Microstructure and stiffness of Scots pine (Pinus sylvestris L) sapwood degraded by Gloeophyllum trabeum and Trametes versicolor – Part I: Changes in chemical composition, density and equilibrium moisture content

Holzforschung ◽  
2012 ◽  
Vol 66 (2) ◽  
Author(s):  
Thomas K. Bader ◽  
Karin Hofstetter ◽  
Gry Alfredsen ◽  
Susanne Bollmus
Keyword(s):  
Moisture Content ◽  
Pinus Sylvestris ◽  
Mass Loss ◽  
Sample Size ◽  
Equilibrium Moisture Content ◽  
Scots Pine ◽  
Trametes Versicolor ◽  
Mass Density ◽  
Gloeophyllum Trabeum ◽  
Physical And Chemical

Abstract Fungal degradation alters the microstructure of wood and its physical and chemical properties are also changed. While these changes are well investigated as a function of mass loss, mass density loss and changes in equilibrium moisture content are not well elucidated. The physical and chemical alterations are crucial when linking microstructural characteristics with macroscopic mechanical properties. In the present article, a consistent set of physical, chemical and mechanical characteristics is presented, which were measured on the same sample before and after fungal degradation. In the first part of this two-part contribution, elucidating microstructure/stiffness-relationships of degraded wood, changes in physical and chemical data are presented, which were collected from specimens of Scots pine (Pinus sylvestris) sapwood degraded by Gloeophyllum trabeum (brown rot) and Trametes versicolor (white rot) for up to 28 weeks degradation time. A comparison of mass loss with corresponding mass density loss demonstrated that mass loss entails two effects: firstly, a decrease in sample size (more pronounced for G. trabeum), and secondly, a decrease of mass density within the sample (more pronounced for T. versicolor). These two concurrent effects are interrelated with sample size and shape. Hemicelluloses and cellulose are degraded by G. trabeum, while T. versicolor was additionally able to degrade lignin. In particular because of the breakdown of hemicelluloses and paracrystalline parts of cellulose, the equilibrium moisture content of degraded samples is lower than that in the initial state.

Mass loss and moisture dynamics of Scots pine (Pinus sylvestris L.) exposed outdoors above ground in Sweden

Holzforschung ◽  
2005 ◽  
Vol 59 (2) ◽  
pp. 183-189 ◽  
Author(s):  
Åsa Rydell ◽  
Mikael Bergström ◽  
Torbjörn Elowson
Keyword(s):  
Moisture Content ◽  
Pinus Sylvestris ◽  
Mass Loss ◽  
Scots Pine ◽  
Annual Ring ◽  
Water Storage ◽  
Ring Width ◽  
Moisture Uptake ◽  
Annual Ring Width ◽  
Moisture Dynamics

Abstract The durability of 566 Scots pine (Pinus sylvestris) samples was tested during a period of 9 years of exposure to weather in Sweden. The parameters investigated were heartwood/sapwood, origin, surface treatment, end-seal, storage and drying method, annual ring width and density. The weight was measured on 67 occasions during 9 years in order to assess the moisture content of the samples. The mass loss was determined for each sample at the end of the trial. Sapwood had a higher moisture uptake and a higher mass loss compared with heartwood. Even if sapwood was painted with an impermeable paint and then end-sealed, it still had higher average moisture content than heartwood. The results also demonstrated that sapwood was more sensitive to different handling conditions than heartwood. Sapwood was sensitive to air-drying and water storage, which was evident in the higher moisture uptake. In terms of mass loss, some differences were evident but they were not statistically significant due to the large standard deviation of the sapwood samples from water-stored logs. The only positive influence of water storage was on samples end-dipped in oil. One explanation could be that water storage led to increased permeability due to bacterial attack, which in turn enhanced the penetration of the oil. Heartwood had low and stable moisture dynamics during the test period, almost independent of treatment or handling conditions. No correlation with moisture uptake or mass loss was evident among annual ring width, origin or density.

