A COMPARISON OF DIPTERANS FROM 10 CREATED AND 10 NATURAL WETLANDS

This study compares densities of common larval dipterans collected fro m areas dominated by Pontederia cordata in 10 natural and 10 created f reshwater herbaceous wetlands in central Florida. At each wetland, 7 c ore samples were collected from each of 5 stations during summer 1993. In addition, stem densities, vegetation areal coverage, pH, dissolved oxygen, water temperature, water depth, conductivity, sediment qualit y, and leaf litter were measured at 3 locations near each of the 5 sta tions in each wetland. Of the 57 dipteran taxa collected, 20 occurred with sufficient abundance to justify statistical comparison. Despite a large sampling effort, there were no significant differences in densi ties of 20 commonly occurring taxa found in created and natural wetlan ds after considering the effect of multiple univariate tests. Comparis on of environmental variables showed significant differences in stem d ensities for vegetation other than P. cordata, pH, conductivity, and s ediment quality. Canonical correspondence analysis, used to relate env ironmental and biological variables, suggests that pH, conductivity, a nd sediment quality are only weakly related to dipteran community stru cture. Despite differences in environmental conditions, there is no co nvincing evidence of differences in natural and created wetland dipter an communities.