Benicians, others urged to help stop spread of Sudden Oak Death

Benicians can join other coastal-area Californians and become “citizen scientists” by helping stop the spread of a rampant tree-killing disease this spring, a UC-Berkeley professor said.

Matteo Garbelotto organizes training sessions called Sudden Oak Death (SOD) “blitzes” that bring people together to learn about the disease, which is caused by a pathogen, Phytophthora ramorum.

“SOD is a serious invasive disease that is killing tanoak, coast live oak, California black oak, Shreve’s oak and canyon live oak trees in California,” Garbelotto said. “It is the primary cause of tree mortality in coastal California, with more than three million trees having died in 15 counties since its discovery in the mid-1990s.”

Garbelotto’s blitzes teach people how to look for the disease in their neighborhoods, and to thereby help in early detection of new outbreaks. “Early detection is essential for containment, and possibly even local eradication of the pathogen,” he said.

One-hour training sessions will start Friday and be offered through May 30. Educating people to become “citizen scientists” is becoming essential in the effort to halt the spread of the disease, Garbelotto said.

“Really, citizen scientists are the cornerstone to maintaining such a large-scale, ongoing urban monitoring program,” he said. “We simply couldn’t generate the necessary people power without them.”

California bay laurel leaves often show the initial signs that the pathogen is in an area, before oak and tanoak infections are discovered, Garbelotto said.

Participants in the blitzes will be trained to identify bay leaves that are showing symptoms of sudden oak death, and how they can collect those leaves and record sample locations.

Those who previously have attended a training session may return to a blitz this year to receive supplies and to refine their skills in spotting the illness in bay trees, which can help the pathogen survive during droughts.

Participants are asked to bring smart phones so they can upload the free application SODmap Mobile, a Sudden Oak Death distribution map of laboratory-confirmed positive and negative samples in California outside of nurseries, Garbelotto said.

The application helps in identifying potential collection sites, he said. Samples will be taken to the Garbelotto Laboratory at UC-Berkeley to determine the presence or absence of the disease, and results will be posted this fall to SODMAP, available online at www.sodblitz.org.

Garbelotto said the SODMAP site helps homeowners and property owners learn about the risk of infection for their oaks and tanoaks.

He said options are available to help infected trees, but the methods are more effective if they are started before the oaks and tanoaks are affected. They include sanitation, treatment of chemical preventatives and selective bay removal.

Because it’s better to start the prevention measures before an area becomes affected, Garbelotto said “timely detection” of the disease on bay laurel leaves is crucial.

“The risk of infection is highest if infected bay trees are within 200 yards of oaks,” he said.

SOD blitzes are led by local organizers and are cosponsored by the California Native Plant Society. The training sessions are underwritten by the United States Forest Service, state and private forestry organizations and the Pacific Gas and Electric Foundation.

“Thanks to data collected in the last eight years by hundreds of volunteers during SOD Blitzes, SOD in California may have the best known distribution of any forest disease,” Garbelotto said. In addition, places where the pathogen has been found have been viewed by thousands of visitors to the www.sodmap.org site, he said.

Those interested in learning more about sudden oak death and P. ramorum may visit the California Oak Mortality Task Force website, www.suddenoakdeath.org, or contact Katie Harrell at 510-847-5482 or kpalmieri@berkeley.edu.

None of the classes is offered in Solano County, but two are slated April 11 for the East Bay. One, at 10 a.m., will be in the Garden Room of the Orinda Library, 26 Orinda Way, Orinda; the other, at 1:30 p.m. will be at the University of California-Berkeley campus in 159 Mulford Hall.

A class at the University of California Cooperative Extension Office meeting room, 1710 Soscol Ave., Napa, will be at 10 a.m. April 18; and one at Room 103 of the Joseph R. Fink Science Hall of Dominican University in San Rafael will be at 10 a.m. May 30.

Three classes will take place in Sonoma County. All will be at 10 a.m. May 30. One is at Graton Community Club, 8996 Graton Road, Graton; one is at Spring Lake Park Environmental Discovery Center, 393 Violetti Road, Santa Rosa; and the third is at Cloverdale Historical Society, 215 North Cloverdale Blvd., Cloverdale.

Those interested may visit the website http://nature.berkeley.edu/garbelottowp/?page_id=816.