![Interdunal wetland](https://upload.wikimedia.org/wikipedia/commons/0/00/Interdunal_wetland.jpg)
An interdunal wetland, interdunal pond or dune slack is a water-filled depression between coastal
sand dune
A dune is a landform composed of wind- or water-driven sand. It typically takes the form of a mound, ridge, or hill. An area with dunes is called a dune system or a dune complex. A large dune complex is called a dune field, while broad, fl ...
s. It may be formed either by wind erosion or by dunal encroachment on an existing wetland.
The wind erosion process involves wind scooping out sufficient sand to reach the
water table
The water table is the upper surface of the zone of saturation. The zone of saturation is where the pores and fractures of the ground are saturated with water. It can also be simply explained as the depth below which the ground is saturated.
T ...
, and typically occurs behind the first line of
foredune
A foredune is a dune ridge that runs parallel to the shore of an ocean, lake, bay, or estuary. Foredunes consist of sand deposited by wind on a vegetated part of the shore. Foredunes can be classified generally as ''incipient'' or ''established'' ...
s.
The Indiana Dunes contain interdunal wetlands.
[Smith, S. & Mark, S. (2009). The Historical Roots of the Nature Conservancy in the Northwest Indiana/Chicagoland Region: From Science to Preservation. The South Shore Journal, 3. ] Many conservation efforts have been made to preserve parts of the Indiana Dunes.
[Smith, S. & Mark, S. (2007). The cultural impact of a museum in a small community: The Hour Glass of Ogden Dunes. The South Shore Journal, 2. ]
Because they are typically very shallow, interdunal wetlands warm quickly, and provide an abundant source of
invertebrate
Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...
s eaten by many species of
shorebird
245px, A flock of Dunlins and Red knots">Red_knot.html" ;"title="Dunlins and Red knot">Dunlins and Red knots
Waders or shorebirds are birds of the order Charadriiformes commonly found wikt:wade#Etymology 1, wading along shorelines and mudflat ...
s.
Many interdunal wetlands are ephemeral, drying out during periods of low rain or low water.
In the
Great Lakes
The Great Lakes, also called the Great Lakes of North America, are a series of large interconnected freshwater lakes in the mid-east region of North America that connect to the Atlantic Ocean via the Saint Lawrence River. There are five lakes ...
region of
North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...
, interdunal communities are typically mildly
calcareous
Calcareous () is an adjective meaning "mostly or partly composed of calcium carbonate", in other words, containing lime or being chalky. The term is used in a wide variety of scientific disciplines.
In zoology
''Calcareous'' is used as an adje ...
and dominated by
rush
Rush(es) may refer to:
Places
United States
* Rush, Colorado
* Rush, Kentucky
* Rush, New York
* Rush City, Minnesota
* Rush Creek (Kishwaukee River tributary), Illinois
* Rush Creek (Marin County, California), a stream
* Rush Creek (Mono Cou ...
es,
sedge
The Cyperaceae are a family of graminoid (grass-like), monocotyledonous flowering plants known as sedges. The family is large, with some 5,500 known species described in about 90 genera, the largest being the "true sedges" genus ''Carex'' wit ...
s and shrubs.
They are tentatively classified as G2, or globally imperiled, under the
NatureServe
NatureServe, Inc. is a non-profit organization based in Arlington County, Virginia, US, that provides proprietary wildlife conservation-related data, tools, and services to private and government clients, partner organizations, and the public. Nat ...
rankings.
A distinction is sometimes made between interdunal and intradunal wetlands such as
pannes, which form within a single dune as part of a
blowout.
References
See also
{{Wetlands
Dunes
Wetlands