EFFECT OF TIMBER HARVEST PRACTICES ON POPULATIONS OF CORNUS-FLORIDA AND SEVERITY OF DOGWOOD ANTHRACNOSE IN WESTERN NORTH-CAROLINA

Stand composition and severity of dogwood anthracnose, caused by Discu la destructiva, were measured on 39 plots located at the Coweeta Hydro logic Laboratory in western North Carolina. The 0.08-ha plots were sel ected along transects across watersheds previously clearcut, partially harvested, or not harvested. Basal diameter, percent leaf area with d ogwood anthracnose symptoms, and percent branch dieback were estimated for Cornus florida. Dogwood anthracnose was most severe on partially harvested watersheds and least severe on the clearcut watershed. Densi ty of C. florida was greatest on the clearcut watershed, and the numbe r of dogwood stems was inversely correlated (r = -0.31, P = 0.05) with disease severity. Dogwood basal area, species importance value, and s tand basal area were not significantly affected by harvest treatment a nd were not correlated with disease severity. In a second study, anthr acnose severity was rated in 21 plots of yellow poplar near Asheville, North Carolina, that had been thinned to varying densities in the ear ly 1960s. Among these 0.1-ha plots, thinning intensity did not affect disease severity. Disease severity was inversely related to dogwood si ze.