Encountering Prescribed Fire: Characterizing the Intersection of Prescribed Fire and Wildfire in the CONUS.

Abstract

Prescribed fire is applied across the United States as a fuel treatment to manage the impact of wildfires and restore ecosystems. While the recent application of prescribed fire has largely been confined to the southeastern US, the increase in catastrophic wildfires has accelerated the growth of prescribed fire more broadly. To effectively achieve wildfire risk reduction benefits, which includes reducing the amount of smoke emitted, the area treated by prescribed fire must come into contact with a subsequent wildfire. In this study, we applied timely and consistent geospatially resolved data sets of prescribed fires and wildfires to estimate the rate at which an area treated by prescribed fire encounters a subsequent wildfire. We summarize these encounter rates across time intervals, prescribed fire treatment area, and number of previous prescribed fires and by region. On all U.S. Forest Service lands across the Conterminous US (CONUS) 6.2% of prescribed fire treated area from 2003-2022 encountered a subsequent wildfire in 2004-2023. Encounter rates were highest in western US forests, which tend to be more impacted by wildfire than the eastern US, and lower in the eastern US. Encounter rates increased with treatment area in the southeastern US but were relatively flat in the northwest. For the CONUS, encounter rates increased with longer time intervals, associated with diminished potential for reducing wildfire severity, between prescribed fire and the subsequent wildfire area burned. Our results provide timely information on prescribed fire and wildfire interactions that can be leveraged to optimize analyses of the trade-offs between prescribed fire and wildfire.