Community Structure and Environmental Conditions in Florida Shallow Lakes Dominated by Submerged Aquatic Vegetation

Abstract

Florida inland waters are dominated by shallow lakes, many of which support the growth of submerged aquatic vegetation (SAV). We examined the species composition and selected environmental variables of SAV-dominated lakes using data from the Florida LAKEWATCH program. Our analysis revealed eight genera with approximately 15 species of SAV among these shallow lakes, which range in size from <2–2,300 ha. The SAV community within each lake primarily consisted of a single or a few species. Utricularia and Hydrilla were the most common SAV genera found in these lakes. Many SAV species grew well in a wide range of water quality conditions, although biodiversity and biomass tended to increase with increasing alkalinity and calcium concentration. More SAV species were also found in lakes with higher pH and Secchi depth. On average, Ceratophyllum, Najas and Vallisneria dominated lakes with high total phosphorus (TP) concentrations (0.034–0.053 mg/L) while Chara, Utricularia, Potamogeton and Myriophyllum corresponded with relatively low TP concentrations (0.008–0.013 mg/L). However, there was a large overlap in nutrient concentrations in lakes dominated by different species.

Key Words:

• biodiversity
• biomass
• Florida lakes
• light
• phosphorus
• submerged aquatic vegetation (SAV)