scholarly journals The Effect of Eutypella parasitica on the Wood Decay of Three Maple Species

Forests ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 671
Author(s):  
Ana Brglez ◽  
Barbara Piškur ◽  
Miha Humar ◽  
Jožica Gričar ◽  
Nikica Ogris
Keyword(s):  
Cell Wall ◽  
Moisture Content ◽  
Mass Loss ◽  
Significant Positive Correlation ◽  
Wood Decay ◽  
Fungal Species ◽  
Acer Pseudoplatanus ◽  
Calculated Mass ◽  
Effective Decay ◽  
Calculated Mass Loss

Eutypella parasitica R.W. Davidson & R.C. Lorenz is the causative agent of Eutypella canker of maple, a destructive disease of maples in Europe and North America. The fungus E. parasitica is known to cause wood stain and decay. However, it is not known how effectively it decomposes the wood of the most widespread maple species in Europe. Wood samples of Acer pseudoplatanus L., A. platanoides L., and A. campestre L. were exposed to four isolates of E. parasitica and nine other fungal species for comparison, according to the modified EN 113 standard. After 15 weeks of incubation, mass loss and microscopical analysis of samples showed evidence of colonization and different wood decay potentials among fungal species. A highly significant positive correlation was found between mass loss and moisture content for all fungal species. Similarly, the measured cell wall thickness correlated well with the calculated mass loss of the samples. On average, the fungal species caused the lowest mass loss in A. pseudoplatanus (10.0%) and the highest in A. campestre (12.6%) samples. Among the samples exposed to E. parasitica isolates, the highest mass loss was recorded in A. pseudoplatanus (6.6%). Statistical analysis showed significant differences in mass loss and moisture content between different E. parasitica isolates. Based on the results of staining, we discuss the type of decay caused by E. parasitica. Although E. parasitica isolates caused smaller mass loss of samples compared to other more effective decay species, we should not disregard its capability of degrading maple wood. Because E. parasitica usually infects the lower portion of the trunk, which is the largest and most valuable part of the tree, any damage can cause significant economic and resource loss.

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.

Decomposition of Nothofagus wood in vitro and nutrient mobilization by fungi

2009 ◽  
Vol 39 (11) ◽  
pp. 2193-2202 ◽  
Author(s):  
Peter W. Clinton ◽  
P. K. Buchanan ◽  
J. P. Wilkie ◽  
S. J. Smaill ◽  
M. O. Kimberley
Keyword(s):  
Mass Loss ◽  
Nutrient Dynamics ◽  
Wood Decay ◽  
Nutrient Release ◽  
Fungal Species ◽  
Nutrient Mobilization ◽  
Soil Matrix ◽  
Decay Fungi ◽  
Nutrient Contents

The role of fungi in determining rates of wood decomposition and nutrient release in forest ecosystems is poorly understood. The decomposition of wood from three species of Nothofagus by 12 species of widely occurring New Zealand wood-decay fungi was investigated in vitro under standardized conditions. Wood mass loss varied strongly among fungal species and to a lesser extent with the species of wood. The species of fungi in this study were divided into three groups based on the extent of mass loss after 15 weeks: (1) rapid (>65% reduction in mass, Fomes hemitephrus , Pleurotus purpureoolivaceus , Trametes versicolor , and Ganoderma cf. applanatum), (2) intermediate (15%–30%, Phellinus sp., Schizopora radula , Phellinus nothofagi , and Skeletocutis stramenticus ), and (3) slow (<10%, Armillaria novaezelandiae , Postia pelliculosa , Australoporus tasmanicus , and Laetiporus portentosus ). For several fungal species, the final contents of nitrogen, phosphorus, and calcium in the remaining wood exceeded the initial nutrient contents in the wood, indicating that nutrient sequestration from the supporting soil matrix occurred during decomposition. Nutrient dynamics during decomposition varied with wood species, but the variation among different fungal species was much greater, indicating that fungal diversity is an important factor in determining nutrient flux in decaying wood.

scholarly journals Monitored conditions in wooden wall plates in relation to mold and wood decaying fungi

