Los Angeles, for example, received only 5.85 inches of rain from July 2012 through June 2013, compared with 8.71 inches a year before and a 30-year average of 14.93 inches, said Eric Boldt, a meteorologist with the National Weather Service.
Tom Scott, a natural resources specialist who teaches at University of California campuses in Riverside and Berkeley, said plants can have a harder time staying hydrated under such conditions.
“The whole system is like a bank account — it’s being drawn down,” he said.
Richard A. Minnich, a professor of earth sciences at University of California, Riverside, said much of Southern California is in pretty good shape because older vegetation burned off during a spate of wildfires over the past decade, but there are spots at serious risk because of the prevalence of old-growth chaparral.
“Wherever there is very old chaparral, we’ve got a tremendous threat,” he said.