Download (PDF 1.21 MB): https://research.fs.usda.gov/download/treesearch/69629.pdf
Abstract
When smoke from a prescribed fire pops up on an otherwise clear day, people may question the rationale behind the haze. After all, smoke from wildland fires can be a major health hazard due to fine particulates (PM2.5) and gaseous pollutants. At the same time, prescribed fires are one of our best tools to reduce hazardous fuels and restore fire-prone forests and grasslands. In recent years, land managers have been asked to expand the use of prescribed fire, but smoke is consistently cited as a barrier. New research by USDA Forest Service scientists sheds light on one key smoke challenge - long-term smoldering of decomposed organic matter, also known as duff.
Citation
Leirfallom, Signe; Urbanski, Shawn. 2025. Clearing the air: The truth about smoldering duff. Science You Can Use (in 5 Minutes), September 2025. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 2 p.
