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.
Desertification is a type of land degradation in drylands in which biological productivity is lost due to natural processes or induced by human activities whereby fertile areas become arid. It is the spread of arid areas caused by a variety of factors, such as overexploitation of soil as a result of human activity and the effects of climate change. Geographic areas most affected include the Sahel region in Africa, the Gobi Desert and Mongolia in Asia as well as parts of South America. Drylands occupy approximately 40–41% of Earth's land area and are home to more than 2 billion people.
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.
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 Nile river to the west and the Red Sea and Gulf of Suez to the east. It extends through Egypt, Eritrea, Sudan and Ethiopia. The Eastern Desert is also known as the Red Sea Hills. 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, the saxaul, black saxaul, sometimes sacsaoul or saksaul, is a plant belonging to the family Amaranthaceae.
The Tarim Basin deciduous forests and steppe is a temperate broadleaf and mixed forests ecoregion in the Xinjiang Uyghur Autonomous Region of western China. The ecoregion includes deciduous riparian forests and steppes sustained by the region's rivers in an otherwise arid region.
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.
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).m.m.m.s It is bound by the piedmont of the northern Salt Range, the Indus River flood plains in the west and the Jhelum and Chenab River 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.
The Great Green Wall, officially known as the Three-North Shelter Forest Program, also known as the Three-North Shelterbelt Program, is a series of human-planted windbreaking forest strips (shelterbelts) in China, designed to hold back the expansion of the Gobi Desert, and provide timber to the local population. The program started in 1978, and is planned to be completed around 2050, at which point it will be 4,500 kilometres (2,800 mi) long.
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 are typically desert regions like the Sahara, and places in the Alps or the Arctic. Popular examples of xerophytes are cacti, pineapple and some Gymnosperm plants.
Desert greening is the process of afforestation or revegetation of deserts for ecological restoration (biodiversity), sustainable farming and forestry, but also for reclamation of natural water systems and other ecological systems that support life. The term "desert greening" is intended to apply to both cold and hot arid and semi-arid deserts. It does not apply to ice capped or permafrost regions. It pertains to roughly 32 million square kilometres of land. Deserts span all seven continents of the Earth and make up nearly a fifth of the Earth's landmass, areas that recently have been increasing in size. As some of the deserts expand and global temperatures increase, the different methods of desert greening may provide a potential solution. Planting suitable flora in deserts has a range of environmental benefits from carbon sequestration to providing habitat for native desert fauna to generating employment opportunities to creation of habitable areas for local communities. The prevention of land desertification is one of 17 sustainable development objectives outlined by the United Nations, desert greening is a process that aims to not only combat desertification but to foster an environment where plants can create a sustainable environment for all forms of life while preserving its integrity.
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.
The Mu Us Desert is a desert in northern China. Its south-eastern end is crossed by the Great Wall of China. The Mu Us forms the southern portion of the Ordos Desert and part of the Ordos Loop. The Wuding River drains the area, and then flows into the Yellow River.
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.
The Alashan Plateau semi-desert ecoregion covers the southwestern portion of the Gobi Desert where precipitation in the mountains is sufficient for a short part of the summer to support sparse plant life. The terrain is basin and range, with elevations from 1,000 to 2,500 metres. The region straddles the China–Mongolian border, with the Tibetan Plateau to the south, and the more arid regions of the Gobi to the north and east.
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.