Exchange of Nitrogen, Phosphorus, and Organic Carbon between Transplanted Marshes and Estuarine Waters
- C. B. Craft *,
- S. W. Broome and
- E. D. Seneca
Fluxes of N, P, and organic C were measured between irregularly flooded transplanted marshes and estuarine waters at two sites in North Carolina. Hydrologic flux was regulated by pumping estuarine water into the marsh, holding the water for 24 h and pumping the water out. Samples were collected from waters flowing into and out of each marsh and analyzed for salinity, N, P, and organic C. Concentrations of dissolved organic C were significantly higher in water flowing out of the two transplanted marshes compared to concentrations in inflow waters. In contrast, inflow waters contained significantly higher concentrations of phosphate than outflow waters. Phosphate flux was seasonal with maximum uptake by the marsh during the summer. Estimates of nutrient fluxes indicate that transplanted marshes export dissolved organic C (3–48 mmol m−2 event) and N (0.2–5.6) and import ammonium (300–600 µmol m−2 event) and phosphate (300–1000). The transplanted marshes are young communities that lack the large soil organic matter reservoirs and reducing environment characteristic of many natural marshes. These systems probably will continue to import ammonium and phosphate until the soils become reduced and soil nutrient reservoirs develop.
Copyright © . .