The effect of brown-rot decay on water adsorption and chemical composition of Scots pine heartwood

Abstract

-• The effect of brown-rot (Coniophora puteana) decay on the water adsorption capacity and concentration of extractives of Scots pine (Pinus sylvestris L.) heartwood were studied by comparing corresponding properties of decayed and undecayed wood samples.• The samples derived from 39 felled trees having a large between-tree variation in the extractive concentrations, and subsequently in the mass loss in the decay test. The water adsorption capacity, expressed as equilibrium moisture content (EMC), was measured at a high relative humidity (RH ∼100%, 21• C).• In contrast to the widely held belief, the water adsorption capacity of brow-rotted heartwood appeared to be significantly higher than that of undecayed heartwood.• The chemical composition of heartwood was changed radically by the fungus: the concentration of stilbenes, resin acids and free fatty acids decreased, while the concentration of soluble sugars increased as a result of decay. In addition, fungal sugars were found in the decayed samples. The concentration of total phenolics increased, which obviously reflected chemical changes in cell wall constituents other than extractives.• As a conclusion, the information concerning the hygroscopicity of brown-rotted wood might be valuable e.g. when carrying out repairs on buildings damaged by advanced decay.brown-rot decay / extractives / Scots pine heartwood / mass loss / moisture content Résumé -Effet des pourritures brunes sur l'adsorption de l'eau et la composition chimique du bois de Coeur du pin sylvestre.• Nous avons étudié l'effet de la présence de pourriture brune (Coniophora puteana) sur la capacité d'adsorption de l'eau et sur la concentration d'extractibles du bois de coeur du pin sylvestre (Pinus sylvestris L.) en comparant des échantillons contaminés et sains obtenus pour 39 arbres échantillonnés.• Dans les essais de décomposition, on obtient une grande variation entre arbres de la concentration en extractibles et de la perte de masse. La capacité d'adsorption de l'eau, exprimée comme l'humidité d'équilibre, a été mesurée à une humidité relative de 100 % à 21• C.• Contrairement à ce qui était attendu, la décomposition augmente la capacité d'adsorption de l'eau du bois de coeur en atmosphère très humide. La différence entre arbres des variations de l'humidité d'équilibre (décomposé-contrôle) augmente significativement avec l'augmentation de la perte de masse.• La composition chimique du bois de coeur est radicalement modifiée par le champignon : la concentration de stilbènes, de résines acides et d'acides gras libres décroît tandis que la concentration de sucres solubles augmente, cela résultant de la décomposition. La concentration de composés phéno-liques totaux, mesurée par le test de décomposition de Folin-Ciocalteu, augmente. De plus des sucres fongiques dérivant des hyphes de C. puteana ont été retrouvés dans les échantillons décomposés.• En conclusion, les informations concernant l'hygroscopicité du bois brun pourraient être utiles par exemple au moment de procéder à la réparation d...

Log moisture capacity does not predict epixylic bryophyte growth under thinned and unthinned forest canopies

“…Wood decomposition may be nutritionally beneficial to mosses; compared to soil or undecayed wood, rotting wood often has greater availability of sugars (Karppanen et al . ), base cations (Gruba & Zwydak ), nitrogen (Fukasawa, Osono & Takeda ), and phosphorus (Wiklund ), all of which can increase the growth of some moss species at observed concentrations (Sargent ; Wiklund ; Duckett et al . ).…”

“…Several mechanisms have been proposed to explain the association of moss diversity with rotting CWD. Wood decomposition may be nutritionally beneficial to mosses; compared to soil or undecayed wood, rotting wood often has greater availability of sugars (Karppanen et al 2008), base cations (Gruba & Zwydak 2010), nitrogen (Fukasawa, Osono & Takeda 2009), and phosphorus (Wiklund 2003), all of which can increase the growth of some moss species at observed concentrations (Sargent 1988;Wiklund 2003;Duckett et al 2004). Others have speculated that CWD may act as a moisture capacitor (sensu Proctor & Tuba 2002), by absorbing water during precipitation events, and slowly releasing it during dry periods, thereby extending the duration of humid conditions and increasing the growth of species living on the surface (S€ oderstr€ om 1988a; Rambo & Muir 1998;Jansov a & Sold an 2006;Botting & DeLong 2009).…”

