An inventory and typology of permanent floodplain lakes in the Mississippi Alluvial Valley: a first step to conservation planning

The alluvial valley of the Mississippi River is an extensive area harboring hundreds of lakes created by fluvial dynamics. These floodplain lakes are scattered throughout the valley and carved over thousands of years by shifting river courses and other hydro-fluvial processes associated with contemporary and prehistoric rivers. These lakes have significant ecological importance as they support a large component of North American biodiversity. We used remote sensing to catalog lakes, to characterize morphology, and to construct a typology via cluster analysis. We identified over 1300 permanent lakes totaling over 100,000 ha. The lakes were classified into 12 types according to lake size, shape, depth, connectivity, inundation frequency, and surrounding landcover. We anticipate that biotic characteristics differ among the 12 types, but large-scale systematic analyses of biotic assemblages of floodplain lakes in the region are mostly absent. Our typology can provide the framework essential for organizing research to define water dynamics, water quality, and ecological conditions such as forests, mussel, fish, and avian communities to construct conservation plans. The typology encourages a large-scale view of the properties of floodplain lakes in the alluvial valley. It is a functional tool that can be used to begin identifying conservation and research needs, adapt monitoring and management programs, customize environmental programs, and use conservation resources more effectively to achieve large-scale management objectives.