Technological Properties of Wood from Trees in Polluted Regions

IAWA Journal ◽  
1986 ◽  
Vol 7 (4) ◽  
pp. 389-397 ◽  
Author(s):  
A. Frühwald

Wood quality from about 230 healthy and diseased fir, spruce, pine and beech trees from various locations in West Germany was tested. In general results are satisfactory for mechanical wood properties, but some physical, chemical and biological indicators lead to the conclusion that logs from heavily diseased trees may be attacked a !ittle earlier and faster by microorganisms during storage. Width of growth rings is reduced in severely damaged softwood trees on most locations whereas beech shows no significant reduction. Declining health of the trees had no or little influence on wood density; the modulus of elasticity and strength were at normal levels and independent of tree damage. Width and moisture content of sapwood were reduced little in pines but more in spruce and fir. A tendency to a more intensely developed irregular brown heartwood in severeIy damaged beech trees could not be proved until now. Storage of spruce in a log yard for four months has shown a slightly faster development of discoloration caused by fungi in diseased trees whereas after seven months wood from healthy trees was more discoloured. After storage strength properties are not or only slightly reduced, but no difference was found between trees assigned to the various health classes. After two years of storage under sprinkling water, pine logs from healthy and diseased trees show no difference in discoloration.

2021 ◽  
Vol 71 (3) ◽  
pp. 240-245
Author(s):  
Rubin Shmulsky ◽  
Frederico José Nistal França ◽  
J. Tedrick Ratcliff ◽  
Benjamin Farber ◽  
C. Adam Senalik ◽  
...  

Abstract Southern yellow pine (SYP) is one of the most used softwood species in the world. Most of this raw material come from fast-grown plantation trees. It is of interest to determine if SYP clear wood properties may have changed over the long term, in particular whether such properties may have declined. Herein, specific gravity (SG), ultimate compression strength parallel to grain (UCS‖), and UCS perpendicular to grain (UCS⊥) from three samples were compared: Sample 1 tested in 2014; Sample 2 from molding and millwork producers tested in 2017–2019; and Sample 3 from a study conducted in the mid-1960s. With respect to specific gravity (SG), the wood in Sample 1 was significantly lower than that from Samples 2 and 3. With respect to UCS‖, all three samples were statistically different. Adjusting to 12 percent moisture content had no influence on the mean separation of UCS‖. With respect to UCS⊥, no statistically significant differences were detected among the test data from any of the three samples. However, for the UCS data generated from the SG and moisture content–related model, Sample 2 was higher than Sample 3, and Sample 3 was higher than Sample 1, and these differences were statistically significant. Overall, these findings do not suggest that broad or consistent changes or declines of these wood strength properties have occurred during the past five decades.


2013 ◽  
Vol 89 (05) ◽  
pp. 595-606 ◽  
Author(s):  
Brigitte Leblon ◽  
Oluwatosin Adedipe ◽  
Guillaume Hans ◽  
Ataollah Haddadi ◽  
Satoru Tsuchikawa ◽  
...  

This review article examines past and current research on the application of near-infrared (NIR) reflectance/transmittance spectroscopy (NIRS) for real-time monitoring of moisture content and density of solid wood. Most of the applications of NIRS on solid wood have focussed on the application of multivariate statistics as exploratory tools for the prediction of physical, chemical and mechanical properties, such as moisture content, density, stiffness, cellulose and lignin content. However, very few studies on the development of optical models and the use of NIRS transmittance techniques on solid wood have been reported. NIRS technology has the potential to be used as a rapid tool that could be employed for at-line measurement and monitoring of wood properties in the forest products industry.


OENO One ◽  
1987 ◽  
Vol 21 (3) ◽  
pp. 191
Author(s):  
René Keller

<p style="text-align: justify;">Il existe de nombreuses espèces de chênes dans le monde: quelques-unes d'entre elles sont présentes en France où deux ont une importance forestière considérable.</p><p style="text-align: justify;">Les propriétés du bois dépendent de l'espèce et des conditions de milieu dans lesquelles se développent les arbres. La sylviculture joue un rôle important sur la qualité du bois produit et donc sur ses utilisations. Certaines propriétés correspondent plus particulièrement à certains emplois, que ce soient des propriétés physiques, physicochimiques, chimiques, biologiques, anatomiques. L'ensemble de ces propriétés présente une variabilité souvent importante, comme c'est d'ailleurs le cas pour toutes les espèces ligneuses. Certaines de ces propriétés sont évoquées pour illustrer les questions liées à l'aptitude à l'emploi de certaines espèces de chênes, notamment en matière de tonnelerie.</p><p style="text-align: justify;">+++</p><p style="text-align: justify;">Here is a lot of species of oaks in the world: some species are present in France, where two have a considerable forest importance.</p><p style="text-align: justify;">The wood properties of the oaks depend on the species and on the environ mental conditions in which the trees grow. The sylviculture plays an important part on the wood quality and then on the uses of the wood. Some properties suit more particularly to some uses: physical, chemical, biological, anatomical properties. All these properties often have an important variability: it is besides the case for all the species of trees. Some of these properties are called up in order to illustrate the questions related to the capacity of some oaks species to a given use, specially for the cooperage.</p>


