Measuring the decay resistance of Scots pine heartwood indirectly by the Folin-Ciocalteu assay

2006 ◽  
Vol 36 (7) ◽  
pp. 1797-1804 ◽  
Author(s):  
Anni M Harju ◽  
Martti Venäläinen
Keyword(s):  
Mass Loss ◽  
Scots Pine ◽  
Total Phenolics ◽  
Brown Rot ◽  
Strong Relationship ◽  
Decay Resistance ◽  
Wood Products ◽  
Decay Test ◽  
Decay Tests

To exploit the variation in the natural durability of heartwood timber, screening of a large number of trees or timber is necessary. We suggest that the concentration of total phenolics, measured by the Folin–Ciocalteu (FC) assay, can be used to supplement or even replace in vitro decay tests for screening the variation in the resistance of Scots pine (Pinus sylvestris L.) heartwood timber against the brown-rot fungus Coniophora puteana (Schum. ex Fr.). We screened the juvenile heartwood of 520 Scots pine trees with the FC assay. Samples from 40 trees, with total phenolics concentrations ranging from 1.9 to 21.7 mg tannic acid equivalents (TAE)/g of heartwood, were subjected to an in vitro decay test. The correlation (r) between the total phenolics concentration and mass loss was –0.82 (p < 0.001) in the 7 week long decay test. The relationship was expressed with a linear regression equation: mass loss (mg/g) = 487 – 25 × concentration of total phenolics (mg TAE/g). This strong relationship could be exploited by replacing the decay test with the FC assay to more rapidly assess the durability of wood products.

scholarly journals Resistance of thermally modified and pressurized hot water extracted Scots pine sapwood against decay by the brown-rot fungus Rhodonia placenta

2019 ◽  
Vol 78 (1) ◽  
pp. 161-171 ◽  
Author(s):  
Michael Altgen ◽  
Suvi Kyyrö ◽  
Olli Paajanen ◽  
Lauri Rautkari
Keyword(s):  
Cell Wall ◽  
Mass Loss ◽  
Scots Pine ◽  
Elevated Temperatures ◽  
Brown Rot ◽  
Decay Resistance ◽  
Hot Water ◽  
Decay Fungi ◽  
Effective Reduction ◽  
Cell Wall Porosity

AbstractThe thermal degradation of wood is affected by a number of process parameters, which may also cause variations in the resistance against decay fungi. This study compares changes in the chemical composition, water-related properties and decay resistance of Scots pine sapwood that was either thermally modified (TM) in dry state at elevated temperatures (≥ 185 °C) or treated in pressurized hot water at mild temperatures (≤ 170 °C). The thermal decomposition of easily degradable hemicelluloses reduced the mass loss caused by Rhodonia placenta, and it was suggested that the cumulative mass loss is a better indicator of an actual decay inhibition. Pressurized hot water extraction (HWE) did not improve the decay resistance to the same extent as TM, which was assigned to differences in the wood-water interactions. Cross-linking reactions during TM caused a swelling restraint and an effective reduction in moisture content. This decreased the water-swollen cell wall porosity, which presumably hindered the transport of degradation agents through the cell wall and/or reduced the accessibility of wood constituents for degradation agents. This effect was absent in hot water-extracted wood and strong decay occurred even when most hemicelluloses were already removed during HWE.

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.

Decay resistance, extractive content, and water sorption capacity of Siberian larch (Larix sibirica Lebed.) heartwood timber

Holzforschung ◽  
2006 ◽  
Vol 60 (1) ◽  
pp. 99-103 ◽  
Author(s):  
Martti Venäläinen ◽  
Anni M. Harju ◽  
Nasko Terziev ◽  
Tapio Laakso ◽  
Pekka Saranpää
Keyword(s):  
Siberian Larch ◽  
Brown Rot ◽  
Decay Resistance ◽  
Extractive Content ◽  
Strong Negative Correlation ◽  
Average Mass ◽  
Brown Rot Fungi ◽  
Hygroscopic Properties ◽  
Decay Test

