Loading of nutrients to surface waters causes changes in ecological function, and often has undesirable environmental and economic consequences.
Wetlands perform many important biogeochemical functions in watersheds.
The N cycle in wetlands plays an important role in transport, storage and biological availability of N in the surrounding watershed. Organic matter, including plant detritus, organic sediments and peat, is broken down by a variety of microorganisms that utilize organic carbon as a source of energy. This process occurs in aerobic, or oxygenated, regions of the wetland, usually confined to the surface water and the top few millimeters of the underlying soil. The release of nitrous oxide is of particular concern, because of ozone-layer impacts. Denitrification occurs only in the anaerobic, or oxygen-depleted, regions of the wetland that typically exist below the soil surface.