Sudden Oak Death flourishes just north of San Luis Obispo County border

May 14, 2015

Central Coast residents concerned with protecting the area's coastal live oak trees are joining forces in the coming days to stop the spread of a serious disease. Sudden Oak Death (SOD) has been a problem in California for years, but now scientists have tools to track—and possibly slow—its spread.

Locations on the Google Earth SOD Blitz map where trees either tested infected (red) or clean (green).

Volunteers play a crucial role in this process, according to Lauren Brown, a trainer with the 2015 Spring SOD Blitz, a campaign aimed at mapping the location and status of trees throughout the state.

"What we're doing is, definitely what's called citizen science," said Brown. She's teaching volunteers how to properly sample and record the trees in their area.

Brown said California bay laurels are carriers of the disease and are the trees used to determine whether SOD is a concern in the area.

The disease is caused by a pathogen called phytophthora, which the bay laurels harbor. If leaves from a laurel test positive for phytophthora, then oaks within 200 yards are in danger.

SOD has not yet been detected in San Luis Obispo County, but it's right on the border along the Big Sur coastline where it's really taken a foothold.

 The Blitz project is now nearly a decade old. Information collected by volunteers over those years has helped create an interactive map that's free to the public. You can see just how close an infected tree may be to your yard, and possibly an oak.

It's the brainchild of Doctor Matteo Garbelotto at Cal Berkeley. He says even though volunteers do much of the work, it's still an expensive undertaking.

"It's a fairly expensive effort because you've to organize a lot of meetings throughout the state, you've got to get all the people involved, and then you've have to pay all the cost of processing the samples, which is fairly high," said Garbelotto.

The doctor says funding to help pay for those costs comes from the US Forest Service and the PG&E Foundation.

The spread of SOD has slowed in recent years because the pathogen travels using water. So, the current drought is actually a positive for controlling the disease.