A fire regime is often described as the frequency and severity of wildfires in a given area or ecosystem. Forest managers and policy makers are increasingly interested in knowing how these fire regime characteristics (fire frequency and severity) will change under a future climate. Although many studies have focused on how fire activity is expected to change under future climate scenarios, there have been little to no studies on how fire severity is expected to change. Most efforts to map fire regimes have been qualitative, making it difficult to determine the climatic factors driving fire regimes.
To better under understand how fire severity will change in the future, a necessary first step is to better understand the climatic drivers of contemporary fire severity patterns.
In a recent study, Aldo Leopold Wilderness Research Institute scientists quantified relationships between climatic variables and both fire activity and severity. These quantitative relationships are being used to map current fire regimes in the western United States and to map the distribution of fire regimes under a future climate. The scientists relied heavily on climate and fire data from wilderness areas and national parks in the western US, where anthropogenic influences, such as forest management, are minimal relative to unprotected lands.
An unexpected finding of this study was that the relationships between climate and fire weakened as the human footprint increased. This study provides insight into the “natural” relationships between climate and fire and now allows researchers to identify areas with disrupted fire regimes that may be in need of restoration.