2020 ◽  
Vol 172 ◽  
pp. 20004
Author(s):  
Tessa Kvist Hansen ◽  
Nickolaj Feldt Jensen ◽  
Eva Møller ◽  
Ernst Jan de Place Hansen ◽  
Ruut Peuhkuri
Keyword(s):  
Mass Loss ◽  
Indoor Air ◽  
Prediction Models ◽  
Wood Decay ◽  
Fungal Species ◽  
Masonry Buildings ◽  
Mold Growth ◽  
Health Concerns ◽  
Historic Masonry ◽  
Threshold Conditions

In historic masonry buildings, wood can be embedded in the walls as storey partition beams, or as supportive wall plates. Half-timbered masonry constructions, or wooden frames, e.g. combined with internal insulation, are other examples of wooden elements. Wood decaying fungi can cause serious damage to wood, which may lose mass and strength, ultimately yielding the risk of collapse. In addition, some fungal species may even be hazardous for occupants. All wood decaying fungi depend on favorable moisture and temperature conditions, although the threshold conditions may vary with various fungal species and types, and state of the wood. To predict the risk of occurrence of wood rot, several models have been developed, however most of these are based on a limited number of experiments, or very specific cases. For these reasons, the applicability of the models to other scenarios (fungal species, wood species) may not be appropriate. Furthermore, another failure mode for wood and moisture, is mold growth, which is initiated at lower moisture levels. An indication of risk of mold growth would indicate problems or risks before the initiation of wood rot. Mold growth does not deteriorate the wood, but is usually equally undesired due to health concerns of occupants. For this reason, there might be places where some mold growth would be acceptable, e.g. embedded beam ends if there is no transfer of air from the moldy area to the indoor air. Therefore, risk of rot could be important. The paper investigates models for mass loss due to wood decay and mold growth based on exposure time to favorable hygrothermal conditions. The investigation is based on inspection of wood samples (wall plates) from a full-scale experimental setup of masonry with embedded wood and monitored conditions, to which the prediction models will be applied. Monitored hygrothermal conditions were implemented in mold and wood decay models, and samples were removed from the test setup. The implemented models yielded high mold index and mass loss, whereas neither mold nor decay was observed in the physical samples. Results indicate that the implemented models, in these cases appear to overestimate the risks of mold and rot in the supportive lath behind the insulation.

scholarly journals Effect of the degree of decay on the electrical resistance of wood degraded by brown-rot fungi

2019 ◽  
Vol 49 (2) ◽  
pp. 145-153 ◽  
Author(s):  
Shan Gao ◽  
Xiaoquan Yue ◽  
Lihai Wang
Keyword(s):  
Moisture Content ◽  
Mass Loss ◽  
Electrical Resistance ◽  
Dominant Role ◽  
Treated Wood ◽  
Wood Decay ◽  
Brown Rot ◽  
Brown Rot Fungi ◽  
Study Results ◽  
Significant Difference

There have been limited efforts to investigate the association between wood decay and electrical resistance; consequently, we have examined the change in the electrical resistance of wood progressively decayed by brown-rot fungi to elucidate the effect of the degree of decay. The rate of mass loss of wood was used as an indicator of the degree of fungal decay. The changes in the moisture content and ion concentrations were measured at various decay stages. The results showed a significant difference in the electrical resistances of sound wood and fungal-treated wood after 24 weeks. The electrical resistance significantly decreased with the exposure time. The degree of decay increased as the mass loss increased, resulting in the severe breakdown of cell walls and the accumulation of fungal mycelia. Empirical models related to the rate of mass loss and the percent decrease in the electrical resistance were established. The moisture content and cation concentrations increased to various degrees in decayed wood. This increase in the cation concentration was considered to play a dominant role in the decrease in the electrical resistance. The study results provide valuable information for developing an electrical resistance based method coupled with ion content measurements for incipient wood decay detection.

scholarly journals Wood modification by furfuryl alcohol caused delayed decomposition response inRhodonia (Postia) placenta

2018 ◽  
Author(s):  
Inger Skrede ◽  
Monica Hongrø Solbakken ◽  
Jaqueline Hess ◽  
Carl Gunnar Fossdal ◽  
Olav Hegnar ◽  
...  
Keyword(s):  
Cell Wall ◽  
Mass Loss ◽  
Plant Cell Wall ◽  
Wood Decay ◽  
Environmentally Benign ◽  
Treatment Level ◽  
Cell Wall Polysaccharides ◽  
Decay Fungi ◽  
Postia Placenta ◽  
Modified Wood

