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A psammosere is the sequence of plant succession in stages, initiated on sand. [1] It is seral community, an ecological succession that began life on newly exposed coastal sand. Most common psammoseres are sand dune systems.
Psammosere is a form of xerosere (or xerarch) succession as it begins in an environment with limited to no freshwater availability. [2]
Psammosere's literal meaning is “originating on sand". It was named by Frederic E. Clements who described the sequence in Plant Succession 1916. [3]
In a psammosere, the organisms closest to the sea will be pioneer species: [4] halophytes (salt-tolerant species) such as littoral algae and glasswort with marram grass stabilising the dunes.
Progressing inland, many characteristic features change and help determine the natural succession of the dunes. For instance, the drainage slows down as the land becomes more compact and the soils improve in quality, and the pH drops as the proportion of seashell fragments reduces and the amount of humus increases. Sea purslane, sea lavender, meadow grass and heather eventually grade into a typical non-maritime terrestrial eco-system. The first trees (or pioneer trees) that appear are typically fast-growing trees such as pine, birch, willow or rowan. In turn these will be replaced by slow-growing, larger trees such as ash and oak. This is the climax community, defined as the point where a plant succession does not develop any further because it has reached equilibrium with the environment, in particular the climate.
The later stages of a psammosere appear when the sand stops moving due to lower wind speeds. These lower wind speeds can be because of distance from the shoreline or the formation of higher dunes, acting as windbreaks, or a combination of both of these factors. [5]
The process by which different stages succeed each other is known as "plant colonisation". [4]
In an idealised coastal psammosere model, at the seaward edge of the sand dune the pH of the soil is typically alkaline/neutral with a pH of 7.0/8.0 particularly where shell fragments provide a significant component of the sand. Tracking inland across the dunes a podsol develops with a pH of 5.0/ 4.0 followed by mature podsols at the climax with a pH of 3.5 - 4.5.
Psammosere succession is also extremely vulnerable to human activities. At beaches, footpaths over dunes will trample grass, creating exposed sand. This exposed sand can be blown away very easily, leading to the roots becoming exposed, leading to neighbouring plants dying. This creates blowouts, which can set back the Psammosere. [6]
Efforts have also been made to improve the Psammosere in some regards. Pine trees are in some areas an invasive species, and can take over heathland. [7] The National Trust in the UK encourages people to pull up small Pine trees [8] as they can leave needles on the ground and prevent further psammosere succession.
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.
Holkham National Nature Reserve is England's largest national nature reserve (NNR). It is on the Norfolk coast between Burnham Overy Staithe and Blakeney, and is managed by Natural England with the cooperation of the Holkham Estate. Its 3,900 hectares comprise a wide range of habitats, including grazing marsh, woodland, salt marsh, sand dunes and foreshore. The reserve is part of the North Norfolk Coast Site of Special Scientific Interest, and the larger area is additionally protected through Natura 2000, Special Protection Area (SPA) and Ramsar listings, and is part of both an Area of Outstanding Natural Beauty (AONB) and a World Biosphere Reserve. Holkham NNR is important for its wintering wildfowl, especially pink-footed geese, Eurasian wigeon and brant geese, but it also has breeding waders, and attracts many migrating birds in autumn. Many scarce invertebrates and plants can be found in the dunes, and the reserve is one of the only two sites in the UK to have an antlion colony.
In scientific ecology, climax community or climatic climax community is a historic term for a community of plants, animals, and fungi which, through the process of ecological succession in the development of vegetation in an area over time, have reached a steady state. This equilibrium was thought to occur because the climax community is composed of species best adapted to average conditions in that area. The term is sometimes also applied in soil development. Nevertheless, it has been found that a "steady state" is more apparent than real, particularly across long timescales. Notwithstanding, it remains a useful concept.
Ecological succession is the process of change in the species that make up an ecological community over time.
A sandhill is a type of ecological community or xeric wildfire-maintained ecosystem. It is not the same as a sand dune. It features very short fire return intervals, one to five years. Without fire, sandhills undergo ecological succession and become more oak dominated.
