Djibouti xeric shrublands

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Djibouti xeric shrublands
Ethiopian xeric grasslands and shrublands
Awash near Asaita.jpg
AT1305 map.png
location of the Djibouti Xeric Shrublands
Ecology
Realm Afrotropical
Biome deserts and xeric shrublands
Borders
Geography
Area235,685 km2 (90,998 sq mi)
Countries
Conservation
Conservation status Vulnerable
Protected4.68% [1]

The Djibouti xeric shrublands is an ecoregion defined by One Earth, [2] consisting of a semi-desert strip on or near the Red Sea and the Gulf of Aden coasts in Eritrea, Ethiopia, Djibouti and Somalia. 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 (Heteromirafra archeri), a species of dragon tree ( Dracaena ombet ), and a large suite of desert ungulates, including the last viable population of African wild ass (Equus africanus somalicus). [2] [3]

Contents

Location and description

This ecoregion extends inland from the Red Sea and the Gulf of Aden, stretching from the Sudanese-Eritrean border, south through coastal Eritrea to Ethiopia and Djibouti and eastwards into western Somaliland. It covers the Afar Triangle or Afar Depression, a lowland bounded on the south and east by the Ethiopian Highlands, and extends southwest through the Great Rift Valley as far as Lake Awasa. The ecoregion includes Eritrea's Dahlak Archipelago in the Red Sea. While it mainly lies between sea level and 800 m, there are many arid hills and massifs up to 1300 m, including the Danakil Alps along the Eritrea-Ethiopia border. Juniper woodlands in the Goda and Mabla mountains in Djibouti are considered to be outliers of the Ethiopian montane grasslands and woodlands ecoregion, which also covers the Ethiopian Highlands above about 1000 meters elevation. There are also fault-induced depressions, such as the Danakil Depression and Lac Assal, lying as much as 160 m below sea level. Elevation generally increases westward towards the Ethiopian and Eritrean highlands, which form steep escarpments. [3] [4]

The region is extremely active tectonically, and it experiences many earthquakes associated with the continuing enlargement of the Rift Valley. Volcanoes in the ecoregion are also intermittently active. Basement rocks are composed mainly of Tertiary lava flows, although there are also Quaternary basinal deposits at the northern end and pre-Cretaceous basinal deposits on the northern coast of Somalia. Soils developed over the lava deposits are mainly lithosols, while regosols are predominant on the Quaternary and pre-Cretaceous basinal deposits. There are very few permanent watercourses. The most notable is the Awash River of Ethiopia that terminates in a series of lakes near the border with Djibouti. [3]

Climate

The climate is very hot and dry. Mean annual rainfall varies from less than 100 mm close to the coast to around 200 mm further inland. Mean minimum temperatures range from 21° to 24 °C, and mean maximum temperature is around 30 °C. [3] Most of the people have to build their houses with clay to keep the hot outside and the cold outside.

Flora

The predominant vegetation dry shrub steppe and grassland. Vachellia tortilis, Vachellia nubica , and Balanites aegyptiaca grow as scattered trees or shrubs on the sandy plains. Senegalia mellifera and Rhigozum somalense grow as shrubs or small trees on basaltic lava fields. The palm Hyphaene thebaica grows along seasonal watercourses (wadis) and depressions with year-round groundwater. The endangered Bankoualé palm (Livistona carinensis) grows in three wadi systems in the Goda Mountains of Djibouti between 165 and 970 meters elevation. Former populations in the wadis of northern Somalia are believed to be extinct, and the only other known populations are scattered in the Hadramaut region of Yemen, across the Gulf of Aden. [5] The endangered Gabal Elba dragon tree (Dracaena ombet) is found in the ecoregion's mountains above 1000 meters elevation.

Mangroves occur along the coast, in muddy wadi mouths and inlets. [3]

The plant life of the region needs more study, which has been hampered by long-term political strife in the region. Due largely to political instability in the region over the last 30 years, many elements of the fauna and flora remain poorly known. As a suggestion of floral richness, an estimated 825 to 950 species have been observed in Djibouti, although many of these have been found only in the small outlying patches of the Ethiopian montane grasslands and woodlands. These outliers are part of the Day Forest and Mabla Mountains above 1,100 m in Djibouti. [3]

Fauna

Mammals found here include the last Somali wild ass (Equus africanus somalicus) to be found in the wild, on the Buri Peninsula of Eritrea. Other grazing animals include beira, dorcas gazelle, Soemmerring's Gazelle, gerenuk and the beisa oryx (Oryx beisa). The only purely endemic mammal is a gerbil, Gerbillus acticola . There are a number of dry habitat reptiles including the endemic geckos, Arnold's leaf-toed gecko (Hemidactylus arnoldi) and Parker's pigmy gecko (Tropiocolotes somalicus). Birds include the endemic Archer's lark (Heteromirafra archeri). [3]

People

Human population density is typically less than ten persons per square kilometer (km2). In some areas, there is less than one person per km2. The dominant ethnic groups are the nomadic pastoralist Afars and a Somali clan, the Issas. Human density, however, does not account for grazing animals. Urban areas in the region include the ports of Massawa in Eritrea, Djibouti city, and Berbera in Somalia. Smaller towns include the former Afar Region capital of Asaita in Ethiopia and smaller ports along the coast such as Tadjoura in Djibouti and Zeila in Somalia. Tourism in the region includes diving in the Dahlak islands.

