The Atlantic coastal desert is the westernmost
ecoregion
An ecoregion (ecological region) is an ecological and geographic area that exists on multiple different levels, defined by type, quality, and quantity of environmental resources. Ecoregions cover relatively large areas of land or water, and c ...
in the
Sahara Desert
The Sahara (, ) is a desert spanning across North Africa. With an area of , it is the largest hot desert in the world and the list of deserts by area, third-largest desert overall, smaller only than the deserts of Antarctica and the northern Ar ...
of
North Africa
North Africa (sometimes Northern Africa) is a region encompassing the northern portion of the African continent. There is no singularly accepted scope for the region. However, it is sometimes defined as stretching from the Atlantic shores of t ...
. It occupies a narrow strip along the
Atlantic
The Atlantic Ocean is the second largest of the world's five oceanic divisions, with an area of about . It covers approximately 17% of Earth's surface and about 24% of its water surface area. During the Age of Discovery, it was known for se ...
coast, where the more frequent
fog and
haze generated offshore by the cool
Canary Current provides sufficient moisture to sustain a variety of
lichen
A lichen ( , ) is a hybrid colony (biology), colony of algae or cyanobacteria living symbiotically among hypha, filaments of multiple fungus species, along with yeasts and bacteria embedded in the cortex or "skin", in a mutualism (biology), m ...
s,
succulents, and shrubs.
Geography
It covers in
Western Sahara
Western Sahara is a territorial dispute, disputed territory in Maghreb, North-western Africa. It has a surface area of . Approximately 30% of the territory () is controlled by the Sahrawi Arab Democratic Republic (SADR); the remaining 70% is ...
and
Mauritania
Mauritania, officially the Islamic Republic of Mauritania, is a sovereign country in Maghreb, Northwest Africa. It is bordered by the Atlantic Ocean to the west, Western Sahara to Mauritania–Western Sahara border, the north and northwest, ...
. It is bounded on the west by the
Atlantic Ocean
The Atlantic Ocean is the second largest of the world's five borders of the oceans, oceanic divisions, with an area of about . It covers approximately 17% of Earth#Surface, Earth's surface and about 24% of its water surface area. During the ...
, on the east by the
North Saharan steppe and woodlands, on the north by the
Mediterranean Acacia–Argania dry woodlands, and on the south by the
Sahelian Acacia savanna
The Sahel region (; ), or Sahelian acacia savanna, is a biogeographical region in Africa. It is the transition zone between the more humid Sudanian savannas to its south and the drier Sahara to the north. The Sahel has a hot semi-arid clima ...
.
Climate
The cool ocean current gives an even higher
atmospheric stability in the desert, by cooling air at the base. This increase in atmospheric stability serves to further reduce the amount of rainfall. Therefore, the climate is extremely dry with some 30 mm of annual precipitation in
Dakhla, Western Sahara and 40 mm of annual precipitation in
Nouadhibou, Mauritania. Several years may pass without any rainfall at all. The climate is very sunny year-round with around 3,200 hours of annual bright sunshine, though far less sunny than in other parts of the desert of North Africa due to
fog and
haze. Air in the Atlantic coastal desert is rather moist and the
relative humidity
Humidity is the concentration of water vapor present in the air. Water vapor, the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation (meteorology), precipitation, dew, or fog t ...
is generally over 60% while farther in the interior, it quickly lowers to 30% or less. Temperatures are also much more moderated in this coastal desert and are relatively warm to truly hot in all seasons. Averages daily temperature is 20 °C (68 °F) in Dakhla. Maximum average high temperatures are 27 °C (80.6 °F) while minimum average low temperatures are 13 °C (55.4 °F) in Dakhla.
Ecology
This bioregion is fairly rich in
endemic
Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...
plants but has no endemic fauna. The flora consists of a variety of
lichen
A lichen ( , ) is a hybrid colony (biology), colony of algae or cyanobacteria living symbiotically among hypha, filaments of multiple fungus species, along with yeasts and bacteria embedded in the cortex or "skin", in a mutualism (biology), m ...
s,
succulents and drought-resistant shrubs. The
Mediterranean monk seal (''Monachus monachus'') is found here and the broad bays are important overwintering grounds for large numbers of Palearctic wading birds.
Greater flamingoes (''Phoenicopterus roseus'') and many other waterbirds congregate on the wetlands during their
migrations. Mammals found here include the
Dorcas gazelle
The dorcas gazelle (''Gazella dorcas''), also known as the ariel gazelle, is a small and common gazelle. The dorcas gazelle stands about at the shoulder, with a head and body length of and a weight of . The numerous subspecies survive on veget ...
(''Gazella dorcas''),
golden wolf (''Canis lupusater''),
fennec fox
The fennec fox (''Vulpes zerda'') is a small fox native to the deserts of North Africa, ranging from Western Sahara and Mauritania to the Sinai Peninsula. Its most distinctive feature is its unusually large ears, which serve to dissipate hea ...
(''Fennecus zerda''),
Rüppell's fox (''Vulpes rueppelli''),
sand cat (''Felis margarita''),
honey badger
The honey badger (''Mellivora capensis''), also known as the ratel ( or ), is a mammal widely distributed across Africa, Southwest Asia, and the Indian subcontinent. It is the only living species in both the genus ''Mellivora'' and the subfami ...
(''Mellivora capensis'') and
striped hyena
The striped hyena (''Hyaena hyaena'') is a species of hyena native to North and East Africa, the Middle East, the Caucasus, Central Asia, and the Indian subcontinent. It is the only extant species in the genus ''Hyaena''. It is listed by the IU ...
(''Hyaena hyaena'').
[
]
References
{{Palearctic desert and xeric shrubland ecoregions
Deserts and xeric shrublands
Deserts of Africa
Ecoregions of Mauritania
Ecoregions of Western Sahara
Flora of North Africa
Palearctic ecoregions