Soil processes regulating water quality in wetlands

Inorganic nitrogen transformations are largely mediated by microorganisms. These reactions mainly consist of coupled oxidation-reduction reactions in the water column and in the soil. In aerobic zones (water column and soil-water interface), oxidation of NH⁺ ₄, to NO^- ₃ may occur. Nitrate formed readily diffuses into anaerobic zones where it is subesquently utilized as electron acceptor and lost from the system. Similarly, nitrification-denitrification reactions also occur in the root zone of wetland plants. Denitrification of nitrate to gaseous end-products is probably the most significant process involved in the removal of large quantities of nitrogen from the system. Although phosphorus transformations in wetlands are also biologically mediated, abiotic factors, such as chemical precipitation-complexation and adsorption of inorganic phosphorus with iron and aluminum oxhydroxides or CaCO₃ play an important role in the fate of phosphorus in the soil-water column. The main factors which influence these chemical reactions are pH and oxidation-reduction potential. -from Authors