107 Natural and Constructed Wetlands
Part 9. Ecological and Hydrological Interactions
Published Online: 15 APR 2006
Copyright © 2005 John Wiley & Sons, Ltd
Encyclopedia of Hydrological Sciences
How to Cite
Craft, C. B. 2006. Natural and Constructed Wetlands. Encyclopedia of Hydrological Sciences. 9:107.
- Published Online: 15 APR 2006
Wetlands are characterized by periodic to continuous inundation or saturation with water (wetland hydrology), soils that are periodically deficient in oxygen (hydric soils), and vegetation that is adapted to periods of anaerobic or anoxic soil conditions (hydrophytic vegetation). Wetlands include herbaceous marshes and fens, forested swamps, and Sphagnum-dominated peat bogs. Wetland plants possess morphological adaptations (aerenchyma, buttressed trunks, pneumatophores, hypertrophied lenticels) to facilitate transport of oxygen to the roots and metabolic pathways to respire anaerobically without toxic effects. Duration, depth, and frequency of inundation, water source (precipitation, surface flow, groundwater), and water quality (fresh, saline, oligotrophic, eutrophic) determine the distribution, productivity, and nutrient cycling characteristics of wetland vegetation. Floodplain swamp forests and estuarine marshes and mangroves receive large quantities of water and nutrients during overbank flooding and tidal inundation that enhances plant productivity and sediment, nutrient, and pollutant retention as compared to wetlands that receive most of their water from precipitation. The ability of natural wetlands to filter pollutants has led to construction of artificial wetlands to treat wastewater, stormwater, acid mine drainage, nonpoint runoff and other sources of pollutants. Wetlands also are constructed to replace important ecological functions (water storage, biological productivity, biodiversity) that are lost when natural wetlands are damaged or destroyed by human activities.
- anaerobic soils;
- plant productivity;
- treatment wetlands;