Vulnerability in California’s carbon stocks: understanding post-fire regeneration in the state’s high elevation forests
Principal Investigator: Emily Brodie
Project Partners: Hugh Safford, Ph.D.
Institution: University of California, Davis
Project Type: Graduate Student
Grant Award #8GG19808
Amount awarded: $53,835
Award Date: September 2019
Subalpine forests are the highest elevation forested ecosystems in California. They are important because they are predicted to store and uptake carbon well into the future, even as conditions become more stressful for lower elevation forests. Subalpine forests also help to safeguard the state’s water supply by increasing snowpack retention at the headwaters of many important watersheds and are likely to become climate refugia for bird, mammal, and plant species fleeing warming temperatures at lower elevations. However, while these forests are generally considered pristine and unaffected by human and climate influences, change is afoot. Longer growing seasons are leading to denser forest stands due to an increase in small trees, and in the last three decades area burned has increased more in subalpine forest than any other forest type. Taken together these changes foretell an uncertain future for subalpine forests and the ecosystem services that they provide.
Due to the importance of California’s subalpine forests, our study seeks to understand one key element of subalpine forest persistence: tree regeneration following wildfire. While post-fire regeneration of lower elevation forests has been well-studied, very little is known about how Mediterranean-type subalpine forest (like those we have in California) respond to wildfire. By counting and measuring seedlings in 13 fires across subalpine forests in the Sierra Nevada and San Bernardino mountains, we will determine how wildfire severity affects the regeneration of iconic high elevation tree species such as western white pine and foxtail pine. This study supports the priorities of the Forest Health Research Program as it proactively seeks to understand the resilience of subalpine forests to wildfires in order to better manage carbon storage in a unique and climate-impacted system.