ABSTRACTThe aim of this study was to investigate differential expression profiles of the brown rot fungusRhodonia placenta(previouslyPostia placenta) harvested at several time points when grown onPinus radiata(radiata pine) andP. radiatawith three different levels of modification by furfuryl alcohol, an environmentally benign commercial wood protection system. For the first time the entire gene expression pattern of a decay fungus is followed in untreated and modified wood from initial to advanced stages of decay. Results support the current model of a two-step decay mechanism, with an initial oxidative depolymerization followed by hydrolysis of cell-wall polysaccharides. The wood decay process is finished, and the fungus goes into starvation mode after five weeks when grown on unmodifiedP. radiatawood. The pattern of repression of oxidative processes and oxalate synthesis found inP. radiataat later stages of decay is not mirrored for the high furfurylation treatment. The high treatment level provided a more unpredictable expression pattern throughout the entire incubation period. Furfurylation does not seem to directly influence the expression of core plant cell wall hydrolyzing enzymes, as a delayed and prolonged, but similar pattern was observed in theP. radiataand the modified experiments. This indicates that the fungus starts a common decay process in the modified wood, but proceeds at a slower pace as access to the plant cell wall polysaccharides is restricted. This is further supported by the downregulation of hydrolytic enzymes for the high treatment level at the last harvest point (mass loss 14%). Moreover, the mass loss does not increase the last weeks. Collectively, this indicates a potential threshold for lower mass loss for highly modified wood.IMPORTANCEFungi are important decomposers of woody biomass in natural habitats. Investigation of the mechanisms employed by decay fungi in their attempt to degrade wood is important for both the basic scientific understanding of ecology and carbon cycling in nature, and for applied uses of woody materials. For wooden building materials long service life and carbon storage is essential, but decay fungi are responsible for massive losses of wood in service. Thus, optimizing durable wood products for the future are of major importance. In this study we have investigated the fungal genetic response to furfurylated wood, a commercial environmentally benign wood modification approach, that improves service life of wood in outdoor applications. Our results show that there is a delayed wood decay by the fungus as a response to furfurylated wood and new knowledge about the mechanisms behind the delay is provided.

scholarly journals The effect of corrosion on shear behaviour of self-consolidating concrete beams

2021 ◽  
Author(s):  
Nabil Al-Bayati
Keyword(s):  
Reinforced Concrete ◽  
Mass Loss ◽  
Failure Mode ◽  
Concrete Beams ◽  
Shear Behaviour ◽  
Accelerated Corrosion ◽  
Self Consolidating Concrete ◽  
Calculated Mass ◽  
Real Mass ◽  
Calculated Mass Loss

The objectives of this research are to compare the effect of corrosion on shear behavior in particular, and the overall structural response in both NC and SCC beams in general. Twenty reinforced concrete beams were used, with ten specimens cast using normal concrete (NC), and the other ten were cast using self-consolidating concrete (SCC). The dimensions for each beam were 150mm x 220mm x 1400mm. Using accelerated corrosion through the application of a constant current of one ampere, four stages of corrosion were established at 5%, 10%, and 20% of mass loss. Simply supported beams were loaded with two concentrated loads, and a four-point loading test was applied to the reinforced concrete (RC) beams. If (a) is the distance from the concentrated load to the reaction, and (d) is the distance from the center of the tensile flexural rebars to the top of the concrete beam, then a/d=2.5 was applied to assure the highest probability of shear failure mode. The data collected from load cell, LVDTs, corrosion crack patterns and loading cracks patterns were used to study the effects of multiple stages of corrosion on the shear behaviour of reinforced NC and SCC concrete beams. The corroded rebars were then retrieved and cleaned to compare the calculated mass loss with real mass loss. The results showed high correlation between the calculated mass loss (according to Faraday law) and real mass loss. The accelerated corrosion resulted in a corrosion crack pattern, which was documented and analyzed. In this research, the use of NC and SCC showed minor influences on failure mode, while the different states of corrosion showed a higher degree of influence on failure mode and the structural capacity of beams made from both types of concrete. The apparent changes in failure mode were associated with the increased corrosion stage.

