SITE PREPARATION BURNING TO IMPROVE SOUTHERN APPALACHIAN PINE HARDWOODS - VEGETATION COMPOSITION AND DIVERSITY OF 13-YEAR-OLD STANDS

Stand restoration of low-quality, mixed pine-hardwood ecosystems conta ining a Kalmia latifolia L. dominated understory, through cutting, bur ning, and planting of Pinus strobus L., is common on xeric southern Ap palachian forest sites. We examined the effects of this treatment on e arly vegetation composition and diversity. Four 13-year-old stands wer e examined. Two of the four stands were mechanically released at age 6 . Density and basal area were estimated for understory and overstory c omponents, and density and percent cover for the herb component. Speci es diversity (Shannon-Wiener index) was estimated and comparisons were made between layers, sites, and treatments (release vs. nonrelease). Diversity estimates were 3.19, 1.74, and 2.45 for the herb, shrub, and overstory layers, respectively, across all sites and treatments. For perspective, comparisons were made with an untreated reference stand t hat was typical of stands receiving site preparation burning in the so uthern Appalachians. Overstory and herb diversity estimates were signi ficantly lower for the reference stand than for the 13-year-old stands .