“…However, increased decay and porosity may not always result in greater moisture capacity. Compared to sapwood, decayed heartwood of Pinus sylvestris L. absorbs more water under high humidity, but less under moderate humidity (Karppanen et al 2008). Moisture exchange processes may also be accentuated or interrupted by log surface coverings, such as mosses, litter, fine woody debris, the presence of vascular plant roots, and bark (Dynesius, Astr€ om & Nilsson 2008;Dynesius, Gibb & Hj€ alt en 2010;Pichlerov a & Homol ak 2013), as well as by simple vertical stratification from differential exposure to evaporative stresses (Pichler et al 2012).…”

Modificaciones anatómicas y químicas en el leño de ejemplares del arbolado de la ciudad de La Plata (Buenos Aires) causadas por Laetiporus sulphureus (Basidiomycota, Polyporales).

“…Los hongos responsables de pudrición castaña como L. sulphureus degradan holocelulosa; la lignina sólo es parcialmente oxidada (Blanchette, 1995;Schwarze, 2007). La intensa despolimerización de la celulosa y de las hemicelulosas determina en la madera degradada aumentos relativos en los porcentajes de lignina y extraíbles, estos últimos también influenciados por los carbohidratos fúngicos (Kirk & Highley, 1973;Pandey & Pitman, 2003;Karppanen et al, 2008). Los hongos causantes de pudrición castaña despolimerizan selectivamente la holocelulosa rápidamente desde los estadios iniciales del proceso a velocidad mayor a la que los productos resultantes de su degradación pueden ser metabolizados (Zabel & Morrell, 1992;Schmidt, 2006).…”

Profiling of water-soluble carbohydrates in pine and spruce extracts by capillary zone electrophoresis with direct UV detection

“…Novelty is also presented regarding commercially available equipment by showing the advantages of interpreting the recorded migration times and the correlation of multiple wavelengths in identifying compounds. Stilbenes, pinocembrin (Willför et al 2003b), total phenolics (Willför et al 2003a;Venäläinen et al 2004;Harju et al 2003;Hovelstad et al 2006;Kähkönen et al 1999), total pinosylvins (Venäläinen et al 2004;Hovelstad et al 2006;Lindberg et al 2004;Pietarinen et al 2006), pinosylvin, PMME, PDME3 (Karppanen et al 2008;Valentín et al 2010), lignans (Willför et al 2003a;Pietarinen et al 2006), oligolignans, 3,4-dihydroxybenzoic acid, catechin, vanillic acid (Valentín et al 2010) Bark Total phenolics (Kähkönen et al 1999;Stolter et al 2009;Kanerva et al 2008), apigenin-7-glucoside, catechin, catechin derivative, gallocatechin, dicoumarylastragalin, quercitrin, dicoumarylisoquercitrin derivatives (Stolter et al 2009;Roitto et al 2008), mono-coumaroylisoquercitrin derivatives, quercetin-3-galactoside, kempferol-3-glucoside, taxifolinmonoglycoside (Stolter et al 2009), benzoic acid glycoside (Stolter et al 2009;Kanerva et al 2008;Roitto et al 2008), condensed tannins, myricetin-3-galactoside, hyperin, neolignans (Roitto et al 2008) Needles and twigs Taxifolin, taxifolin-3 0 -glucoside, quercetin, quercetin-3-glucoside, quercetin-3 0 -glucoside (Oleszek et al 2002), total phenolics (Willför et al 2003a;Malá et al 2011Zeneli et al 2006, astringin (Hammerbacher et al 2011;Zeneli et al 2006), isorhapontin, piceid (polydatin), catechin (Zeneli et al 2006), lignans …”