Protection of wood against fungal degradation is crucial for its outdoor application. As traditional biocide-based protections systems are being banned, inspiration for environmentally friendly solutions may be found in tree species that form durable heartwood, such as Larix spp.
It is known that antifungal agents have a bigger impact if they cover several attack mechanisms of the fungus (Schultz and Nicholas, 2002). Most investigations focussed on the acetone- or water-soluble extractives; their distribution, effects on water sorption and resistance to degradation (i.e. Gierlinger et al, 2004, Venäläinen et al, 2006, Zule et al, 2015 and 2017, Skjövist et al, 2018, Nisula, 2018). The role of hydrophobic extractives, alone or together with hydrophilic extractives has not received much attention.
Identity and quantity of hydrophobic and hydrophilic extractives in Kurian larch and Norway spruce were assessed. The effects of removal of mainly hydrophobic and/or hydrophilic extractives on degradation by the brown rot Rhodonia placenta were tested. Additionally, the sorption isotherm of Kurian larch was determined for native and extracted specimens.
Keywords: fungal degradation, extractives, degradation resistance
Authors
Sophie Füchtner
University of Copenhagen (KU), Copenhagen, Denmark
Theis Brock-Nannestad
Annika Smeds
Maria Fredriksson
Annica Pilgård
Lisbeth G. Thygesen
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