scholarly journals Effects of epyxilous fungus Laetiporus sulphureus (Bull. ex Fr.) murrill on the deccomposition of oak wood

2017 ◽  
pp. 21-30
Author(s):  
Miroslava Marković ◽  
Snežana Rajković ◽  
Mara Tabaković-Tošić ◽  
Marija Milosavljević
Keyword(s):  
Regression Line ◽  
Brown Rot ◽  
Wood Properties ◽  
Quercus Petraea ◽  
Modulus Of Rupture ◽  
Oak Wood ◽  
Brown Rot Fungi ◽  
Static Modulus ◽  
Laetiporus Sulphureus ◽  
The Impact

Testing samples were collected from the medulla of healthy oak trees in Eastern Serbia, from the association of Quercetum montanum. Over the periods of 2, 4 and 6 months the wood samples were exposed to influence of the mycelia of the fungus causing cubical brown rot on oak. Given that static modulus of rupture provides the quickest and clearest way to observe destruction caused by epixylous fungi, this paper researched the decrease in modulus of rupture of Sessile oak wood due to influence of causers of cubical brown rot. The samples have been exposed to the impact of the mycelia of the brown rot fungus on oak tree Laetiporus sulphureus (Bull. ex Fr.) Murrill (Sulphur Polypore). Effect of to the impact of the brown rot fungi was investigated, in decrease of static modulus of rupture Quercus petraea agg. The static modulus of rupture caused by L. sulphureus after 2, 4 and 6 months decreased in comparison with initial ones (100%) and reached 91.73, 75.17 and 63.25%. By using correlation analyses of Q. petraea agg. static modulus of rupture - ss (dependent variable) of fungi time influence (T-independent variable) strong correlation between variables was established, and regression equation is: ss= 151.514 ± 30,657 √ T The regression line obtained through data processing opened the possibility to prognosticate the changes of wood properties in certain time periods of the effect of the fungus under the unchanged external conditions, which is significant for practical purposes in terms of taking protective measures and wood usability.

Unraveling the natural durability of wood: revealing the impact of decay-influencing characteristics other than fungicidal components

Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Liselotte De Ligne ◽  
Jan Van den Bulcke ◽  
Jan M. Baetens ◽  
Bernard De Baets ◽  
Gang Wang ◽  
...  
Keyword(s):  
Wood Species ◽  
Prunus Avium ◽  
Brown Rot ◽  
Natural Durability ◽  
Anatomical Features ◽  
Brown Rot Fungi ◽  
Material Characteristics ◽  
The One ◽  
Block Test ◽  
The Impact

AbstractThe effect of fungicidal components in wood has been known for ages, yet there is no method to assess the impact of such components on the durability of a wood species, as compared to other material characteristics that influence decay. In this paper, the importance of fungicidal effects on the natural durability of 10 wood species is assessed in relation to other decay-influencing factors with a new test, the so-called ‘paste test’. By comparing results from this test with the ‘mini-block test’, on both heartwood and leached sapwood, insight is gained into the significance of fungicidal components on the one hand and other material characteristics on the other hand. The durability of species such as Prunus avium was attributed mainly to fungicidal components. For species such as Pterocarpus soyauxii, durability seemed to be an effect of both fungicidal components and moisture-regulating components, while the latter seemed to be of main importance in regulating the decay of Aucoumea klaineana and Entandrophragma cylindricum. Wood-anatomical features, such as the parenchyma content (in case of brown rot fungi) and the vessel-fiber ratio, possibly affect degradation as well. This work shows that fungicidal components are not always of major importance for the durability of a wood species. The authors hereby emphasize the importance of moisture-regulating components and wood anatomy on the durability of wood.

scholarly journals Comparative Transcriptomics During Brown Rot Decay in Three Fungi Reveals Strain-Specific Degradative Strategies and Responses to Wood Acetylation

2021 ◽  
Vol 2 ◽  
Author(s):  
Martina Kölle ◽  
Maria Augusta Crivelente Horta ◽  
J. Philipp Benz ◽  
Annica Pilgård
Keyword(s):  
Oxidative Degradation ◽  
Brown Rot ◽  
Gene Clusters ◽  
Brown Rot Fungi ◽  
Platform Chemicals ◽  
Regulatory Circuits ◽  
Detection And Identification ◽  
Brown Rot Decay ◽  
Underlying Mechanisms ◽  
The Impact

