Tree & Forest Health

Tree and forest health are affected by many issues, including drought, tree pests, wildfire, among others. This page provides information on the specific concerns in San Diego County, as well as suggestions on what you can do to make a difference.


Don’t move firewood: Destructive insects and diseases often lurk in firewood. Moving firewood can help transport pests that destroy trees and forests – sometimes even hundreds of miles away. Click here to learn how to protect the trees you love from tree killing bugs:

Tree mortality crisis: Due to the deadly combination of drought and bark beetles, California is experiencing a tree mortality crisis. Weakened by four consecutive years of drought, over 66 million conifers and hardwood trees have succumbed to bark beetle attacks, and died. This is a serious issue – especially as it pertains to wildfire – that needs all of our support.


Goldspotted Oak Borer (GSOB) Agrilus auroguttatus is an invasive pest contributing to the on-going oak tree mortality occurring on federal, state, private, and local Native American lands in many areas of San Diego County.  Due to the current and potential impacts to California oaks and communities, public and private organizations are working together in the research, education and outreach efforts related to GSOB management.

The Oak Grove GSOB Project is supported as a California Department of Conservation Regional Forest and Fire Capacity Demonstration Project through the Resource Conservation District of Greater San Diego County. This video shows how to save our great oak trees by using the practical tools and techniques developed by a UC Wildlife Biologist and Certified Arborist. 

Learn more about GSOB identification, impacts, and distribution at

Shot Hole Borers: The Polyphagous SHB and Kuroshio SHB attack many types of trees, including native, ornamental, and fruit trees (such as avocado), destroying both natural environments and commercial groves. They spread a disease called Fusarium Dieback, which can lead to tree mortality. The Polyphagous SHB and Kuroshio SHB are different insects, and currently only KSHB is known to occur in San Diego County. However, the two insects and the damage they do are very similar.

Click here for an overview on the two beetles, including links to a wide variety of resources: