Sudden Oak Death infections nearly double in California

survey conducted by UC Berkeley scientists shows that the number of trees infected with Sudden Oak Death (SOD) has almost doubled since 2018.

Matteo Garbelotto, the director of the UC Berkeley Forest Pathology and Mycology Laboratory, has been involved in conducting the survey for the past 12 years.

“We found this year the sharpest increase ever in the number of trees affected,” said Garbelotto. However, this was expected due to the wet winters California has had for the past two years. Spores spread faster with significant rainfall.

“I saw a lot of outbreaks that we had seen before in the 12 years of our program, but I saw all the outbreaks being expressed at once this year,” he said. In previous years, some outbreaks would decrease while others would flare up, this year, every outbreak flared up. “This patterns shows me that the organism has really spread into the ecosystem of Coastal California. Now it’s already established everywhere, and it flares up when the weather is favorable. “

While analyzed by UC Berkeley scientists, the data from the survey is 100-percent collected by volunteers. UC Berkeley goes to local communities were SOD is an issue and trains local volunteers to identify the symptoms. This year’s results are particularly alarming, but Garbelotto sees one positive takeaway: “It’s kind of a testament to what you can achieve by working with volunteers.”

Residents can monitor the progress of SOD through a mobile app so they can take precautions before it is too late.