iForest - Biogeosciences and Forestry

Moisture in modified wood and its relevance for fungal decay

iForest - Biogeosciences and Forestry, Volume 11, Issue 3, Pages 418-422 (2018)
doi: https://doi.org/10.3832/ifor2406-011
Published: Jun 05, 2018 - Copyright © 2018 SISEF

Review Papers

Collection/Special Issue: COST action FP1407
Understanding wood modification through an integrated scientific and environmental impact approach
Guest Editors: Giacomo Goli, Andreja Kutnar, Dennis Jones, Dick Sandberg

Water plays an essential role in fungal decay of wood, and limiting the cell wall moisture content by chemical modification can effectively improve the durability of the material. Investigating the wood-water relations of modified material under climatic conditions relevant for fungal decay are, however, experimentally challenging. Most studies in literature therefore focus on moisture sorption under conditions outside those of importance for fungal decay. This review discusses the validity of such data for characterising the wood-water relations at very humid climatic conditions, relevant for fungal decay. Moreover, the review attempts to cover the basics of fungal decay, the important role of water, and how controlling water content by modification can improve durability.

Modification, Wood, Moisture, Experimental Techniques


Some of the most widespread, economically important, and devastating wood-decaying organisms are basidiomycetes fungi ([74], [22], [1], [65]). A lot of research is therefore dedicated to understand their degradation mechanisms and the basic conditions necessary for decay ([2], [70], [71], [61], [62], [63], [87], [47], [55]), in order to prevent fungal attack of wood. Protection of wood structures has traditionally been accomplished by using toxic preservative systems, i.e., fungicides, but environmental concerns and restrictions of their use have increased the focus on non-toxic alternatives such as chemical modification ([36]). A large number of physicochemical modification processes exist aimed at improving various aspects of the performance of wood materials. In this review, the focus is on modifications targeting an improved durability, and how their performance is linked to wood-water relations of the modified material. Recent years have seen several new findings regarding the protection mechanism, and this reviews attempts to cover both the basics of fungal decay, the important role of water, and how controlling water content by modification can improve durability.

  Fungal decay mechanisms and the importance of water 

Fungi employ enzymes for the conversion of cell wall polymers into smaller fragments which can be consumed. However, as cell wall pores, even in the water-saturated state, are too small for enzymes to enter ([67], [19], [20], [21]), fungi break up cell walls by oxidative action ([18]). While fungi classified as white-rot fungi rely on enzymes for this task ([73], [40], [60]), another class of fungi termed brown-rot fungi have evolved a non-enzymatic strategy based on Fenton chemistry to disrupt cell walls in the initial stage of attack ([30], [81], [34], [8], [35], [64], [61], [89]). It is speculated that through transportation of chelated iron ions into wood cell walls and reaction of these with hydrogen peroxide, brown-rot fungi create highly reactive free radicals which disrupt chemical bonds of the cell wall constituents. This mechanism can work at a distance of several microns from the fungi to create pathways within cell walls, through which the lignocellulolytic enzymes can penetrate ([32], [31], [80], [8], [9], [61], [43]). That such a combination of non-enzymatic and enzymatic degradation machinery is effective is apparent from the high relative occurrence (73-85 % of cases) of brown-rot in decaying wooden structures compared with white-rot decay ([22], [74], [1], [65]).

A prerequisite for fungal decay is sufficient ambient temperature and moisture conditions of the wood. Being a hygroscopic material, wood can absorb/desorb and exchange water molecules with the surrounding air. Water in wood, often termed moisture, can be found both within cell walls as bound water and outside cell walls in the wood void structure (pits, lumens, vessels, etc.) as capillary water or vapour ([24]). The moisture distribution between cell walls and voids depends on the climatic conditions. Thus, for relative humidity (RH) levels up to about 97-98 %, the moisture content in equilibrium with the ambient RH is dominated by bound water ([23]). However, as the RH approaches saturation (100% RH) the contribution from capillary water held in the void structure becomes significant and eventually dominates the moisture content at very high (> 99 %) RH ([68], [33], [27], [17], [3], [4], [29], [28]). In line with common practice within building materials research, the RH-range from 0% to 97-98 % is in this review referred to as “hygroscopic” and the range above as “over-hygroscopic” (see Fig. 1).

Fig. 1 - Schematic illustration of sorption isotherms for wood in absorption from absolute dry state (lower black line) and desorption from fully water-saturated state (upper black line) in the entire relative humidity (RH) range.

