MACROINVERTEBRATE COMMUNITY STRUCTURE AS A PREDICTOR OF WATER DURATION IN WISCONSIN WETLANDS

In 54 wetlands located across an environmental gradient in Wisconsin, the relationship between hydroperiod and macroinvertebrate community structure was examined. Five wetland hydroperiod classes were defined based on the average water duration in a typical nondrought year. Canonical correspondence analysis was used to explore the relationship between the macroinvertebrate community structure and 11 environmental variables consisting of water duration and ten chemical parameters. Mayflies, scuds, pygmy backswimmers, dragonflies, phantom midges, a caddisfly, and some snails were chosen as persistent indicator taxa; fairy shrimp, mosquitoes, some snails, a cased caddisfly, damselflies, and backswimmers were selected as ephemeral indicators; and spiders, worms, sowbugs, rove beetles, and terrestrial insects were selected to represent dry or riparian habitats. The subsequent development of a predictive model revealed that the hydroperiod of a wetland could be predicted based on the occurrence of specific taxa.