Native Plant Communities

Eutrophic Lakes

Synonyms: High Nutrient Lakes
Community Variants: Floodplain Lakes

These lakes typically have major inflows and outflows and the character of the water and vegetation usually reflect the high nutrient content. They may have deep peats and typically have broad vegetated zones near shore. Most would be considered to be eutrophic. Vegetation in shallow areas tends to be dense and to include such species as cattails.

Given that the water is typically murky, emergent vegetation is characteristic. Submergent vegetation is rare in deep water areas.  Most invasive aquatic plants tend to be associated with these lakes (Hoyer et al. 1996).

Most of these lakes have seen major alterations by man, both in terms of their hydrology and in terms of the nutrient loads that they receive from either input streams or as runoff from adjacent uplands. 

One study elucidates the change in water chemistry for a small lake in central Florida.  The study evaluated the effects of land use changes since 1890 Little Lake Jackson in south-central Florida. The lake currently is alkaline despite the prevalence of acidic lakes in its region. Little Lake Jackson becasme significantly alkalized during the 1900s apparently dues to increased ionic loading and increased nutrient loading. By inference, this was due to management of golf courses and residential lawns in the watershed (liming and irrigation with alkaline waters from deep wells, with direct and indirect drainage into the lake) with additional nutrient from tormwater runoff and septicleaching from septic systems that increased nutrient levels in the lake.  (Whitmore et al., 2006). While not the focus of this particular study, water clarity and the nature of vegetation in the lake would have altered significantly. 

Despite water quality issues, many of these lakes have distinct plant communities and provide important habitat for birds, fish, and insects along with available water for upland animal species. Cypress fringes are common.  Also common is emergent vegetation.  In general, compared to clear lakes, emergent vegetation is restricted to  quite shallow areas since areas that would otherwise support submergent and floating-leaved vegetation may get inadequate light for these species to persist.

Examples include Lake Thonotosassa (Hillsborough County, Lake Okeechobee, and Lake Istokpoga (Highlands County), and most if not all of the lakes along the St. Johns River.

Floodplain Lakes occur along major stream systems.  The water source is the stream, and essentially all of them are eutrophic due to water quality in the streams.

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Map of Florida Lakes, from Florida Lake Watch website with the map restricted to showing lakes and ponds only.  This map does not classify lakes by pH or trophic state.

References:

Florida Natural Areas Inventory (FNAI). 2010. Guide to the natural communities of Florida: 2010 edition. Florida Natural Areas Inventory, Tallahassee, FL. http://fnai.org/naturalcommguide.cfm.

Schiffer, Donna M. Hydrology of central Florida lakes : a Primer. U.S. Geological SurveyCircular 1137. http://fl.water.usgs.gov/PDF_files/c1137_schiffer.pdf.

Hoyer, M., D. E. Canfield Jr., C. A. Horsburgh, and K. Brown.  1996.  Florida Freshwater Plants.  A Handbook of Common Aquatic Plants in Florida Lakes.  University of Florida, Institute of Food and Agricultural Sciences.

USF Water Institute.  2020.  Florida Atlas of Lakes.  https://maps.wateratlas.usf.edu/AtlasOfLakes/.

Whitney, E.N., D. B. Means, A. Rudloe. 2004. Priceless Florida: Natural Ecosystems and Native Species. Pineapple Press.

Whitmore, Thomas & Brenner, Mark & Kolasa, Keith & Kenney, William & Riedinger-Whitmore, Melanie & Curtis, Jason & Smoak, Joseph. 2006. Inadvertent alkalization of a Florida lake caused by increased ionic and nutrient loading to its watershed. Journal of Paleolimnology. 36. 

Date Updated 2020-05-17 11:47:34

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Eutrophic Floodplain Lake (Lake Kissimmee) by Shirley Denton.  American lotus is found along some of the lake fringes.

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Blue Cypress Lake on the Upper St. Johns River.  Photo by Shirley Denton.  The lake is noted for dramatic cypress trees many with osprey nests (upper left).