The Upland System is classified into four major types: cliff and talus, glades and outcrops, grass-dominated communities (prairies, barrens, balds, savannas), and tree and shrub-dominated communities (forests, woodlands, shrublands). The cliff and talus community is a bedrock-dominated and sparsely vegetated community associated with vertical, near-vertical, or overhanging cliffs and their associated rocky clifftops and their non-forested talus communities located at the cliff base (if present) (Larson et al. 2005). Glades and outcrops are similar to cliffs in having exposed bedrock at or near the surface and by being sparsely vegetated but range from level to steeply sloping but are not vertical or nearly so. Grasslands and savannas are represented by prairies, barrens, balds, and savannas, communities that are generally dominated by perennial grasses but which may have scattered shrubs or scattered trees (<30% canopy coverage). Forests, woodlands, and shrublands are communities where the uppermost stratum consists of either trees or shrubs that cover more than 30% of the site.