Understanding and Managing Sudden Oak Death in California

SIDEBAR 2-1—Costs of SOD-Related Mortality

The loss of SOD-susceptible species from forests can lead to significant losses in ecosystem services. For example, many animals eat acorns, and many birds are dependent on the rich diversity of insects that are associated with oaks. In addition, acorns provided by oaks and tanoaks have an important place in the traditional cultures of many Native American tribes. Because SOD-related impacts may depend on the roles of individual trees or groups of trees in the landscape, a given amount of tree mortality can have widely different effects in different areas. Individual trees or groups of trees may be important for erosion protection, visual screening, or property values.

Trees killed by SOD may also impose additional costs and risks. Undesirable plant species may invade canopy gaps created by tree mortality, increasing the need for monitoring and suppression activities. The increased failure potential of SOD affected trees (see below 2.2.3 After: Dealing with Impacts of SOD) can put lives, property, and other resources at risk. Steps taken to mitigate the risk of tree failure, such as tree removal, can be costly. Tree and debris removal may also be needed to mitigate increased fire hazards due to fuels from SOD-killed trees.

Landowners with SOD-affected forests may therefore both lose valuable services provided by trees and incur additional costs associated with adverse effects of SOD-related mortality. The costs of management activities that can reduce SOD-related impacts need to be considered in comparison to the losses that would be incurred if no actions are taken.