Twenty-three communities across California will come together for the 11th annual Sudden Oak Death Blitz surveys this spring from San Luis Obispo to Mendocino counties in an effort to help researchers track the spread of the pathogen that causes the disease.

The scientific name for sudden oak death, or SOD, is Phytophthora ramorum.

“SOD Blitzes are key to California’s sudden oak death monitoring program. Without the help of countless blitz citizen scientists, we would be ill informed as to where the pathogen is present and active throughout the populated areas of California’s impacted counties. Thanks to their help, we can maintain a pulse on the ebb and flow of pathogen spread, which enables communities and homeowners to make informed decisions about where preventative treatments should be focused and how to manage for the pathogen to help protect at-risk oaks. With no known cure, prevention is primary,” said Matteo Garbelotto, UC Berkeley faculty who runs the Blitzes.

The free events take place from March 31 to May 19 and require one-hour trainings. For locations and local details, go to www.sodblitz.org.

Attendees should bring mobile devices or GPS units if they have them.

People living or recreating near areas known to be impacted by SOD are encouraged to participate in a blitz. Volunteers with a smartphone should bring it to the training with the free "SODMAP Mobile" app already installed as it can help in identifying potential collection locations.

Symptomatic California bay laurel and tanoak leaves generally precede oak infections and are often the first sign that P. ramorum is in a location. Participants will be trained to identify and collect symptomatic bay and tanoak leaves as well as tanoak twigs and record sample locations. All materials necessary for sampling will be provided during training sessions.

SOD Blitz samples will be taken to the UC Berkeley Garbelotto lab to determine the presence or absence of the pathogen. Results will be posted online in the fall to SODMAP (www.sodmap.org) and to the SODMAP Mobile app (www.sodmapmobile.org). These two tools are updated annually with laboratory-confirmed (positive and negative) landscape findings and can be used to help inform people as to the presence and risk of SOD at a given location.

SOD is a serious disease that is caused by an invasive pathogen that is killing tanoak, coast live oak, California black oak, Shreve’s oak, and canyon live oak trees in California. It is the primary cause of tree mortality in coastal California, with more than five million trees having died in since its discovery in the mid-1990s. A water-loving organism, the pathogen continues to spread in drought years, but at a much slower rate than wet years.

SOD Blitzes are made possible by the work of local volunteers, along with funding from the PG&E Foundation and the USDA Forest Service, State and Private Forestry.

For more information on the blitzes, go to www.sodblitz.org or contact Matteo Garbelotto at 510-410-7058.

For more information on Sudden Oak Death and P. ramorum, go to the California Oak Mortality Task Force Web site at www.suddenoakdeath.org.