Heath Balds
Heath balds are dominated by broad-leafed, evergreen shrubs adapted to harsh, xeric conditions. These shrubsinclude Catawba rhododendron (Rhododendron catawbiensis), rosebay rhododendron (R. maximum), Carolina rhododendron (R. carolinianum), mountain laurel (Kalmia latifolia ), and blueberries (Vaccinium spp.). Catawba rhododendron is dominant at higher elevations, and mixtures of the other species occupy lower sites (Schafale and Weakley 1990). Soils under the shrub cover are usually rocky, shallow, and acidic. The harsh soil conditions, heavy shrub cover, and thick leaf litter seem to preclude the establishment of trees making these stable, shrub dominated communities (Whittaker 1956, White and others 1993). The largest heath balds occur on steep south- and west-facingslopes of high rugged ridges. White and others (2001) described the topographic conditions associated with heath balds in the Great Smoky Mountains. They also found that many sites having similar topography were occupied by forest, not heath balds. While the factors leading to the establishment of these communities may be complex and stochastic, competitive interactions seem to prevent the invasion of trees once shrub dominance is established.
Representative species of Heath Balds:
- Catawba rhododendron (Rhododendron catawbiense)
- Rosebay rhododendron (Rhododendron maximum)
- Carolina rhododendron (Rhododendron carolinianum)
- Mountain laurel (Kalmia latifolia)
- Galax (Galax urceolata)
- Mountain ash (Sorbus americana)
Encyclopedia ID: p1596
