Lakeplain oak openings occur within glacial lake plains on sand ridges, level sandplains, or adjacent depressions. This fire-dependent savanna type is dominated by oaks and has a graminoid-dominated ground layer of species associated with both lakeplain prairie and forest communities. Within this community are the:
Lakeplain wet prairies occur on the glacial lake plains of the Great Lakes in southeastern Wisconsin, northeastern Illinois, northern Indiana, southern Michigan and northern Ohio; and in southern Ontario, Canada. Included in this community type is the:
Lakeplain wet-mesic prairies occur along the glacial lake plains of the Great Lakes, in southeastern Wisconsin, northeastern Illinois, northern Indiana, southern Michigan, and northwestern Ohio, as well as in southern Ontario, Canada. Included in this community is the:
Wet-mesic flatwoods is a somewhat poorly drained to poorly drained forest on mineral soils dominated by a mixture of lowland and upland hardwoods. Seasonal hydrologic fluctuations and windthrow are important natural disturbances that influence community structure, species composition, and successional trajectory of wetmesic flatwoods. Included in this community type is the:
Floodplain forests occupy the low-lying areas adjacent to streams and rivers which are third order or greater and subject to periodic over-the-bank flooding and cycles of erosion and deposition. The floodplain forest is a broadly defined community type, where species composition and community structure vary regionally along with varying flooding frequency and duration. Silver maple Acer saccharinum and red ash Fraxinus pennsylvanica are the major overstory dominants. These dynamic forested systems represent an interface between terrestrial and aquatic ecosystem
Alvar (alvar grassland) is a grass- and sedge-dominated community, with scattered shrubs and sometimes trees. Alvar occurs on broad, flat expanses of calcareous limestone or dolomite (dolostone) bedrock covered by a thin veneer of mineral soil, often less than 25 cm deep. Alvars are only known from three areas of the world: the Basaltic region of northern Europe, County Clare of northwest Ireland, and the Great Lakes region south of the Canadian shield. While the MNFI site shows the range of this type of community located in norther Michigan, small relics of this type of system have been found in Monroe County Michigan and Lucas County Ohio.