The West Sudanian savanna is a

tropical savanna Tropical and subtropical grasslands, savannas, and shrublands is a terrestrial biome defined by the World Wide Fund for Nature. The biome is dominated by grass and/or shrubs located in semi-arid to semi-humid climate regions of subtropical and t ...

ecoregion An ecoregion (ecological region) or ecozone (ecological zone) is an ecologically and geographically defined area that is smaller than a bioregion, which in turn is smaller than a biogeographic realm. Ecoregions cover relatively large areas of ...

that extends across

West Africa West Africa or Western Africa is the westernmost region of Africa. The United Nations defines Western Africa as the 16 countries of Benin, Burkina Faso, Cape Verde, The Gambia, Ghana, Guinea, Guinea-Bissau, Ivory Coast, Liberia, Mali ...

Geography

The ecoregion stretches east and west across West Africa, from the

Atlantic The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...

coast of Senegal to the

Mandara Mountains The Mandara Mountains are a volcanic range extending about 190 km (about 120 mi) along the northern part of the Cameroon–Nigeria border, from the Benue River in the south () to the north-west of Maroua in the north (). The highest e ...

on Nigeria's eastern border. The drier

Sahelian Acacia savanna The Sahel (; ar, ساحل ' , "coast, shore") is a region in North Africa. It is defined as the ecoclimatic and biogeographic realm of transition between the Sahara to the north and the Sudanian savanna to the south. Having a hot semi-arid cli ...

lies to the north, and the more humid Guinean forest-savanna mosaic lies to the south.

Climate

The climate is a

tropical savanna climate Tropical savanna climate or tropical wet and dry climate is a tropical climate sub-type that corresponds to the Köppen climate classification categories ''Aw'' (for a dry winter) and ''As'' (for a dry summer). The driest month has less than of ...

and a hot

semi-arid climate A semi-arid climate, semi-desert climate, or steppe climate is a dry climate sub-type. It is located on regions that receive precipitation below potential evapotranspiration, but not as low as a desert climate. There are different kinds of semi ...

(

Köppen climate classification The Köppen climate classification is one of the most widely used climate classification systems. It was first published by German-Russian climatologist Wladimir Köppen (1846–1940) in 1884, with several later modifications by Köppen, nota ...

''Aw'' and ''BSh'') with a dry season and a wet season and the temperature being warm and hot year-round. Annual rainfall ranges from 1000 mm in the south to 600 mm in the north on the edge of the Sahel. Rainfall and temperature vary seasonally, with a hot rainy season from May to September, and a cooler dry season from October to April. Temperatures range from 30 °C to 33 °C during the hottest month, and 18 °C to 21 °C during the coolest month.

Examples

Flora

Savanna and open woodland are the characteristic vegetation types. Species of ''

Combretum ''Combretum'', the bushwillows or combretums, make up the type genus of the family Combretaceae. The genus comprises about 272 species of trees and shrubs, most of which are native to tropical and southern Africa, about 5 to Madagascar, but th ...

'' and '' Terminalia'' are the typical savanna trees, and the ground is covered with long grasses, herbs, and shrubs. Species of ''

Hyparrhenia ''Hyparrhenia'' is a genus of grasses. Many species are known commonly as thatching grass. They are mostly native to tropical Africa; some can be found in warmer areas in temperate Eurasia, Australia, and Latin America. These are annual and per ...

'', or elephant grass, is the predominant grass, and often grows 1 meter or more in height. Trees in the drier woodlands generally less than 10 meters high, and include ''

Anogeissus ''Anogeissus'' is a genus of trees in the family Combretaceae. The 10''Anogeissus''.
...

'' spp. with ''

Acacia ''Acacia'', commonly known as the wattles or acacias, is a large genus of shrubs and trees in the subfamily Mimosoideae of the pea family Fabaceae. Initially, it comprised a group of plant species native to Africa and Australasia. The genus nam ...

'' spp., ''

Balanites aegyptiaca ''Balanites aegyptiaca'' (also known as the Egyptian balsam) is a species of tree, classified as a member of either the Zygophyllaceae or the Balanitaceae. This tree is native to much of Africa and parts of the Middle East. There are many comm ...

Combretum glutinosum ''Combretum glutinosum'' is a shrub species of the genus ''Combretum'', found in the Sahel belt in parts of Senegal, Burkina Faso, Ghana, Mali, the Gambia, Niger, Nigeria and Cameroon, across to parts of Sudan. It is known as dooki in Pulaar, Ka ...

, Commiphora africana,

Prosopis africana ''Prosopis africana'' is a flowering plant species in the genus Fabaceae. It is found in Africa. Its common names include African mesquite, iron tree, ''gele'' (Malinke) (traditional djembe wood) or ''somb'' tree. In the Serer creation myth, i ...

