California’s recent widespread death of trees — affecting 102 million trees since 2010 — is raising environmental concerns among fire and ecology experts.
Five years into the state drought, the tree die-off has affected 10 “high-hazard” counties in the central east side of California from Placer County to Kern County, according to CAL FIRE spokesperson Lynne Tolmachoff. While Alameda County is not specifically identified as “high-hazard” by the state Tree Mortality Task Force, much of the hillside in the East Bay is at risk.
“The tree mortality has been ongoing,” Tolmachoff said. “Until we receive a significant amount of rain and pull out of this drought, we are expecting this problem to persist.”
The ongoing drought has been one of the most severe ones experienced by California in centuries, according to U.S. Geological Survey ecologist Adrian Das, who added that the major tree die-off is in part an effect of climate change.
Das highlighted that heavily impacted California forests and mountains can have a significant role on the state’s ecosystem. In addition, residents in these areas can be compromised by the threat of wildfires or falling trees.
“From the science side, there is a lot we don’t know about forests and how climates affect them,” Das said. “There is a big effort to learn as much as we can to prevent these trees from dying.”
Some experts are advocating for immediate solutions to the problem. Jon Kaufman, vice president of the Claremont Canyon Conservancy, said relying on weather patterns is not a sufficient way to combat issues that face California residents as a result of the tree die-off.
“We are hopeful that this will be a wet year, but we don’t know,” Kaufman said. “Last year we (had) a bit of rain but not later on. Removing trees before they become a danger is the only real answer.”
Tolmachoff said large devastating wildfires become more probable as the number of dead trees grows. Director of the UC Berkeley Forest Pathology and Mycology Lab Matteo Garbelotto said the drought is a key factor of increased disaster risk.
“Lack of water makes trees more combustible and at the same time more susceptible to what we call secondary insects and diseases,” Garbelotto said in an emailed statement. “These secondary agents are the ones that really predispose trees to be affected by catastrophic fires.”
Removing dead trees, however, is not an easy task. Kaufman said as trees get bigger, the cost of their removal increases as well. He urged the campus to file a lawsuit against the Federal Emergency Management Agency to restore funds for tree removal programs that were recently terminated.
Although homeowners can remove trees from their own property, the widespread removal of dead trees is unfeasible. Tolmachoff said CAL FIRE is prioritizing keeping those in the affected areas safe and ensuring they can evacuate areas sufficiently in the case of a wildfire.