Most natural grasslands of the world are maintained by fire, grazing or climatic factors (e.g. lack of rainfall, persistent cold/freezing in tundra), but in the depths of some of the deepest river gorges of Southern Appalachia are poorly known flood-maintained grasslands known to community ecologists as riverscours.
#3 Nashville Basin Limestone Savanna
#2 Blue Ridge Montane Basins Shortleaf Pine-Post Oak Savanna
The Blue Ridge Montane Basins Shortleaf Pine-Post Oak Savanna (found in portions of southwestern North Carolina near Hayesville, northern Georgia, and extreme southeastern Tennessee) is extremely poorly known. One of the earliest (1818) references to vegetation from this region recorded shortleaf pine and post oak. A high incidence of shortleaf pine and post oak would suggest adaptation to fire.
#1 Blue Ridge Serpentine Barrens
One of the rarest of all grassland types in the world is the Blue Ridge Mountains Serpentine Barrens! This community is represented by just a couple of examples in western North Carolina. The heavy metals in the soil resulting from the underlying serpentine rock combined with shallow soils, make these steep mountainsides more suitable to open woodlands and grassy barrens instead of forests.
