摘要：In southwest Georgia there are three types of shallow, seasonally inundated limesink wetlands based on soil characteristics and vegetation—grass-sedge marshes, cypress savannas, and cypress-gum swamps. We sampled wetlands of the three types from February 1997 through June 1998 during early, mid, and late hydroperiod in 1997. The wetlands had similar water chemistry soon after inundation. Over time, water in swamps generally had higher levels of dissolved organic carbon, NH 4 -N, NO 3 -N, and PO 4 -P, was more darkly stained, and had lower temperatures than in other wetland types. We collected 121 macroinvertebrate taxa, with 40 taxa occurring in >10% of the samples. Marshes had higher macroinvertebrate numbers and taxa richness than other wetland types. Early in the hydroperiod, macroinvertebrate assemblages were composed of taxa that overwintered in wetlands. Later, predators were abundant in the marshes, and detritivore numbers declined in swamps. Our findings suggest that water quality is influenced by interactions of vegetation, soils, and time since inundation. We believe that macroinvertebrate assemblages differed among the wetland types due mainly to vegetation. Macroinvertebrates in marshes probably have a wider variety of food sources (i.e., algae) and greater habitat structure available, whereas in swamps macroinvertebrates have more stressful conditions (i.e., low dissolved oxygen) caused by processing of large detrital inputs.
