Managing Sudden Oak Death

Managing Sudden Oak Death in California forests and woodlands:  before, during, and after Phytophthora ramorum invasion; by T.J.  Swiecki and E.A. Bernhardt

Citation: Swiecki, T.J and Bernhardt, E. A.  In review. Managing sudden oak death in California forests and woodlands:  before, during, and after Phytophthora ramorum invasion. Gen. Tech. Rep. PSW-GTR-242. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station. 129 pages.

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T.J.  Swiecki, T.J and E.A. Bernhardt. 2011. This publication is intended to help resource management professionals and landowners understand and manage sudden oak death (SOD) in California forests. The publication is divided into three parts:  Part 1 discusses the epidemiology of SOD in California. This includes information on biology of the pathogen (Phytophthora ramorum), host-pathogen interactions, disease spread, and environmental conditions that affect disease. An understanding of these relationships is needed to choose the most appropriate strategies for managing SOD at a given location.  Part 2 describes how to develop a plan to manage SOD within a stand and how to identify and prioritize areas that may be suitable for SOD management activities. Options for managing SOD are presented by stage in the disease epidemic: before the SOD pathogen has reached a susceptible forest; during the local epidemic, while disease is active in an area and many hosts are still at risk of becoming diseased; and after SOD has killed so many host trees that forest restoration needs to be considered.  Part 3 provides detailed descriptions of the management techniques.

Key words: Sudden oak death, Phytophthora ramorum, tree disease management, tanoak, coast live oak, mixed-evergreen forests

Author information: Ted Swiecki  and Elizabeth Bernhardt are  founders and principals of Phytosphere Research,, in Vacaville, CA.


Funding was provided by the USDA Forest Service, State and Private Forestry, Forest Health Protection, Midpeninsula Regional Open Space District, the San Francisco Public Utility Commission and the USDA Forest Service, Pacific Southwest Research Station.  The authors wish to thank the following for review and guidance; Everett Hansen, Oregon State University; Phil Cannon, USDA Forest Service, Pacific Southwest Region, Forest Health protection;  Chris Lee,  University of California Cooperative Extension, Humboldt and Del Norte Counties;  Susan Frankel, USDA Forest Service, Pacific Southwest Research Station and Janice Alexander, UC Cooperative Extension, Marin County.

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