  Enlarge/Shrink   Download   Full Width  Open in Viewer

It is often assumed that liquid water, e.g., capillary water in the wood void structure, should be available for fungal decay to be possible ([46], [65]). While it is evident that fungal decay is only relevant at high RH (Fig. 1) and that in general wood moisture contents of 40-70 % are most favourable for decay ([74]), the essential presence of capillary water is questionable. For instance, the lowest RH capable of supporting brown-rot decay is around 92-97 % RH ([33], [15], [75], [65]), the exact threshold depending on temperature and fungal species ([75]). Wood in equilibrium with this level of RH only contains minuscule amounts of capillary water that is found in pores smaller than 70 nm. For Norway spruce, this amount of water outside cell walls is of the order of 10 µg water per gram wood ([23]). The question of whether capillary water is essential for fungal decay is, however, obscured by experimental limitations. It is difficult to maintain a stable climate above 97 % RH ([33]), and studies of moisture in wood in the over-hygroscopic regime therefore requires special techniques, e.g., pressure plate. For this reason, studies on the effect of initial wood moisture conditions on fungal decay often employ wood specimens exposed to liquid water and perhaps partially dried to specific wood moisture contents ([58]). This inevitably causes moisture gradients in the specimens, but further complications arise with controlling the moisture conditions during decay tests ([6]). During such tests both the hygroscopicity of the material changes ([13], [5], [66], [79], [7]), and the amount of water increases due to fungal respiration ([53], [39], [51], [76], [71]). These issues of lack of climate control and changes in the substrate during the tests seriously complicate the interpretation of the limiting moisture conditions for decay.

  Improving durability by chemical modification 

Since sufficient moisture conditions are central to fungal decay, it has long been recognised that durability can be obtained by keeping wood dry ([52], [46], [16]). However, for some applications keeping wood dry is impossible, e.g., under direct exposure to rain or in very humid environments. In these cases, alternative strategies are needed to avoid fungal decay. While traditional wood protection depends on toxic preservatives, chemical modification improves the durability the modified material by non-toxic means. The exact mechanisms behind the increased resistance to fungal decay observed for several kinds of chemical modification is not fully clear, but it is undoubtedly linked with reductions in the moisture content of cell walls ([70]). Thus, even at high moisture contents where fungal decay of untreated wood is possible, modified wood can be decay resistant ([14], [26], [25], [78], [37], [71]). This illustrates that the total amount of water available to fungi is not a predictor of the potential for wood decay as sufficient cell wall moisture content needs to be present as already speculated a century ago ([88]).

As described previously, investigating the wood-water relations in the over-hygroscopic regime, relevant for fungal decay, is challenging. Therefore, the vast majority of studies of wood-water relations for modified wood focus on the hygroscopic range, while the over-hygroscopic range is only covered in two studies on modified wood ([72], [82]) and few more for unmodified wood ([68], [33], [27], [17], [3], [4], [29], [28], [86]). This raises the important question of whether observations about wood-water relations in the hygroscopic range are valid for the over-hygroscopic range as well. For instance, Thybring ([70]) found a common moisture threshold for decay in several different types of modified wood, where a reduction of about 40 % in moisture content at similar hygroscopic RH conditions (in the range 30-90 %) was found to correlate with resistance to fungal decay across widely different modifications. One exception is thermally modified wood which is not fully decay resistant ([45], [77], [50]), despite a 40 % reduction in moisture content under hygroscopic conditions. This illustrates the need for determining wood-water relations at moisture conditions relevant for fungal decay (Fig. 1).

  Potential mechanisms for improved durability of modified wood towards brown-rot decay 

