Plant communities in the Mississippi River corridor fall into two major biomes - eastern deciduous forest and tallgrass prairie. These communities are only remnants of pre-settlement vegetation that have survived fire, logging, agricultural expansion, and urbanization. They include floodplain forest, upland prairie, maple-basswood forest, oak-savanna, oak woodland, lowland hardwood, dry oak forest, mesic oak forest, brush land, wetlands, wet meadows, and rare fens. Floodplain forests and wetlands are considered sensitive habitats and are a high priority for protection. They are very important for reducing the adverse effects of flooding, maintaining water quality, providing wildlife habitat, and biological diversity.

By 1880, these natural plant communities were forever altered. Today only 6% of the total area that remains is native habitat (Marschner 1974, Minnesota County Biological Survey 1995). About 6% of the forests and 1% of the prairies present at the time of Euro-American settlement exist today. There is only 3% of the oak savanna and woodlands and 25% of the floodplain forests and swamps. Less than 11% of the marshes and wetmeadows are intact. Still, remnants of these pre-settlement plant communities can be found along the Mississippi’s banks and upland areas. While these once dense stands of upland and floodplaindeciduous forests, open savanna and upland prairie are few and far between they do exist if one knows where to go and what to look for.

The remaining native plant communities that are scattered throughout the Mississippi River corridor support significant populations of mammals, birds, fish, and amphibians. They also contain species that are considered rare, threatened, or endangered as well as a variety of introduced and invasive exotic species that, if not controlled, threaten the integrity or existence of the native plant communities. Examples of invasive species that are difficult to control include common buckthorn, garlic mustard, spotted knapweed, and Canadian thistle.  Restoration of native plant communities and removal of exotic species are high priorities for the Mississippi River corridor.