Regional Landscape Ecosystems of Michigan, Minnesota, and Wisconsin
SUB-SUBSECTION IV.3.3. Mississippi River Ravines
DISCUSSION: This subsection is designated on the basis of extensive sugar maple-basswood-dominated forests, concentrated in the steepest, most fire protected topography along the Mississippi River and some of its major tributaries.
ELEVATION: 625 to 1,378 feet (190 to 420 m).
AREA: 1,695 square miles (4,393 sq km).
STATES: Minnesota.
CLIMATE: See section.
BEDROCK GEOLOGY: Large exposures of bedrock occur in the steep ravines, primarily Ordovician dolomite, limestone, and sandstone; and Cambrian sandstone, shale, and dolomite are exposed along the valley walls of the Mississippi River (Morey 1981, Sims et al. 1966).
LANDFORMS: See section.
LAKES AND STREAMS: No natural lakes. The Mississippi River forms the eastern boundary of the sub-subsection.
SOILS: Soils are silt loam (loess) over residuum; texture of the residuum ranges from clay to sand (Cummins and Grigal 1981). The underlying bedrock is dolomite. Soils are classified as Udalfs on ridges and Orthents on flood plains (Anderson and Grigal 1984, Cummins and Grigal 1981).
PRESETTLEMENT VEGETATION: Maple-basswood forest on highly dissected topography of the sub-subsection, protected from fire by the steep ravines of the Mississippi River and its major tributaries.
NATURAL DISTURBANCE: Fire was probably less prevalent within the maple-basswood forest than in adjacent oak savanna or prairie.
PRESENT VEGETATION AND LAND USE: Most of the forest has been cleared for agriculture except on the steep valley walls.
RARE PLANT COMMUNITIES: None identified to date.
RARE PLANTS: Dodecatheon amethystinum (jewelled shooting star), Sanicula trifoliata (black snakeroot), Solidago sciaphila (cliff goldenrod), Talinum rugospermum (rough-seeded fameflower).
RARE ANIMALS: Fish: Lampetra appendix (American brook lamprey), Notropis amnis (pallid shiner), Notropis emiliae (pugnose minnow), Cycleptus elongatus (blue sucker), Ictalurus furcatus (blue catfish), Etheostoma chlorosomum (bluntnose darter), Ammocrypta asprella (crystal darter); Mussels: Fusconaia ebena (ebony shell), Elliptio crassidens (elephant ear); Insects: Cicindela splendida cyanocephalata (tiger beetle); Arthropods: Sassacus papenhoei, Phidippus apacheoanus (jumping spiders).
NATURAL AREAS: State Natural Areas: Kellogg-Weaver Dunes, Mound Prairie, Rushford Sand Barrens. Research Natural Areas: Reno Bottoms.
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| Figure 17.—Sub-subsection IV.3.3: Extensive flood plain forest occupies the broad flood plain of the Mississippi River in the foreground. The highly dissected slopes of the Driftless Area (Paleozoic Plateau) are in the background. Minnesota Department of Natural Resources photo by H. Dunevitz. |
PUBLIC LAND MANAGERS: State Parks: Beaver Creek Valley, Forestville, O.L. Kipp, John A. Latsch Whitewater. State Forests: R.J. Dorer. State Trails: Root River. Wildlife Management Areas: Keller, McCarthy Lake, Whitewater. Other: Upper Mississippi River Wildlife and Fish Refuge.
CONSERVATION CONCERNS:
BOUNDARIES: Boundaries are based on my interpretations of Marschner (1974) and topographic maps.
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