Tracking & Subduing the Plague of California’s Oak Woodlands

November 07, 2023

The introduced forest disease known as Sudden Oak Death (SOD) is endangering California coastal woodlands, where keystone trees such as oaks and tanoaks are being killed by the thousands. 

Matteo Garbelotto is a Professor of Cooperative Extension in the Department of Environmental Science, Policy, and Management who has been focusing his research and outreach on SOD for over 20 years. Garbelotto, researcher Douglas Schmidt, and UC Davis professor of plant pathology David Rizzo launched a concerted SOD defensive campaign in 2000. In an effort to fingerprint the pathogen and trace its origins, the researchers were part of a multi-institutional, multi-investigator effort that included the DOE Joint Genome Institute to decode the complex Phytophthora ramorum genome. 

Once the genome sequence for the plant pathogen was complete, Garbelottto and Schmidt developed methods for rapid diagnoses of sudden oak death (SOD), and launched the SOD Blitz Project, a citizen science program that trains and coordinates one of the largest volunteer-based surveys in the world, aimed at identifying active SOD infestations across California.

They also developed the SODmap Mobile app, which enabled SOD Blitz participants to geotag specimens they collect. Later, those are annotated with the results of the lab SOD infection analysis. These collaborations represent the first-ever large-scale “citizen science” project to generate real-time data for modeling and predicting the spread of a plant disease, according to Garbelotto. 

The results of the 2023 SOD blitzes will be announced starting later this week, at a meeting open to the public at the Santa Rosa University of California Cooperative Extension office, followed by a town hall meeting in Woodside on the following Monday and then through an online webinar on Friday, November 17. More information about all meetings is available on the website.  Given we may have two wet years in a row, it may be important for people to protect their oaks where outbreaks have been identified in 2023, said Garbelotto, who urges citizens to join one of the meetings to learn where and how to fight back against the disease. “Ultimately this may save your oaks,” he said.

“If you have knowledge on the presence of active disease outbreaks in your neighborhoods, there are options to curb the disease and protect your oaks,” said Garbelotto. “Likewise, if the new EU1 variant is detected near you, the State and Federal Government will try to eradicate it at no or minimal cost to you, but only if the detection occurs at an early stage.”

 A longer version of this article was published by the Joint Genome Institute. Read the full story on the JGI website. You can also learn more about SOD and Garbelotto's lab's work in the videos produced by the JGI below.