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 Discula destructiva, were measured on 39 plots located at the Coweeta Hydrologic Laboratory in western North Carolina. The 0.08-ha plots were selected along transects across watersheds previously clearcut, partially harvested, or not harvested. Basal diameter, percent leaf area with dogwood 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. Density of C. florida was greatest on the clearcut watershed, and the number of dogwood stems was inversely correlated (r = -0.31, P = 0.05) with disease severity. Dogwood basal area, species importance value, and stand basal area were not significantly affected by harvest treatment and were not correlated with disease severity. In a second study, anthracnose severity was rated in 21 plots of yellow poplar near Asheville, North Carolina, that had been thinned to varying densities in the early 1960s. Among these 0.1-ha plots, thinning intensity did not affect disease severity. Disease severity was inversely related to dogwood size.