Abstract The aim of this study was to find chemical or physical properties of Siberian larch heartwood timber that correlate with the variation in decay resistance. Juvenile heartwood from 24-year-old grafts of 15 clones was exposed to three brown-rot fungi according to the standard in vitro decay test (European standard EN 113). The mass losses caused by the brown rot fungi Coniophora puteana, Poria placenta, and Gloeophyllum trabeum were 20%, 28% and 17% of the dry mass, respectively. The average mass loss over the three fungi had a strong negative correlation with the concentration of taxifolin (r=–0.673, P=0.006), as well as with the concentration of total phenolics determined by the Folin-Ciocalteu assay (r=–0.677, P=0.006). Thus, the concentration of flavonoids is a promising property for indirect measurement of the decay resistance of Siberian larch timber. The most abundant heartwood extractives, arabinogalactans, had a non-significant relationship with the decay resistance, but their concentration correlated positively with the capacity of the wood to adsorb water (r=0.736, P=0.002). The hygroscopic properties of the wood or the wood density were not associated with the decay resistance.

Genetic variation in the decay resistance of Scots pine wood against brown rot fungus

2001 ◽  
Vol 31 (7) ◽  
pp. 1244-1249 ◽  
Author(s):  
Anni M Harju ◽  
Martti Venäläinen ◽  
Egbert Beuker ◽  
Pirkko Velling ◽  
Hannu Viitanen
Keyword(s):  
Genetic Variation ◽  
Mass Loss ◽  
Scots Pine ◽  
Brown Rot ◽  
Decay Resistance ◽  
Phenotypic Variance ◽  
Increment Core ◽  
Genetic Components ◽  
Brown Rot Fungus ◽  
The Mean

The role of genotype in the durability of Scots pine (Pinus sylvestris L.) wood against decay by brown rot fungus (Coniophora puteana (Schum. ex Fr.) Karst. (strain Bam EBW 15)) was studied in a laboratory test. The wood material was obtained from 32-year-old half-sib progenies of Scots pine. The increment core samples of sapwood and juvenile heartwood were decayed using a modification of the standardized EN 113 method. The mean densities of the sapwood and heartwood samples were 391 and 337 mg·cm–3, respectively, and the mean mass losses were 114 and 80 mg·cm–3, respectively. The additive genetic components were small compared with the total phenotypic variance, which resulted in small narrow-sense heritabilities in mass loss. The most marked feature was the wide phenotypic variation in mass loss observed in heartwood (range 199 mg·cm–3) compared with sapwood (range 72 mg·cm–3) samples. Low heritability, together with the relatively high coefficient of additive genetic variation (CVA) in heartwood mass loss, suggests that advances in breeding can only be made through intensive testing in the environments which the studied experiment represents.

Growth behavior of wood-destroying fungi in chemically modified wood: wood degradation and translocation of nitrogen compounds

Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Lukas Emmerich ◽  
Maja Bleckmann ◽  
Sarah Strohbusch ◽  
Christian Brischke ◽  
Susanne Bollmus ◽  
...  
Keyword(s):  
Protective Action ◽  
Treated Wood ◽  
Untreated Wood ◽  
Brown Rot ◽  
Decay Resistance ◽  
White Rot ◽  
Decay Fungi ◽  
Chemically Modified ◽  
Decay Tests ◽  
Modified Wood

Abstract Chemical wood modification has been used to modify wood and improve its decay resistance. However, the mode of protective action is still not fully understood. Occasionally, outdoor products made from chemically modified timber (CMT) show internal decay while their outer shell remains intact. Hence, it was hypothesized that wood decay fungi may grow through CMT without losing their capability to degrade non-modified wood. This study aimed at developing a laboratory test set-up to investigate (1) whether decay fungi grow through CMT and (2) retain their ability to degrade non-modified wood. Acetylated and 1,3-dimethylol-4,5-dihydroxyethyleneurea (DMDHEU) treated wood were used in decay tests with modified ‘mantle specimens’ and untreated ‘core dowels’. It became evident that white rot (Trametes versicolor), brown rot (Coniophora puteana) and soft rot fungi can grow through CMT without losing their ability to degrade untreated wood. Consequently, full volume impregnation of wood with the modifying agent is required to achieve complete protection of wooden products. In decay tests with DMDHEU treated specimens, significant amounts of apparently non-fixated DMDHEU were translocated from modified mantle specimens to untreated wood cores. A diffusion-driven transport of nitrogen and DMDHEU seemed to be responsible for mass translocation during decay testing.

