The wetland zooplankton community occurring on the Savannah River Site (SRS) in South Carolina is remarkably diverse. Previous studies have indicated that over 100 species of microcrustacean zooplankton exist within this landscape, with individual wetlands hosting communities in excess of 25 species. This includes 11 Calanoids, at least 25 Cyclopoids, 61 Cladocerans, 2 fairy shrimps and 2 clam shrimps. A literature review reveals the zooplankton community on the SRS to be the most species rich among any comparable system yet studied. To address why this remarkable diversity occurs here, we began conducting a biweekly survey of the zooplankton communities of 15 wetlands representing a range of sizes, environmental conditions, and hydrology.
Preliminary results show that wetland hydroperiod has a uniquely strong impact on the species richness of a wetland. Also notable are temporal changes in richness across a hydroperiod, indicating that temporal turnover provides an additional mechanism for the explanation of alpha diversity. These results are of importance to ongoing debates over the mechanisms that promote diversity in semi-isolated ecosystems.