A characterization of the data, including its intended use and limitations.
Abstract: Florida's lakes provide important habitats for plants, birds, fish, and other animals, and comprise a valuable resource for human activities and enjoyment. More than 7,700 lakes are found in Florida, and they occur in a variety of ecological settings. The physical, chemical, and biological diversity of these lakes complicates lake assessment and management. In many states, it has been shown that water resources can be managed more effectively if they are viewed within a regional framework that reflects differences in their quality, quantity, hydrology, and their sensitivity or resilience to ecological disturbances. To develop cost effective lake management strategies that protect or restore water quality in Florida lakes, regional differences in the capabilities and potentials of lakes must be considered. Hydrologic unit or basin frameworks are often used for water quality assessments and ecosystem management activities, but these units or basins do not correspond to the spatial patterns of characteristics that influence the physical, chemical, or biological nature of Florida lakes. General patterns of geology and physiography have been used previously to explain regional differences in Florida lake water chemistry (Canfield and Hoyer 1988; Pollman and Canfield 1991), and ecosystem characteristics of Florida lakes have been summarized (Brenner et al.1990). Building on this work, as well as on a Florida ecoregion framework (Griffith et al. 1994), we have defined these forty-seven lake regions as part of the Florida Department of Environmental Protection's (FL DEP) Lake Bioassessment/Regionalization Initiative.
The spatial framework was developed by mapping and analyzing water quality data sets in conjunction with information on soils, physiography, geology, hydrology, vegetation, climate, and land use/land cover, as well as relying on the expert judgment of local limnologists and resource managers. This framework delineates regions within which there is homogeneity in the types and quality of lakes and their association with landscape characteristics, or where there is a particular mosaic of lake types and quality. More detailed descriptions of methods, materials, and lake region characteristics can be found in Griffith et al. (1997). The identifier for each lake region consists of two numbers: the first number (65, 75, or 76) relates to the United States Environmental Protection Agency (US EPA) ecoregion number (Omernik 1987; US EPA 1997), and the second number refers to the Florida lake regions within an ecoregion. The Florida lake regions and associated maps and graphs of lake chemistry are intended to provide a framework for assessing lake characteristics, calibrating predictive models, guiding lake management, and framing expectations by lake users and lakeshore residents.
Literature cited:
Brenner, M., M.W. Binford, and E.S. Deevey. 1990. Lakes. In: Ecosystems of Florida. R.L. Myers and J.J. Ewel (eds.). University of Central Florida Press, Orlando, FL. pp. 364-391.
Canfield, D.E., Jr., and M.V. Hoyer. 1988. Regional geology and the chemical and trophic state characteristics of Florida lakes. Lake and Reservoir Management 4(1):21-31.
Griffith, G.E., J.M. Omernik, C.M. Rohm, and S.M. Pierson. 1994. Floridaregionalization project. EPA/600/Q-95-002. U.S. Environmental Protection Agency, Corvallis, OR. 83p.
Griffith, G.E., D.E. Canfield, Jr., C.A. Horsburgh, J.M. Omernik, and S.H. Azevedo. 1996. Lake regions of Florida. Report to the Florida Department of Environmental Protection. U.S. Environmental Protection Agency, Corvallis, OR.
Omernik, J.M, 1987. Ecoregions of the conterminous United States (map supplement, scale 1:7,500,000): Annals of the Association of American Geographers 77(1):118-125.
Pollman, C.D. and D.E. Canfield, Jr. 1991. Florida. In: Acidic Deposition and Aquatic Ecosystems, Regional Case Studies. D.F. Charles and S. Christie(eds). Springer-Verlag, New York. pp.367-416.
U.S. Environmental Protection Agency, 1996. Level III ecoregions of the continental United States. Map M-1, various scales (revision of Omernik, 1987). U.S. Environmental Protection Agency - National Health and Environmental Effects Research Laboratory, Corvallis, Oregon.
Comments and questions regarding Ecoregions should be addressed to Glenn Griffith, USGS, c/o US EPA., 200 SW 35th Street, Corvallis, OR 97333, (541)-754-4465, email:griffith.glenn@epa.gov Alternate: James Omernik, USGS, c/o US EPA, 200 SW 35th Street, Corvallis, OR 97333, (541)-754-4458, email:omernik.james@epa.gov
Supplemental information: PRINCIPAL AUTHORS: Glenn Griffith (US EPA), Daniel Canfield, Jr. (University of Florida), Christine Horsburgh (University of Florida), James Omernik (US EPA), Sandra Azevedo (OAO Corp.)
COLLABORATORS AND CONTRIBUTORS: Mark Hoyer, Eric Schulz, Roger Bachmann, and Sandy Fisher (University of Florida); James Hulbert, Michael Scheinkman, Ellen McCarron, and Russ Frydenborg (FL DEP); Craig Dye (Southwest Florida Water Management District); Alan Woods (Dynamac Corp.); Curtis Watkins (Florida Lake Management Society); citizen volunteers of Florida LAKEWATCH
Electronic versions of lake region maps and posters as well as other ecoregion resources are available at: http://www.epa.gov/wed/pages/ecoregions.htm. The lake regions were digitized at 1:250,000 scale and are intended for large geographic extents (i.e. states, multiple counties, or river basins). Use for smaller areas, such as individual counties or a 1:24,000 scale map boundary, is not recommended.