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Iron additions to seagrass-dominated sediments of Florida Bay have been used to explore short-term changes in the dynamics of iron, phosphorus and sulfur cycling. For the present study, we have completed iron additions to vegetation plots from two locations in the sawgrass-dominated freshwater Everglades to determine whether similar objectives can be met. At each location, three 1-sq. meter plots received one-time enrichments by broadcasting iron oxide filings on the soil surface. Three additional plots served as controls. Sampling of the soils in enrichment and control plots takes place 1-2 times each year; vegetation sampling for stem density and stem height of sawgrass was completed every two months through 2004. Soils analysis are completed for bulk density, organic matter, extractable iron, easily extractable phosphorus, metals-bound phosphorus, carbonate-bound phosphorus, organic phosphorus, iron monosulfide, and pyrite. We expect to determine the relative importance of the sulfate reduction pathway in anaerobic Everglades soils, and to determine whether iron-bound phosphorus retention (via iron addition) stimulates changes in vegetation structure and/or function.
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