CHANGES IN SNAG-DWELLING INVERTEBRATE COMMUNITIES, KISSIMMEE RIVER, FLORIDA: RESPONSE TO RESTORATION OR RECOVERY FROM DROUGHT?

M.R. Alicia¹, D.H. Anderson², C.L. Rockett¹, and R.L. Lowe¹. ¹Deparment of Biology, Bowling Green State University, Bowling Green, Ohio 43403, ²Archbold Biological Station, Lake Placid, Florida 33862

The success of the Kissimmee River restoration in south-central Florida is being determined by the South Florida Water Management District with a comprehensive evaluation program. To aid this effort, we studied invertebrate communities in a reach of the river that has been utilized to test different restoration methods (weirs, backfilling), which have enhanced the flow conditions. We sampled in January 2001 during severe drought, which resulted in no flow, and again in January 2002 after sustained flow for greater than 6 months. Invertebrate communities were sampled on woody snags of a large live oak (Quercus virginiana) by taking 10 sweeps with a D-frame dipnet (500 micron mesh) and by collecting branch segments. Preliminary data indicate substantial changes in invertebrate communities between sampling dates, including a shift from dominance by chironomids to a mixture of chironomids and the polycentropid caddisfly Cyrnellus fraternus. This increase in Cyrnellus may indicate recovery from drought, rather than a restoration effect, because previous studies at the same site found moderate densities of Cyrnellus, when flow was present. This result indicates the need to consider potential confounding effects when evaluating restoration success.