Black Oak (Quercus kelloggii) Multiple Management Release Restoration in California

Oaks are a keystone species, aid in regulating many ecological processes, provide critical habitat and are a food source for many wildlife species. However, there is mounting documentation that various California oak species (Quercus spp.) are not regenerating or have begun to decline. Due to this decline, there is a strong movement toward multiple management oak habitat release restoration; nevertheless, effectiveness of this type of restoration is not well studied. We evaluated two multiple management release restoration projects on black oaks (Quercus kelloggii) as a case study. We evaluated the effectiveness of two previously multiple managed sites for black oak restoration in the Shasta-Trinity National Forest in northern California. Multiple management consisted of timber acquisition, fuel reduction, and black oak release. Multiple management involved conifer removal, woody debris mastication and the selected retention of black oaks. This type of multiple management is thought to release oaks from competition from coniferous trees, giving oaks more access to water, sunlight and nutrients. Managed sites had lower black oak tree and sapling densities than unmanaged sites. Results suggest that the multiple management oak habitat release restoration projects provide no benefits for black oaks. It is possible that the heavy machinery used in the multiple management for timber acquisition and woody debris mastication decreased the viability of the oaks and oak saplings in the managed sites.