scholarly journals Changes in microstructure and stiffness of Scots pine (Pinus sylvestris L) sapwood degraded by Gloeophyllum trabeum and Trametes versicolor – Part II: Anisotropic stiffness properties

Holzforschung ◽  
2012 ◽  
Vol 66 (2) ◽  
Author(s):  
Thomas K. Bader ◽  
Karin Hofstetter ◽  
Gry Alfredsen ◽  
Susanne Bollmus
Keyword(s):  
Mechanical Properties ◽  
Pinus Sylvestris ◽  
Scots Pine ◽  
Trametes Versicolor ◽  
Brown Rot ◽  
White Rot ◽  
Cellulose Microfibrils ◽  
Gloeophyllum Trabeum ◽  
Fungal Decay ◽  
Tangential Stiffness

Abstract Fungal decay considerably affects the macroscopic mechanical properties of wood as a result of modifications and degradations in its microscopic structure. While effects on mechanical properties related to the stem direction are fairly well understood, effects on radial and tangential directions (transverse properties) are less well investigated. In the present study, changes of longitudinal elastic moduli and stiffness data in all anatomical directions of Scots pine (Pinus sylvestris) sapwood which was degraded by Gloeophyllum trabeum (brown rot) and Trametes versicolor (white rot) for up to 28 weeks have been investigated. Transverse properties were found to be much more deteriorated than the longitudinal ones. This is because of the degradation of the polymer matrix between the cellulose microfibrils, which has a strong effect on transverse stiffness. Longitudinal stiffness, on the other hand, is mainly governed by cellulose microfibrils, which are more stable agains fungal decay. G. trabeum (more active in earlywood) strongly weakens radial stiffness, whereas T. versicolor (more active in latewood) strongly reduces tangential stiffness. The data in terms of radial and tangential stiffnesses, as well as the corresponding anisotropy ratios, seem to be suitable as durability indicators of wood and even allow conclusions to be made on the degradation mechanisms of fungi.

Knotwood as a window to the indirect measurement of the decay resistance of Scots pine heartwood

Holzforschung ◽  
2007 ◽  
Vol 61 (5) ◽  
pp. 600-604 ◽  
Author(s):  
Outi Karppanen ◽  
Martti Venäläinen ◽  
Anni M. Harju ◽  
Stefan Willför ◽  
Suvi Pietarinen ◽  
...  
Keyword(s):  
Pinus Sylvestris ◽  
Mass Loss ◽  
Scots Pine ◽  
Total Phenolics ◽  
Decay Resistance ◽  
Indirect Measurement ◽  
The Other ◽  
Extractive Content ◽  
Standing Trees ◽  
Further Development

Abstract There is wide variation in the extractive content and decay resistance of Scots pine (Pinus sylvestris L.) heartwood. The heartwood is not visible in standing trees and only poorly visible in timber. Therefore, it is difficult to identify extractive-rich trees, and consequently the most decay-resistant heartwood. On the other hand, knots are clearly visible in standing trees and timber. In the present paper we studied the possibility of measuring the decay resistance of Scots pine heartwood indirectly on the basis of the extractive concentration of knotwood. The material investigated consisted of 40 felled trees with a wide between-tree variation for extractive content and decay resistance of their heartwood. The extractive content of knotwood was found to be four- to five-fold higher than that of heartwood. Statistically significant correlations were found between the mass loss of heartwood and the concentrations of total phenolics and stilbenes in knotwood (r=-0.54, P<0.001 and r=-0.40, P=0.011, respectively), and for the concentration of total phenolics (r=0.42, P=0.008) and stilbenes (r=0.39, P=0.012) between heartwood and knotwood. We suggest further development of this technique in the context of rapid industrial screening of durable pine heartwood.

scholarly journals Outdoor Wood Mats-Based Engineering Composite: Influence of Process Parameters on Decay Resistance against Wood-Degrading Fungi Trametes versicolor and Gloeophyllum trabeum

Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3173
Author(s):  
Minzhen Bao ◽  
Neng Li ◽  
Yongjie Bao ◽  
Jingpeng Li ◽  
Hao Zhong ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Mass Loss ◽  
Process Parameters ◽  
Trametes Versicolor ◽  
Decay Resistance ◽  
Resin Content ◽  
White Rot ◽  
White Rot Fungus ◽  
Gloeophyllum Trabeum ◽  
Influence Of Process Parameters

The process parameters significantly influence the preparation and final properties of outdoor wood mats-based engineering composite (OWMEC). During outdoor use, wood composites are susceptible to destruction by rot fungi. Herein, the role of process parameters such as density and resin content on OWMEC resistance to fungal decay was investigated. The poplar OWMEC samples were exposed to white-rot fungus Trametes versicolor and brown-rot fungus Gloeophyllum trabeum for a period of 12 weeks. The chemical composition, crystallinity, and morphology were evaluated to investigate the effect of process parameters on the chemical composition and microstructure of the decayed OWMEC. With an increase in the density and resin content, the mass loss of the decayed OWMEC decreased. The highest antifungal effect against T. versicolor (12.34% mass loss) and G. trabeum (19.43% mass loss) were observed at a density of 1.15 g/m3 and resin content of 13%. As results of the chemical composition and microstructure measurements, the resistance of OWMEC against T. versicolor and G. trabeum fungi was improved remarkably by increasing the density and resin content. The results of this study will provide a technical basis to improve the decay resistance of OWMEC in outdoor environments.

Differences in Resin Acid Concentration between Brown-Rot Resistant and Susceptible Scots Pine Heartwood

Holzforschung ◽  
2002 ◽  
Vol 56 (5) ◽  
pp. 479-486 ◽  
Author(s):  
A. M. Harju ◽  
P. Kainulainen ◽  
M. Venäläinen ◽  
M. Tiitta ◽  
H. Viitanen
Keyword(s):  
Moisture Content ◽  
Equilibrium Moisture Content ◽  
Scots Pine ◽  
Abietic Acid ◽  
Resin Acid ◽  
Brown Rot ◽  
Decay Resistance ◽  
Resin Acids ◽  
Hydrophobic Properties

Summary The concentration of individual resin acids and the equilibrium moisture content at a relative humidity of 100% were studied in brown-rot resistant and susceptible Scots pine (Pinus sylvestris L.) heartwood. About 90% of the resin acids in the heartwood were of the abietane type, abietic acid being the most abundant. The concentration of resin acids was higher in the decay-resistant heartwood than in the decay-susceptible heartwood. Resin acids are presumably in part responsible for the decay resistance of Scots pine heartwood. However, no clear relationship was found between the concentration of resin acids and the equilibrium moisture content. The role of resin acids may also be ascribed to mechanisms other than their hydrophobic properties alone. The reasons for the slight differences in moisture content between the decay classes require further study.

Wood decay by indoor basidiomycetes at different moisture and temperature

Holzforschung ◽  
2014 ◽  
Vol 68 (1) ◽  
pp. 9-15 ◽  
Author(s):  
Tristan Stienen ◽  
Olaf Schmidt ◽  
Tobias Huckfeldt
Keyword(s):  
Moisture Content ◽  
Pinus Sylvestris ◽  
Mass Loss ◽  
Wood Decay ◽  
Metal Ring ◽  
Wood Moisture ◽  
Erlenmeyer Flask ◽  
Moisture Flow ◽  
Moisture Source ◽  
Coniophora Puteana

Abstract Some of the most important indoor wood-decay basidiomycetes were investigated in Erlenmeyer flask experiments, in which 50 Pinus sylvestris sapwood samples with moisture content (MC) of 16% were piled, in view of the parallel influence of wood moisture and temperature on decay in buildings. In the piles, the moisture flow from the liquid at the bottom was interrupted by a metal ring at layer 7. Laboratory incubations with Antrodia xantha, Coniophora puteana, Donkioporia expansa, and Gloeophyllum abietinum over the temperature range of 10°C–25°C showed that fungi are able to colonize, moisten, and thereafter degrade wood samples below fiber saturation, if a moisture source nearby is available. In extreme cases, mycelium grew on wood with 17.4% final MC, and wood mass loss of more than 2% occurred at 24.6% moisture.

