We propose to synthesize recent literature supporting management that restores the role of fire to fire-adapted forests in the western United States. The synthesis will address common misconceptions about forest restoration and fuel reduction treatments as well as confusion in the literature around evidence for departures in current fire behavior and associated changes in spatial patterns of forest composition and structure. In a set of two peer-reviewed articles, we will summarize science-based recommendations and on-going research needs for restoring structures and spatial patterns that demonstrated resistance and resilience to warmer climate, fire and other agents of change. In our first

paper, we will present a concise and balanced review of the literature on fuel treatments, science-based ecological forestry principles, and approaches to dry forest restoration. Skepticism about the advisability of active management, particularly mechanical thinning, often impedes efforts to accelerate the pace and scale of restoration projects to support fire and climate-resilient landscapes under the National Cohesive Wildland Fire Management Strategy. Our main objective for the paper is to provide a synthesis of the multiple lines of evidence supporting management that restores the role of fire and resiliency to frequent-fire ecosystems in the western United States. In addition to being a useful tool for managers, this synthesis will be accessibly written for journalists, policy makers, or others seeking a balanced summary of the existing literature. Misconceptions to be addressed by a synthesis of empirical studies of fuel reductions (e.g., reintroduced wildfire, managed wildfire, prescribed fire, and mechanical fuel reductions) include:

• “Wildfires alone can do the work of fuel treatments”
• “Forest thinning alone will mitigate wildfire severity”
• “The scale of the fuel treatments needed is too great – we’ll never catch up”
• “Fuel treatments don’t work under extreme fire weather”
• “High severity, large fires are no more common today than historical records”
• “Fuel reduction treatments may contribute to the wildfire deficit by assisting in fire suppression operations”

Our second paper will synthesize the literature rebutting the relatively small but often-cited set of papers that assert active forest and fuels management are not necessary because (1) there is little evidence for departure in forest structure and landscape patterns of vegetation across fire-excluded ecosystems in the western US and (2) recent large, high severity fires are within the historical distribution of mixed-severity fire regimes. Methods and conclusions supporting these two assertions have been repeatedly rebutted by experts in the fields of fire ecology and management. Project deliverables will include two peer-reviewed publications, a summary white paper for CALFIRE, and an in-person workshop in Sacramento to present our findings to CALFIRE managers.

Hessburg, P. F., Prichard, S. J., Hagmann, R. K., Povak, N. A., & Lake, F. K. (2021). Wildfire and climate change adaptation of western North American forests: a case for intentional management. Ecological applications, 31(8), e02432.

Hagmann, R. K., Hessburg, P. F., Prichard, S. J., Povak, N. A., Brown, P. M., Fulé, P. Z., ... & Waltz, A. E. M. (2021). Evidence for widespread changes in the structure, composition, and fire regimes of western North American forests. Ecological Applications. 31 (8): 24-., 31(8), 1-34.

Prichard, S. J., Hessburg, P. F., Hagmann, R. K., Povak, N. A., Dobrowski, S. Z., Hurteau, M. D., ... & Kolden, C. A. (2021). Adapting western North American forests to climate change and wildfires: 10 common questions. Ecol. Appl, 31(8).