Mixed-conifer forests throughout the interior northwest, and the ecosystem services they provide, are vulnerable to severe fires and loss of post-fire resilience from nearly a century of fire exclusion

This $636,200 Cooperative Agreement award from the U.S. Department of the Interior's Bureau of Land Management, through the Joint Fire Science Program (CFDA 15.232), will support research to address knowledge gaps about the effective duration and impacts of fuel reduction treatments (mechanical thinning, prescribed fire) in mixed-conifer forests across the interior Pacific Northwest. The project will leverage existing data from the Fire and Fire Surrogates study that was burned in subsequent wildfires to analyze: (1) the effective duration of fuel treatments and their effects on fuel loads and predicted fire behavior, (2) the impact of fuel treatments on resistance to subsequent fire (e.g., burn severity, tree mortality), and (3) the impact of fuel treatments on post-fire resilience (e.g., tree regeneration, fuel loads). This research will provide critical insights to public and private land managers seeking to increase the pace and scale of forest restoration treatments to address altered fire regimes and high fire risk across millions of hectares in the region.

Public and private land managers need to increase the pace and scale of restoration treatments region wide, but key knowledge gaps remain about the effective duration of fuel-reduction treatments (mechanical thinning, prescribed fire) for reducing fire potential and increasing post-fire recovery. This project will leverage existing data on fuels treatments from the fire and fire surrogates (FFS) study that were burned in a subsequent wildfire to fill the above research gaps, asking: (Q1) what is the effective duration of FFS treatments and their effects on fuel loads and predicted fire behavior (Q2) do FFS treatments affect resistance to subsequent fire (e.g., burn severity or fire-caused tree mortality) (Q3) do FFS treatments affect resilience following subsequent wildfire (e.g., post-fire tree regeneration and post-fire fuel loads) analyses will be conducted across scales from individual trees to stands within treatment units. Insight will have particularly high relevance for dry forests affected by altered fire regimes and high fire risk across millions of hectares across the state of washington and the interior pacific northwest.