Appalachian balds

Two types have been identified: those completely covered by grasses and those with a scattered overstory of mixed hardwoods with a grassy herbaceous layer.

rudgei, Carex pensylvanica), and forbs such as three-toothed cinquefoil (Sibbaldiopsis tridentata) and Blue Ridge St. Johns-wort (Hypericum mitchellianum).

[3] Heath balds are typically found along narrow ridges and mountain crests, and consist of dense evergreen shrubs.

[4] Weigl and Knowles note that "the presence of both rare, endemic plants and northern relicts requiring open habitat suggests a long evolutionary history" and offer a scenario in which grazing pressure of the giant herbivores of the Pleistocene retained the open tundra habitat as the Wisconsin glaciation retreated far to the north.

Some recent studies have attempted to uncover the vegetation history of some balds through analysis of the soil's organic component, since grasses leave a characteristic carbon-13 fingerprint.