Understanding and Managing Sudden Oak Death in California

Part 3. Technical Management Guidelines

This section provides technical information about:

Additional information related to SOD management, including Best Management Practices for various user groups developed by the California Oak Mortality Task Force, is available at http://www.suddenoakdeath.org.

3.1. Excluding P. ramorum From Non-Infested Areas

Exclusion is the preferred management tactic in susceptible forest types where SOD has not been detected. Exclusion is most likely to be effective if the site is relatively distant from existing infestations and if exclusion can be implemented over a large area, such as an entire watershed or isolated stand. Exclusion is a worthwhile strategy for small parcels, but may be less effective if the land manager cannot exclude P. ramorum from adjacent parcels.

Practices related to sanitation and exclusion can also have an important role in P. ramorum-infested stands At early stages of an epidemic, the distribution of P. ramorum can be spotty. Practices that avoid spreading the pathogen throughout the site may slow the rate of SOD spread and provide a longer time for implementing control treatments. Sanitation practices also help prevent the spread of P. ramorum from an infested location to other noninfested locations.

Exclusion and sanitation measures are also important for preventing the introduction of additional strains of P. ramorum. Additional strains introduced via nursery stock or from other forested locations may be more aggressive or better adapted to the site than the existing strain (see Sidebar 1-4—Strains of Phytophthora ramorum). In addition, exclusion and sanitation can reduce the chances that additional exotic pests and pathogens would be introduced into the stand (see Sidebar 2-2—Disease, Damage, and Mortality Related to other Agents).

P. ramorum may be inadvertently introduced into forests in a variety of ways. Methods for preventing P. ramorum introductions are discussed below.