Bookmark and Share

More press releases

For Immediate Release, October 1, 2013


Chad Hanson, John Muir Project, (530) 273-9290
Justin Augustine, Center for Biological Diversity, (415) 436-9682 x 302

New Study: Sierra Forest Fire Severity Is Not Increasing

SAN FRANCISCO— A new scientific study finds that fire severity is not increasing in the forests of California’s Sierra Nevada. The findings are contrary to claims by those who have tried to use recent fires in the region to justify more logging in the state’s forests.

The study, by Dr. Chad Hanson of the John Muir Project, and Dr. Dennis Odion of the Earth Research Institute at University of California, Santa Barbara, was published in the International Journal of Wildland Fire. It found no trend of increasing fire severity in the Sierra Nevada management region in California over the past three decades. In fact, the study found that between 1984 and 2010, the amount of high-severity fire in the Sierra was lower than its natural level, before modern fire suppression. 

“The scientific data is telling us that we need not fear fire in our forests. Fire is doing important and beneficial ecological work, and we need more of it, including large, intense fires,” said Hanson.

The publication comes as the U.S. Forest Service begins rewriting management plans for the Inyo, Sequoia and Sierra national forests; it runs counter to the longstanding claim that Sierra fires are becoming too severe. The study is the first to include all of the available fire data for the Sierra Nevada, and recommends shifting Sierra fire management away from a focus on reducing extent or severity of fire in wildlands, and to instead focus on protecting human communities from fire.

“For years now, claims about excessive high-severity fire have been used to try to justify unnecessary logging in California,” said Justin Augustine with the Center for Biological Diversity. “This new study is part of a growing body of scientific literature showing that what we actually need, ecologically speaking, is more fire on the landscape as well as an increased emphasis on making homes and buildings more fire safe.”

High-severity fire is a natural component of Sierra Nevada forests. The “snag forest” habitat created by these fires supports levels of biodiversity and wildlife abundance that are equal to, or higher than, old-growth forests. Currently snag forests are extremely rare in the Sierra Nevada, and even when they do occur, they are often destroyed by salvage logging.

Wildlife species that depend on snag forests, such as the black-backed woodpecker, are harmed by insufficient amounts and intensities of fire, as well as by post-fire logging. The Center for Biological Diversity and John Muir Project have submitted a scientific petition to protect black-backed woodpeckers under the Endangered Species Act. In responses the U.S. Fish and Wildlife Service agreed to initiate a status review for protecting the black-backed woodpecker.

The new paper can be found at the website for the International Journal of Wildland Fire; the abstract follows.

Research in the Sierra Nevada range of California, U.S.A., has provided conflicting results about current trends of high-severity fire. Previous studies have used only a portion of available fire severity data, or considered only a portion of the Sierra Nevada. Our goal was to investigate whether a trend in fire severity is occurring in Sierra Nevada conifer forests currently, using satellite imagery. We analyzed all available fire-severity data, 1984–2010, over the whole ecoregion and found no trend in proportion, area or patch size of high-severity fire. The rate of high-severity fire has been lower since 1984 than the estimated historical rate. Responses of fire behavior to climate change and fire suppression may be more complex than assumed. A better understanding of spatiotemporal patterns in fire regimes is needed to predict future fire regimes and their biological effects. Mechanisms underlying the lack of an expected climate- and time since fire-related trend in high-severity fire need to be identified to help calibrate projections of future fire. The effects of climate change on high-severity fire extent may remain small compared with fire suppression. Management could shift from a focus on reducing extent or severity of fire in wildlands to protecting human communities from fire.

The Center for Biological Diversity is a national, nonprofit conservation organization with more than 625,000 members and online activists dedicated to the protection of endangered species and wild places.

Go back