Severity outweighs pyrodiversity in shaping avian and bat species distributions following an oak woodland mega-fire

Anthropogenic pressures have altered fire regimes across the western
United States. These altered fire regimes, and the megafires they often
produce, threaten ecologically and economically critical ecosystems and
biodiversity across this region. Oak woodland savannas may be particularly
sensitive to altered fire regimes, but there remains a significant gap in
our understanding of how different characteristics of wildfire impact
these ecosystems and the wildlife species that reside within them. In this
study, we used an occupancy modeling framework to investigate how fire
severity and pyrodiversity, the diversity of severity patches, impact the
distributions of bird and bat species assemblages following a major
wildfire in northern California. We used acoustic monitors deployed across
the Hopland Research and Extension Center following the 2018 Mendocino
Complex Fire and compared how patterns of fire severity and pyrodiversity
influence habitat preferences across a diverse community of woodland bird
and bat species. We found that fire enhances habitat use and increased
occupancy for several species and species-groups across both taxonomic
groups. Specifically, low to moderate severity fire increased occupancy
for several species and species-groups. Pyrodiversity had smaller,
negligible effects on species distributions relative to fire severity.
Fires that reproduce the natural heterogeneity of oak woodland landscapes
are likely key in sustaining high biodiversity across oak woodland
ecosystems.