The Sandhills or Carolina Sandhills is a 10-35 mi wide physiographic region within the U.S. Atlantic Coastal Plain province, along the updip (inland) margin of this province in the states of North Carolina, South Carolina, and Georgia. The extent of the Carolina Sandhills is shown in maps of the ecoregions of North Carolina, South Carolina, and Georgia.
Primary succession is the beginning step of ecological succession after an extreme disturbance, which usually occurs in an environment devoid of vegetation and other organisms. These environments are typically lacking in soil, as disturbances like lava flow or retreating glaciers scour the environment clear of nutrients.
Rome Sand Plains is a 15,000-acre (61 km2) pine barrens about five miles (8.0 km) west of the city center of Rome in Oneida County in central New York. It consists of a mosaic of sand dunes rising about 50 feet (15 m) above low peat bogs that lie between the dunes. The barrens are covered with mixed northern hardwood forests, meadows, and wetlands. About 4,000 acres (16 km2) are protected in conservation preserves. Pine barrens are typical of seacoasts; the Rome Sand Plains is one of only a handful of inland pine barrens remaining in the United States. A second inland pine barrens, the Albany Pine Bush, is also found in New York, located north and west of state's capital Albany.
Frederic Edward Clements was an American plant ecologist and pioneer in the study of plant ecology and vegetation succession.
Blowouts are sandy depressions in a sand dune ecosystem (psammosere) caused by the removal of sediments by wind.
Xerosere is a plant succession that is limited by water availability. It includes the different stages in a xerarch succession. Xerarch succession of ecological communities originated in extremely dry situation such as sand deserts, sand dunes, salt deserts, rock deserts etc. A xerosere may include lithoseres and psammoseres.
Secondary succession is the secondary ecological succession of a plant's life. As opposed to the first, primary succession, secondary succession is a process started by an event that reduces an already established ecosystem to a smaller population of species, and as such secondary succession occurs on preexisting soil whereas primary succession usually occurs in a place lacking soil. Many factors can affect secondary succession, such as trophic interaction, initial composition, and competition-colonization trade-offs. The factors that control the increase in abundance of a species during succession may be determined mainly by seed production and dispersal, micro climate; landscape structure ; bulk density, pH, and soil texture.
A seral community is an intermediate stage found in ecological succession in an ecosystem advancing towards its climax community. In many cases more than one seral stage evolves until climax conditions are attained. A prisere is a collection of seres making up the development of an area from non-vegetated surfaces to a climax community.
Henry Allan Gleason (1882–1975) was an American ecologist, botanist, and taxonomist. He was known for his endorsement of the individualistic or open community concept of ecological succession, and his opposition to Frederic Clements's concept of the climax state of an ecosystem. His ideas were largely dismissed during his working life, leading him to move into plant taxonomy, but found favour late in the twentieth century.
Błędów Desert, is an area of sands and gravels located between Błędów and the villages of Chechło and Klucze in Poland. The area lies mainly on the Silesian Highlands in the Lesser Poland Voivodeship. The Błędów Desert is Central Europe's largest accumulation of loose sand in an area away from any sea, deposited thousands of years ago by a melting glacier. It occupies an area of 32 km2 (12 sq mi). The sands have an average depth of 40 m, up to 70 m at the maximum. The Biała Przemsza River divides the desert in two from east to west. The northernmost part of the desert is closed to visitors because it is a military zone, where exercises take place.
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.
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.
In ecology, a priority effect refers to the impact that a particular species can have on community development as a result of its prior arrival at a site. There are two basic types of priority effects: inhibitory and facilitative. An inhibitory priority effect occurs when a species that arrives first at a site negatively affects a species that arrives later by reducing the availability of space or resources. In contrast, a facilitative priority effect occurs when a species that arrives first at a site alters abiotic or biotic conditions in ways that positively affect a species that arrives later. Inhibitory priority effects have been documented more frequently than facilitative priority effects. Studies indicate that both abiotic and biotic factors can affect the strength of priority effects.. Priority effects are a central and pervasive element of ecological community development that have significant implications for natural systems and ecological restoration efforts.
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.