scholarly journals The use of sewage sludge and diatomite as growing medium in scots pine (Pinus sylvestris L.) seedling production and evaluation of its land performance

2020 ◽  
Vol 144 (11-12) ◽  
pp. 564-564
Author(s):  
Murat Kose ◽  
Ilker Angin ◽  
Fatih Demirci ◽  
Omer Oncul ◽  
Caglar Ugurlu
Keyword(s):  
Sewage Sludge ◽  
Pinus Sylvestris ◽  
Scots Pine ◽  
Morphological Characteristics ◽  
New Materials ◽  
Pine Seedlings ◽  
Growing Medium ◽  
Inorganic Substrates ◽  
Physical And Chemical ◽  
Made In

Although several organic and inorganic substrates are added to growing media for improving its physical and chemical characteristics, the need for search of new materials and/or mixtures that reduces the high-priced peat content in substrates is still interesting. This study evaluated the feasibility of reducing the peat content in substrates by replacing it with different amounts of diatomite and sewage sludge for Scots pine seedling (Pinus sylvestris L.) growth and their land performance. In order to evaluate the feasibility of reducing the peat content in substrates by replacing it with different amounts of diatomite and sewage sludge, an experiment was carried out in a temperature-controlled greenhouse under natural light. To evaluate the land performance of Scots pine seedlings grown in different substrates, a trial was established between the years 2013-2017 in Sar&#305;kam&#305;ş, Kars (NE Anatolia). Sewage sludge application, due to its high organic matter and macro and micronutrient content, has improved the composition of the rhizosphere, thereby resulting in growth acceleration. As a result of the evaluations made in terms of both seedling morphological characteristics and land performance; the best performance was determined in the 9<sup>th</sup> (50%P+50%SS) and 3<sup>rd</sup> (75%SS+25%DE) mixtures.

scholarly journals CHANGES IN GROSS CALORIFIC VALUE OF THERMALLY TREATED SCOTS PINE (PINUS SYLVESTRIS L.) AND SESSILE OAK (QUERCUS PETRAEA L.) WOOD AND THEIR EXPLANATION USING FTIR SPECTROSCOPY

Wood Research ◽  
2021 ◽  
Vol 66 (2) ◽  
pp. 243-254
Author(s):  
Emília Orémusová ◽  
Eva Výbohová
Keyword(s):  
Pinus Sylvestris ◽  
Mass Loss ◽  
Ftir Spectroscopy ◽  
Scots Pine ◽  
Calorific Value ◽  
Quercus Petraea ◽  
Gross Calorific Value ◽  
Pine Wood ◽  
Oak Wood ◽  
Sessile Oak

Scots pine (Pinus sylvestris L.) and Sessile oak (Quercus petraea L.) wood were thermally treated in an oven at the temperatures of 160°C, and 200°C under atmospheric pressure in the presence of air for 3 and 9 hrs. The mass loss and gross calorific value were determined. Non-treated wood samples achieved a gross calorific value of 22 193 J.g-1 for pine wood and 19 277 J.g-1 for oak wood. Whereas the calorific value of pine wood with increasing severity of treatment decreased, in the case of oak it increased. The mass loss increased with increasing treatment severity by both wood species. Mentioned differences in pine and oak wood behaviour using ATR-FTIR spectroscopy were explained. In the case of pine wood with increasing temperature and time of exposure a decrease of resin acids was observed. This may be contributed to decrease in GCV. In the case of oak wood, mainly at temperature of 200°C the degradation of hemicelluloses was observed that results in relative increasing in the lignin content with followed increase in the GCV.

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