If you haven't heard about Sudden Oak Death, it's a fungal disease that can wipe out a variety of California's tree species, it's spread by wind and rain, and after first becoming an epidemic here in 2002, it's now gotten to the point where any efforts to stop it will likely not help. SFist first wrote about the problem in 2004 (in the first year this site existed) when the disease, with the Latin pathogenic name of Phytophthora ramorum, was first recorded in Golden Gate Park, killing trees in the AIDS Memorial Grove. As the Washington Post now reports in a disturbing update, California's coastal forests, especially those north of Monterey County, are all affected now, with whole areas of California bay laurel, oak, and tanoak trees either dead or dying and becoming crispy tinder for potential wildfires in the process.
Fortunately, not all trees are susceptible, but it's still an upsetting site and a major threat to Northern California as another fire season approaches.
Per the Post:
The pathogen is a fungus that affects different trees differently, and not all are susceptible. It will tear through a forest and kill some trees while leaving others standing.
But in some trees, the pathogen causes tree trunks to crack open a ‘canker’ and literally bleed out sap. The disease is actually related to the pathogen that caused the Irish potato famine in the 1800s.
Experts say that while some extremely costly and unprecedented efforts could have been taken to clear out affected trees back in 2002, the time for that is long past, and no similar effort would be likely to stave off what is now a "phase 3" epidemiological state covering millions of acres of forest.
Adding to the anxiety over this is a different problem, connected with our ongoing drought: the bar beetle. As we saw in this drone footage last month, bark beetles, which are a part of the ecosystem in California's pine forests, are doing severe damage across large areas near Yosemite and elsewhere, killing trees in large numbers that could similarly create a fire hazard. The cause is a lack of sufficient sap coming from the trees, as a result of the drought, the sap being the natural enemy of the beetles and the trees' only defense against them.
The P. ramorum pathogen, meanwhile, is an invasive species of fungus that, as UC Davis postdoc fellow Richard Cobb told the Post, was barely seen as a threat before making its way from Europe to here. "It was known as this minor pathogen of Rhododendron in the Netherlands prior to arrival in California," he said.
The new alert about California's trees and Sudden Oak Death comes via some new research published Monday by Cobb and his colleagues in The Proceedings of the National Academy of Sciences.
And even though the pathogen can't be eradicated at this point, efforts by foresters and others can at least contain it and save trees in certain areas of the state.