The Wetlands of Missouri
redwing blackbirds. Other animals at home in emergent marshes include leopard frogs, muskrats and dragonflies. Periodic fires and flooding help maintain the open, herbaceous (non-woody) nature of emergent marshes.
Deep marsh zones are at the margin between open water and wetland. They almost always are covered with standing water. Here we find aquatic plants such as pondweeds, spatterdock and water lilies. Grebes, ducks, geese, dragonflies and fish rely on these deep marshes for feeding and shelter. Swallows often forage for insects over them.
Sinkholes are natural depressions formed by the dissolution of limestone or the collapse of a cavern roof. When they contain water, they are considered a wetland type.
Water enters sinkholes from a combination of rain, overland flow and groundwater conduits. Sinkhole ponds are found in karst landscapes in the Ozarks.
Most sinkhole ponds are a striking contrast to the dry upland forests and open woodlands that surround them. Sinkhole ponds usually have an outer ring of buttonbush. The center of the pond may have open water but is dominated by sedges and grasses. A few sinkhole ponds harbor swamp trees, such as water tupelo. Because of their long isolation from other wetlands, sinkhole ponds may contain swamp loosestrife or other rare plants. Sinkhole ponds provide breeding habitat for spring peepers and many salamanders.
Buttonbush and short-statured willows dominate these often impenetrable wetland thickets. While they may be hard for us to navigate, shrub swamps provide homes for yellow warblers and green herons. Shrub swamps often are found in or near marshes, swamps or bottomland forests.
These primeval-looking wetlands are found only in the southeastern part of the state in the ancient floodplain of the Mississippi River. Trees that are usually associated with the Deep South, such as bald cypress (some are more than 500 years old), water tupelo and water locust, grow over open water around sloughs and oxbow lakes. These areas contain many interesting plants, such as water canna, swamp rose and water violet. You'll also find black-crowned night herons, green treefrogs and swamp darters.
Towering trees and vine lattices characterize mature bottomland forests. In the lowlands bordering a river are forests of cottonwood, willow, ash, elm, sycamore, silver maple and hackberry. Periodic flooding keeps the understory of these riverfront bottomland forests fairly open.
They provide habitat for gray treefrogs, red-shouldered hawks and northern parula warblers, as well as nesting trees for bald eagles and great blue herons.
On terraces farther from