By Kimberly Mullen, CPG
Students will be able to define a wetland using a number of different criteria.
There are many different ways of defining a wetland. Many have evolved as scientists learn more about these unique ecosystems. Different scientific fields may define wetlands differently. Different government agencies may define wetlands differently. For the purpose of high school-aged students, a general definition that seems to fit into all definitions should be given. R.L. Smith (Ecology and Field Biology, 3rd edition, Harper and Row, New York,1980) states, “Wetlands are a half-way world between terrestrial and aquatic ecosystems and exhibit some characteristics of each.” Perhaps this is the best way to look at defining wetlands, a combination of many different criteria and great variety, based on specific environments. The best way, then, to define a wetland is to determine the characteristics that are held in common by the many different types.
There are many different ways of defining a wetland. Many have evolved as scientists learn more about these unique ecosystems. Different scientific fields may define wetlands differently. Different government agencies may define wetlands differently. For the purpose of high school-aged students, a general definition that seems to fit into all definitions should be given.
R.L. Smith (Ecology and Field Biology, 3rd edition, Harper and Row, New York,1980) states, “Wetlands are a half-way world between terrestrial and aquatic ecosystems and exhibit some characteristics of each.”
Perhaps this is the best way to look at defining wetlands, a combination of many different criteria and great variety, based on specific environments. The best way, then, to define a wetland is to determine the characteristics that are held in common by the many different types.
A wetland must: Have standing water present for at least part of the year. The water may be meteoric, from surface water, or from groundwater. Typically groundwater, levels are very close to, or at, the ground surface, however, this is not a requirement. There must be some kind of water source to provide needed water to the wetland. Have a type of soil that is considered “hydric” or that can hold water. Sand and other highly permeable soils do not make good wetland soils. Soils that have a high clay content or have low permeability are the typical types of soil found in most wetland areas. The mineral content in the soil can determine the type of wetland that may be present. Have the right kind of biology. Plants and animals that are identified as “wetland” varieties should live in the vicinity of the defined wetland area. There are many different types of plants that can define a wetland area (in other words, they cannot grow unless the water levels are right). The biology of the area is just as important as the type of soils and the hydrology of the area. If these three conditions exist, the area may be considered a wetland area.
A wetland must:
If these three conditions exist, the area may be considered a wetland area.