A psammophyte is a plant that grows in sandy and often unstable soils. Psammophytes are commonly found growing on beaches, deserts, and sand dunes. Because they thrive in these challenging or inhospitable habitats, psammophytes are considered extremophiles, and are further classified as a type of psammophile.
The word "psammophyte" consists of two Greek roots, psamm-, meaning "sand", and -phyte, meaning "plant". [1] [2] [3] The term "psammophyte" first entered English in the early twentieth century via German botanical terminology. [4]
Psammophytes are found in many different plant families, so may not share specific morphological or phytochemical traits. They also come in a variety of plant life-forms, including annual ephemerals, perennials, subshrubs, hemicryptophytes, and many others. [5] [6] What the many diverse psammophytes have in common is a resilience to harsh or rapidly fluctuating environmental factors, such as shifting soils, strong winds, intense sunlight exposure, or saltwater exposure, depending on the habitat. [6] [7] Psammophytes often have specialized traits, such as unusually tenacious or resilient roots that enable them to anchor and thrive despite various environmental stressors. [8] Those growing in arid regions have evolved highly efficient physiological mechanisms that enable them to survive despite limited water availability. [9] [10]
Psammophytes grow in regions all over the world and can be found on sandy, unstable soils of beaches, deserts, and sand dunes. [5] [6] [7] [11] [12] In China's autonomous Inner Mongolia region, psammophytic woodlands are found in steppe habitats. [13]
Psammophytes often play an important ecological role by contributing some degree of soil stabilization in their sandy habitats. [14] They can also play an important role in soil nutrient dynamics. [15] Depending on the factors at play at a given site, psammophyte communities exhibit varying degrees of species diversity. [16] [17] [5] [12] For example, in the dunes of the Sahara Desert, psammophyte communities exhibit limited diversity and are predominantly made up of plants from the grass and mustard families. [5]
Like many other types of plants, psammophytes can have symbiotic relationships with microorganisms called endophytes that live inside of their tissues, which can impart enhanced growth or other benefits. [18]
A major threat to psammophytes in many regions is dune destabilization, which is exacerbated by human development projects and factors associated with climate change, such as drought and temperature increases. [11] Encroachment of non-psammophytic plants and invasive species poses another threat to psammophyte species in some areas. [12] [16] [19] Ecological restoration efforts in psammophyte habitats often aim to utilize the natural soil stabilizing and nutrient enhancement abilities of psammophytes as part of restoration strategies. [16] [15] Another important strategy is restoring and protecting the requisite soil microbiome some psammophytes require to thrive. [19]
China's Minqin Garden of Desert Plants is one organization that is actively working on efforts to conserve both wild and horticultural psammophyte species. [20]
Some examples of psammophyte species include:
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.
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.
The fat sand rat is a terrestrial mammal from the gerbil subfamily that is mostly found in North Africa and the Middle East, ranging from Mauritania to the Arabian Peninsula. This species usually lives in sandy deserts, but may also be found in rocky terrain or saline marsh areas. Fat sand rats are very selective in their diet, only eating stems and leaves of plants from the family Amaranthaceae, more commonly known as the amaranth family. In captivity, fat sand rats can become obese and rapidly develop diabetes-like symptoms when fed the diet typically given to other rodents. P. obesus has an average lifespan of 14 months in the wild and 3–4 years in captivity.
Desert ecology is the study of interactions between both biotic and abiotic components of desert environments. A desert ecosystem is defined by interactions between organisms, the climate in which they live, and any other non-living influences on the habitat. Deserts are arid regions that are generally associated with warm temperatures; however, cold deserts also exist. Deserts can be found in every continent, with the largest deserts located in Antarctica, the Arctic, Northern Africa, and the Middle East.
The Eastern Desert is the part of the Sahara Desert that is located east of the Nile River. It spans 223,000 square kilometres (86,000 sq mi) of northeastern Africa and is bordered by the Gulf of Suez and the Red Sea to the east, and the Nile River to the west. It extends through Egypt, Eritrea, Ethiopia, and the Sudan. The Eastern Desert consists of a mountain range which runs parallel to the coast, wide sedimentary plateaus extending from either side of the mountains and the Red Sea coast. The rainfall, climate, vegetation and animal life sustained in the desert varies between these different regions. The Eastern Desert has been a mining site for building materials, as well as precious and semi-precious metals, throughout history. It has historically contained many trade routes leading to and from the Red Sea, including the Suez Canal.
Haloxylon ammodendron, variously called the saxaul, black saxaul, also spelled sacsaoul or saksaul is a plant belonging to the family Amaranthaceae. "Saksaul" is a common Turkic word that entered Russian through Kazakh.
The Swan Coastal Plain in Western Australia is the geographic feature which contains the Swan River as it travels west to the Indian Ocean. The coastal plain continues well beyond the boundaries of the Swan River and its tributaries, as a geological and biological zone, one of Western Australia's Interim Biogeographic Regionalisation for Australia regions. It is also one of the distinct physiographic provinces of the larger West Australian Shield division.
