Bedrock Grassland is a unique group that includes one natural community type, alvar. Alvar is a grassland community that occurs on level exposures of limestone and dolomite bedrock and thin soils over these calcareous bedrock types. Alvar occurs on the Niagaran Cuesta in the eastern and south-central Upper Peninsula and northeastern Lower Peninsula. Alvar is characterized by the dominance of grasses and sedges with scattered shrubs and trees. Bedrock Grassland is differentiated from Bedrock Glade based on canopy cover. Bedrock Grasslands typically support less than 10% canopy cover whereas Bedrock Glades support between 10 and 60% canopy cover.