Comparison of Postfire Seedling Recruitment of 2019 in Three Key Chaparral Species

Fire is a common natural disaster that sweeps through Southern California. Combined with periods of acute, and most recent, chronic drought, we have seen an increase in the damage and frequency of these fires in recent years. Three chaparral species are common to the Pepperdine campus: Malosma laurina, Ceanothus spinosus, and Ceanothus megacarpus. The survival of these three native species is essential because they serve as biomarkers for the changes that are occurring in our local ecosystem and provide further implications for how our ecosystem is responding to natural disaster. Seedling recruitment is a mechanism that is used by some chaparral species to respond to fire. Without postfire recruitment, there would be local extinctions of each of these species postfire. Data was recorded for these three species of chaparral postfire in 1986 and postfire in 2008 at the same study site. Our group replicated these experiments to follow up on their previous findings within the same 21 grid locations. When compared to postfire 1996 and 2008, we found that each specie postfire 2019 experienced significant decline in seedling recruitment. In addition, we observed a local extinction of Ceanothus megacarpus, as there was no seedling recruitment found postfire 2008 and 2019. This study highlights the detriment of fire frequency on native chaparral species on Pepperdine University\u27s campus, as well as throughout the Santa Monica Mountains