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Posts Tagged: Sudden Oak Death

Drought is slowing the spread of sudden oak death

A coast live oak killed by sudden oak death. (Photo: Bruce Hagen)
Finally, some good news about the drought. Dry conditions have apparently curbed the spread of sudden oak death in 12 coastal California counties, reported Guy Kovner in the Santa Rosa Press Democrat.

"If we had one more year of drought, it would really be ideal," said Matteo Garbelotto, UC Cooperative Extension specialist in the Department of Environmental Science, Policy and Management at UC Berkeley.

The article said Garbelotto isn't hoping for more drought, but evidence shows that the drought is helping reduce SOD infection rates and in some cases is curing infected trees, "because the pathogen dies."

Each spring, the UC Berkeley SOD lab hosts a "blitz" to gauge the spread of Sudden Oak Death. Volunteers fan out across areas susceptible to SOD and collect leaf samples for analysis.

In the Cloverdale area, where an outbreak was confirmed last year, none of the trees sampled had the disease this year, the article reported.

"I would say it is there, but we just didn't find it," Garbelotto said.

East of Highway 101, the rate dropped from 26 percent infected last year to 23.3 percent in 2014, the story said.

Complete SOD blitz results will be available Sept. 29 on the UC Berkeley Forest Pathology and Mycology Lab website.

Posted on Thursday, September 25, 2014 at 10:51 AM

Sudden oak death continues to spread in California

Cleaning boots after a hiking trip helps prevent the spread of sudden oak death.
Sudden oak death is creeping into Carmel Valley, and scientists have found infected trees in Gilroy and Prunedale, reported the Salinas Californian.

Warm weather seems to be keeping SOD out of the Salinas Valley, but it is having a deadly effect on the surrounding forests.

“The organism has a really significant impact on our forests,” said Matteo Garbelotto, UC Cooperative Extension specialist in the Department of Environmental Science, Policy and Management at UC Berkeley. He said that adult tanoaks – an evergreen species closely related to oaks – are almost entirely wiped out in some areas.

To help prevent the spread of sudden oak death, people visiting invested areas should not remove leaves or branches and should clean dirt from their shoes before leaving.

Posted on Monday, December 16, 2013 at 9:27 AM

Citizen scientists being mobilized in Sonoma County

A Sudden Oak Death "Blitz" planned for Sonoma County June 15-16 will prepare local residents to spot infected plants, collect samples from their neighborhoods and submit them for laboratory testing, reported the Kenwood Press.

The session is hosted by UC Cooperative Extension Master Gardeners and Matteo Garbelotto, UCCE specialist in the Department of Environmental Science, Policy and Management at UC Berkeley.

Trees susceptible to sudden oak death include California bay laurel, tan oak, live oak, black oak, canyon live oak and shreve oak. After the laboratory analysis is complete, Garbeletto will schedule a return visit to discuss the findings of the survey and provide guidelines for action.

"If the disease front is 100 yards away, then one needs to decide whether some of his oaks should be protected," Garbeletto said. "For oaks up to 30 inches in diameter, removal of small and medium size laurels for a 10-yard radius around the oak trunk plus the application of AgriFos on the bark each year or every other year will protect the oak."

The information collected by the citizen scientists will also be added to Garbelotto's OakMapper website, a portal where SOD appearance in California is monitored.

An image from the Oak Mapper website (oakmapper.org) where citizen-submitted scientific data is collected.
An image from the Oak Mapper website (oakmapper.org) where citizen-submitted scientific data is collected.

Posted on Wednesday, May 15, 2013 at 9:23 AM

Citizen scientists map Sudden Oak Death

Citizen scientists are once again beginning their annual Northern California search for signs of Sudden Oak Death, reported Lisa Krieger in the San Jose Mercury-News. Volunteers were trained in Santa Cruz on Friday and training sessions are planned for Orinda, Berkeley, San Francisco, Saratoga, Burlingame, Woodside, Atherton and Los Altos Hills.

"This outreach is really important because it not only teaches people how to look for the disease, but it also helps them to monitor for it in their community, allowing them to identify new outbreaks quickly," said Matteo Garbelotto, UC Cooperative Extension specialist in the Department of Environmental Science, Policy and Management at UC Berkeley.

Sudden Oak Death is caused by Phytophthora ramorum, a microbe that came to California from overseas. The disease has killed more than a million trees in 14 coastal counties from Monterey to Humboldt.

In this cross-section of a coast live oak killed by sudden oak death, the black-stained tunnels of adult ambrosia beetles can be seen extending into the wood.
In this cross-section of a coast live oak killed by sudden oak death, the black-stained tunnels of adult ambrosia beetles can be seen extending into the wood.

Posted on Monday, April 15, 2013 at 2:15 PM

Sudden oak death expands in San Francisco Bay Area

An dramatic increase in sudden oak death incidence it believed to be tied to recent weather patterns.
Aerial and ground surveys have documented 375,700 new cases of dead live oak and tan oak trees over 54,400 acres of California where the pathogen that causes sudden oak death is known to exist, reported the San Francisco Chronicle. Last year there were 38,000 dead trees covering 8,000 acres.

Diseased trees were even found in Golden Gate Park, where there is no obvious source of the pathogen, such as nurseries or wildland.

"It's puzzling that we found it there because it's a totally urban environment, and I really didn't expect it. It shows how complicated and adaptable this organism is," said Matteo Garbelotto, UC Cooperative Extension specialist in the Department of Environmental Science, Policy and Management at UC Berkeley. "The area doesn't have a lot of oaks, so I'm not worried about oaks there, but I'm worried about other plants being infected and, of course, people carrying it on their shoes."

Garbelotto's lab is mapping the spread of the pathogen that causes sudden oak death by plotting the test results from thousands of bay laurels and other hosts taken by citizen volunteers. SODMAP is updated every year to help cities, counties and homeowners protect endangered oak trees.
Posted on Wednesday, October 10, 2012 at 2:33 PM

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