Cooperative Fish and Wildlife Research Units Program: Washington
Education, Research and Technical Assistance for Managing Our Natural Resources

Calhoun, Kendall L., et al. "Spatial overlap of wildfire and biodiversity in California highlights gap in non‐conifer fire research and management." Diversity and Distributions 28.3 (2022): 529-541.


Global change has spurred the escalation of megafires in California over the last 20 years throughout a variety of ecosystems. Here, we examine the spatial distribution of California wildfires and megafires from the last two decades (2000–2020) in relation to ecosystem types and biodiversity metrics. We offer insights into the prevalence of fire across vegetation types and its potential implications for biodiversity, and for fire and land management. These results challenge the prevailing discourse that wildfire in California is chiefly an issue of forest management.

California, United States of America.

We calculated burned area across vegetation types from 2000 to 2020 by integrating fire perimeter and land cover data and compared this to a content analysis of coverage of wildfires by media and scientific research across California. We then compared the distribution of fire perimeters across biodiversity metrics (richness and endemism) for five terrestrial taxonomic groups (birds, reptiles, plants, mammals and amphibians) and against the distribution of the wildland-urban interface (WUI).

Total burned area from 2000 to 2020 was highest in shrubland ecosystems (38%), followed by conifer (36%), hardwood (17%) and grasslands (9%). In aggregate, ecosystems other than conifer make up the majority (64%) of the area burned in wildfires over the last 20 years. Fires most likely to impact endemic species, overlap areas of high species richness or burn within the WUI occurred predominantly in non-conifer ecosystems.

Main Conclusions
Fires outside of forests have burned biodiverse areas critical to endemic species, but recent research and management in fire ecology continues to focus disproportionately on forests.
Non-conifer forested areas in California represent an important gap in fire research and management. As fire regimes shift dramatically in the state, other ecosystem types must be part of the wider conversation on fire management and policies to better protect people and biodiversity.