Tamarindus indica Tamarind (''Tamarindus indica'') is a leguminous tree bearing edible fruit that is probably indigenous to tropical Africa. The genus ''Tamarindus'' is monotypic, meaning that it contains only this species. It belongs to the family Fabaceae. ...

'', and ''

Ziziphus mucronata ''Ziziphus mucronata'', known as the buffalo thorn, is a species of tree in the family Rhamnaceae, native to southern Africa. It is deciduous and may grow up to 17 metres tall. It can survive in a variety of soil types, occurring in many habitat ...

''. Many trees lose their leaves during the height of the dry season, and the grasses often dry out. Acacia is less common in the wetter woodlands in higher-rainfall areas and along watercourses, where ''

Afzelia africana ''Afzelia africana'', the African mahogany, afzelia, lenke, lengue, apa, or doussi, is a tree species in the family Fabaceae. Range It occurs in Benin, Burkina Faso, Cameroon, Central African Republic, Chad, DRCongo, Ivory Coast, Ghana, Guinea, ...

Burkea africana ''Burkea africana'', the wild syringa ( bm, siri), is a deciduous, medium-sized, spreading, flat-topped tree belonging to the subfamily Caesalpinioideae of the family Fabaceae. The genus was named in honour of Joseph Burke, the botanist and colle ...

'' spp. and '' Terminalia'' spp. are predominant. Smaller areas of ''

Isoberlinia ''Isoberlinia'' is a genus in the family Fabaceae of five species of tree native to the hotter parts of tropical Africa. They are an important component of miombo woodlands. The leaves have three or four pairs of large leaflets and stout seed p ...

'' woodland occur in more humid portions of the southern ecoregion.

Fauna

The ecoregion is home to many large mammals, including

African bush elephant The African bush elephant (''Loxodonta africana'') is one of two extant African elephant species and one of three extant elephant species. It is the largest living terrestrial animal, with bulls reaching a shoulder height of up to and a body ...

(''Loxodonta africana''),

West African giraffe The West African giraffe (''Giraffa camelopardalis peralta''), Niger giraffe or Nigerien giraffe is a subspecies of the giraffe distinguished by its light colored spots. It is found in the Sahel of West Africa. In the 19th century it ranged fr ...

(''Giraffa camelopardalis peralta''),

giant eland The giant eland (''Taurotragus derbianus''), also known as the Lord Derby eland and greater eland, is an open-forest and savanna antelope. A species of the family Bovidae and genus ''Taurotragus'', it was described in 1847 by John Edward Gray. T ...

(''Taurotragus derbianus derbianus''), roan antelope (''Hippotragus equinus''), African buffalo (''Syncerus caffer brachyceros''),

lion The lion (''Panthera leo'') is a large cat of the genus '' Panthera'' native to Africa and India. It has a muscular, broad-chested body; short, rounded head; round ears; and a hairy tuft at the end of its tail. It is sexually dimorphic; adu ...

(''Panthera leo''),

leopard The leopard (''Panthera pardus'') is one of the five extant species in the genus '' Panthera'', a member of the cat family, Felidae. It occurs in a wide range in sub-Saharan Africa, in some parts of Western and Central Asia, Southern Russia, ...

(''Panthera pardus'')

cheetah The cheetah (''Acinonyx jubatus'') is a large cat native to Africa and central Iran. It is the fastest land animal, estimated to be capable of running at with the fastest reliably recorded speeds being , and as such has evolved specialized ...

(''Acinonyx jubatus''), and

African wild dog The African wild dog (''Lycaon pictus''), also called the painted dog or Cape hunting dog, is a wild canine which is a native species to sub-Saharan Africa. It is the largest wild canine in Africa, and the only extant member of the genus '' Lyca ...

(''Lycaon pictus''). Most large mammals are now very limited in range and numbers.

Conservation

A 2017 assessment found that 233,942 km², or 14%, of the ecoregion is in protected areas.Eric Dinerstein, David Olson, et al. (2017). An Ecoregion-Based Approach to Protecting Half the Terrestrial Realm, BioScience, Volume 67, Issue 6, June 2017, Pages 534–545; Supplemental material 2 table S1b

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Notes

External links

References

{{reflist Afrotropical ecoregions Ecoregions of Africa Sub-Saharan Africa Ecoregions of Benin Ecoregions of Burkina Faso Ecoregions of the Gambia Ecoregions of Ghana Ecoregions of Guinea Ecoregions of Ivory Coast Ecoregions of Mali Ecoregions of Niger Ecoregions of Nigeria Ecoregions of Senegal Ecoregions of Togo Tropical and subtropical grasslands, savannas, and shrublands