North Saharan steppe and woodlands | |
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Ecology | |
Realm | Palearctic |
Biome | Deserts and xeric shrublands |
Borders | |
Geography | |
Area | 1,675,300 km2 (646,800 sq mi) |
Countries | |
Conservation | |
Conservation status | relatively intact |
Protected | 0.69% [1] |
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 North Saharan steppe and woodlands covers 1,675,300 square kilometers (646,800 sq mi) in Algeria, Egypt, Libya, Mauritania, Morocco, Tunisia, and Western Sahara. [2]
The climate in this ecoregion is hot and dry in the summer but cooler with some rain in the winter. Atlantic depressions sometimes penetrate inland between October and April. Rainfall is erratic, but averages 100 mm (4 in) in the north and 50 mm (2 in) in the south. During the summer, temperatures regularly rise to 40 to 45 °C (104 to 113 °F) and evaporation far exceeds precipitation. [2]
There are varying habitats in the ecoregion including sandy systems, rocky plateaus, wadis, depressions and mountains. Each has its own characteristic species and there is considerable endemism of both plants and animals in the area.
Plant communities include steppes of grasses, herbs and low shrubs, tall shrublands, and dry woodlands. Shrublands and woodlands typically grow in depressions, in the valleys of intermittent streams (wadis), and on consolidated dunes. Common trees include Vachellia tortilis, Pistacia atlantica , and Tamarix aphylla . Tall shrubs of the woodlands and tall shrublands include Retama raetam, Ziziphus lotus, Calobota saharae , and Calligonum comosum . [2]
Plants have evolved various strategies to adapt to the dry climate and intermittent rainfall. Many herbaceous ephemeral plants, particularly in the north, germinate in January during the wet season and quickly mature and flower before they dry out in the spring. [2]
Small mammals endemic to the Sahara area include the four-toed jerboa (Allactaga tetradactyla), North African gerbil (Gerbillus campestris), James's gerbil (G. jamesi), pale gerbil (G. perpallidus), lesser short-tailed gerbil (G. simoni), sand gerbil (G. syrticus), fat-tailed gerbil (Pachyuromys duprasi) and Shaw's jird (Meriones shawi). Larger mammals include the dorcas gazelle (Gazella dorcas), mountain gazelle (Gazella cuvieri) and slender-horned gazelle (Gazella leptoceros). There are a variety of snakes and lizards, including two endemic species, desert agama (Trapelus mutabilis) and Natterer's gecko (Tropiocolotes nattereri). There are few amphibians, Brongersma's toad (Bufo brongersmai) being endemic to the coastal region of North Africa. Among the bird species, the Houbara bustard (Chlamydotis undulata) and Nubian bustard (Neotis nuba) have decreased in numbers because of hunting pressure. [2]
Only 0.69% of the ecoregion is in protected areas. These include: [1]
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 Sahara is a desert on the African continent. With an area of 9,200,000 square kilometres (3,600,000 sq mi), it is the largest hot desert in the world and the third-largest desert overall, smaller only than the deserts of Antarctica and the northern Arctic.
The Saharan Atlas is a range of the Atlas Mountain System. It is located mainly in Algeria, with its eastern end in Tunisia. Although not as tall as the High Atlas of Morocco its summits are more imposing than the Tell Atlas range that runs parallel closer to the coast. The tallest peak in the range is the 2,236 m (7,336 ft) high Djebel Aissa in the Ksour Range.
The West Saharan montane xeric woodlands is an ecoregion that extends across several highland regions in the Sahara. Surrounded at lower elevations by the largely barren Sahara, the West Saharan montane xeric woodlands are isolated refuges of plants and animals that can survive in the higher humidity and lower temperatures of the highlands.
The dorcas gazelle, also known as the ariel gazelle, is a small and common gazelle. The dorcas gazelle stands about 55–65 cm at the shoulder, with a head and body length of 90–110 cm and a weight of 15–20 kg. The numerous subspecies survive on vegetation in grassland, steppe, wadis, mountain desert and in semidesert climates of Africa and Arabia. About 35,000–40,000 exist in the wild.
