Patterns in Biomass and Cover of Aquatic Macrophytes in Lakes: Test with Florida Lakes

Data from 69 Florida lakes were used to test 15 empirical models that were developed from a worldwide data base to describe the biomass and cover of aquatic macrophytes in lakes. Ten of the models failed to provide useful predictions in Florida because the models did not adequately reflect the limnological characteristics of Florida lakes. Submerged and emergent biomass in the Florida lakes was predicted by the models that estimated these parameters from the areal cover of submerged and emergent vegetation. Total macrophyte cover in Florida lakes could be predicted from a model based on lake size, annual irradiance at the surface, and the mean annual irradiance within the mean depth of the lake. Even the best models, however, overestimated submerged plant biomass and cover in highly colored (>400 Pt–Co units) lakes and lakes with steep (slope >15%) littorals. This suggests that the influence of light (quantity and quality) and littoral slope on the abundance of aquatic macrophytes needs additional research before improved empirical models can be developed for lakes located in limited geographic regions.