2005 ◽  
Vol 35 (2) ◽  
pp. 331-339 ◽  
Author(s):  
G R Johnson ◽  
Amy T Grotta ◽  
Barbara L Gartner ◽  
Geoff Downes

Many stands of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) near coastal areas of Oregon and Washington are heavily infected with the foliar pathogen causing Swiss needle cast (SNC) disease, and yet there is very little research on the resulting wood quality. Modulus of elasticity (MOE), modulus of rupture (MOR), microfibril angle (MFA), wood density, latewood proportion, and sapwood moisture content were examined in 20- to 28-year-old trees from 15 stands that were infected with varying intensities of SNC. SNC severity was quantified by measuring needle retention, the number of needle cohorts retained at three crown levels. Correlations between disease severity and wood properties were examined at both the stand and within-stand levels. Trees from heavily infected stands (needle retention <2 years) had higher MOE, wood density, and latewood proportion and lower sapwood moisture content than trees from healthier stands. Breast-height age (BHage) was also correlated with these properties, but age alone did not explain all of the increases. MFA was not associated with SNC severity. Within stands, needle retention was not associated with MOE or MOR. The increase in latewood proportion in diseased stands appears to be the driving factor behind their increase in stiffness (MOE). Ring width decreased with decreased needle retention, and the examined wood properties generally showed stronger correlations with ring width than with needle retention.


2007 ◽  
pp. 145-154
Author(s):  
Zdravko Popovic ◽  
Nebojsa Todorovic

This paper presents the study results of the basic physical and strength properties of Hungarian oak (Quercus conferta Kit.) wood from the Kakovo Monastery forests of Hilandar Monastery in Greece. Wood properties were analyzed in detail, as an indispensable proof of wood quality and its use for joinery, interiors and wooden floors. The basic physical properties of wood (moisture content at the time of tree felling, density and volume porosity) and the basic strength properties (compressive strength, bending strength and module of elasticity) were researched. The results are presented in Tables and in Diagrams with statistical parameters and compared to the literature data. The correlation of the study properties of wood was also analyzed.


Author(s):  
Klaus Peter Brodersen ◽  
N. John Anderson

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Brodersen, K. P., & Anderson, N. J. (2000). Subfossil insect remains (Chironomidae) and lake-water temperature inference in the Sisimiut–Kangerlussuaq region, southern West Greenland. Geology of Greenland Survey Bulletin, 186, 78-82. https://doi.org/10.34194/ggub.v186.5219 _______________ Climate and water temperature have an important influence on the functioning of lake ecosystems. From limnological and palaeolimnological studies of lakes, information on biological diversity and climate variability in time and space can be gleaned from physical, chemical and biological indicators preserved in the lake sediments. The lakes in southern West Greenland are particularly useful for this purpose – they are numerous, diverse and have minimal anthropogenic impact (Anderson & Bennike 1997). Palaeolimnological data are fundamental for understanding the functioning and development of modern lakes and for understanding the causes of climatic change as well as the effect on lake biota.


IAWA Journal ◽  
2014 ◽  
Vol 35 (2) ◽  
pp. 158-169 ◽  
Author(s):  
Zhao Rongjun ◽  
Yao Chunli ◽  
Cheng Xianbao ◽  
Lu Jianxiong ◽  
Fei Benhua ◽  
...  

