Good wildfires in western U.S. forests (2010-2020)

Abstract

Western U.S. forests have evolved with fire. However, recent wildfire disasters have understandably focused on the tragic consequences in the moment, lives lost and homes destroyed, rather than the longer-term ecosystem benefits. Some of the positive outcomes, particularly from low-moderate severity wildfires, are to reduce fuels and promote regeneration, even in the context of warmer temperatures (1). Here, we estimated the amount of "good wildfire" that burns in an ecologically beneficial way in forests, with a severity and return interval analogous to the historical fire regime. Of western U.S. forest wildfires (2010-2020), 58% burned as good wildfire (49% and 9% burned matching the low-moderate and high severity regimes, respectively). The low-moderate severity good wildfires burned 3.1 million forest ha (N = 18,061 events), more than double the 1.4 million ha of prescribed burning (N = 24,817 events on federal land) over the same period. At the event level, 56% of wildfires (N = 3479; >10% forest cover) had over half of their area burned as good wildfire--highlighting the opportunity that each fire presents for suppression teams to cultivate more beneficial wildfire in western landscapes. Good wildfires are an underrecognized but important tool to mitigate the risk of future wildfire disasters. With fires likely to increase in frequency and area with warming (2), the coming decade provides an essential opportunity to promote good wildfire for ecosystems, people, and property.