Threats and conservation

The conservation status of this ecoregion is not good, with few protected areas and lack of enforcement in existing ones. Habitats however have been degraded, mainly by grazing of livestock as well as cutting of trees for firewood and clearing of land for planting.

Protected areas

4.68% of the ecoregion is in protected areas. Protected areas include Yangudi Rassa National Park and Mille-Serdo Wildlife Reserve in Ethiopia, Nakfa Wildlife Reserve in Eritrea, and the Djalélo and Assamo terrestrial protected areas in Djibouti. [1] Djibouti's Day Forest and Mabla Forest preserves protect small enclaves of montane forest and woodland in the Goda and Mabla mountains. [6] There are two internationally designated Ramsar Sites (wetlands of international importance) in the ecoregion – Suakin–Gulf of Agig in Sudan and Haramous–Loyada in Djibouti. [1]

Related Research Articles

<span class="mw-page-title-main">Geography of Djibouti</span> Country geography

Djibouti is a country in the Horn of Africa. It is bordered by Eritrea in the north, Ethiopia in the west and south, and Somalia in the southeast. To the east is its coastline on the Red Sea and the Gulf of Aden. Rainfall is sparse, and most of the territory has a semi-arid to arid environment. Lake Assal is a saline lake which lies 155 m (509 ft) below sea level, making it the lowest point on land in Africa and the third-lowest point on Earth after the Sea of Galilee and the Dead Sea. Djibouti has the fifth smallest population in Africa. Djibouti's major settlements include the capital Djibouti City, the port towns of Tadjoura and Obock, and the southern cities of Ali Sabieh and Dikhil. It is the forty-six country by area in Africa and 147st largest country in the world by land area, covering a total of 23,200 km2 (9,000 sq mi), of which 23,180 km2 (8,950 sq mi) is land and 20 km2 (7.7 sq mi) is water.

<span class="mw-page-title-main">Geography of Eritrea</span> Overview of geography in Eritrea

Eritrea is located in the Horn of Africa and is bordered on the northeast and east by the Red Sea, on the west and northwest by Sudan, on the south by Ethiopia, and on the southeast by Djibouti. The country has a high central plateau that varies from 1,800 to 3,000 meters (5,906–9,843 ft) above sea level. A coastal plain, western lowlands, and some 350 islands comprise the remainder of Eritrea's land mass.

<span class="mw-page-title-main">Geography of Somalia</span> Geographical features of Somalia

Somalia is a country located in the Horn of Africa which officially consists of the intra-46th meridian east territory, the seven federal member states, namely Galmudug, Hirshabelle, Jubaland, South West, Puntland, and the municipality of Benadir. It is bordered by Ethiopia to the west, the Gulf of Aden to the north, the Somali Sea and Guardafui Channel to the east, and Kenya to the southwest. With a land area of 637,657 square kilometers, Somalia's terrain consists mainly of plateaus, plains and highlands. Its coastline is more than 3,333 kilometers in length, the longest of mainland Africa. It has been described as being roughly shaped "like a tilted number seven".

<span class="mw-page-title-main">Afar Triangle</span> Geological depression caused by the Afar Triple Junction

The Afar Triangle is a geological depression caused by the Afar Triple Junction, which is part of the Great Rift Valley in East Africa. The region has disclosed fossil specimens of the very earliest hominins; that is, the earliest of the human clade, and it is thought by some paleontologists to be the cradle of the evolution of humans. The Depression overlaps the borders of Eritrea, Djibouti and the entire Afar Region of Ethiopia; and it contains the lowest point in Africa, Lake Assal, Djibouti, at 155 m (509 ft) below sea level.

<span class="mw-page-title-main">Goda Mountains</span>

The Goda Mountains lie northwest of the Gulf of Tadjoura, Tadjoura Region in Djibouti. They rise to 1,750 metres (5,740 ft) above sea level and are the nation's largest heavily vegetated area and is the second highest point in Djibouti. The name Goda in Afar means "twisted" or "devoured" and refers to a ridge. A part of the mountains is protected within the Day Forest National Park, Djibouti's only national park. The ecology of this landform is considered an isolated outlier of the Ethiopian montane grasslands and woodlands ecoregion, an important island of forest in a sea of semi-desert.

<span class="mw-page-title-main">Afar people</span> Cushitic ethnic group native to the Horn of Africa

The Afar, also known as the Danakil, Adali and Odali, are a Cushitic ethnic group inhabiting the Horn of Africa. They primarily live in the Afar Region of Ethiopia and in northern Djibouti, as well as the entire southern coast of Eritrea. The Afar speak the Afar language, which is part of the Cushitic branch of the Afroasiatic family. Afars are the only inhabitants of the Horn of Africa whose traditional territories border both the Red Sea and the Gulf of Aden.

