Floodplain ecology--Florida--Kissimmee River Watershed

Floodplains are important elements of river-floodplain systems. Numerous riverine fishes utilize floodplain habitats for reproduction, feeding, and protection. Largemouth bass and bluegill sunfish were tracked using radiotelemetry, and environmental parameters were measured at fish locations. Bass and bluegill used habitats with the same physical and chemical characteristics. Floodplain habitats were utilized frequently, as much as main river channel habitats. Fishes used habitats dominated by vegetation, with sand substrates, and that were more stable with regard to environmental conditions. Largemouth bass were more mobile than bluegill sunfish. Fish movements may have been in response to unfavorable environmental conditions, as more mobile fishes were associated with higher water temperatures and lower concentrations of dissolved oxygen.

This study focused on whether wetland vegetation could become re-established on a newly restored floodplain of the Kissimmee River if seasonal floodplain inundation were re-established. The wetland was re-created by back-filling a section of the Kissimmee Canal and diverting water flow into remnant river meanders. Seasonal flooding did occur during the study period. There were no other interventions to promote wetland plant growth. Ten vegetation quadrats were stratified between the back-filled canal and adjacent floodplain. These quadrats were monitored for 11 months. Of the 68 plant species recorded, 72% were obligate, facultative wetland or aquatic species. Diversity, richness, and percent cover of wetland plants increased with time. Coverage of broadleaf marsh habitat increased with increasing water depths. Vegetation at the end of the study period was similar to pre-channelized estimates. Restoration of hydrologic fluctuations appears sufficient to re-establish wetland habitat in this area of the Kissimmee River basin.