Mammal Response to Wildfire in Redwood Forests in Northern California
Abstract
California has historically experienced recurrent wildfires that have shaped many of the region’s unique ecosystems such as coast redwood (Sequoia sempervirens) forests. Redwood forests, particularly old-growth redwoods, are vital habitats for many wildlife species. Still, these long-living, fire-resistant trees are facing altered fire regimes due to fire suppression and climate change. The 2020 CZU Lightning Complex Fire was a consequence of these changes and significantly altered the landscape of the Santa Cruz Mountain region. This study analyzes mammal recovery after wildfire in high and low fire severity locations of the CZU Fire using two camera trap grids. The high-severity grid was placed in Big Basin Redwoods State Park, which was significantly altered by the fire. The low severity grid was placed in Butano Redwoods State Park, which experienced fire that more closely resembles the historic fire regime or prescribed fire. This study found equal species richness at both sites, indicating that there is no difference in wildlife species returning to the burned area. Although richness was comparable, the activity levels of each species were higher in the low severity site for every species detected except Northern raccoon. Statistically significant differences in relative activity levels between the high and low sites include bobcat, puma, rabbit, Virginia Opossum, and Western spotted skunk. The finding from this study can be used to identify vulnerable species after wildfires in redwood forests and to manage land in ways that benefit native wildlife species.