The anatomical characteristics, chemical composition, and physical and mechanical properties of fast-growing Populus × euramericana cv. ‘74/76’ juvenile wood were investigated. Four- to five-year-old clonal plantation trees were harvested from two different experimental sites in the suburbs of Beijing. The Shunyi site had black alkali soil with a planting density of 4 × 6 m and the Miyun site had sandy loam soil with a planting density of 3 × 5 m. The test results showed that the poplar trees from the two sites were both fast growing, with poplar at Shunyi growing faster than at Miyun. There were no significant differences in wood properties between trees grown at the two sites. Fiber length at breast height varied from 872 to 1300 μm between growth rings, average fiber width varied from 21.0 to 25.5 μm and double wall thickness varied from 5.0 to 6.6 μm. Average cellulose, lignin and hemicellulose contents in the samples were 48.9%, 25.4%, and 18.8%, respectively. MFA was higher in the first two growth rings (20–25°), and then decreased rapidly to 12° close to the bark. The average air-dry density at breast height was 401 kg/m3 while the average MOE at breast height was 9.3 GPa. The trees showed large growth rates in both height and stem diameter during the growing season. However, wood properties of the juvenile poplar appeared to be similar to those of poplars with a slower growth rate.


2008 ◽  
Vol 84 (3) ◽  
pp. 392-400
Author(s):  
Steen Magnussen ◽  
Dave Harrison

The number and size of checks, wood moisture content, extent of blue-stain, rot and decay was examined by stem analysis in 360 mature standing beetle-killed lodgepole pines. Trees came from three areas (Burns Lake, Quesnel, and Vanderhoof) in Central British Columbia. Each area was represented by 14 to 16 sampling areas (stands) distributed evenly across three soil moisture regimes (dry, mesic, wet). Year of death was estimated from tree ring-analysis, local knowledge and insect and disease survey maps. An approximately equal number of trees had been dead for one or two years, three or four years, or for five or more years. During the first five years since death by beetle attack the number of checks per tree increased from 2.5 to 10.2 and the average depth of checks increased from 4.3 cm to 5.1 cm. Checks were deeper, wider, and longer on the drier sites than on mesic and wet sites. Moisture content of sapwood and heartwood was near the fibre saturation point (ca 30%) one year after death and continued to decrease at a rate of approximately 1.7% per year. Both the incidence and the extent (relative to basal area) of rot and decay increased significantly with time since death. All trees had an extensive blue-stain discoloration. Deterioration of wood quality was fastest during the first two years after a beetle attack. Key words: wood checks, moisture content, blue-stain, wood quality, spiral grain, bark beetle


2013 ◽  
Vol 43 (1) ◽  
pp. 1-6 ◽  
Author(s):  
S.G. Kennedy ◽  
A.D. Cameron ◽  
S.J. Lee

The trend towards shorter rotations in planted conifer stands has resulted in a reduction in the proportion of mature wood relative to juvenile core wood, raising concerns that the mechanical performance of sawn battens will be affected. The potential to improve the wood quality of the juvenile core of Sitka spruce (Picea sitchensis (Bong.) Carrière) without compromising growth rate was investigated. Rapid and inexpensive indirect methods of assessing wood properties on standing trees using a Pilodyn gun and acoustic velocity were compared with direct measurements made on wood samples cut from the juvenile core. Strong genetic correlations were observed between Pilodyn gun values and direct measures of density (–0.76) and between the square of acoustic velocity and modulus of elasticity (0.73). The genetic correlation between the square of acoustic velocity and microfibril angle was also strong (–0.84). These results suggest that indirect assessments of wood properties within juvenile core wood are sufficiently reliable for these techniques to be used in the Sitka spruce breeding programme. Although a strong negative genetic correlation between diameter at breast height and density was noted (–0.79), sufficient variation exists within the breeding population to select families with both good growth rate and high modulus of elasticity wood.


Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1647 ◽  
Author(s):  
Edward Roszyk ◽  
Elżbieta Stachowska ◽  
Jerzy Majka ◽  
Przemysław Mania ◽  
Magdalena Broda

European ash (Fraxinus excelsior L.) is one of the species commonly used for wood thermal modification that improves its performance. The presented research aimed to investigate a moisture-dependent strength anisotropy of thermally-modified European ash in compression. Wood samples were modified at 180 °C and 200 °C. Their mechanical parameters were determined in the principal anatomical directions under dry (moisture content of 3%) and wet (moisture content above fibre saturation point) conditions. Effect of heat treatment temperature and moisture content on the ash wood mechanical parameters concerning each anatomical direction were determined. The results show that thermal treatment kept the intrinsic anisotropy of wood mechanical properties. It decreased wood hygroscopicity, which resulted in improved strength and elasticity measured for wet wood when compared to untreated and treated samples. Higher treatment temperature (200 °C) increased wood elasticity in compression in all the anatomical directions despite wood moisture content during the measurements. Multivariate analysis revealed that the modification temperature significantly affected the modulus of elasticity perpendicular to the grain, while in the case of compression strength, the statistically significant effect was observed only parallel to the grain. The results obtained can be useful from an industrial perspective and can serve as part of a database for further modelling purposes.


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