The Sahara desert, as defined by the World Wide Fund for Nature (WWF), includes the hyper-arid center of the Sahara, between latitudes 18° N and 30° N. It is one of several desert and xeric shrubland ecoregions that cover the northern portion of the African continent.
The Arabian Desert is a vast desert wilderness in West Asia that occupies almost the entire Arabian Peninsula with an area of 2,330,000 square kilometers (900,000 sq mi). It stretches from Yemen to the Persian Gulf and Oman to Jordan and Iraq. It is the fifth largest desert in the world and the largest in Asia. At its center is Ar-Rub' al-Khali, one of the largest continuous bodies of sand in the world. It is an extension of the Sahara Desert.
The Eastern Gobi desert steppe is a deserts and xeric shrublands ecoregion in Mongolia and northern China. It is the easternmost of the ecoregions that make up the larger Gobi Desert. It lies between the more humid Mongolian–Manchurian grassland on the north, east, and southeast, and the drier Alashan Plateau semi-desert to the west.
Dasht-e Kavir or Kavir Desert, also known as Kavir-e Namak or the Great Salt Desert, is a large desert lying in the middle of the Iranian Plateau. It is about 800 kilometres (500 mi) long by 320 kilometres (200 mi) wide with a total surface area of about 77,600 km2 (30,000 sq mi), making it the world's 24th largest desert. The desert stretches from the Alborz mountain range in the north-west to the Dasht-e Lut in the south-east. It is spread across the Iranian provinces of Khorasan, Semnan, Tehran, Isfahan and Yazd.
The North Saharan steppe and woodlands is a desert ecoregion, in the deserts and xeric shrublands biome, that forms the northern edge of the Sahara. It extends east and west across Northern Africa, south of the Mediterranean dry woodlands and steppe ecoregion of the Maghreb and Cyrenaica, which is part of the Mediterranean forests, woodlands, and scrub biome. Winter rains sustain shrublands and dry woodlands that form an ecotone between the Mediterranean climate regions to the north and the hyper-arid Sahara Desert ecoregion to the south.
The South Saharan steppe and woodlands, also known as the South Sahara desert, is a deserts and xeric shrublands ecoregion of northern Africa. This band is a transitional region between the Sahara's very arid center to the north, and the wetter Sahelian Acacia savanna ecoregion to the south. In pre-modern times, the grasslands were grazed by migratory gazelles and other ungulates after the rainfalls. More recently, over-grazing by domestic livestock have degraded the territory. Despite the name of the ecoregion, there are few 'woodlands' in the area; those that exist are generally acacia and shrubs along rivers and in wadis.
The Great Lakes Basin desert steppe ecoregion covers the enclosed basin centered on Uvs Lake, a saline, endorheic basin in northwestern Mongolia. A portion of the ecoregion stretches across the region into Russia. The lake district is important for migrating birds, waterfowl, and seabirds. The ecoregion is in the Palearctic realm and the deserts and xeric shrublands biome. It has an area of 157,212 square kilometres (60,700 sq mi).
The Tian Shan foothill arid steppe ecoregion covers the northern and western approaches to the Tian Shan mountains, centered on Lake Issyk-Kul in Kyrgyzstan. This region receives more moisture from Central Asia, thereby supporting more vegetation and diversity of plant and animal species than the deserts to the south.
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 Gobi Lakes Valley desert steppe ecoregion covers the narrow, flat valley in southwestern Mongolia that lies between the Khangai Mountains, and the Gobi-Altai Mountains. The region is known as the "Valley of the Lakes" because runoff from the mountains collect in lakes that have no outlet to the sea. Although the valley is a semi-arid desert steppe, it has areas of wetlands near the lakes that are important habit for water birds.
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 Kopet Dag semi-desert ecoregion is a small ecoregion that crosses the border of southwestern Turkmenistan into northeastern Iran. It covers a transition zone between the deserts to the north and west, and the foothill steppes and woodlands in the higher Kopet Dag mountains to the east and the Alborz Mountains to the south. The terrain is mostly barren semi-desert and widespread 'takir', a type of seasonal salt flat or dried clay deposit in an interdune depression.
The Kopet Dag woodlands and forest steppe ecoregion coincides with the Kopet Dag mountains, straddling the southern border of Turkmenistan and the northeastern border of Iran. The region is one of high biodiversity, as it includes a full range of altitude zones, and variety of habitats included juniper-wooded slopes, montane grasslands, and tugay.
The Kuh Rud and Eastern Iran montane woodlands ecoregion covers hills and mountains in central and eastern Iran. The habitat is wetter and cooler than the surrounding desert of the Iranian Plateau, supporting the vulnerable goitered gazelle and small populations of the cheetah. The ecoregion is under conservation threat from overgrazing and conversion of steep slopes to cultivation.
The South Iran Nubo–Sindian desert and semi-desert ecoregion covers the northern coastal plain of the Persian Gulf and the inland desert hills south of the Zagros Mountains of Iran. The region also has extensions reaching into southeastern Iraq, and eastward into southwestern Pakistan. The region is one of hot sand deserts, shrubland, and open thorn woodlands inland. Mangrove forests and swamps are found along the coast.
The Registan–North Pakistan sandy desert ecoregion covers the dry Sistan Basin of southern Afghanistan and portions of eastern Iran and southwest Pakistan. The Registan Desert is the eastern portion of the Sistan Basin. The region is almost entirely dry sandy desert, with some irrigated cropland along the rivers. There are some seasonal wetlands at the western terminus of the Helmand River into Hamun Lake. The region support five endemic species of reptiles.
The Paropamisus xeric woodlands ecoregion covers the portion of northeastern Afghanistan north of the central mountain range and the Hindu Kush Mountains. The name is derived from the Old Persian name for the region, Parupraesanna. While there are low canopy woodlands in the northeast of the ecorgegion, most of the territory is desert or xeric (dry) scrubland.
The Mesopotamian shrub desert is a deserts and xeric shrublands ecoregion in Western Asia. It extends across portions of Israel, Jordan, Syria, Iraq, and Iran.
The Saharan halophytics ecoregion covers a series of low-lying evaporite depressions and wetlands spread across North Africa. The depressions are characteristically saline, variously chotts or sabkhas. The plants of the areas are highly specialized to survive in the harsh environment, with many being xerophytes (drought-tolerant) and halophytes (salt-tolerant). The biodiversity of the areas has been relatively protected by their isolation, and unsuitability of alkaline soil for farming.
