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Seventh Sudden Oak Death Science & Management Symposium: Key Messages

Inside a greenhouse, people wearing name tags gather around a table covered in plants.
In addition to the talks and workshops, Symposium participants enjoyed a hands-on tour of the Presidio Native Plant Nursery, where science-based best practices are in place to prevent the spread of Phytophthora.

July 2019 - This June, scientists and land managers from as far as Australia and New Zealand gathered at the Presidio’s Golden Gate Club for “Healthy Plants in a World with Phytophthora: the Seventh Sudden Oak Death Science and Management Symposium."

The symposium series began as a way for people to come together across disciplines to address the massive devastation that Sudden Oak Death has caused up and down the West Coast. It maintains that focus. Sudden Oak Death is a disease caused, in turn, by plant pathogen Phytophthora ramorum. Thus, over the course of the symposium, we learned all about pathogens in the Phytophhthora genus.

Some disease in an ecosystem is normal. For example, native Phytophthora species are present at low levels in undisturbed park wildlands. However, introduced species have the potential to cause more damage. In the case of Phytophthora ramorum, the exotic fungus was particularly deadly to California native oaks and tanoaks.

Researchers are developing new tools to understand how and why some Phytophthora species cause so much damage. So far, the data is showing that restoration using infected plants from nurseries is a major way that new species are introduced into landscapes in the first place. There is also evidence that Phytophthora strains growing in nursery facilities tend to spread faster and be more deadly. Could it be that out-planting natives with the aim of restoring degraded habitat is doing more harm than good?

Fortunately, scientists, land managers, and nursery practitioners are becoming savvy to the problem. They're figuring out ways to make sure that restoration efforts are solely a force for improving our irreplaceable park ecosystems. One equation to cut the risk of habitat restoration efforts? Ensuring plant stock is clean, and continuing to monitor Phytophthora on the landscape.

Read the full article for more key messages about what scientists, nursery practitioners, and land managers are learning and doing about Phytophthora. For more information on the Seventh Sudden Oak Death Science and Management Symposium, including abstracts and videos, please visit the University of California Division of Agriculture and Natural Resources website.

Golden Gate National Recreation Area, Presidio of San Francisco

Last updated: August 14, 2019