The East Saharan montane xeric woodlands is an ecoregion of central Africa, a number of high mountains in the middle of the huge area of savanna on the edge of the Sahara Desert.
The Eastern Mediterranean conifer-sclerophyllous-broadleaf forests, also known as the Eastern Mediterranean conifer-broadleaf forests, is an ecoregion in the eastern Mediterranean Basin. It covers portions of Turkey, Syria, Iraq, Lebanon, Israel, Palestinian territories, Jordan, and Saudi Arabia.
The Atlantic coastal desert is the westernmost ecoregion in the Sahara Desert of North Africa. It occupies a narrow strip along the Atlantic coast, where the more frequent fog and haze generated offshore by the cool Canary Current provides sufficient moisture to sustain a variety of lichens, succulents, and shrubs.
The Mediterranean Acacia-Argania dry woodlands and succulent thickets is a Mediterranean forests, woodlands, and scrub ecoregion in North Africa centered mainly on Morocco but also including northwestern Western Sahara and the eastern Canary Islands.
The Mediterranean woodlands and forests is an ecoregion in the coastal plains, hills, and mountains bordering the Mediterranean Sea and Atlantic Ocean in North Africa. It has a Mediterranean climate, and is in the Mediterranean forests, woodlands, and scrub biome.
The Mediterranean dry woodlands and steppe is a Mediterranean forests, woodlands, and scrub ecoregion of North Africa. It occupies interior plateaus and mountain ranges of the Maghreb region, lying generally between the coastal Mediterranean woodlands and forests to the north and the Sahara to the south.
Mediterranean conifer and mixed forests is an ecoregion, in the temperate coniferous forest biome, which occupies the high mountain ranges of North Africa. The term is also a botanically recognized plant association in the African and Mediterranean literature.
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 Tibesti-Jebel Uweinat montane xeric woodlands is a deserts and xeric shrublands ecoregion in the eastern Sahara. The woodlands ecoregion occupies two separate highland regions, covering portions of northern Chad, southwestern Egypt, southern Libya, and northwestern Sudan.
The Ethiopian xeric grasslands and shrublands ecoregion is a semi-desert strip on or near the Red Sea and the Gulf of Aden coasts in Eritrea, Ethiopia, Djibouti and Somaliland. This ecoregion lies mainly between sea level and 800 meters (m) elevation. There are, however, many hills and massifs, which range up to 1300 m as well as outstanding fault-induced depressions, such as the Danakil, lying as low as 155 m below sea level. This region is extremely active tectonically, experiencing many earthquakes and intermittently active volcanoes. Rainfall is very low and yearly averages range from 100 to 200 millimeters (mm), with less rain falling closer to the coast. There are many species of interest, including the endemic Archer's lark, a species of dragon tree, and a large suite of desert ungulates, including the last viable population of African wild ass.
The Central Asian northern desert is an ecoregion in the deserts and xeric shrublands biome, located in the Central Asian countries of Kazakhstan and Uzbekistan. The annual precipitation ranges from 100 to 150 mm, the winters are cold at −10 to −15 °C and the summers hot at around 25 °C (77 °F). There are a range of habitat types including salt flats, clay desert, rocky desert and some sand desert. The vegetation consists of scanty xeric shrubs including Artemisia and Salsola. The fauna is varied, as well as mammals and birds, there are a large number of reptiles and many species of invertebrate. Some protected areas are included in this ecoregion but other parts are being degraded by conversion to farmland, overgrazing and poaching.
The Grand Bara, Bara Wein or Bada Wein, is a desert in southern Djibouti. It consists of large areas of sand flats, with sparse, semi-desert and desert grasses and scrub vegetation. A road built in 1981 passes through the area, connecting the capital Djibouti City with the south. Prior to the arrival of the French, the extremely arid interior was inhabited primarily by the Issa Somali. Runners make their way across the Grand Bara Desert during the Annual Grand Bara 15K race.
The Red Sea coastal desert is deserts and xeric shrublands ecoregion of Egypt and Sudan.
The Azerbaijan shrub desert and steppe is a deserts and xeric shrublands ecoregion in western Asia. It lies in the lowlands west of the Caspian Sea, and covers portions of Azerbaijan, Georgia, 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.