scholarly journals Studies into Fungal Decay of Wood in Ground Contact—Part 2: Development of a Dose–Response Model to Predict Decay Rate

Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 698
Author(s):  
Brendan Nicholas Marais ◽  
Philip Bester van Niekerk ◽  
Christian Brischke
Keyword(s):  
Soil Moisture ◽  
Service Life ◽  
Moisture Content ◽  
Mass Loss ◽  
Dose Response ◽  
Soil Moisture Content ◽  
Wood Decay ◽  
Response Model ◽  
Soil Water Holding Capacity ◽  
Water Holding

In this article a dose–response model was developed to describe the effect of soil temperature, soil moisture content, and soil water-holding capacity, on the decay of European beech (Fagus sylvatica) wood specimens exposed to soil contact. The developed dose–response model represents a step forward in incorporating soil-level variables into the prediction of wood decay over time. This builds upon prior models such as those developed within the TimberLife software package, but also aligns with similar modeling methodology employed for wood exposed above ground. The model was developed from laboratory data generated from terrestrial microcosm trials which used test specimens of standard dimension, incubated in a range of soil conditions and temperatures, for a maximum period of 16 weeks. Wood mass loss was used as a metric for wood decay. The dose aspect of the developed function modelled wood mass loss in two facets; soil temperature against wood mass loss, and soil water-holding capacity and soil moisture content against wood mass loss. In combination, the two functions describe the wood mass loss as a function of a total daily exposure dose, accumulated over the exposure period. The model was deemed conservative, delivering an overprediction of wood decay, or underprediction of wood service-life, when validated on a similar, but independent dataset (R2 = 0.65). Future works will develop similar models for outdoor, field-trial datasets as a basis for service-life prediction of wooden elements used in soil contact.

scholarly journals Wood Modification by Furfuryl Alcohol Resulted in a Delayed Decomposition Response in Rhodonia (Postia) placenta

2019 ◽  
Vol 85 (14) ◽  
Author(s):  
Inger Skrede ◽  
Monica Hongrø Solbakken ◽  
Jaqueline Hess ◽  
Carl Gunnar Fossdal ◽  
Olav Hegnar ◽  
...  
Keyword(s):  
Cell Wall ◽  
Mass Loss ◽  
Plant Cell Wall ◽  
Wood Decay ◽  
Radiata Pine ◽  
Treatment Level ◽  
Cell Wall Polysaccharides ◽  
Decay Fungi ◽  
Content Type ◽  
Postia Placenta

ABSTRACT The aim of this study was to investigate differential expression profiles of the brown rot fungus Rhodonia placenta (previously Postia placenta) harvested at several time points when grown on radiata pine (Pinus radiata) and radiata pine with three different levels of modification by furfuryl alcohol, an environmentally benign commercial wood protection system. The entire gene expression pattern of a decay fungus was followed in untreated and modified wood from initial to advanced stages of decay. The results support the current model of a two-step decay mechanism, with the expression of genes related to initial oxidative depolymerization, followed by an accumulation of transcripts of genes related to the hydrolysis of cell wall polysaccharides. When the wood decay process is finished, the fungus goes into starvation mode after five weeks when grown on unmodified radiata pine wood. The pattern of repression of oxidative processes and oxalic acid synthesis found in radiata pine at later stages of decay is not mirrored for the high-furfurylation treatment. The high treatment level provided a more unpredictable expression pattern throughout the incubation period. Furfurylation does not seem to directly influence the expression of core plant cell wall-hydrolyzing enzymes, as a delayed and prolonged, but similar, pattern was observed in the radiata pine and the modified experiments. This indicates that the fungus starts a common decay process in the modified wood but proceeds at a slower pace as access to the plant cell wall polysaccharides is restricted. This is further supported by the downregulation of hydrolytic enzymes for the high treatment level at the last harvest point (mass loss, 14%). Moreover, the mass loss does not increase during the last weeks. Collectively, this indicates a potential threshold for lower mass loss for the high-furfurylation treatment. IMPORTANCE Fungi are important decomposers of woody biomass in natural habitats. Investigation of the mechanisms employed by decay fungi in their attempt to degrade wood is important for both the basic scientific understanding of ecology and carbon cycling in nature and for applied uses of woody materials. For wooden building materials, long service life and carbon storage are essential, but decay fungi are responsible for massive losses of wood in service. Thus, the optimization of durable wood products for the future is of major importance. In this study, we have investigated the fungal genetic response to furfurylated wood, a commercial environmentally benign wood modification approach that improves the service life of wood in outdoor applications. Our results show that there is a delayed wood decay by the fungus as a response to furfurylated wood, and new knowledge about the mechanisms behind the delay is provided.