<span class="mw-page-title-main">Afromontane</span> Subregion of the Afrotropical realm

The Afromontane regions are subregions of the Afrotropical realm, one of the Earth's eight biogeographic realms, covering the plant and animal species found in the mountains of Africa and the southern Arabian Peninsula. The Afromontane regions of Africa are discontinuous, separated from each other by lower-lying areas, and are sometimes referred to as the Afromontane archipelago, as their distribution is analogous to a series of sky islands.

<span class="mw-page-title-main">Wildlife of Djibouti</span> Flora and fauna of Djibouti

The wildlife of Djibouti, consisting of its flora and fauna, is in a harsh landscape with forest accounting for less than one percent of its area. Most species are found in the northern part of the country in the Day Forest National Park at an average elevation of 1,500 metres (4,900 ft), including the massif Goda, with a peak of 1,783 metres (5,850 ft). It covers an area of 3.5 square kilometres (1.4 sq mi) of Juniperus procera forest, with many of the trees rising to 20 metres (66 ft) height. This forest area is the main habitat of the critically endangered and endemic Djibouti spurfowl, and another recently noted vertebrate, Platyceps afarensis. The area also contains many species of woody and herbaceous plants, including boxwood and olive trees, which account for sixty percent of the identified species in the country.

<span class="mw-page-title-main">North Saharan steppe and woodlands</span> Ecoregion in North Africa

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 Ethiopian montane grasslands and woodlands is a montane grasslands and shrublands ecoregion in Ethiopia. It occupies the middle elevations of the Ethiopian Highlands, between the high-elevation Ethiopian montane moorlands and lowland woodlands, savannas, shrublands, and thickets.

<span class="mw-page-title-main">Mabla Mountains</span> Mountain range in Djibouti

The Mabla Mountains are a mountain range in the northern Obock and Tadjoura Region of Djibouti. The endemic Djibouti spurfowl makes its home here as well as in the Forêt du Day. With a mean height of 1370 metres, is the fifth highest point in Djibouti.

<span class="mw-page-title-main">Grand Bara</span> Desert in Djibouti

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 Danakil Alps are a highland region in Ethiopia and Eritrea with peaks over 1000 metres in height and a width varying between 40 and 70 kilometres. The area is known in the Afar language as Arrata. The alps lie along the southern Red Sea to the east of the Danakil Depression and separate it from the sea. The alps are asymmetric in cross-section with a comparatively gentle rift escarpment facing the Red Sea and intense normal faulting on the inland side.

Northern <i>Acacia</i>–<i>Commiphora</i> bushlands and thickets

The Northern AcaciaCommiphora bushlands and thickets are a tropical grasslands, savannas and shrublands ecoregion in eastern Africa. The ecoregion is mostly located in Kenya, extending north into southeastern South Sudan, northeastern Uganda and southwestern Ethiopia and south into Tanzania along the Kenya-Tanzania border.

Somali <i>Acacia</i>–<i>Commiphora</i> bushlands and thickets

The Somali AcaciaCommiphora bushlands and thickets is a semi-arid tropical grasslands, savannas, and shrublands ecoregion in the Horn of Africa. It is home to diverse communities of plants and animals, including several endemic species.

<span class="mw-page-title-main">Southwestern Arabian foothills savanna</span>

The Southwestern Arabian foothills savanna, also known as the Southwestern Arabian Escarpment shrublands and woodlands, is a desert and xeric shrubland ecoregion of the southern Arabian Peninsula, covering portions of Saudi Arabia, Yemen, and Oman.

Mille-Serdo Wildlife Reserve is a protected area in Ethiopia. It is located in Afar Region of Ethiopia. The reserve protects a portion of the Awash River and the surrounding desert.

References

  1. 1 2 3 "Ethiopian xeric grasslands and shrublands". DOPA Explorer. Accessed 27 February 2022.
  2. 1 2 Margin, Emma; Burgess, Neil. "Djibouti Xeric Shrublands". One Earth. Retrieved 2024-05-27.
  3. 1 2 3 4 5 6 7 "Ethiopian xeric grasslands and shrublands". Terrestrial Ecoregions. World Wildlife Fund.
  4. Ib Friis, Sebsebe Demissew, and Paulo van Breugel (2010) Atlas of the Potential Vegetation of Ethiopia. The Royal Danish Academy of Sciences and Letters, Copenhagen, Denmark
  5. Cosiaux, A.; Welch, H.; Gardiner, L.M.; Welch, G.; Couvreur, T.L.P. (2018). "Livistona carinensis". IUCN Red List of Threatened Species . 2018: e.T30402A95306943. doi: 10.2305/IUCN.UK.2018-1.RLTS.T30402A95306943.en . Retrieved 27 February 2022.
  6. Witsen, Deirdre (2012) Djibouti Biodiversity and Tropical Forests: 118/119 Assessment. US Forest Service Office of International Programs for the US Agency for International Development (USAID), November 2012.