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Determining Sources of Water and Nutrients to Great Lakes Coastal Wetlands: A Classification Approach.
Citation:
MORRICE, J. A., A. S. TREBITZ, J. R. KELLY, M. E. SIERSZEN, A. M. COTTER, AND T. HOLLENHORST. Determining Sources of Water and Nutrients to Great Lakes Coastal Wetlands: A Classification Approach. WETLANDS. The Society of Wetland Scientists, McLean, VA, 31:1199-1213, (2011).
Impact/Purpose:
Results confirmed that classification based on quantitative hydrology data was successful in identifying groups of wetlands with similar water sources.
Description:
Water and associated nutrients can enter freshwater and marine coastal wetlands from both watershed and offshore sources. Identifying the relative contribution of these potential sources, and the spatial scale at which sources are influenced by anthropogenic activities, are critical steps in wetland protection and restoration. We developed a hydrology-based classification scheme for Great Lakes coastal wetlands for the purpose of identifying dominant hydrologic influences and water sources. Classes were determined through analysis of data quantifying hydrologic linkages to lake (seiche) and watershed (watershed area, tributary discharge) in 58 wetlands distributed along the U.S. shoreline of the Laurentian Great Lakes. Wetlands were partitioned into 4 classes of hydrology (Watershed-dominated, Lake-dominated, Mixed-influenced, Weakly-influenced) that were predicted to differ in sources of water. Source water predictions were tested by comparing chloride concentrations in wetland, lake and tributary waters of the wetlands in each class. Results confirmed that classification based on quantitative hydrology data was successful in identifying groups of wetlands with similar water sources. Correlations between wetland chloride, an indicator of anthropogenic disturbance, and agricultural land cover suggest that differences among classes in water sources resulted in differences in the scale at which wetlands were connected to and influenced by landscapes. While water quality in wetlands with watershed dominated hydrology strongly reflected land-use in their watersheds, water quality in wetlands from the lake dominated hydrology class reflected land-use practices at larger spatial scales.