Forests are an integral component of the global carbon cycle, capturing CO2 from the atmosphere through photosynthesis, and storing it as carbon in trees and other organisms. Their continued contribution to regulating climate depends in part on their resilience to wildfire, drought, and other disturbances that can cause release of greenhouse gases.

Land owners, managers, and agencies across California are adopting various strategies to promote forest health and resilience, reduce the impacts of wildfires and drought, as well as to protect people, property and the multitude of services forests provide. Forest thinning and prescribed fire are two of these strategies. In the wake of recent destructive mega-fires and the most severe drought-induced tree mortality event in California history, understanding the effects and effectiveness of these treatments on forest carbon is more important than ever.

Led by Dr. Matthew Hurteau from the University of New Mexico, this CCI-funded research project continues important work that began over 20 years ago at the Teakettle Experimental Forest in the southern Sierra Nevada mountains to quantify the effects of prescribed fire and thinning on the ecosystem. The long-term “Teakettle Experiment” examines six different treatment options, including different intensities of thinning as well as prescribed fire, with each treatment replicated three times. After initial treatments and measurements in 2001, a second prescribed burn was performed in 2017. This provided an important opportunity for Dr. Hurteau to study the long-term effects of these treatments, including their maintenance through repeated application of fire.

“This project is central to helping us understand how restoring the right type of fire to mixed-conifer forests will influence the forest’s role in regulating climate,” says Hurteau. He and his collaborators have completed pre-burn sampling of surface fuels and understory vegetation, followed by a complete re-inventory of the Teakettle Experiment that includes all forest carbon pools (e.g. soils, fuels, understory vegetation and trees), as well as tree-coring for growth analysis. “Matthew Hurteau’s work with collaborators at Teakettle and across California on carbon dynamics as related to forest restoration and disturbance has been indispensable,” says Amarina Wuenschel, Southern Sierra Associate Province Ecologist for the U.S. Forest Service. Their “progressive body of work has helped us usher in a new era of forest management wherein we have gained focus on the stability of long-term carbon stores on our forested landscapes in a changing climate.”

Zald, H. S., Callahan, C. C., Hurteau, M. D., Goodwin, M. J., & North, M. P. (2022). Tree growth responses to extreme drought after mechanical thinning and prescribed fire in a Sierra Nevada mixed-conifer forest, USA. Forest Ecology and Management, 510, 120107.

Steel, Z. L., Goodwin, M. J., Meyer, M. D., Fricker, G. A., Zald, H. S. J., Hurteau, M. D., & North, M. P. (2021). Do forest fuel reduction treatments confer resistance to beetle infestation and drought mortality?. Ecosphere, 12(1), e03344.

Odland, M. C., Goodwin, M. J., Smithers, B. V., Hurteau, M. D., & North, M. P. (2021). Plant community response to thinning and repeated fire in Sierra Nevada mixed-conifer forest understories. Forest Ecology and Management, 495, 119361.

Goodwin, M. J., North, M. P., Zald, H. S., & Hurteau, M. D. (2020). Changing climate reallocates the carbon debt of frequent‐fire forests. Global Change Biology, 26(11), 6180-6189.

For more information please visit the Teakettle Experiment website here.

This project was highlighted by the California Climate Investments Annual Report. You may access this project's profile by clicking here.