Timelines of vegetation recovery following fire in a shrub-dominated Mediterranean-type ecosystem

Christian John , Ellen C. Bolas, Ashley Grupenhoff, Mark Mendelsohn, Joseph Algiers, Jr., Justine A. Smith

Fire is a natural disturbance in many Mediterranean-type ecosystems, but wildfires are increasing in frequency and severity in many places worldwide, including California. Vegetation recovery following wildfire is critical for landscape stability and foundational to resilience of many ecosystem processes in the years and decades that follow fire. While remote sensing tools are increasingly important for mapping changes in vegetation following fire, to date these tools have limited application in shrubland systems such as those found in parts of California, hindering assessments of vegetation recovery timelines and inferences about ecological impacts. Using a 100-year fire history dataset alongside both field vegetation surveys (2014-2025) and modeled percent vegetation cover (1986-2025), we analyzed temporal cover dynamics of dominant vegetation classes in the years leading up to, and following, major wildfire events in the Santa Monica Mountains of California. Field survey data broadly corresponded with modeled vegetation cover, particularly for shrubs and herbaceous/graminoid cover. We identified consistent patterns in vegetation cover classes among dominant vegetation communities, including reductions in shrub and tree cover following fire in chaparral and grasslands, and pulses in herbaceous and graminoid cover in chaparral and upland woodlands, in the initial 2-5 years following fire. Herbaceous and graminoid cover returned to baseline levels faster than shrubs, which in turn recovered faster than trees. These results corroborate previous field-based studies of vegetation recovery following wildfire, and point toward modeled remote sensing products as a feasible tool for tracking post-fire recovery dynamics in remote and rugged terrain.