Brown rot fungi degrade wood in a two-step process in which enzymatic hydrolysis is preceded by an oxidative degradation phase. While a detailed understanding of the molecular processes during brown rot decay is mandatory for being able to better protect wooden products from this type of degradation, the underlying mechanisms are still not fully understood. This is particularly true for wood that has been treated to increase its resistance against rot. In the present study, the two degradation phases were separated to study the impact of wood acetylation on the behavior of three brown rot fungi commonly used in wood durability testing. Transcriptomic data from two strains of Rhodonia placenta (FPRL280 and MAD-698) and Gloeophyllum trabeum were recorded to elucidate differences between the respective decay strategies. Clear differences were found between the two decay stages in all fungi. Moreover, strategies varied not only between species but also between the two strains of the same species. The responses to wood acetylation showed that decay is generally delayed and that parts of the process are attenuated. By hierarchical clustering, we could localize several transcription factors within gene clusters that were heavily affected by acetylation, especially in G. trabeum. The results suggest that regulatory circuits evolve rapidly and are probably the major cause behind the different decay strategies as observed even between the two strains of R. placenta. Identifying key genes in these processes can help in decay detection and identification of the fungi by biomarker selection, and also be informative for other fields, such as fiber modification by biocatalysts and the generation of biochemical platform chemicals for biorefinery applications.

Predicting selected wood properties of jack pine following commercial thinning

2008 ◽  
Vol 38 (7) ◽  
pp. 2030-2043 ◽  
Author(s):  
Robert Schneider ◽  
S. Y. Zhang ◽  
D. Edwin Swift ◽  
Jean Bégin ◽  
Jean-Martin Lussier
Keyword(s):  
Wood Density ◽  
Ring Width ◽  
Wood Properties ◽  
Jack Pine ◽  
Modulus Of Rupture ◽  
Mixed Effect ◽  
Ring Density ◽  
Commercial Thinning ◽  
Cambial Age ◽  
The Impact

This paper examined the impact of commercial thinning on selected wood properties of jack pine ( Pinus banksiana Lamb.). Wood properties evaluated include wood density (ring density, earlywood ring density, and latewood ring density), percentage of latewood in the ring, and wood bending properties. Nonlinear, mixed-effect models have been developed using data from three commercially thinned sites in eastern Canada. Ring density followed the same pattern as percentage of latewood, in which cambial age, relative height, and ring width were found to have important effects. Earlywood and latewood ring densities changed within the juvenile wood zone until a plateau was reached. Ring width affected earlywood and latewood ring densities mainly in narrow rings. Wood bending stiffness (measured by modulus of elasticity) and strength (measured by modulus of rupture) increased with cambial age and wood density; whereas, wood strength was also affected by ring width. Commercial thinning did not influence the developed models, but it had an indirect effect through increased ring width.

scholarly journals Properties of Oak Roundwood with and without Frost Cracks

Forests ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 538
Author(s):  
Przemysław Mania ◽  
Arkadiusz Tomczak
Keyword(s):  
Compressive Strength ◽  
Modulus Of Elasticity ◽  
Wood Quality ◽  
Frost Damage ◽  
Quercus Petraea ◽  
Modulus Of Rupture ◽  
Mechanical Parameters ◽  
Entire Volume ◽  
Oak Wood ◽  
Tangential Directions

The aim of this study was to examine certain properties of sessile oak wood (Quercus petraea (Matt.) Liebl.) with frost cracks, such as density (ρ), modulus of rupture (MOR), modulus of elasticity (MOE), and compressive strength in all anatomical directions and to compare it with control trees without frost cracks. Oak with frost cracks had a higher wood density (ρ = 765 kg × m−3) than the control (ρ = 650 kg × m−3). However, despite its lower density, the control oak was characterized by noticeably better mechanical parameters, with the exception of the compressive strength in radial and tangential directions. Differences in mechanical parameters reached up to 26%. The tests were performed on wood taken from trees with frost cracks that formed over 10 years to several decades ago. Frost cracks can render wood vulnerable to fungi growth, which leads to rotting and discoloration. Differences in strength were found on samples with no visible signs of decay, as they were cut at a distance from the crack. Nonetheless, the observed differences in strength allowed us to conclude that the shreds of fungi, as well as decay, may occur in the entire volume of the frost-damaged log. Such wood is, therefore, of a lower quality than that made of logs without any frost damage. Trees with frost cracks should be progressively be felled during the periodic intermediate cutting, as their wood quality may systematically deteriorate over the years.

scholarly journals Influence of Soil Characteristics on Wood Biodeterioration by Brown Rot Fungi

2020 ◽  
Vol 10 (24) ◽  
pp. 8837
Author(s):  
Javier Ribera ◽  
Elisabeth Michel ◽  
Francis W. M. R. Schwarze
Keyword(s):  
Humic Acid ◽  
Wood Decay ◽  
Brown Rot ◽  
Soil Conditions ◽  
Wood Preservatives ◽  
Premature Failure ◽  
Brown Rot Fungi ◽  
Weight Losses ◽  
The Impact ◽  
Impregnated Wood