Changes in Carbon Sequestration in Wood During Decay by Brown- and White-Rot Fungi

2020 ◽  
Vol 14 (3) ◽  
pp. 414-419
Author(s):  
Huadong Xu ◽  
Jiedong Wei ◽  
Yanan Di ◽  
Ruixia Qin ◽  
Zonglin Zhen
Keyword(s):  
Carbon Sequestration ◽  
Mass Loss ◽  
Decay Time ◽  
Carbon Emission ◽  
Wood Decay ◽  
Brown Rot ◽  
White Rot ◽  
Korean Pine ◽  
Decay Test ◽  
The Absolute

Wood decay is a releasing process of carbon fixed in the wood. The study on carbon sequestration change caused by decay can provide a theoretical basis for wood preservation and utilization. At present, there are few reports on decay influence on wood carbon emission and no corresponding quantitative data. Therefore, one broad-leaved species, Poplar, and one coniferous species, Korean pine, were selected as the research object, and brown rot fungus (Gloeephyllum trabeum) and white rot fungus (Coriolus versicolor) were used to conduct accelerated decay test on wood samples in the laboratory. During decay, specimens were taken out in different periods to measure chemical properties, mass loss and carbon sequestration. The influence of decay time on carbon sequestration, chemical component and mass loss were then analyzed and the change rule of carbon sequestration were finally studied. The results showed that with increasing decay time, the relative carbon sequestration content of wood affected by different types rot fungi decreased, which was consistent with the change rule of mass loss, indicating that decay would lead to a loss of wood mass and affect its carbon sequestration. However, the absolute carbon sequestration (measured value of carbon sequestration) after brown rot treatment did not decrease but increased slightly, which was different from previous expectation. According to the analysis, with increasing brown rot time, the absolute content and proportion of lignin in wood samples increased slightly, while the corresponding value of holocellulose (including α-cellulose and hemicellulose) decreased significantly. The carbon content of lignin per unit mass is higher than that of holocellulose (Poplar 64.08% > 37.38%; Korean pine 66.37% > 35.94%), resulting in absolute carbon sequestration in wood increases instead of decreases. In conclusion, the change of lignin proportion during the process of brown rot is the decisive factor affecting the change of absolute carbon sequestration. This study focused on two aspects of wood decay and wood carbon sequestration, systematically analyzed the change rule and internal mechanism of wood carbon sequestration with the increase of wood decay degree, and accumulated basic data for wood carbon emission reduction and wood prevention.

Relation of transverse compression properties and the degree of brown rot biodeterioration of Pinus glabra in the soil block test

Holzforschung ◽  
2016 ◽  
Vol 70 (11) ◽  
pp. 1067-1071 ◽  
Author(s):  
Steve Janzen ◽  
Darrel D. Nicholas
Keyword(s):  
Compression Strength ◽  
Strain Analysis ◽  
Brown Rot ◽  
Strength Loss ◽  
Wood Products ◽  
Transverse Compression ◽  
Decay Fungi ◽  
Significant Strength ◽  
Soil Block ◽  
Decay Test

Abstract Improved methods are needed for detecting and quantifying the effect of decay fungi on wood products. The focus of the present paper is a soil block decay test with exposure to the brown rot fungus Gloeophyllum trabeum, where the changes in elasticity and strength were compared in both the radial and tangential directions as a function of the decay degree. The stress-strain analysis was employed by a transverse compression (transC) testing technique in which a load was applied over the specimen’s tangential or radial surface. It was found that early effects of decay were detected in either direction of loading, but the overall reduction in elasticity and compression strength after 7 days of exposure to the fungus was approximately two times greater in the radial direction. This difference is interpreted that decay occurs mainly in the earlywood (EW). Significant strength loss at 5% compression was detected after 2 days of exposure to the fungus. However, 3 days of exposure was required before significant strength loss was evident as a result of the reduction in modulus of elasticity (MOE) or mass loss (ML). In comparison to ML, the compression strength loss was found to be a more sensitive measure of wood decay.

Stilbene impregnation retards brown-rot decay of Scots pine sapwood

Holzforschung ◽  
2016 ◽  
Vol 70 (3) ◽  
pp. 261-266 ◽  
Author(s):  
Jinrong Lu ◽  
Martti Venäläinen ◽  
Riitta Julkunen-Tiitto ◽  
Anni M. Harju
Keyword(s):  
Scots Pine ◽  
Fungal Growth ◽  
Brown Rot ◽  
Monomethyl Ether ◽  
Wood Preservation ◽  
High Concentration ◽  
Brown Rot Fungi ◽  
Decay Test ◽  
Antifungal Efficiency ◽  
Brown Rot Decay

Abstract Stilbenes are abundant in the heartwood of Scots pine (Pinus sylvestris L.) and are known to have strong antifungal efficiency. In this study, Scots pine sapwood blocks were impregnated with crude heartwood extract containing the stilbenes pinosylvin (PS) and the pinosylvin monomethyl ether (PSM). Impregnated blocks were submitted to brown-rot fungi, Coniophora puteana, Gloeophyllum trabeum, and Rhodonia (Poria) placenta, and fungal growth test and decay test were performed. Both tests showed that the impregnation with a high concentration of stilbenes (60 mg g-1 dry wood) significantly suppressed the growth of fungi and slowed down the decay process of wood blocks, especially in case of G. trabeum. However, chemical analysis showed that PS and PSM were degraded by all the three types of fungi, obviously via modification to resveratrol and methylresveratrol. Rhodonia placenta displayed the fastest rate of degradation. Thus, impregnation with biodegradable stilbenes could be a viable alternative for wood preservation only in service situations with low or transient risk of decay.

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.

scholarly journals Feasibility of Manufacturing Strand-Based Wood Composite Treated with β-Cyclodextrin–Boric Acid for Fungal Decay Resistance

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 274 ◽  
Author(s):  
Lili Cai ◽  
Hyungsuk Lim ◽  
Nicholas C. Fitzkee ◽  
Bojan Cosovic ◽  
Dragica Jeremic
Keyword(s):  
Boric Acid ◽  
Mass Loss ◽  
Chemical Shifts ◽  
Brown Rot ◽  
Decay Resistance ◽  
Attenuated Total Reflection ◽  
Fungal Decay ◽  
Scanning Calorimetry ◽  
Decay Fungi ◽  
Average Mass

The feasibility of using β-cyclodextrin (βCD) as an eco-friendly carrier of boric acid for the protection of strand-based wood composites against decay fungi was evaluated. The formation of a βCD–boric acid (βCD–B) complex was confirmed by the appearance of the boron–oxygen bond by using attenuated total reflection–Fourier transform infrared spectroscopy. Chemical shifts of around 6.25 and 1.41 ppm were also observed in 1H Nuclear Magnetic Resonance (NMR) and 11B NMR spectra, respectively. The βCD–B preservatives at two levels (5 and 10 wt.%) were uniformly blended with southern pine strands that were subsequently sprayed with polymeric methylene diphenyl diisocyanate (pMDI) resin. The blended strands were formed into a loose mat by hand and consolidated into 25 × 254 × 12 mm oriented strand boards (OSB) using a hot-press. The OSB panels were cut to end-matched internal bonding (IB) strength and fungal decay resistance test specimens. The vertical density profiles (VDPs) of the IB specimens were measured using an X-ray based density profiler and the specimens with statistically similar VDPs were selected for the IB and decay tests. The IB strength of the treated specimens was lower than the control specimens but they were above the required IB strength of heavy-duty load-bearing boards for use in humid conditions, specified in the BS EN 300:2006 standard. The reduced IB of preservative-treated OSB boards could be explained by the destabilized resin upon the addition of the βCD–B complex, as indicated by the differential scanning calorimetry (DSC) results. The resistance of the OSB panels against two brown-rot fungi (i.e., G. trabeum or P. placenta) was evaluated before and after accelerated leaching cycles. The treated OSBs exposed to the fungi showed an average mass loss of lower than 3% before leaching, while the untreated OSBs had 49 and 35% mass losses due to decay by G. trabeum or P. placenta, respectively. However, upon the leaching, the treatment provided protection only against G. trabeum to a certain degree (average mass loss of 15%). The experimental results suggest that protection efficacy against decay fungi after leaching, as well as the adhesion of the OSB strands, can be improved by increasing the amount of pMDI resin.

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