Understanding and Managing Sudden Oak Death in California

Table of Contents

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Citation for this website:

Swiecki, T. J., Bernhardt, E. A. Understanding and Managing Sudden Oak Death in California. Phytosphere Research, Vacaville, CA. http://phytosphere.com/treeord/index.htm. Accessed: (Access date)

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About this site

Pesticide Precautionary Statement

Nondiscrimination statement

USDA Disclaimers

Authors

Acknowledgments

Preface

Part 1. Sudden Oak Death in California: An Overview

• 1.1. Diseases Caused by Phytophthora ramorum

SIDEBAR 1-1—Taxonomic Relationships Between Susceptible Trunk Canker Hosts

SIDEBAR 1-2—Native Foliar Hosts of Phytophthora ramorum

SIDEBAR 1-3—Host Susceptibility Versus Spore Production

• 1.1.1. Pathogen Biology

• 1.1.2. Origin and Distribution of Phytophthora ramorum in California

SIDEBAR 1-4—Strains of Phytophthora ramorum

• 1.2. SOD Disease Cycle in California Forests

• 1.2.1. SOD in Tanoak Stands

• 1.2.2. SOD in Oak / California Bay Forests

• 1.2.2.1. California bay–oak distance and disease risk—

• 1.2.2.2. Other sources of inoculum—

• 1.3. Factors That Influence SOD Development

• 1.3.1. Environmental Conditions

• 1.3.2. Variation in Host Susceptibility

• 1.3.2.1. Effects of tree size and condition—

• 1.3.2.2. Genetic resistance—

• 1.3.3. Pathogen Dispersal

• 1.4. SOD Development on Trunk Canker Hosts

• 1.4.1. Symptom Development

• 1.4.1.1.Canker location—

• 1.4.1.2. Early symptoms - bleeding cankers—

• 1.1.4.3. Late symptoms - secondary agents—

• 1.4.1.4. Patterns of canker development—

• 1.4.2. Patterns of Disease Progression

• 1.4.3. Survival of SOD-Affected Trees

SIDEBAR 1-5—Diagnosing SOD

• 1.5. Stand-Level SOD Impacts

Part 2. Managing Stands Before, During, and After SOD

• 2.1. Developing a SOD Management Plan

• 2.1.1. Why is Management Needed?

SIDEBAR 2-1—Costs of SOD-Related Mortality

• 2.1.2. Why Develop a Management Plan?

• 2.1.3. Elements of a Management Plan

SIDEBAR 2-2—Disease, Damage, and Mortality Related to Other Agents

• 2.2. Management Strategies for Different Stages of the SOD Epidemic

SIDEBAR 2-3—Time Considerations and SOD

• 2.2.1. Before: Reducing SOD Potential in Areas not Currently Infested

• 2.2.2. During: Managing Disease in Areas Currently Impacted by SOD

• 2.2.3. After: Dealing With Impacts of SOD

• 2.2.3.1. Survival and failure potential of SOD-affected trees

• 2.2.3.2. SOD-related mortality and fire—

• 2.2.3.3. Assessing restoration needs—

SIDEBAR 2-4—Restoration in Developed Versus Wildland Settings

• 2.3. Prioritizing Areas for SOD Disease Management Activities

• 2.3.1. Prioritization Categories

• 2.3.2. Developing Overall Priority Rankings

SIDEBAR 2-5—Developing a Numeric Priority Ranking Scale

Part 3. Technical Management Guidelines

• 3.1. Excluding P. ramorum From Non-Infested Areas

• 3.1.1. Nursery Stock

• 3.1.2. Plant Material – Pruning Waste, Wood

• 3.1.3. Firewood

• 3.1.4. Soil

• 3.1.5. Water

SIDEBAR 3-1—Cleaning Contaminated Tools and Equipment

• 3.2. Reducing Disease Risk in Susceptible Stands

• 3.2.1. Timing of Pruning or Other Wounding

• 3.2.2. Removing California Bay

• 3.2.2.1. Oak forests—

• 3.2.2.2. Tanoak forests—

• 3.2.2.3. California bay removal strategies—

• 3.2.2.4. Oak-California bay clearance distance—

• 3.2.2.5. Timing of California bay removal operations—

• 3.2.2.6. Mechanical removal—

• 3.2.2.6.1. Dealing with cut bay—

• 3.2.2.7. Herbicides—

• 3.2.2.8. Sprout regrowth / retreatment intervals—

• 3.2.3. Removal of Other Sporulating Hosts

• Climbing poison oak—/

• Other species—

• 3.2.4 Use of Chemical Protectants to Prevent Infection

SIDEBAR 3-2—Selecting and using fungicides

• 3.2.4.1. Fungicide treatment of tanoak—

• 3.2.4.2. Fungicide treatment of oaks—

• 3.2.4.3. Use of phosphites (phosphonates) to manage SOD—

• 3.2.4.3.1. Environmental and user safety—

• 3.2.4.3.2. Comparison of application methods—

3.2.4.3.3. Injection—

3.2.4.3.4. Bark spray application (basal bark spray)—

• 3.2.5. Non-recommended treatments—

• 3.3. Monitoring Oaks With SOD to Assess Survival and Failure Potential

• 3.3.1 Overview

• Sources of information on tree hazard assessment methods—

• 3.3.2. Guidelines for Assessing SOD-Related Mortality and Failure Risk

• 3.4. Assessing Fire Hazard Related to SOD-Killed Trees

• 3.5. Restoring SOD-Affected Forests

• 3.5.1. Species Selection

• 3.5.2. Factors That Constrain Regeneration

• 3.5.3. Natural Regeneration

• 3.5.4. Planting

• 3.5.5. Monitoring restoration outcomes

English Equivalents

References