Wildfire Ecology

I’ve been interested in natural vegetation response to wildfire for more than 40 years. Most of my work involves the desert shrublands and woodlands of western North America. From the beginning of my studies, I saw that Asian weeds brought by European sheep and cattle herders had heavily infested native vegetation. It soon became clear that added fuel provided by the weeds was allowing fires to increase in size and number. During the past century and a half, the weeds have replaced vast areas of native shrublands and woodlands that could not contend with the increasing wildfires.

Fire-prone invasive plants fueled fires that converted this formerly diverse Sonoran Desert landscape of small trees and tall Saguaro cactus into an impoverished shrubland.

This is one of the study sites that Jeff Steele and I established in 1974. Two fires (1974 and 1985), converted this formerly diverse Sonoran Desert landscape of small trees and tall Saguaro cactus into an impoverished shrubland.

Humans with their weeds and livestock led the first devastating wave of wildfire across the arid and semi-arid lands of the world. The next wave will come from human-caused global warming.

The following is from Global Warming Forecasts

[Click this link for my review of the Forecasts. Below, I’ve include 2050 as an example of the forecasts.]

2050 Wildfires

“2050. Forest wildfire burn area in the U.S. is projected to increase by over 50% and as much as 175% in some areas by 2050. “The area of forest burnt by wildfires in the United States is set to increase by over 50% by 2050, according to research by climate scientists. The study [Impacts of climate change from 2000 to 2050 on wildfire activity and carbonaceous aerosol concentrations in the western United States], predicts that the worst affected areas will be the forests in the Pacific Northwest and the Rocky Mountains, where the area of forest destroyed by wildfire is predicted to increase by 78% and 175% respectively.

“The research is based on a conservative temperature increase of 1.6 degrees Celsius over the next 40 years [2010-2050]. Published in the Journal of Geophysical Research, scientists also say that the increase in wildfires will lead to significant deterioration of the air quality in the western United States due to greater presence of smoke. . . . This work was funded by the U.S. Environmental Protection Agency (EPA) and National Aeronautics and Space Administration. Dr. Dominick Spracklen carried out the research whilst at Harvard’s School of Engineering and Applied Sciences (SEAS) in collaboration with Jennifer Logan and Loretta Mickley.” (NASA press release, “Wildfires Set to Increase 50 Percent by 2050,” NASA Earth Observatory, Twitter NASA EO, Greenbelt, Maryland, July 28, 2009 reporting findings in D.V. Spracklen, L.J. Mickley, J.A. Logan, R.C. Hudman, R. Yevich, M.C. Flannigan, and A.L. Westerlin, “Impacts of climate change from 2000 to 2050 on wildfire activity and carbonaceous aerosol concentrations in the western United States,” Journal of Geophysical Research, Vol. 114, D20301, doi:10.1029/2008JD010966, published October 20, 2009.” —Global Warming Forecasts.