scholarly journals Variability of spruce (Picea abies [L.] Karst.) compression strength with present reaction wood

2009 ◽  
Vol 55 (No. 9) ◽  
pp. 415-422 ◽  
Author(s):  
V. Gryc ◽  
H. Vavrčík

The aim of research was to find out the variability of spruce (<I>Picea abies</I> [L.]) Karst.) wood compression strength limits in the direction parallel to grain. The wood strength was examined using samples from a tree with present reaction (compression) wood. The strength was found out for individual stem zones (CW, OW, SWL and SWR). The zone with present compression wood (CW) demonstrated slightly higher values of wood strength limits. The differences in the limits of compression strength parallel to grain in individual zones were not statistically significant. All the data acquired by measuring were used to create 3D models for each zone. The models describe the strength along the radius and along the stem height. The change of strength along the stem radius was statistically highly significant. There was an obvious tendency towards an increase in the strength limit in the first 40 years. With the increased stem height, there is a slight decrease in wood strength.

2008 ◽  
Vol 53 (No. 3) ◽  
pp. 129-137 ◽  
Author(s):  
V. Gryc ◽  
P. Horáček

The study was aimed to assess the integral value that determines wood properties &minus; wood density at a moisture content of 0% and 12%. The wood density was researched in a sample tree with the presence of reaction compression wood. The density was determined for individual zones (CW, OW, SWL and SWR). The zone where compression wood (CW) is present has a higher density than the remaining zones. On the basis of the acquired data, 3D models were created for individual zones; they describe the variability of wood density along the stem radius and stem height. The influence of the radius seems to be a statistically highly significant factor. The wood density is significantly higher in samples with the presence of compression wood. When the proportion of compression wood in the sample was 80%, the wood density was 1.5 times higher compared to wood without compression wood.


Beskydy ◽  
2017 ◽  
Vol 10 (1-2) ◽  
pp. 17-26 ◽  
Author(s):  
Petr Horáček ◽  
Marek Fajstavr ◽  
Marko Stojanović

This study relates to the variability of wood density and compression strength parallel to grain within the stem of spruce trees (Picea abies/L./Karst.). The sample tree originated from the Giant Mountains and was an adult autochtonous mountain spruce. The properties were analysed for wood that formed between 1850 and 1990 along (1) the north-south oriented radius and along (2) the stem height on test specimens with the following dimensions: 20×20×30 mm, prepared from logs taken from the stem base at distances of 2, 4, 6, 10, 14, 20, 22, 24 and 26 m. In individual sections, the properties of the samples oriented in the north or south direction did not differ, while the effect of different ages on the properties showed statistically significant differences at each orientation (p < 0.05). Along the radius, the properties showed an increasing trend in tree-rings that developed between 1850 and 1940 with a slight decrease in the following years. The coefficient of variation in various decades was 1–7 % (wood density) and 3–15 % (wood compression strength). Along the stem height, the properties gradually increased to a height of 20 m, while the increase in values ​​was more pronounced in the 22–26 m interval. The variability of the wood properties along the stem height corresponded to the variability of the properties along the stem radius. A linear dependence between wood strength and density was demonstrated. Compared to what had been previously written, wood density showed a greater impact, probably due to the biomechanical optimization of the stem with regard to mechanical wind and snow loads in the mountains.


Author(s):  
Vladimír Gryc ◽  
Petr Horáček

The paper was aimed at the determination of variability of horizontal resin canal dimension in spruce wood in relation to the position in a spruce stem. Significant changes of dimensions in horizontal resin canal along the stem length and radius were found. On the basis obtained of results 3D models (for CW, OW, SWL and SWP zones) describing changes in resin canal dimensions in spruce in relation to the position in a stem were created. In the models, the resin canal dimension decreases with the height of a stem and on the other hand, with an increasing distance from the stem pith the dimension of resin canal increases. The importance of the paper consists in the enlargement of findings about the structure of spruce with compression wood.


Holzforschung ◽  
2009 ◽  
Vol 63 (3) ◽  
Author(s):  
Asghar Tarmian ◽  
Patrick Perré

Abstract The air permeability in longitudinal and radial directions of compression wood in spruce (Picea abies) and tension wood in beech (Fagus sylvatica) was compared with that of the corresponding normal wood. The primary aim of the present study was to explain why the reaction woods dry more slowly than the normal woods in the domain of free water. A number of boards conventionally dried to an average final moisture content of 12% were chosen to perform the measurements. Bordered pits on the radial walls of longitudinal tracheids in the compression and normal wood and intervessel or intervascular pits in the tension and normal wood were also examined. The reaction wood of both species is less permeable than the normal wood, both in longitudinal and radial directions. The difference in permeability was more pronounced between compression and normal wood of spruce, especially in longitudinal direction. From an anatomical point of view, this is likely related to some differences in anatomical characteristics affecting the airflow paths, such as the pit features. Such results can explain the difference in drying kinetics of the reaction and normal woods in the capillary regime of drying.


