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, flat regions covered with wind-swept sand or dunes with little or no vegetation are called ergs or sand seas. Dunes occur in different shapes and sizes, but most kinds of dunes are longer on the stoss (upflow) side, where the sand is pushed up the dune, and have a shorter slip face in the lee side. The valley or trough between dunes is called a dune slack.
A beach is a landform alongside a body of water which consists of loose particles. The particles composing a beach are typically made from rock, such as sand, gravel, shingle, pebbles, etc., or biological sources, such as mollusc shells or coralline algae. Sediments settle in different densities and structures, depending on the local wave action and weather, creating different textures, colors and gradients or layers of material.
Ammophila is a genus of flowering plants consisting of two or three very similar species of grasses. The common names for these grasses include marram grass, bent grass, and beachgrass. These grasses are found almost exclusively on the first line of coastal sand dunes. Their extensive systems of creeping underground stems or rhizomes allow them to thrive under conditions of shifting sands and high winds, and to help stabilize and prevent coastal erosion. Ammophila species are native to the coasts of the North Atlantic Ocean where they are usually the dominant species on sand dunes. Their native range includes few inland regions, with the Great Lakes of North America being the main exception. The genus name Ammophila originates from the Greek words ἄμμος (ámmos), meaning "sand", and φίλος (philos), meaning "friend".
Aeolian processes, also spelled eolian, pertain to wind activity in the study of geology and weather and specifically to the wind's ability to shape the surface of the Earth. Winds may erode, transport, and deposit materials and are effective agents in regions with sparse vegetation, a lack of soil moisture and a large supply of unconsolidated sediments. Although water is a much more powerful eroding force than wind, aeolian processes are important in arid environments such as deserts.
Grey dunes are fixed, stable sand dunes that are covered by a continuous layer of herbaceous vegetation. These dunes are typically located 50–100 meters from the ocean shore and are found on the landward side of foredunes. Grey dunes are named for their characteristic grey color which is a result of the ground cover of lichen combined with a top soil layer of humus.
This article gives an overview of the shingle, strandline and sand-dune communities in the British National Vegetation Classification system.
Blowouts are sandy depressions in a sand dune ecosystem (psammosere) caused by the removal of sediments by wind.
Guadalupe-Nipomo Dunes is the largest remaining dune system south of San Francisco and the second largest in the U.S. state of California. It encompasses an 18-mile (29 km) stretch of coastline on the Central Coast of California and extends from southern San Luis Obispo County to northern Santa Barbara County.
Ammophila arenaria is a species of grass in the family Poaceae. It is known by the common names marram grass and European beachgrass. It is one of two species of the genus Ammophila. It is native to the coastlines of Europe and North Africa where it grows in the sands of beach dunes. It is a perennial grass forming stiff, hardy clumps of erect stems up to 1.2 metres (3.9 ft) in height. It grows from a network of thick rhizomes which give it a sturdy anchor in its sand substrate and allow it to spread upward as sand accumulates. These rhizomes can grow laterally by 2 metres in six months. One clump can produce 100 new shoots annually.
Sand dune ecology describes the biological and physico-chemical interactions that are a characteristic of sand dunes.
Ammophila breviligulata is a species of grass native to eastern North America, where it grows on sand dunes along the Atlantic Ocean and Great Lakes coasts. Beachgrass thrives under conditions of shifting sand, sand burial, and high winds; it is a dune-building grass that builds the first line of sand dunes along the coast. Beachgrass is less vigorous in stabilized sand, and is only infrequently found further inland than the coastal foredunes. On the Atlantic coastline of North America, Ammophila breviligulata has been observed as far south as North Carolina, and is often planted in dune restoration projects. Ammophila breviligulata was introduced to the Pacific coast of North America in the 1930s. It is proving to be invasive, and is increasingly important to coastal ecology and development in Oregon, Washington, and British Columbia.
The Lanphere Dunes National Natural Landmark a unit of the Humboldt Bay National Wildlife Refuge Complex, is located in Humboldt County, California. The dune complex consists of the wave slope, fore dune, herbaceous and woody swales, coniferous and riparian forest, freshwater swamp, freshwater marsh, brackish marsh, salt marsh, and intertidal mudflats. The site exemplifies dunes succession.
NVC community SD19 is one of the 16 sand-dune communities in the British National Vegetation Classification system. It is one of six communities associated with foredunes and mobile dunes.
Sand dune stabilization is a coastal management practice designed to prevent erosion of sand dunes. Sand dunes are common features of shoreline and desert environments. Dunes provide habitat for highly specialized plants and animals, including rare and endangered species. They can protect beaches from erosion and recruit sand to eroded beaches. Dunes are threatened by human activity, both intentional and unintentional. Countries such as the United States, Australia, Canada, New Zealand, the United Kingdom, and Netherlands, operate significant dune protection programs.
The Schaabe is a bar, almost twelve kilometres long, on the German Baltic Sea island of Rügen. It joins the peninsulas of Jasmund and Wittow.
Leymus mollis is a species of grass known by the common names American dune grass, American dune wild-rye, sea lyme-grass, strand-wheat, and strand grass. Its Japanese name is hamaninniku. It is native to Asia, where it occurs in Japan, China, Korea, and Russia, and northern parts of North America, where it occurs across Canada and the northern United States, as well as Greenland. It can also be found in Iceland.
The Ma-le’l Dunes Cooperative Management Area (CMA) is located south of Lanphere Dunes at the upper end of the North Spit of Humboldt Bay, being approximately one mile north of the unincorporated town of Manila and 3.5 miles west of the City of Arcata, in Humboldt County, California. It consists of approximately 444 acres of public land. Ma-le’l dunes are divided into northern and southern sections. The northern portion is part of Humboldt Bay National Wildlife Refuge and is administered by the U.S. Fish and Wildlife Service (FWS). The southern portion of Ma-le’l is managed by the Bureau of Land Management (BLM) and provides access to the coastal dune environment for dog-walking and equestrian use on designated trails.
Inland dunes are eolian sand dunes that are found inland, away from coastal regions.
The Cresmina Dune extends over 66 hectares and is a part of the Guincho-Oitavos dune system, located on the edge of the Sintra-Cascais Natural Park near Cascais in Portugal. This dune system is considered fairly unique because, as a result of the prevailing northwest winds, the sand from the Guincho and Cresmina beaches eventually returns to the sea 5 km further to the south near Guia, after migrating over the flat, rocky and largely uninhabited area of Cabo Raso.
Dabas parks Piejūra is a nature park along the Gulf of Riga in Latvia founded in 1962. It is a protected nature reserve and a Natura 2000 location. The park stretches 36.6 kilometres (22.7 mi) over an 4,180 hectares area from Riga, through Carnikava Municipality, and up to Saulkrasti. It is a popular seasonal recreation location, notably for beach access. The park is notable for its protected biotopes, particularly its dunes and boreal forests. The park's conservation plan for 2020 onwards was developed under the "LIFE CoHaBit" project.
