New, NW CASC-Supported Study Explores Relationships Between Future Fire Size and Patterns of Burn Severity to Understand Ecological Effects for the Region
by University of Washington, Northwest Climate Adaptation Science Center
June 28, 2024
In the western United States, warmer and drier conditions have contributed to increases in large wildfire events in recent decades, a trend that’s expected to continue as the climate changes. A new, NW CASC-supported study led by Research Fellowship alum Michele Buonanduci, with University of Washington Associate Professor Brian Harvey and colleagues, describes an approach for anticipating the relationships between future fire sizes and burn severity patterns on a regional scale. The findings from this study can help scientists and managers better anticipate the ecological effects of future fire and plan management responses that promote fire-adapted landscapes.
Within individual wildfires, there is typically a range of burn severity. Areas of low- or moderate-severity fire burn less intensely and often leave behind surviving vegetation, while areas of high-severity fire burn more intensely and kill most or all the vegetation in an area.
The amount of forest experiencing high-severity fire is often strongly tied to the size of a given fire. Larger wildfires tend to contain bigger patches of high-severity fire, which leave behind burned areas that may be too far away from living trees for effective seed dispersal after fire. Because of this, larger wildfires tend to have a greater impact on forest structure than smaller wildfires, in which the patches of severely burned forest are smaller and closer to live seed sources, making forest recovery more rapid or likely.
These relationships between fire size and expected patterns of burn severity — referred to as spatial scaling relationships — prompt the question of how, at a regional scale, burn severity patterns will change as fire sizes shift under climate change. To answer this question, NW CASC-supported researchers set out to quantify the potential range of burn severity patterns that might be expected in a region, depending on the distribution of sizes of future fire events.
Read the Ecosphere paper: https://esajournals.onlinelibrary.wiley.com/doi/10.1002/ecs2.4875