Analysis of the hyphal load during early stages of wood decay by basidiomycetes in the presence of the wood preservative fungicides CuSO4 and cyproconazole

Holzforschung ◽  
2006 ◽  
Vol 60 (6) ◽  
pp. 637-642 ◽  
Author(s):  
Damiano Vesentini ◽  
David J. Dickinson ◽  
Richard J. Murphy
Keyword(s):  
Cell Wall ◽  
Mass Loss ◽  
Wood Decay ◽  
Wood Preservative ◽  
Recovery Phase ◽  
Fungal Mycelium ◽  
Gloeophyllum Trabeum ◽  
Low Concentrations ◽  
Initial Decrease ◽  
Decaying Wood

AbstractThis study considers variations in hyphal load in decaying wood in the presence of the fungicides CuSO4and cyproconazole. Variations in the chitin content of hyphae following exposure to both fungicides have been detected. Increasing concentrations of CuSO4and cyproconazole in wood caused an increase in the amount ofN-acetyl glucosamine in the mycelia ofCoriolus versicolorandGloeophyllum trabeum, which may be associated with increased deposition of chitin. This may in turn be an expression of the formation of a thicker cell wall at increased fungicide concentrations. Low concentrations of both fungicides also caused an increase in the amount of mycelium produced byG. trabeum. However, the same concentrations were effective at preventing mass loss, indicating that the fungal mycelium was less effective at decaying wood, despite being present in relatively large amounts. In the case ofC. versicolor, this effect was not observed, as increasing concentrations of both fungicides caused an initial decrease in the amount of mycelium, followed by a recovery phase at intermediate chemical concentrations. Again, mass loss was greatly inhibited by the presence of low concentrations of both fungicides.

scholarly journals The effect of corrosion on shear behaviour of self-consolidating concrete beams

2021 ◽  
Author(s):  
Nabil Al-Bayati
Keyword(s):  
Reinforced Concrete ◽  
Mass Loss ◽  
Failure Mode ◽  
Concrete Beams ◽  
Shear Behaviour ◽  
Accelerated Corrosion ◽  
Self Consolidating Concrete ◽  
Calculated Mass ◽  
Real Mass ◽  
Calculated Mass Loss

The objectives of this research are to compare the effect of corrosion on shear behavior in particular, and the overall structural response in both NC and SCC beams in general. Twenty reinforced concrete beams were used, with ten specimens cast using normal concrete (NC), and the other ten were cast using self-consolidating concrete (SCC). The dimensions for each beam were 150mm x 220mm x 1400mm. Using accelerated corrosion through the application of a constant current of one ampere, four stages of corrosion were established at 5%, 10%, and 20% of mass loss. Simply supported beams were loaded with two concentrated loads, and a four-point loading test was applied to the reinforced concrete (RC) beams. If (a) is the distance from the concentrated load to the reaction, and (d) is the distance from the center of the tensile flexural rebars to the top of the concrete beam, then a/d=2.5 was applied to assure the highest probability of shear failure mode. The data collected from load cell, LVDTs, corrosion crack patterns and loading cracks patterns were used to study the effects of multiple stages of corrosion on the shear behaviour of reinforced NC and SCC concrete beams. The corroded rebars were then retrieved and cleaned to compare the calculated mass loss with real mass loss. The results showed high correlation between the calculated mass loss (according to Faraday law) and real mass loss. The accelerated corrosion resulted in a corrosion crack pattern, which was documented and analyzed. In this research, the use of NC and SCC showed minor influences on failure mode, while the different states of corrosion showed a higher degree of influence on failure mode and the structural capacity of beams made from both types of concrete. The apparent changes in failure mode were associated with the increased corrosion stage.

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