Seaver College Baird Distinguished Lecture Series Offers New Insights on Native Plant Life and Wildfires

Two Seaver College biology professors, Stephen Davis and Helen Holmund, recently served as keynote speakers in a special W. David Baird Distinguished Lecture Series pop-up event on March 24, 2025, which focused on ecology, native plant life, and the recent wildfires that impacted Pepperdine University. 

“During the wildfires, whether it was the Los Angeles County Fire Department or CAL FIRE, all the experts were discussing fuel—the plants of the Santa Monica Mountains,” said Lee Kats, dean of Seaver College, while introducing the event. “It struck me that at Pepperdine we have two academic experts—two world-leading experts on that fuel.”

Stephen Davis working with research students

Davis and Holmlund both specialize in plant biology and focus much of their research on vegetation found in the Santa Monica Mountains. Throughout his 49-year career as a faculty member at Seaver College, Davis, a distinguished professor emeritus,  published more than 90 articles on plant ecology—many of which featured students as coauthors. Holmlund, an assistant professor of biology, has furthered this research tradition, earning numerous scholarly publications and a $500,999 National Science Foundation grant to study desiccation ferns. 

Together, these Seaver College professors collected more than 40 years’ worth of plant data from the mountains surrounding Pepperdine’s campus and studied the six different wildfires that afflicted the area from 1985 to 2024. At the pop-up lecture, they shared their findings on the native chaparral that inhabit much of Pepperdine’s acreage. 

“Don’t blame [the fire problem] on the chaparral,” said Davis during the discussion. “They’re really our best friends.”

Big pod ceanothus, greenbark ceanothus, and laurel sumac are the three plants that traditionally make up the Santa Monica Mountains’ vegetation. Each of these species is accustomed to wildfires and even relies on semi-regular blazes to sprout new seedlings over time. Davis explained that their presence in the mountains is vital to the entirety of the natural ecosystem, as they play a key role in the water cycle and help anchor loose soil to the cliffs with their root systems.  

Helen Holmlund and her research students

However, the population of these native chaparral have begun to dwindle for three main reasons—drought, fungal infections, and frequent wildfires. Holmlund explained that from 2014 to 2016 a chronic drought swept over Southern California, killing off much of the native chaparral and weakening the immune system of the more durable species. Many of the plants that survived were eventually killed by a fungal infection that blocked the vegetation's ability to absorb water. This series of events allowed invasive grasses and weeds to infest the mountain range and act as potential fuel for loose fire embers. 

“The fire frequency [at Pepperdine] should be every 30 to 100 years,” said Davis. “When I came to Pepperdine, I analyzed the fire maps, and the fire frequency was once every 12 years. What is it today? Every 6.7 years.”  

Davis went on to explain that 95 percent of wildfires are sparked by humans, and those that aren’t are still influenced by humans because most non-native plants are introduced to ecosystems by people. 

Now, with an impressive data set and conclusive findings, Davis and Holmlund are beginning to study how humans can help support native chaparral and encourage new growth in the region. Using their respective research labs at Pepperdine, the two professors are teaming with Seaver College undergraduates to discover the solution to a destructive new trend. 
 
“Chaparral restoration research is tricky because you can invest five or six years, but if a fire comes back before the seedlings have hatched, you’re back to square one,” explained Holmlund. “The good news is that we have areas on campus where chaparral are continuing to thrive, providing us with a local source of seeds to study and work with.”

To view a recording of Davis and Holmlund’s lecture, visit the W. David Baird Distinguished Lecture Series website.