Scientists conducted a study using fire history atlases, fire progression maps, and weather station data to quantify the ability of wildfire to act as a fuel break. The results of this study provide an improved understanding of feedbacks between previous and subsequent wildfire under varying weather conditions and will be useful to fire managers who seek to restore natural fire regimes or to exploit recent burns when managing fire.
Scientists with the Aldo Leopold Wilderness Research Institute quantified the ability of wildfire to limit the spread of subsequent fires and essentially, act as a fuel break. They also evaluated the influence of daily weather in diminishing this effect. The scientists found that wildfires act as fuel breaks in all of four study areas they evaluated, but this effect decays over time. Wildfires no longer act as fuel breaks after six years in the southwestern United States and after approximately 16 years in the central and northern Rocky Mountains. They also found that the ability of fire to act as a fuel break was substantially reduced under extreme compared to moderate weather conditions in all four study areas.
These results provide an improved understanding of the relationship between previous and subsequent wildfire under varying weather conditions, and as such, will help fire managers evaluate whether a previous wildfire will act as a fuel break based on its age, ecosystem type, and expected weather. With knowledge of the conditions under which fire spread is limited by previous wildfire, managers can more confidently and flexibly manage fire in a manner in which resilient landscapes can be better realized.