Vegetation Patterns on a Southern Appalachian Watershed after Successive Clearcuts

ABSTRACT
A 16.1 hectare watershed at Coweeta Hydrologic Laboratory in southwestern North Carolina was clearcut in 1939-1940 and again in 1962. No timber was removed during the clearcuts. Present vegetation composition (woody and herbaceous species), and tree species distributions in relation to site characteristics were of primary interest. <em>Liriodendron tulipifera</em> had the highest basal area and Importance Value (IV) of all tree species; <em>Quercus prinus</em> had the highest density, <em>Acer rubrum</em> the highest frequency. Stand basal area in 1984, 21 years after the second clearcut was 20.82 m2 ha-l which is over 80% of that before the first clearcut. <em>Kalmia latifolia</em> and <em>Rhododendron maximum</em> have responded vigorously to past clearcuts; and, the herbaceous layer is far from depauperate. Of the site variables measured, those related to site quality were the best predictors of the dominant species and the community types. <em>Liriodendron tulipifera</em> and the Cove Hardwoods community type are highly and positively correlated with higher soil moisture, pH, and fertility, whereas <em>Quercus prinus</em> and the Mixed Oak/Oak-Pine types are negatively correlated with these variables. Mesic species, especially <em>Liriodendron tulipifera</em> and <em>Betula lenta</em> have increased tremendously in importance since the inventory made in 1934 which was prior to either clearcut and the full effect of chestnut blight in this region. These species now occupy portions of the watershed which previously supported less mesic species (e.g., <em>Quercus</em> spp.) and the watershed appears to be supporting vegetation of a more mesic nature.