WILDFIRESScientists Dig into Wildfire Predictions, Long-Term Impacts

Wildfires are an ancient force shaping the environment, but they have grown in frequency, range and intensity in response to a changing climate. At the Department of Energy’s Oak Ridge National Laboratory, scientists are working on several fronts to better understand and predict these events and what they mean for the carbon cycle and biodiversity.

Two months into the 2023 peak summer fire season from June through August, Canadian wildfires had burned more than 25 million acres, disrupted the lives of millions and spread beyond the traditional confines of western Canada east to Nova Scotia. The phenomenon attracted renewed attention as smoke drifted to heavily populated regions, turning the New York City skyline orange and drifting across the Atlantic Ocean to Europe by late June.

Understanding the many risks and impacts of wildfires is at the heart of several projects at ORNL. Henriette “Yetta” Jager, an ORNL scientist whose research sits at the intersection of energy and ecology, has studied how selective forest thinning can both remove fuel for wildfires and provide plant material for conversion into biofuels.

“It’s a complex topic,” Jager said. “The science is showing that although it may be difficult to remove undergrowth and thin trees in some roadless areas, simply leaving old growth forest alone may cause more harm than good. For at-risk species such as spotted owls, letting fuel build up can cause larger and more widespread fires that can be worse in the long run.”

Jager has worked with colleagues to build a framework that can support decision-making around forest-thinning practices, landscape patterns and even spatial firefighting tactics. Results of their work could be used to protect terrestrial and aquatic species that need safe passage to move away from wildfire and then return later.

“Wildfire disturbance is a part of nature, and species are adapted to it, but we’re in a different situation now with climate change,” Jager said. “There are going to be big shifts in when these fires happen, their size and severity, which will cause big shifts in vegetation and new impacts on animal species.

“By continuing our research, we can help forest managers plan for these shifts.”

Unearthing Data in the Carbon-Rich Arctic Tundra
Advancing the understanding of wildfire effects on the carbon cycle is a focus for ORNL scientist Fernanda Santos. She studies not only single events, but also repeated wildfires over decades. She examines what these fires portend for the land’s ability to lock away