Oak decline is a complex disease involving interactions between initiating environmental or biological stresses and subsequent attack by normally secondary pests. It causes crown dieback, reduced radial growth and tree mortality, which in tum, influences wildlife habitat. In upland hardwood stands, oaks (Quercus spp.) are affected most while other species infrequently show crown symptoms or mortality. Recent surveys of declining stands in the southeastern United States show that 80% of the dominant and codominant trees are affected. Species in the red oak group are damaged more than those in the white oak group, with black (Q. velutina) and scarlet (Q. coccinea) oaks most prone to mortality. The annual increase in newly symptomatic trees is estimated at 6.5%. Potential wildlife habitat impacts include reduced mast yield and quality, reduced oak regeneration capacity, and altered species composition in subsequent stands. Estimates of current and 5-year projected mast yield in an affected stand show a 41% current reduction and a 58% projected reduction when compared to potential mast yield without decline. The consistent association of damage with specific stand and site conditions indicate that risk rating systems can be developed to guide management decisions. Habitat managers should consider oak decline in inventory procedures and resource management planning.
Wildlife Outstanding Technical Paper