California Native Plant Society
San Gabriel Mountains Chapter

Previous programs


Thursday, May 26, 2016, 7:30 p.m.: The effects of historic drought in California on chaparral with Stephen Davis: Dr. Davis writes of this talk: “Over the last three years, California has experienced the worst drought in recorded history. We hypothesized that drought-hardy chaparral shrubs would display differential levels of drought–induced mortality, depending on their species. Our results supported this hypothesis, indicating the possibility of drought-induced changes in plant community structure. We also observed novel seed germination among obligate seeding species (non-sprouters after fire), even though seeds typically require a fire cue to promote germination. Evidently, drought-induced adult death and canopy dieback increased radiation loads to the soil surface, increasing soil temperatures, stimulating premature germination without a fire event.  We were surprised to find that species documented to have high resistance to water stress-induced embolism in stem xylem often displayed the highest adult mortality, 56 to 93%, whereas species with documented low resistance to embolism of stem xylem had low mortality, 0 to 3.6%.”

Dr. Stephen Davis is Distinguished Professor of Biology at Pepperdine University. He has been selected as a Harriet and Charles Luckman Distinguished Teaching Fellow at Pepperdine University, Teacher of the Year at Pepperdine University, and most recently received an internationally competitive award from Baylor University, the Robert Foster Cherry Award for Great Teaching. Much of Davis's research centers on plant physiological ecology, including adaptations of chaparral shrubs to wildfire, drought, and freezing. He has published in such journals as Nature, Ecology, The American Journal of Botany, Plant Cell and Environment, Biological Journal of the Linnaean Society, and the International Journal of Plant Science. Davis earned his Ph.D. in 1974 from Texas A&M University after which he joined the faculty at Pepperdine University in Malibu. He has been a visiting scholar at Stanford University, UCLA, University of Utah, and Baylor University.