In the wake of a devastating wildfire, burnt land has a respite before the next blaze. But until now, no one has known just how long that effect lasted across the US West. Researchers from the University of Colorado Denver and Portland State looked into the increasing rates and intensity of fires in the U.S. West, like Colorado’s Hayman Fire and California’s Camp Fire, are up tenfold over the last 40 years. They wanted to know, once the shrubs, trees and other woody fuels have burned up, how long before the next one?
“We generally get about 10 to 15 years of ‘protection’ post burn, meaning a lower probability of reburning—not a long time,” says Brian Buma, PhD, assistant professor in the Department of Integrative Biology at CU Denver. His work with CU Denver grad student Katherine Hayes, as well as Melissa Lucash, PhD, and Shelby Weiss of Portland State, found that the reburn effect is shorter in California and longer in the Rockies.
The study is published in the journal Environmental Research Letters.
Wetter locales see more wildfires
Reburning is incredibly impactful ecologically and can rapidly eliminate forests for the long term, as forest systems aren’t generally resilient to high rates of high intensity fire. Logically, it seems like the increase in fires would eventually self-regulate; that an increase in fire rates could limit future fire occurrence—called a “negative feedback.” Buma and his team found that this negative feedback and downtime between fires depended on climate, drought conditions, and the ecosystem type/fuel (read: trees, shrubs, grass).
Read more at University of Colorado Denver
Image Credit: University of Colorado Denver