anisotropy and basic density did not differ statistically between the tensionand opposite wood.


2017 ◽  
Vol 41 (1) ◽  
Author(s):  
Delmar Santin ◽  
Marcelino Breguez Gonçalves Sobrinho ◽  
Angélica de Cássia Oliveira Carneiro ◽  
Eliziane Luiza Benedetti ◽  
Nairam Félix de Barros

ABSTRACT In mate crop, the commercial part consists of leaves and thin branches, while the large branches (LB) are considered unused residues and left in the field, although they may have potential for use as energy. The objective of this paper was to evaluate the influence of phosphorus fertilization and harvest interval in productivity of mate large branches and in their physical and energetic properties, as well as in derived briquettes. In a seven-year-old plantation, doses of 0, 20, 40, 80, 160 and 320 kg.ha-1 of P2O5 were applied considering harvest intervals of 12, 18 and 24 months. Dry mass, average diameter, P content, and physical and energetic properties of LB were determined. With LB, after its transformation into particles and briquetting, physical and energetic properties were determined, as well as P availability in soil. The phosphorus fertilization increased LB productivity in larger harvest intervals, increasing the amount of energy produced per unit of area, but did not change basic density and gross calorific value of wood. Mate harvest intervals did not affect the apparent density and calorific value of briquettes produced by LB. LB harvested at intervals of 18 and 24 months produced wood with higher basic density and gross calorific value. LB or briquettes have adequate energetic and physical properties, being technically a plant residue with great potential for use as energy.


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.


CERNE ◽  
2017 ◽  
Vol 23 (3) ◽  
pp. 291-297
Author(s):  
Walter Torezani Neto Boschetti ◽  
Juarez Benigno Paes ◽  
Graziela Baptista Vidaurre ◽  
Marina Donária Chaves Arantes ◽  
João Gabriel Missia da Silva

ABSTRACT This study aims to evaluate the quality of normal, tension and opposite wood of eucalyptus trees lengthwise, in straight and inclined stems, affected by wind action. It also aims to explain the pulping parameters resultant from the quality of the wood. The trees were grouped into four tilt ranges, ranging from 0 to 50º, and the basic density, chemical composition of the wood, and performance in kraft pulping were assessed. Normal and tension wood had similar basic densities; while for opposite wood, the density was lower, being responsible for a decrease in reaction wood density. The chemical composition of the wood was influenced by the presence of reaction wood in the stem. Tension and opposite wood showed lower levels of extractives and lignin and higher holocellulose content when compared to normal wood, with favorable wood quality for pulping. The increase in holocellulose content and the reduction of lignin and extractives content contributed positively to a more delignified pulp and reduction of the Kappa number. However, after cooking the reaction wood under the same conditions as those of normal wood, reaction wood pulping tends to have a lower screen yields. Due to differences in basic density and chemical constituents between opposite and normal wood, it is recommended not to designate the opposite wood as normal wood.


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.


Holzforschung ◽  
2019 ◽  
Vol 73 (2) ◽  
pp. 219-222
Author(s):  
Bruno Charles Dias Soares ◽  
José Tarcísio Lima ◽  
Selma Lopes Goulart ◽  
Claudineia Olímpia de Assis

AbstractTree stems deviating from the vertical position react by the formation of tension wood (TW) or compression wood (CW), which are called in general as reaction wood (RW), in which the cells are modified chemically and anatomically. The focus of the present work is the mechanical behavior of TW in five 37-year-oldEucalyptusspecies, which were grown on a planting area with an average slope of 28% leading to decentralized pith in the trees, which is an unequivocal indication of the presence of RW. TW and opposite wood (OW) samples were isolated and subjected to a compression-parallel-to-grain test. It was observed that TW is less resistant and less stiff than the OW.


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