Landscape fuel treatments and wildland fire management strategies within recent large fire events of north-central Washington State.
Over the past two decades, large wildfires have burned the majority of forested area in north-central Washington State. The 2014 and 2015 fire seasons were particularly large regional fire years, with multiple fires burning simultaneously under similar weather conditions. These fire seasons provided the opportunity to examine multi-scale drivers of fire severity within and across fires, including climatic and weather controls and bottom-up factors such as topography, vegetation, and fuels. Fuel reduction treatments represent a minor fraction of the study area but are significant factors in mitigating fire severity. Compared with first-entry fires, reburned areas exhibited a greater influence from vegetation, fuels and topography than fire weather. Although wind-driven progressions were associated with larger areas of high severity, bottom-up drivers were still influential within these burn progressions. Lessons from recent wildfires in north-central Washington State underscore the importance of understanding drivers of fire severity within reburn events. With rapid climate change and the increasing reality of large wildfire events, repeat fire events are the future for many fire-prone western forests and will strongly shape trajectories of vegetation change.