It is apparent that the durability of wood can be improved by reducing the cell wall moisture content through modification, but the actual mechanism of protection has not yet been resolved. In a recent review, Zelinka et al. ([87]) discuss the potential mechanisms behind decay resistance from modification based on the observation by Zelinka et al. ([85]) that ions within cell walls have a threshold moisture content below which they cannot diffuse. Ion transport in wood has been linked with the formation of a continuous network of cell wall water (a percolation threshold - [84], [83], [44]), and limiting the cell wall moisture might prevent the formation of such a network, hereby disrupting the physical pathways for transport of solutes. As the initial stage of brown-rot attack involves the transport of ions into cell walls ([47]), it seems reasonable that the formation of a continuous water-swollen porosity of sufficient pore size is a prerequisite for this transport. Hosseinpourpia & Mai ([41], [42], [43]) have conducted a series of experiments where modified wood veneers are exposed sequentially to solutions of iron ions and hydrogen peroxide, mimicking the oxidative Fenton chemistry of brown-rot fungi. Their results show that for acetylated and phenol-formaldehyde modified wood, hydrogen peroxide is not consumed in a solution with iron ions and modified wood after 48 hours of exposure given that the modification intensity (WPG) is high enough ([41], [42]). Moreover, controls of modified wood of adequately high WPG exposed only to the iron ion solution did not take up iron during the 48 hour experiment. The threshold WPG in both cases was consistent with the 17-20 % WPG reported for acetylated exposed in laboratory and field tests ([59], [48], [69], [10], [12], [56], [54], [37], [57], [11], [38]). For thermally modified wood, the uptake of iron ions and consumption of hydrogen peroxide was markedly reduced during the 48 hour exposure time for wood of high modification intensity ([43]), but no threshold was found. This indicates that solute transport is slowed but not hindered in thermally modified wood, since fungal agents presumably can be transported in the micro-porosity created as cell wall material is lost during modification ([49], [50]). If the pore size is sufficiently large, enzymes may even be transported into the cell walls. This is seen for pretreated wood material where the water-swollen volume in cell walls accessible to 5.1 nm probe molecules correlates linearly with hydrolysis yield ([32], [31], [80]). Perhaps the durability of thermally modified wood could be optimised further if the created micro-porosity could be tuned. This would require detailed investigations of the cell wall micro-porosity in thermally modified wood, and how processing conditions potentially affect it.


Water plays an essential role in fungal decay of wood, and limiting the cell wall moisture content by chemical modification can effectively improve the durability of the material. Investigations of the wood-water relations under climatic conditions relevant for fungal decay are, however, difficult, and thus many studies focus on the relative humidity (RH) range below 95 %. While the cell wall moisture content in the over-hygroscopic range (> 98 % RH) is underestimated by extrapolation of data obtained below 95 % RH, the relative reductions in cell wall moisture content appear similar for acetylated wood. This might not be the case for other types of modification.

Reductions in cell wall moisture content are thought to prevent fungal decay by hindering transport of fungal agents into the cell walls, presumably from a disruption of the continuous water network within cell walls otherwise found in untreated wood at high moisture contents.


EET gratefully acknowledges financial support from the VILLUM FONDEN Postdoc programme. KM and LR gratefully acknowledges financial support from European Regional Development Fund through South Savo Regional Council from Finland and industrial partners. The authors acknowledge COST Action FP1407 “Understanding wood modification through an integrated scientific and environmental impact approach (ModWoodLife)”.