Soil conditions can directly influence the inoculum potential of wood decay fungi, which is likely to be a major factor in the premature failure of utility poles across Europe. The objective of our study was to assess the influence of soil pH, humic acid and iron on wood decay. For this purpose, we incubated Fe-impregnated wood specimens on artificial medium to evaluate the influence of the metal on the activity of brown rot fungi. Moreover, the impact of Cu-leaching from impregnated wood specimens that were exposed to humic acid solutions was measured. In addition, weight losses caused by brown rot fungi in impregnated wood pole segments and stiffness (Young’s modulus of Elasticity) of Cu-impregnated wood specimens were quantified. The pH measurements showed that the soil samples were slightly acid (pH = 6.7 ± 0.7). In comparison to non-impregnated controls, the Fe-impregnated samples significantly increased weight losses by brown rot fungi (>30–40%). In the presence of humic acid the release of copper from chromium-free wood preservatives (up to 143.34 mg L−1) was enhanced. Weight losses in impregnated wood segments by brown rot fungi ranged from 5.3 to 20.4%. The recorded reduction in stiffness by brown rot fungi ranged from approximately 3.96 to 55.52% for Cu-impregnated wood specimens after 12 weeks. Our study shows that the pH, humic acid, iron content and selected wood preservatives greatly influence susceptibility of impregnated wood to brown rot fungi during ground contact.

scholarly journals The Effect of the Rate of Longitudinal Compression on Selected Wood Properties

2018 ◽  
Vol 14 (1) ◽  
pp. 83-92 ◽  
Author(s):  
Mátyás Báder ◽  
Róbert Németh
Keyword(s):  
Beech Wood ◽  
Wood Properties ◽  
Quercus Petraea ◽  
Modulus Of Rupture ◽  
Compression Rate ◽  
Bending Properties ◽  
Longitudinal Compression ◽  
Bending Tests ◽  
Bending Modulus ◽  
Length Reduction

Abstract Longitudinal compression of wood and relaxation after compression (held compressed for a while) is called pleating and results in improved bending properties. The examinations conducted on the longitudinal compression of air-dried oak (Quercus petraea (Matt.) Liebl.) and beech wood specimens (Fagus sylvatica L.) revealed the effects of different compression rates (10, 20, 40, 60 mm/min). The comparison of the various treatment methods showed that the stress in wood specimens during longitudinal compression increases with the rising compression rate. The remaining length reduction due to pleating slightly decreases and the bending modulus of elasticity increases at higher compression rates. The highest deflection of the specimens during the 4-point bending tests lowers with the increasing compression rate, while the change of modulus of rupture is negligible. Taking into account the differences between these results and the industrial effectiveness of the treatment according to the compression rates, it can be stated that a procedure with a higher rate should be preferred.

scholarly journals Reduction the mechanical properties of oakwood under the influence of epyxilous fungus

2015 ◽  
pp. 7-17
Author(s):  
Miroslava Marković ◽  
Snežana Rajković ◽  
Ljubinko Rakonjac
Keyword(s):  
Modulus Of Elasticity ◽  
Regression Line ◽  
Field Research ◽  
Wood Properties ◽  
Coniophora Puteana ◽  
Static Modulus ◽  
Oak Trees ◽  
Accurate Forecast ◽  
External Conditions ◽  
Static Modulus Of Elasticity

Within the scope of field research on diagnostics of harmful organisms in Serbia in the year 2015, in the area of Forest Estate Boljevac, the presence of epixylous fungus Coniophora puteana (Schumm. ex Fr.) Karst was found on dead oak trees following the ice break. In order to give a more accurate forecast of prospective spread of the pathogen, i.e. determine the speed of the process, the laboratory of the Institute for Forestry conducted the testing of the rate of reduction of the oak tree modulus of elasticity after 2, 4 and 6 months of exposure to the fungus. Testing samples were collected from the medulla of healthy oak trees, from the association of Quercetum montanum. Over the periods of 2, 4 and 6 months the wood samples were exposed to influence of the mycelia of the fungus Coniophora puteana (Schumm. ex Fr.) Karst. After 2, 4 and 6 months under the effect of the fungus, the static modulus of elasticity of oak wood substantially decreased compared to the initial value (100%) and amounted to 61.07%, 60.61% and 51.38% respectively. The regression line obtained through data processing opened the possibility to prognosticate the changes of wood properties in certain time periods of the effect of the fungus under the unchanged external conditions, which is significant for practical purposes in terms of taking protective measures and wood usability.

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