Durability of Heat-Treated Eucalyptus Wood Against Decay Fungi

Abstract

Eucalyptus hybrids exhibit rapid growth, and their wood is widely used in construction, furniture production, reconstituted panels, energy, pulp, and paper manufacturing. However, they are commonly affected by decay fungi, which reduce their durability, jeopardizing the integrity of structures and the safety of individuals. Therefore, this study aimed to evaluate the effects of thermal treatment on the biological resistance of 14-year-old hybrid Eucalyptus clone wood. Chemical analyses were conducted on the wood (lignin and holocellulose), and tests with brown rot fungi (Gloeophyllum trabeum and Rhodonia placenta) and white rot fungi (Irpex lacteus) were performed over 12 weeks, along with colorimetric variable assessments. It was concluded that brown rot fungi caused more severe damage to the wood, also influencing its coloration. Under the conditions studied, a temperature of 200 °C promoted wood deterioration of the clones by xylophagous fungi. Regarding resistance classes, the clones were classified as highly resistant (A, C, and E) to the fungus I. lacteus, regardless of heat treatment. For the fungi G. trabeum and R. placenta, the clones detected as highly resistant (A and C) were those exposed to a temperature of 185 °C.