Alfredsen G, Solheim H, Jenssen KM (2005). Evaluation of decay fungi in Norwegian buildings. IIn: Proceedings of the “International Research Group on Wood Protection”. Bangalore (India) 24-28 April 2005. Document IRG/WP 05-10562, IRG, Stockholm, Sweden, pp. 12.
Online | Gscholar
Alfredsen G, Flaete PO, Militz H (2013). Decay resistance of acetic anhydride modified wood: a review. International Wood Products Journal 4: 137-143.
CrossRef | Gscholar
Almeida G, Hernandez RE (2006). Changes in physical properties of yellow birch below and above the fiber saturation point. Wood and Fiber Science 38: 74-83.
CrossRef | Gscholar
Almeida G, Hernandez RE (2007). Influence of the pore structure of wood on moisture desorption at high relative humidities. Wood Material Science and Engineering 2: 33-44.
CrossRef | Gscholar
Ammer U (1963). Untersuchungen über die Sorption pilzbefallenen Holzes [Investigations of the sorption of fungally attacked wood]. Holz als Roh- und Werkstoff 21: 465-470. [in German]
CrossRef | Gscholar
Ammer U (1964). Uber den Zusammenhang zwischen Holzfeuchtigkeit und Holzzerstörung durch Pilze [On the relationship between wood moisture content and wood decay by fungi]. Holz als Roh- und Werkstoff 22: 47-51. [in German]
Anagnost SE, Smith WB (1997). Hygroscopicity of decayed wood: Implications for weight loss determinations. Wood and Fiber Science 29: 299-305.
Arantes V, Milagres AMF (2007). The synergistic action of ligninolytic enzymes (MnP and Laccase) and Fe3+-reducing activity from white-rot fungi for degradation of Azure B. Enzyme and Microbial Technology 42: 17-22.
CrossRef | Gscholar
Arantes V, Milagres AMF, Filley TR, Goodell B (2011). Lignocellulosic polysaccharides and lignin degradation by wood decay fungi: the relevance of nonenzymatic Fenton-based reactions. Journal of Industrial Microbiology and Biotechnology 38: 541-555.
CrossRef | Gscholar
Beckers EPJ, Militz H, Stevens M (1994). Resistance of acetylated wood to basidiomycetes, soft rot and blue stain. In: Proceedings of the “International Research Group on Wood Protection”. Bali (Indonesia) May 29-June 3 1994. Document IRG/WP 94-40021, IRG, Stockholm, Sweden, pp. 11.
Online | Gscholar
Brelid PL, Westin M (2007). Acetylated wood - results from long-term field tests. In: Proceedings of the “3rd European Conference on Wood Modification” (Hill CAS ed). Cardiff, Wales (UK) 15-16 Oct 2007. BioComposites Centre, Bangor, UK, pp. 71-78.
Brelid PL, Simonson R, Bergman O, Nilsson T (2000). Resistance of acetylated wood to biological degradation. Holz Als Roh-und Werkstoff 58: 331-337.
CrossRef | Gscholar
Buro A (1954). Untersuchungen über den Abbau von Kiefern: und Buchenholz durch holzzerstörende Pilze und deren Einfluß auf einige physikalische Eigenschaften des Holzes [Investigations of the decomposition of pine and beech by wood-decaying fungi and the influence on some physical wood properties]. Holz als Roh- und Werkstoff 12: 258-267. [in German]
CrossRef | Gscholar
Cardias MFC (1992). The protection of wood against fungal decay by isocyanate chemical modification. PhD thesis, University of Wales, Bangor, UK, pp. 243.
Clarke RW, Jennings DH, Coggins CR (1980). Growth of Serpula lacrimans in relation to water potential of substrate. Transactions of the British Mycological Society 75: 271-280.
CrossRef | Gscholar
Clausen CA, Glass SV (2012). Build green: wood can last for centuries. Report no. FPL-GTR-215, Forest Products Laboratory, USDA Forest Service, Madison, WI, USA, pp. 24.
Cloutier A, Fortin Y (1991). Moisture-content - water potential relationship of wood from saturated to dry conditions. Wood Science and Technology 25: 263-280.
CrossRef | Gscholar
Cragg SM, Beckham GT, Bruce NC, Bugg TDH, Distel DL, Dupree P, Etxabe AG, Goodell BS, Jellison J, McGeehan JE, McQueen-Mason SJ, Schnorr K, Walton PH, Watts JEM, Zimmer M (2015). Lignocellulose degradation mechanisms across the tree of life. Current Opinion in Chemical Biology 29: 108-119.
CrossRef | Gscholar
Daniel G, Nilsson T, Pettersson B (1989). Intracellular and extracellular localization of lignin peroxidase during the degradation of solid wood and wood fragments by Phanerochaete chrysosporium by using transmission electron-microscopy and immuno-gold labeling. Applied and Environmental Microbiology 55: 871-881.
Daniel G, Pettersson B, Nilsson T, Volc J (1990). Use of immunogold cytochemistry to detect Mn(II)-dependent and lignin peroxidases in wood degraded by the white rot fungi Phanerochaete chrysosporium and Lentinula edodes. Canadian Journal of Botany 68: 920-933.
CrossRef | Gscholar
Daniel G, Volc J, Niku-Paavola ML (2004). Cryo-FE-SEM and TEM immuno-techniques reveal new details for understanding white-rot decay of lignocellulose. Comptes Rendus Biologies 327: 861-871.
CrossRef | Gscholar