The Thal desert is situated at 31°10’ N and 71°30’ E in the province of Punjab, Pakistan. Located near the Pothohar Plateau, the area falls under the Indomalayan biogeographic realm and stretches for a length of approximately 190 miles (310 km) with a maximum breadth of 70 miles (119 km). It is bound by the piedmont of the northern Salt Range, the Indus River floodplains in the west and the Jhelum and Chenab rivers' floodplains in the east. It is a subtropical sandy desert that resembles the deserts of Cholistan and Thar geographically.
Ord's kangaroo rat is a kangaroo rat native to western North America, specifically the Great Plains and the Great Basin, with its range extending from extreme southern Canada to central Mexico.
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.
Cistanche is a worldwide genus of holoparasitic desert plants in the family Orobanchaceae. They lack chlorophyll and obtain nutrients and water from the host plants whose roots they parasitize. They are often known as desert hyacinths.
A xerophyte is a species of plant that has adaptations to survive in an environment with little liquid water. Examples of xerophytes include cacti, pineapple and some gymnosperm plants. The morphology and physiology of xerophytes are adapted to conserve water during dry periods. Some species called resurrection plants can survive long periods of extreme dryness or desiccation of their tissues, during which their metabolic activity may effectively shut down. Plants with such morphological and physiological adaptations are said to be xeromorphic. Xerophytes such as cacti are capable of withstanding extended periods of dry conditions as they have deep-spreading roots and capacity to store water. Their waxy, thorny leaves prevent loss of moisture.
Plant ecology is a subdiscipline of ecology that studies the distribution and abundance of plants, the effects of environmental factors upon the abundance of plants, and the interactions among plants and between plants and other organisms. Examples of these are the distribution of temperate deciduous forests in North America, the effects of drought or flooding upon plant survival, and competition among desert plants for water, or effects of herds of grazing animals upon the composition of grasslands.
Arctotheca populifolia is a species of flowering plant in the family Asteraceae known by the common names beach daisy, Cape beach daisy, South African beach daisy, coast capeweed, dune arctotheca, beach pumpkin, sea pumpkin, dune cabbage, and in South Africa, seepampoen, tonteldoek, and strandgousblom. This species is native to coastal areas of the Cape Provinces and KwaZulu-Natal in South Africa, and of Mozambique. It was introduced to Australia and is now a common weed of coastal areas in New South Wales, South Australia, Tasmania, Victoria, and Western Australia.
A nabkha, nebkha or nebka is a type of sand dune. Other terms used include coppice dune and dune hummock or hummocky dune, but these more accurately refer to similar, but different, sand dune types. Authors have also used the terms phytogenic hillock, bush-mound, shrub-coppice dune, knob dune, dune tumulus, rebdou, nebbe, and takouit.
A psammophile is a plant or animal that prefers or thrives in sandy areas. Plant psammophiles are also known as psammophytes. They thrive in places such as the Arabian Peninsula and the Sahara and also the dunes of coastal regions.
A nurse plant is one that serves the ecological role of helping seedlings establish themselves, and of protecting young plants from harsh conditions. This effect is particularly well studied among plant communities in xeric environments.
The Central Asian southern desert ecoregion is an arid but ecologically active region between the east coast of the Caspian Sea and steppes at the base of the mountains of central Asia. Most of Turkmenistan and eastern Uzbekistan is in this ecoregion. The winters are milder than in the cold desert to the north, and a large number of endemic species have adapted to living in the particular climate and soil of the region. As with sandy deserts in general, the region is notable for high numbers of endemic species of reptiles and insects.
The Central Persian desert basins ecoregion covers the arid steppe and desert basins of central Iran, stretching into northwestern Afghanistan. The ecoregion extends over the Central Iranian Plateau, which is surrounded by mountain ranges and has no outlets to the sea. Much of the terrain is hot sand-and-gravel desert and large salt flats. The vegetation includes many specialized species of halophytes (salt-tolerant), xerophytes (drought-tolerant), and psammophile (sand-loving) plants.
The Loess Plateau is a plateau in north-central China formed of loess, a clastic silt-like sediment formed by the accumulation of wind-blown dust. It is located southeast of the Gobi Desert and is surrounded by the Yellow River. It includes parts of the Chinese provinces of Qinghai, Gansu, Shaanxi and Shanxi. The depositional setting of the Chinese Loess Plateau was shaped by the tectonic movement in the Neogene period, after which strong southeast winds caused by the East Asian Monsoon transported sediment to the plateau during the Quaternary period. The three main morphological types in the Loess Plateau are loess platforms, ridges and hills, formed by the deposition and erosion of loess. Most of the loess comes from the Gobi Desert and other nearby deserts. The sediments were transported to the Loess Plateau during interglacial periods by southeasterly prevailing winds and winter monsoon winds. After the deposition of sediments on the plateau, they were gradually compacted to form loess under the arid climate.
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