What Is A Wetland?
Wetlands are unique ecosystems which provide water and habitat for a diverse range of plants and animals. Natural wetlands occur where surface water collects or where groundwater discharges to the surface. In urban areas, artificial wetlands are usually fed by stormwater run-off. Due to the water filtration processes which occur at wetlands, they are sometimes referred to as the ‘kidneys’ of a catchment area.
A wetland is an area featuring permanent or temporary shallow water which can be still or flowing, fresh, brackish or saltwater. Wetlands range in size from a small swamp to a vast shallow lake. Wetlands that contain water all year round are called permanent wetlands and those that fill seasonally are called temporal wetlands. Others, called ephemeral wetlands, only contain water after heavy rains or during floods, perhaps once every few years.
Natural wetlands can include:
- Swamps
- Reed marshes
- Billabongs
- Lakes
- Flood plains
- Inland deltas
- Mangrove forests
- Coastal lagoons
- Estuaries
In South Australia there are least 16 different inland wetland types, 9 marine and coastal types and 3 different artificial wetland types.
The six most common wetland types in South Australia are:
- URBAN: constructed in urban areas to improve water quality and catchment health
- RIVERINE: Along rivers and streams
- MARINE: Lagoons and rocky shores where water does not exceed a depth of 6m at low tide.
- ESTUARINE: Deltas, tidal marshes and mangrove swamps.
- LACUSTRINE: Wetlands associated with lakes.
- PALUSTRINE: Marshes, swamps and bogs.
The type of wetland (permanent or temporal), along with climate, soils and water salinity levels (how salty or fresh the water is), will determine the types of plant and animals living in and around wetlands. Wetland vegetation is well adapted to wetting and drying cycles and most fauna can adjust to these changing conditions.
To find out more go to Life In A Wetland