The Wetlands of Missouri
Water is the essence of life, so it should come as no surprise that Missouri's wetlands provide some of the state's richest wildlife habitat. In fact, nearly half of Missouri's total plant species are associated with wetlands, and more than a quarter of Missouri's nesting and migratory birds depend on wetlands for part of their life cycle.
Wetlands are the primary habitat of 200 plant and animal species considered rare or endangered in Missouri. Millions of ducks and shorebirds that migrate through the state each year depend on wetlands for food and shelter. Missouri's 43 species of amphibians depend on wetlands for breeding and larval development.
Many people think of marshes when they hear the word "wetlands," but in Missouri we have nine different wetland natural communities (not counting man-made ponds and lakes). They include marshes, shrub swamps, bottomland prairies, bottomland forests, swamps, sinkhole ponds, oxbow lakes and sloughs, riparian areas and groundwater seeps.
Most natural wetlands change continually, and all have a high degree of biological productivity and diversity. They have soils that develop in saturated conditions and support water-tolerant plants. A wetland's seasonal pattern of water levels drives the establishment and maintenance of specific wetland plants.
From a river's edge to upland slopes, the floodplains of Missouri's rivers and streams contain most of our wetland acreage. Marshes, shrub swamps, bottomland prairies, swamps, oxbow lakes and sloughs, riparian areas and bottomland forests all depend on flowing water and periodic flooding.
Sinkhole ponds and groundwater seeps are usually located in upland areas. Despite their smaller acreage, these lesser-known wetland types are extremely important to our state's biological diversity.
Natural marshes usually develop in remnant river channels and around oxbow lakes and sloughs in north, west, central and southeast Missouri. They are usually categorized by the depth of the standing water. For example, shallow marsh zones, sometimes called wet meadows or moist-soil wetlands, have moist to saturated soils with standing water present sporadically during the growing season. Plants growing there include smartweeds, nut sedges and bur marigolds. Shallow marshes provide important foraging habitat for migratory ducks and shorebirds. They also provide habitat for Woodhouse's and spadefoot toads.
Emergent marsh zones have standing water for long periods during the growing season. This allows the establishment of wetland plants like cattails, bulrushes, bur-reed, arrowheads and sedges. They provide habitat for many rare marsh birds, including bitterns, sora and king rails, pied-billed grebes and moorhens, as well as more common species, like