Big Bald

Treeless shrub or grass-dominated ridges and peaks are collectively called "balds". There are two principal types: heath balds and grassy balds (Ramseur 1960). While heath balds are dominated by a heavy coverof ericaceous shrubs, grassy balds aredominated by grasses and sedges, though scattered shrubs may be present. Balds tend occur at middle to high elevations in exposed locations. They range in area froman acre to several hundred acres. Surrounded by forests,balds often include significant rock outcrops, which should be included as parts of these communities.

The origin and maintenance of bald communities, particularly grassy balds,are not fully understood. Heath balds can form and persist in exposed, infertile landscapes that are not hospitable for trees. However, disturbances such as fires and logging that kill trees and cause soil erosion may play a role their formation (White and others 2001). Disturbance likely plays a more important role in the maintaining grassy balds which are shrinking in area due to invasion by woody plants (Lindsay and Bratton 1979). These balds were used as high elevation pastures by European settlers; their livestock prevented invasion by shrubs and trees. Grazing by bison (Bison bison ), elk (Cervus elaphus), and Pleistocene megafauna may have played a role in establishing these open areas (P. Weigel, personal communication). In a survey of grassy balds, Mark (1958) identified 34 areas he considered "true balds" that existed before European settlement and numerous other balds resulting from more recent clearing. During the early to mid-1900s, many grassy balds came under public ownership, grazing ceased and invasion by woody plants accelerated during the latter half of the 20th century. Now the national parks and forests are attempting to preserve some of these balds in an open condition.

Heath bald

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)
  

Big Yellow Mountain

Round Bald

Grassy balds are dominated by grasses, such as mountain oat grass (Danthonia compressa), and sedges (Carex spp.) (Wells 1937, Mark 1958, Whittaker 1956) occasionally interrupted by small rock outcrops. The largest of these balds occur at elevations over 5,000 ft along the North Carolina-Tennessee state line on the Roan Mountain Massif, the Unaka Mountains and the Great Smoky Mountains, and in the Nantahala Mountains of southwestern North Carolina. While there are no species recognized as being unique to these communities, they harbor regionally endemic and rare species of mammals, birds, and vascular plants associated with grasslands and high-elevation climates (Deselm and Murdock 1993). Example species include: Grays lily (Lilium grayi), Blue Ridge goldenrod (Solidago spithamaea), Roan Mountain bluet (Houstonia montana), Spreading avens (Geum radiatum), rock gnome lichen (Gymnoderma lineare), and alder flycatcher (Empidonax alnorum). Grassy balds cover broad open ridges and dome-shaped peaks, and their topography and environmentare more hospitable for plant growth and large animal use than those of heath balds. A few balds occupy gaps (Mark 1958).

Representative species of Grassy Balds:

• Mountain oat grass (Danthonia compressa)
• Pennsylvania sedge (Carex pensylvanica)
• Wavy hairgrass (Deschampsia flexuosa)
• Dwarf cinquefoil (Potentilla canadensis)
• Filmy angelica (Angelica triquinata)
• Wild strawberry (Fragaria virginiana)
• Allegheny blackberry (Rubus allegheniensis )
• Catawba rhododendron (Rhododendron catawbiense)
• Mountain ash (Sorbus americana)
• Flame azalea (Rhododendron calendulaceum)