BIOLOGICAL FUNCTIONS

Wetlands are among the most diverse and productive ecosystems in the world. In terms of number and diversity of species supported, they compete with tropical rainforests and coral reefs. In terms of primary production rates, wetlands have no rival. The unique hydrology of wetlands allows them to serve as nurturing havens for a wide range of highly specialized and environmentally sensitive species (Mitsch and Gosselink 1986).

There are many plant species that are dependent upon wetland hydrology for their survival. In Illinois, approximately 42 percent of all the native plant species are wetland species (Illinois Department of Natural Resources 1994). There are also are a number of plant species usually associated with upland areas that can survive in wetlands. The USF&WS has identified a total of 6,728 species of plants that occur in wetlands throughout the United States (Reed 1988). Because wetlands are highly productive and support a diversity of plant life, they are an important source of food and habitat for wildlife. This productivity helps support commercial and recreational fish and waterfowl harvests throughout the Illinois and the rest of the world (Illinois Department of Natural Resources 1997).

There are several species of animals dependent upon wetlands for their day to day survival. Most people readily identify some of these animals, such as frogs and ducks, as wetland species. There are, however, many other species of wildlife usually associated with upland or deepwater areas that depend on or use wetlands for feeding, spawning, and/or resting grounds at some point in their life cycles. Most people do not readily identify these various species of shiners, sunfish, bats, and terns with wetlands. They also do not realize many well-known species, such as bald eagles and bobcats, are also commonly found in and around wetlands. The following statistics reflect the diversity of organisms that use wetlands in Illinois.

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