The damage of wood by fungi is essentially caused by the degradation of the cell wall by fungi, which decreases the mechanical wood properties and substantially reduces wood use. However, wood quality is also influenced by bacterial, algal and fungal discolorations (e.g., Grosser 1985; Zabel and Morrell 1992; Eaton and Hale 1993). Discolorations in the wood of living trees, in round wood, timber and wood in service are long-known problems and are based on different biotic and abiotic causes (Bauch 1984, 1986; Kreber and Byrne 1994; Koch et al. 2002; Koch 2004; ). Discolorations in standing trees occur after wounding by wound reactions of the tree and by the colonization of the stemwood with bacteria and fungi as a result of microorganism-own pigments (e.g., melanin of blue-stain fungi, Zink and Fengel 1989) or of their metabolism (brown, white, and soft rot in trees, chemical reactions of accessory compounds after pH-change by wetwood bacteria and in the splash-heart of be
All about Ecology