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An Evaluation of Plant Community Structure, Fish and Benthic Meio- and Macrofauna as Success Criteria for Reclaimed Wetlands

03-086-135Final

Abstract:

As a result of legislative action in 1975 (Florida Administrative Code Section 16C-16, 16C-17), landscape reclamation is required on all lands mined for phosphate in the State of Florida. Between 1975 and 1991, for example, approximately 40,000 ha of land in Florida were strip mined for phosphate and thus subject to provisions of this legislation. In excess of 2,700 ha of mitigation wetlands have been constructed as part of the land reclamation effort, but the degree to which these systems mimic both the structural and functional properties of natural wetlands is poorly known.

There has been a great diversity in the type of wetland created on phosphate mined lands. The basic design has ranged from relatively steep sided systems with a large proportion of open water areas to shallow swales that quickly become colonized throughout by emergent macrophytes. As a presumed aid in system succession, some constructed wetlands have been lined with a layer of organic sediment collected from donor wetlands in areas to be mined, while the bottoms of other wetlands were left as bare inorganic sediments. Some wetlands were planted with select taxa immediately upon flooding, while plant succession via volunteer taxa was allowed to proceed unimpeded in others. Finally, pronounced interbasin differences in hydrological regime are common among constructed wetlands throughout the phosphate region.

The current study was designed to address two major gaps in our knowledge of wetlands constructed on phosphate mined lands of Florida:

  1. Succession of ecosystem structure and function
  2. Development of bioindicators for evaluating water quality