Dennison, Philip E., Brewer, Simon C., Arnold, James D., Moritz, Max A.

Geophysical Research Letters

Published date April 4, 2014

Large wildfire trends in the western United States, 1984–2011

  • Uses a database capturing large wildfires (> 405 ha) in the western U.S. to document regional trends in fire occurrence, total fire area, fire size, and day of year of ignition for 1984–2011
  • Finds a significant, increasing trends in the number of large fires and/or total large fire area per year, over the western U.S. and in a majority of ecoregions
  • Finds that trends were most significant for southern and mountain ecoregions, coinciding with trends toward increased drought severity
  • Finds that for all ecoregions combined, the number of large fires increased at a rate of seven fires per year, while total fire area increased at a rate of 355 km2 per year
  • States that continuing changes in climate, invasive species, and consequences of past fire management, added to the impacts of larger, more frequent fires, will drive further disruptions to fire regimes of the western U.S. and other fire-prone regions of the world