Duncan CG, Lombard FF (1965). Fungi associated with principal decays in wood products in the United States. US Department of Agriculture, Washington, DC, USA, pp. 31.
CrossRef | Gscholar
Engelund ET, Thygesen LG, Hoffmeyer P (2010). Water sorption in wood and modified wood at high values of relative humidity. Part 2: Appendix. Theoretical assessment of the amount of capillary water in wood microvoids. Holzforschung 64: 325-330.
CrossRef | Gscholar
Engelund ET, Thygesen LG, Svensson S, Hill CAS (2013). A critical discussion of the physics of wood-water interactions. Wood Science and Technology 47: 141-161.
CrossRef | Gscholar
Farahani MRM (2003). Decay resistance of modified wood. PhD thesis, University of Wales, Bangor, UK, pp. 279.
Forster S (1998). The decay resistance of chemically modified softwood. PhD thesis, University of Wales, Bangor, UK, pp. 252.
Fortin Y (1979). Moisture content-matric potential relationship and water flow properties of wood at high moisture contents. PhD thesis, University of British Columbia, Vancouver, Canada, pp. 187.
Fredriksson M, Johansson P (2016). A method for determination of absorption isotherms at high relative humidity levels: measurements on lime-silica brick and Norway spruce (Picea abies (L.) Karst.). Drying Technology 34: 132-141.
CrossRef | Gscholar
Fredriksson M, Wadsö L, Johansson P (2013). Small resistive wood moisture sensors: a method for moisture content determination in wood structures. European Journal of Wood and Wood Products 71: 515-524.
CrossRef | Gscholar
Goodell B, Jellison J, Liu J, Daniel G, Paszczynski A, Fekete F, Krishnamurthy S, Jun L, Xu G (1997). Low molecular weight chelators and phenolic compounds isolated from wood decay fungi and their role in the fungal biodegradation of wood. Journal of Biotechnology 53: 133-162.
CrossRef | Gscholar
Grethlein HE (1985). The effect of pore size distribution on the rate of enzymatic hydrolysis of cellulosic substrates. Nature Biotechnology 3: 155-160.
CrossRef | Gscholar
Grethlein HE, Allen DC, Converse AO (1984). A comparative study of the enzymatic hydrolysis of acid-pretreated white pine and mixed hardwood. Biotechnology and Bioengineering 26: 1498-1505.
CrossRef | Gscholar
Griffin DM (1977). Water potential and wood-decay fungi. Annual Review of Phytopathology 15: 319-329.
CrossRef | Gscholar
Halliwell B (2003). Free radical chemistry as related to degradative mechanisms. In: “Wood Deterioration and Preservation” (Nicholas DD, Shcultz TP, Goodell B eds). American Chemical Society, Washington, DC, USA, pp. 10-15. -
Online | Gscholar
Hastrup ACS, Jensen TO, Jensen B (2013). Detection of iron-chelating and iron-reducing compounds in four brown rot fungi. Holzforschung 67: 99-106.
CrossRef | Gscholar
Hill CAS (2006). The use of timber in the twenty-first century. In: “Wood Modification: Chemical, Thermal and Other Processes” (Hill CAS ed). John Wiley and Sons Ltd, Chichester, UK, pp. 1-18.
Hill CAS, Hale MD, Ormondroyd GA, Kwon JH, Forster SC (2006). Decay resistance of anhydride-modified Corsican pine sapwood exposed to the brown rot fungus Coniophora puteana. Holzforschung 60: 625-629.
CrossRef | Gscholar
Hill CAS, Curling SF, Kwon JH, Marty V (2009). Decay resistance of acetylated and hexanoylated hardwood and softwood species exposed to Coniophora puteana. Holzforschung 63: 619-625.
CrossRef | Gscholar
Hoffmann K (1910). Wachstumsverhältnisse einiger holzzerstörenden Pilze [Growth conditions for some wood-decaying fungi]. Zeitschrift für die gesammten Naturwissenschaften 82: 35-128. [in German]
Hori C, Gaskell J, Igarashi K, Samejima M, Hibbett D, Henrissat B, Cullen D (2013). Genomewide analysis of polysaccharides degrading enzymes in 11 white- and brown-rot Polyporales provides insight into mechanisms of wood decay. Mycologia 105: 1412-1427.
CrossRef | Gscholar
Hosseinpourpia R, Mai C (2016a). Mode of action of brown rot decay resistance in phenol-formaldehyde-modified wood: resistance to Fenton’s reagent. Holzforschung 70: 253-259.
CrossRef | Gscholar
Hosseinpourpia R, Mai C (2016b). Mode of action of brown rot decay resistance of acetylated wood: resistance to Fenton’s reagent. Wood Science and Technology 50: 413-426.
CrossRef | Gscholar
Hosseinpourpia R, Mai C (2016c). Mode of action of brown rot decay resistance of thermally modified wood: resistance to Fenton’s reagent. Holzforschung 70: 691-697.
CrossRef | Gscholar
Jakes JE, Plaza N, Stone DS, Hunt CG, Glass SV, Zelinka SL (2013). Mechanism of transport through wood cell wall polymers. Journal of Forest Products and Industries 2: 10-13.
Kamdem DP, Pizzi A, Jermannaud A (2002). Durability of heat-treated wood. Holz Als Roh-und Werkstoff 60: 1-6.
CrossRef | Gscholar
Kirk TK, Cowling EB (1984). Biological decomposition of solid wood. In: “The chemistry of solid wood” (Rowell RM ed). American Chemical Society, Washington, DC, USA, pp. 455-487. -
Online | Gscholar
