Mulch Fuels in Boreal Forests - Structure Moisture and Initial Fire Behaviour Observations

This extension note examines mechanical mastication, a forest management technique used to reduce wildfire risk by shredding ladder fuels into a compacted surface mulch. By converting vertical vegetation into a ground-level fuel bed, the process significantly alters moisture dynamics, as the exposed top layer dries rapidly under sun and wind while deeper layers remain damp and oxygen-deprived. Thos document highlights that while mulched debris shares similar ignition thresholds with other forest materials, its unique structure requires specialized moisture prediction models like MAST to accurately assess fire behavior. This document suggests that maintaining larger particle sizes within the mulch can slow combustion and enhance soil health, providing vital data for practitioners to better manage boreal forest fuel complexes.