Oaks are an important part of the California ecosystem and are considered to be one of the state’s major types of vegetation. To most people, it might just be another tree, but oaks are considered to be a foundation species, in the sense that their presence defines and supports an entire ecological community. Oak woodlands are their own important habitat, providing crucial shelter, foraging opportunities, and watershed protection, along with enhancing the aesthetic value of the California landscape. Whether we know it or not, oak woodlands are right in our backyard. Oak woodlands in Orange County consist almost entirely of Coast Live Oak, an evergreen tree that extends up and down the California coast.
Over the years, these woodlands have been considered at-risk due largely to habitat conversion by humans, which has reduced the trees to 50% of their historical range or less. Other factors in the decline of oak woodlands in California are competition with non-native species, cattle grazing, drought, and new pathogens. One example of a new pathogen that has affected Coast Live Oaks in Orange County is the Goldspotted Oak Borer. This particular pest is native to Arizona and was first identified in California in 2004, but was not linked to extensive oak mortality until 2008.