Kirker G, Zelinka S, Gleber SC, Vine D, Finney L, Chen S, Hong YP, Uyarte O, Vogt S, Jellison J, Goodell B, Jakes JE (2017). Synchrotron-based X-ray fluorescence microscopy enables multiscale spatial visualization of ions involved in fungal lignocellulose deconstruction. Scientific Reports 7: 41798.
CrossRef | Gscholar
Kumar S, Agarwal SC (1983). Biological degradation resistance of wood acetylated with thioacetic acid. In: Proceedings of the “International Research Group on Wood Protection”. Surfers Paradise, QLD (Australia) 9-13 May 1983. Document IRG/WP 83-3223, IRG, Stockholm, Sweden, pp. 13.
Kymäläinen M, Havimo M, Louhelainen J (2014). Sorption properties of torrefied wood and charcoal. Wood Material Science and Engineering 9: 170-178.
CrossRef | Gscholar
Kymäläinen M, Mäkelä MR, Hildén K, Kukkonen J (2015). Fungal colonisation and moisture uptake of torrefied wood, charcoal, and thermally treated pellets during storage. European Journal of Wood and Wood Products 73: 709-717.
CrossRef | Gscholar
Lehmann KB, Scheible E (1923). Quantitative Untersuchung über Holzzerstörung durch Pilze [Quantitative investigation of wood decay by fungi]. Archiv für Hygiene 92: 89-108. [in German]
Levi M (1973). Control methods. In: “Wood deterioration and its prevention by preservative treatments” (Nicholas DD ed). Vol. 1, chap. 5. Syracuse University Press, Syracuse, NY, USA, pp. 183-216.
Mez C (1908). Der Hausschwamm und die übrigen holzzerstörenden Pilze der menschlichen Wohnungen [The dry rot fungus and the other wood-decaying fungi in human homes]. Richard Lincke, Dresden, Germany, pp. 191-192. [in German]
Mohebby B (2003). Biological attack of acetylated wood. PhD thesis, Georg-August-Universität Göttingen, Göttingen, Germany, pp. 147.
Ormondroyd GA, Alfredsen G, Prabhakaran RTD, Curling SF, Stefanowski BK, Spear MJ, Gobakken LR (2017). Assessment of the use of dynamic mechanical analysis to investigate initial onset of brown rot decay of Scots pine (Pinus sylvestris L.). International Biodeterioration and Biodegradation 120: 1-5.
CrossRef | Gscholar
Papadopoulos AN, Hill CAS (2002). The biological effectiveness of wood modified with linear chain carboxylic acid anhydrides against Coniophora puteana. Holz Als Roh-und Werkstoff 60: 329-332.
CrossRef | Gscholar
Papadopoulos AN (2006). Decay resistance in ground stake test of acetylated OSB. Holz Als Roh-und Werkstoff 64: 245-246.
CrossRef | Gscholar
Peterson CA, Cowling EB (1973). Influence of various initial moisture contents on decay of Sitka spruce and sweetgum sapwood by Polyporus versicolor in the soil-block test. Phytopathology 63: 235-237.
CrossRef | Gscholar
Peterson MD, Thomas RJ (1978). Protection of wood from decay fungi by acetylation - an ultrastructural and chemical study. Wood and Fiber Science 10: 149-163.
Riley R, Salamov AA, Brown DW, Nagy LG, Floudas D, Held BW, Levasseur A, Lombard V, Morin E, Otillar R, Lindquist EA, Sun H, LaButti KM, Schmutz J, Jabbour D, Luo H, Baker SE, Pisabarro AG, Walton JD, Blanchette RA, Henrissat B, Martin F, Cullen D, Hibbett DS, Grigoriev IV (2014). Extensive sampling of basidiomycete genomes demonstrates inadequacy of the white-rot/brown-rot paradigm for wood decay fungi. Proceedings of the National Academy of Sciences USA 111: 9923-9928.
CrossRef | Gscholar
Ringman R, Pilgård A, Brischke C, Richter K (2014a). Mode of action of brown rot decay resistance in modified wood: a review. Holzforschung 68: 239-246.
CrossRef | Gscholar
Ringman R, Pilgård A, Richter K (2014b). Effect of wood modification on gene expression during incipient Postia placenta decay. International Biodeterioration and Biodegradation 86 Part B: 86-91.
CrossRef | Gscholar
Ringman R, Pilgård A, Brischke C, Windeisen E, Richter K (2017). Incipient brown rot decay in modified wood: patterns of mass loss, structural integrity, moisture and acetyl content in high resolution. International Wood Products Journal 8: 172-182.
CrossRef | Gscholar
Schilling JS, Duncan SM, Presley GN, Filley TR, Jurgens JA, Blanchette RA (2013). Colocalizing incipient reactions in wood degraded by the brown rot fungus Postia placenta. International Biodeterioration and Biodegradation 83: 56-62.
CrossRef | Gscholar
Schmidt O (2007). Indoor wood-decay basidiomycetes: damage, causal fungi, physiology, identification and characterization, prevention and control. Mycological Progress 6: 261-279.
CrossRef | Gscholar
Schultze-Dewitz G, Lenhart K, Peschka F (1969). Das Sorptionsverhalten des Holzes verschiedener Kiefernarten und der Fichte nach Angriff durch Braunfäulepilze (Basidiomyceten) [The sorption relations of wood of different pine species and spruce after attack by brown-rot fungi (basidiomycetes)]. Holztechnologie 10: 113-118. [in German]
Srebotnik E, Messner K, Foisner R (1988). Penetrability of white rot-degraded pine wood by the lignin peroxidase of Phanerochaete chrysosporium. Applied and Environmental Microbiology 54: 2608-2614.
Online | Gscholar
Stone JE, Scallan AM (1967). Effect of component removal upon porous structure of cell wall of wood. 2. Swelling in water and fiber saturation point. Tappi 50: 496-501.
Takahashi M, Imamura Y, Tanahashi M (1989). Effect of acetylation on decay resistance of wood against brown-rot, white-rot and soft-rot fungi. In: Proceedings of the “International Research Group on Wood Protection”. Lappeenranta (Finland) 22-26 May 1989. Document IRG/WP 89-3540, IRG, Stockholm, Sweden, pp. 16.
Thybring EE (2013). The decay resistance of modified wood influenced by moisture exclusion and swelling reduction. International Biodeterioration and Biodegradation 82: 87-95.
CrossRef | Gscholar
Thybring EE (2017). Water relations in untreated and modified wood under brown-rot and white-rot decay. International Biodeterioration and Biodegradation 118: 134-142.
CrossRef | Gscholar
Thygesen LG, Engelund ET, Hoffmeyer P (2010). Water sorption in wood and modified wood at high values of relative humidity. Part I: Results for untreated, acetylated, and furfurylated Norway spruce. Holzforschung 64: 315-323.
CrossRef | Gscholar
Vaaje-Kolstad G, Westereng B, Horn SJ, Liu Z, Zhai H, Sørlie M, Eijsink VGH (2010). An oxidative enzyme boosting the enzymatic conversion of recalcitrant polysaccharides. Science 330: 219-222.
CrossRef | Gscholar
Viitanen H, Ritschkoff AC (1991). Brown rot decay in wooden constructions - effect of temperature, humidity and moisture. Swedish University of Agricultural Sciences, Uppsala, Sweden, pp. 55.
Viitanen HA (1997). Modelling the time factor in the development of brown rot decay in pine and spruce sapwood - the effect of critical humidity and temperature conditions. Holzforschung 51: 99-106.
CrossRef | Gscholar
Weigl J, Ziegler H (1960). Wasserhaushalt und Stoffleitung bei Merulius lacrymans (Wulf.) Fr [Water balance and matter transport in Merulius lacrymans (Wulf.) Fr]. Archiv für Mikrobiologie 37: 124-133. [in German]
CrossRef | Gscholar
Welzbacher CR, Rapp AO (2007). Durability of thermally modified timber from industrial-scale processes in different use classes: Results from laboratory and field tests. Wood Material Science and Engineering 2: 4-14.
CrossRef | Gscholar
Williams FC, Hale MD (2003). The resistance of wood chemically modified with isocyanates: the role of moisture content in decay suppression. International Biodeterioration and Biodegradation 52: 215-221.
CrossRef | Gscholar
Winandy JE, Morrell JJ (1993). Relationship between incipient decay, strength, and chemical-composition of Douglas-fir heartwood. Wood and Fiber Science 25: 278-288.
Online | Gscholar
Wong KKY, Deverell KF, Mackie KL, Clark TA, Donaldson LA (1988). The relationship between fiber porosity and cellulose digestibility in steam-exploded Pinus radiata. Biotechnology and Bioengineering 31: 447-456.
CrossRef | Gscholar
Xu G, Goodell B (2001). Mechanisms of wood degradation by brown-rot fungi: chelator-mediated cellulose degradation and binding of iron by cellulose. Journal of Biotechnology 87: 43-57.
CrossRef | Gscholar
Zauer M, Meissner F, Plagge R, Wagenführ A (2016). Capillary pore-size distribution and equilibrium moisture content of wood determined by means of pressure plate technique. Holzforschung 70: 137-143.
CrossRef | Gscholar
Zelinka SL, Glass SV (2010). Water vapor sorption isotherms for Southern pine treated with several waterborne preservatives. Journal of Testing and Evaluation 38: 521-525.
Zelinka SL, Glass SV, Stone DS (2008). A percolation model for electrical conduction in wood with implications for wood-water relations. Wood and Fiber Science 40: 544-552.
Online | Gscholar
Zelinka SL, Gleber SC, Vogt S, Rodríguez López GM, Jakes JE (2015). Threshold for ion movements in wood cell walls below fiber saturation observed by X-ray fluorescence microscopy (XFM). Holzforschung 69: 441-448.
CrossRef | Gscholar
Zelinka SL, Glass SV, Boardman CR, Derome D (2016a). Moisture storage and transport properties of preservative treated and untreated southern pine wood. Wood Material Science and Engineering 11: 228-238.
CrossRef | Gscholar
Zelinka SL, Ringman R, Pilgård A, Thybring EE, Jakes JE, Richter K (2016b). The role of chemical transport in the brown-rot decay resistance of modified wood. International Wood Products Journal 7: 66-70.
CrossRef | Gscholar
Zeller SM (1920). Humidity in relation to moisture imbibition by wood and to spore germination on wood. Annals of the Missouri Botanical Garden 7: 51-74.
CrossRef | Gscholar
Zhang J, Presley GN, Hammel KE, Ryu JS, Menke JR, Figueroa M, Hu D, Orr G, Schilling JS (2016). Localizing gene regulation reveals a staggered wood decay mechanism for the brown rot fungus Postia placenta. Proceedings of the National Academy of Sciences USA 113: 10968-10973.
CrossRef | Gscholar