1967 ◽  
Vol 15 (3) ◽  
pp. 377 ◽  
Author(s):  
G Scurfield

Histochemical tests have been applied to a study of the differentiation of the cell walls in reaction wood (compression wood) formed in the stems of horizontally grown seedlings of Pinus radiata. The results are discussed on the basis of the chemical specificity of the tests and the information they provide as to the chemical changes which occur in the cell walls.


IAWA Journal ◽  
2006 ◽  
Vol 27 (1) ◽  
pp. 45-54 ◽  
Author(s):  
Linda C.Y. Hsu ◽  
John C.F. Walker ◽  
Brian G. Butterfield ◽  
Sandra L. Jackson

We investigated the potential for the roots of Pinus radiata D. Don to form compression wood. Compression wood was not observed in either the tap or any lateral roots further than 300 mm from the base of the stem. This suggests that either the roots do not experience the stresses required to induce compression wood formation, or that they lack the ability to form it. Roots artificially subjected to mechanical stress also failed to develop compression wood. It is therefore unlikely that an absence of a compressive load on buried roots can account for the lack of compression wood. Application of auxin to the cambia of lateral roots was similarly ineffective at inducing the formation of compression wood. These observations suggest that the buried roots of radiata pine lack the ability to develop compression wood. We also report the formation of an atypical S3 wall layer in the mechanically-stressed and auxin-treated tracheids and suggest that a reaction wood that is different to compression wood may well form in roots.


2008 ◽  
Vol 43 (1-2) ◽  
pp. 113-130 ◽  
Author(s):  
A. Tarmian ◽  
R. Remond ◽  
M. Faezipour ◽  
A. Karimi ◽  
P. Perré

Author(s):  
Vladimír Gryc ◽  
Hanuš Vavrčík

The paper is aimed at the field of the microscopic structure of wood dealing with the description of the most important anatomic element in softwood – tracheids in a stem with the occurrence of reaction wood. Significant changes of tracheids were found along the height and radius of a stem. There were statistically significant differences between particular annual rings (variability along the stem radius). The height of a stem was also statistically significant. On the basis of the results obtained 3D models were created (for zones compression wood, opposite wood and site wood; models for radial dimension an early-wood tracheid and late-wood tracheid) depicting changes in transverse dimensions of the spruce tracheid in relation to its position in a stem. Structure of ring with compression wood was studied too. It was observed that the ring with occurrence of compression wood has a following structure: early wood tracheids at the beginning of the growing season, transitional tracheids, compression tracheids and at the end of an annual ring typical late wood tracheids. The rings with compression wood show more tracheids as compared with annual rings from the opposite side.


2015 ◽  
Vol 40 (2) ◽  
pp. 315-340 ◽  
Author(s):  
B. A. Molski

The corewood of pine ds very prone to compression wood formation, this changing the whole pattern of the tree ring structure and the siz.es of early and late wood. Compression wood always increases the formation of late wood at the expense of early wood. Tree rings with compression wood are generally wider than those without it, but there occur also tree rings wihout compression wood wider than those in which it is present, formed in the same year and in the same tree.


IAWA Journal ◽  
2020 ◽  
Vol 41 (1) ◽  
pp. 48-60
Author(s):  
Byantara Darsan Purusatama ◽  
Nam Hun Kim

Abstract The characteristics of cross-field pitting among compression wood, lateral wood, and opposite wood, in the stem woods of Ginkgo biloba and Pinus densiflora were investigated with optical and scanning electron microscopy. In Ginkgo biloba, compression wood exhibited piceoid pits, while lateral and opposite wood exhibited cupressoid pits. The compression wood of Pinus densiflora exhibited cupressoid pits and piceoid pits, while lateral wood and opposite wood exhibited pinoid and window-like pits in the cross-field. In both species, compression wood yielded the smallest pit number among each part, while opposite wood yielded the greatest pit number per cross-field. Cross-field pitting diameters of compression wood and opposite wood were significantly smaller than lateral wood in Ginkgo biloba, while the cross-field pitting of compression wood was the smallest in Pinus densiflora. Radial tracheid diameter of compression wood was slightly smaller than lateral and opposite wood in Ginkgo biloba and significantly smaller than lateral and opposite wood in Pinus densiflora. In conclusion, the cross-field pitting type, pit number, and cross-field pitting diameter could be used to identify reaction wood in the stem wood of Ginkgo biloba and Pinus densiflora.


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