Wildfires have long been a natural force shaping our environment, but with the changing climate, they have become more frequent, expansive, and intense. In response to this growing threat, scientists at the U.S. Department of Energy's Oak Ridge National Laboratory (ORNL) are conducting groundbreaking research to better understand and predict wildfires' impacts on the environment, the carbon cycle, and biodiversity.
Two months into the 2023 peak summer fire season, Canadian wildfires had already consumed more than 25 million acres, extending beyond their traditional western confines to Nova Scotia. The smoke from these fires reached as far as New York City and even drifted across the Atlantic Ocean to Europe, drawing renewed attention to the escalating wildfire crisis.
At ORNL, scientist Henriette "Yetta" Jager focuses on the intersection of energy and ecology. She investigates how selective forest thinning can simultaneously mitigate the risk of wildfires and provide raw materials for biofuel production. Her research is shedding light on the complexity of this issue, revealing that leaving old-growth forests untouched can sometimes exacerbate the problem by allowing excessive fuel accumulation. In such cases, wildfires can become larger and more destructive, harming both the environment and at-risk species like spotted owls.
Jager and her colleagues have developed a decision-making framework to guide forest-thinning practices, landscape patterns, and spatial firefighting strategies. The outcomes of their research hold promise for safeguarding terrestrial and aquatic species that require safe passage during and after wildfires.
As wildfires become more frequent and severe due to climate change, Jager emphasizes the need for forest managers to anticipate shifts in wildfire occurrence, size, and severity. By continuing their research, scientists can provide critical insights that enable proactive planning for these changes, ensuring more resilient ecosystems in the face of wildfire challenges.
ORNL scientist Fernanda Santos is dedicated to advancing our understanding of the effects of wildfires on the carbon cycle. Her research not only examines single wildfire events but also the cumulative impact of repeated wildfires over decades. Santos is particularly concerned with how wildfires affect the land's capacity to sequester carbon and how they can release carbon emissions during combustion, potentially intensifying the warming cycle.
Santos highlights the concept of rapid evolution, where plants and soil microbiomes quickly adapt to increased fire occurrences. Her research investigates whether repeated wildfires lead to more or less biodiversity and examines how fire-induced changes affect plant functional traits, soil microbiomes, and overall plant and soil quality. Changes in wildfire regimes can accelerate the transition from tree-dominated to shrub-dominated ecosystems, reducing plant diversity and altering ecological dynamics.
Santos also says the need for further research into how wildfires affect plant-fungal interactions in forests. Moreover, more severe and frequent wildfires can disrupt sensory cues used by animals, including insects, pollinators, and herbivores, to evade fires, further impacting biodiversity in a changing climate.
Santos plays a crucial role in refining large-scale climate simulations, such as the DOE's Energy Exascale Earth System Model (E3SM). E3SM, supported by the DOE Office of Science's Biological and Environmental Research Program, relies on high-performance computing to predict environmental changes that could impact the energy sector. Santos works to ensure that these models accurately represent carbon forms like charred biomass resulting from wildfires.
To enhance the quality and quantity of data available for wildfire research, Santos and her ORNL colleague, Jiafu Mao, have initiated the Fire Community Database Network. This collaborative effort encourages scientists and land managers to contribute environmental data from burned areas to a centralized repository. Sharing such information not only enhances research but also informs more effective land management practices.
Santos's work in the Arctic focuses on understanding the impact of wildfires on carbon-rich soils in high latitudes, such as Alaska and Canada. By integrating field data on historical fires into carbon cycle models, her research aims to reduce uncertainty in predicting how wildfires affect these critical ecosystems.
The research conducted at ORNL on wildfire predictions and long-term impacts is vital for addressing the growing threat of wildfires in the changing climate.
Through a multidisciplinary approach that encompasses forest management, carbon cycle dynamics, and large-scale climate simulations, scientists like Henriette Jager and Fernanda Santos are paving the way for more effective wildfire mitigation and the preservation of biodiversity in the face of this ancient force of nature. Their work is made possible through the support of the DOE BER program and the DOE Office of Energy Efficiency and Renewable Energy's Bioenergy Technologies Office, as well as ORNL's Laboratory Directed Research and Development.
