Wetlands

Functions of a Wetland

Physical/Hydrological

  • Flood control-wetlands act as sponges by capturing, storing, and slowly releasing water. Wetlands slowly release water over weeks and months.
  • Coastal protection-wetlands act as storm buffers. Roots hold soil in place and stalks reduce the energy from storm waves and wind.
  • Groundwater recharge-wetlands can contribute to groundwater and can recharge aquifers.
  • Sediment traps-wetland vegetation can slow water velocity and particles settle out as velocity decreases. Pesticides, heavy metals, and other potentially harmful residues can settle out. Too much sediment in water can cause clogged gills in aquatic animals, and fluctuations in water temperature.

Chemical

  • Waste treatment-wetlands have a high rate of biological production that leads to a large waste consuming capacity. Also, sediment deposition buries waste and bacterial activity can break down and neutralize waste.
  • Pollution interception-wetland plants can take up and filter some pollutants like nitrogen and phosphorous, some pollutants settle into the soil and are chemically reduced over time, other pollutants may be processed by bacteria.

Biological

  • Biological production-as a whole, wetlands outproduce any other type of environment, even tropical rain forests. Wetlands cover approximately 6.4% of the earth's surface, but they account for 24% of total global productivity. Several factors contribute to high biological production including much of wetland vegetation is made of leafy perennials so photosynthesis occurs with constant, inexorable efficiency. Dead or dying plants in wetlands feed populations of larvae, protozoa, bacteria, and fungi. They, in turn, feed fish, worms, birds, and other life continuing up the food web.
  • Habitat-wetlands provide food, shelter, resting places, or predatory opportunities to a variety of animals.

Socioeconomic Benefits

  • Food-wild rice and cranberries are some wetland crops that can be harvested and consumed directly. Wetland soils are rich in nutrients, high in organic matter, and generally less erosive than other soils. Wetlands that have been drained and converted into agricultural land or wetlands that are under cultivation during dry periods in the United States provide over 25% of all major crops. Once wetlands are permanently drained the conditions that created productive soils are lost as well, along with benefits like recreation, fish habitat, and pollution interception.
  • Fuel-peat from wetlands can be harvested, dried and burned for electrical power. Peat mining can have environmental impacts including compromised local water quality, unchecked storm runoff and habitat destruction.
  • Timber and fiber harvest-wetlands have dense stands of vegetation with rapid growth rates which prove beneficial for wood and fiber industries. Draining and clear-cutting wetlands was the normal practice until recently. Selective cutting and vigorous replanting practices are become more common with good results. 
  • Recreation, aesthetics, and education-Birdwatching, canoeing, fishing, hunting, painting, and hiking are all recreational activities that can be enjoyed at wetlands.
  • Cultural Heritage and Archaeological Evidence-anaerobic conditions (conditions without oxygen) create thick layers of organic materials that slow down the decomposition process. Artifacts, clothing, and even human remains are well preserved in these layers. Information about cultures including dietary nuances, clothing materials, and building styles are available for study at these places.