Decay Fungi Associated with Oaks and Other Hardwoods in the Western United States.

An assessment of the presence and extent of the wood decay process should be part of any hazard tree analysis. Identification of the fungi responsible for decay improves both the prediction of the consequences of wood decay and the prescription of management options including tree pruning or removal. Until the outbreak of Sudden Oak Death (SOD), foresters in the Pacific Northwest emphasized conifer diseases and decay with little attention to hardwood pathology. The SOD outbreak has drawn attention to hardwood tree species, particularly for the urban forest in which native or introduced hardwoods may predominate. Consequently, the hazard tree specialist needs a working knowledge of the fungi associated with hardwood decay. We present here some of the common fungi responsible for decay of hardwoods, particularly of oak, tanoak (Lithocarpus densiflorus), and chinquapin (Castanopsis spp.) in the West.