Authors’ Affiliation

Emil Engelund Thybring
University of Copenhagen, Department of Geosciences and Natural Resource Management, Rolighedsvej 23, DK-1958 Frederiksberg C (Denmark)
Maija Kymäläinen
Lauri Rautkari
Aalto University, Department of Bioproducts and Biosystems, PO BOX 6300, F-00076 Aalto (Finland)

Corresponding author

Emil Engelund Thybring


Thybring EE, Kymäläinen M, Rautkari L (2018). Moisture in modified wood and its relevance for fungal decay. iForest 11: 418-422. - doi: 10.3832/ifor2406-011

Academic Editor

Giacomo Goli

Paper history

Received: Feb 13, 2017
Accepted: Mar 18, 2018

First online: Jun 05, 2018
Publication Date: Jun 30, 2018
Publication Time: 2.63 months

© SISEF - The Italian Society of Silviculture and Forest Ecology 2018

  Open Access

This article is distributed under the terms of the Creative Commons Attribution-Non Commercial 4.0 International (https://creativecommons.org/licenses/by-nc/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

Creative Commons Licence

Breakdown by View Type

(Waiting for server response...)

Article Usage

Total Article Views: 5886
(from publication date up to now)

Breakdown by View Type
HTML Page Views: 3759
Abstract Page Views: 224
PDF Downloads: 1696
Citation/Reference Downloads: 11
XML Downloads: 196

Web Metrics
Days since publication: 473
Overall contacts: 5886
Avg. contacts per week: 87.11

Article citations are based on data periodically collected from the Clarivate Web of Science web site
(last update: Aug 2019)

Total number of cites (since 2018): 1
Average cites per year: 0.50


Publication Metrics

by Dimensions ©

List of the papers citing this article based on CrossRef Cited-by.


iForest Similar Articles

iForest Database Search

Google Scholar Search

PubMed Search


This website uses cookies to ensure you get the best experience on our website