Processing and End-Uses of Wood Affected by Forest Fires, Eastern Spruce Budworm and Mountain Pine Beetle Outbreaks.

Abstract

Purpose of review: This review provides an overview of current forest fires and insect outbreaks in North America, examining how these disturbances affect wood quality over time. It highlights two of the most destructive insect pests: the eastern spruce budworm (SBW) and the mountain pine beetle (MPB). The article also examines the challenges of processing disturbance-affected wood and explores its potential uses in lumber, engineered wood products, and wood-based panels.

Recent findings: Forest fires have intensified and become more frequent in recent years, especially in temperate and boreal forests. Unprecedented SBW outbreaks have also been reported in Eastern Canada. While MPB outbreaks have decreased since 2019, they remain cyclical, indicating the possibility of future resurgences. From 2023 to 2025, these disturbances affected over 60 million hectares in Canada, resulting in significant tree damage and mortality. Although disturbance-affected wood can still be used for lumber and high-value products, its quality deteriorates over time while it remains in the forest, particularly after a fire. Manufacturing products from such wood is difficult due to its low moisture content, changed properties, and high defect rate.

Summary: Disturbance-affected wood typically has lower moisture content, increased permeability, greater brittleness, and a higher incidence of defects, such as insect holes, blue stain, decay, and checks, compared to wood from sound trees. These characteristics can negatively impact lumber recovery and grading and reduce its suitability for secondary manufacturing of wood products like laminated veneer lumber, plywood, or oriented strand board. Nonetheless, this type of wood can be transformed into value-added products such as particleboard, fiberboard, or cross-laminated timber, especially when used in limited proportions or in hybrid compositions. Further research is needed to understand how the properties of disturbance-affected wood change over time and how these changes affect the production of various products. Furthermore, optimizing log sorting, conversion processes, and manufacturing techniques to account for the unique characteristics of disturbance-affected wood is important to ensure the quality and performance of the final products.