This presentation will review recent findings on the threats to California native vegetation posed by plant pathogens and management actions needed to prevent introduction and limit spread of exotic species. Plant diseases caused by species, such as sudden oak death (Phytophthora ramorum) have been an increasing concern as new species and hybrids are being discovered at an alarming rate. In California, dozens of Phytophthora species have been found in native plant nurseries, restoration sites, and native landscapes. The first detections of P. tentaculata in the US, ranked as a high priority threat by USDA, were in California native plant nurseries and restoration plantings. Various aspects of the problem will be explained: the impacts of Phytophthora species in California, pathways of spread - including local and global spread via infected nursery stock, current efforts to prevent introductions by clean nursery stock initiatives, the aftermath of introductions in restoration plantings and efforts to contain or eradicate introduced species from field sites. The panel is presented by the Phytophthoras in Native Habitats Work Group: Janice Alexander (UCCE Marin Co.), Ted Swiecki and Elizabeth Bernhardt (Phytosphere Research), Suzanne Rooney-Latham and Cheryl Blomquist (CDFA), and Janell Hillman (Santa Clara Valley Water District)
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