Degradation of thermo-hygro-mechanically (THM)-densified wood by soft-rot fungi

摘要: Thermo-hygro-mechanical (THM)-densified wood is more resistant to colonisation and degradation by brown-rot fungi than untreated wood. Colonisation soft-rot was investigated in treated Norway spruce (Picea abies) beech (Fagus sylvatica) assess their suitability for utility class 4. Three different treatments were applied: thermal-hygro (TH) treatment, mechanical densification THM-treatment including post-treatment under saturated steam conditions at temperatures. For comparison, additional specimens with two concentrations of a chromium-copper (CC) preservative. After 32 weeks incubation, weight losses induced lowest CC. Highest recorded from TH-treated wood, which erosion attack (type 2) exclusively observed spruce. In comparison controls, significantly lower THM-treated but no such differences found Microscopical examination showed that spruce, type 1 commenced the outer surfaces cavity formation not deeper regions samples. susceptible can be partly explained higher syringyl lignin content all kinds degradation. Hyphal facilitated within mainly non-occluded lumina parenchyma cells multiseriate xylem rays. It concluded THtreated therefore inappropriate