Carolina Hemlock Forests
Carolina hemlock (Tsuga caroliniana), a southern Appalachian endemic with a very limited range, dominates or co-dominates the forests of this group. These forests are found only in North Carolina, South Carolina, Tennessee, and Virginia, scattered in the southern Blue Ridge and occasionally in adjacent provinces. In Virginia, this vegetation occupies a few local areas on xeric mountain slopes of the Blue Ridge and Ridge and Valley in the southwestern part of state, south of the James River. A single stand is known from a river bluff in the southern Piedmont (Pittsylvania County). Sites are typically very steep and rocky, with shallow, nutrient-poor soils. Common associates are chestnut oak (Quercus montana, = Quercus prinus), white oak (Quercus alba), scarlet oak (Quercus coccinea), pines (Pinus spp.), blackgum (Nyssa sylvatica), and various ericaceous shrubs. Stand physiognomy varies from closed-canopy to very open, approaching a woodland structure. These communities often occur in patch-mosaics with fire-influenced oak/heath and pine-oak/heath vegetation. Fire may be an important factor that has limited Carolina hemlock, evidently a fire-intolerant species, to rocky areas and bluffs that are somewhat protected from burning. Currently, the introduced insect pest, hemlock woolly adelgid (Adelges tsugae), poses a major threat to the viability of Carolina hemlock stands. Community types in this group are generally considered globally rare.
References: Fleming and Coulling (2001), Rentch et al . (2000), Stevens (1971).