Georgia Coastal Ecosystems Long Term Ecological Research Project Marsh

The central paradigm of the Georgia Coastal Ecosystems project is that variability in estuarine ecosystem processes is primarily mediated by the mixture of fresh and salt water flows across the coastal landscape. The GCE project is investigating the underlying mechanisms by which proximity of marshes to upland habitat drives ecosystem change along lateral gradients in the intertidal zone. Our approach to this question involves taking advantage of marsh hammocks as a natural laboratory for evaluating the influence of landscape structure and freshwater input on marsh processes. The hammock research includes basic characterization of groundwater flow as well as physical and biological characteristics at selected sites, experiments designed to understand the effects of manipulating water flow on marsh processes, and modeling. In 2007 we did a survey of 55 hammocks representing a range of sizes and origin, and these data are still being analyzed. Our activities this past year included processing geological samples; collecting data from instrumented hammocks; and continuing archeological studies. We also continued our analysis of the plant community associated with hammocks and initiated field and greenhouse studies to support our modeling efforts. This portion of the project is under the direction of Alber and Alexander, with involvement from co-PIs Pennings, Joye, Burd, Meile, B. Moore (USC), and V. Thompson (Ohio State).