West Sudanian savanna explained

West Sudanian savanna
Map:File:AT0722 map.png
Ecozone:Afrotropical
Biome:tropical and subtropical grasslands, savannas, and shrublands
Border1:East Sudanian savanna
Border2:Eastern Guinean forests
Border3:Guinean forest-savanna mosaic
Border4:Inner Niger Delta flooded savanna
Border5:Jos Plateau forest-grassland mosaic
Border6:Lake Chad flooded savanna
Border7:Mandara Plateau mosaic
Border8:Sahelian Acacia savanna
Area:1,632,821
Country1:Benin
Country2:Burkina Faso
Country3:Gambia
Country4:Ghana
Country5:Guinea
Country6:Ivory Coast
Country7:Mali
Country8:Niger
Country9:Nigeria
Country10:Senegal
Country11:Togo
Conservation:Critical/endangered
Protected:233,942 km2 (14
Protected Ref:)[1]

The West Sudanian savanna is a tropical savanna ecoregion that extends across West Africa.

Geography

The ecoregion stretches east and west across West Africa, from the Atlantic coast of Senegal to the Mandara Mountains on Nigeria's eastern border.

The drier Sahelian Acacia savanna lies to the north, and the more humid Guinean forest-savanna mosaic lies to the south.

Climate

The climate is a tropical savanna climate and a hot semi-arid climate (Köppen climate classification 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 and Terminalia are the typical savanna trees, and the ground is covered with long grasses, herbs, and shrubs. Species of Hyparrhenia, 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 spp. with Acacia spp., Balanites aegyptiaca, Combretum glutinosum, Commiphora africana, Prosopis africana, Tamarindus indica, and Ziziphus mucronata. 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, Burkea africana, Combretum spp. and Terminalia spp. are predominant. Smaller areas of Isoberlinia woodland occur in more humid portions of the southern ecoregion.

Fauna

The ecoregion is home to many large mammals, including African bush elephant (Loxodonta africana), West African giraffe (Giraffa camelopardalis peralta), giant eland (Taurotragus derbianus derbianus), roan antelope (Hippotragus equinus), African buffalo (Syncerus caffer brachyceros), lion (Panthera leo), leopard (Panthera pardus) cheetah (Acinonyx jubatus), and African wild dog (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.[2]

Notes and References

  1. 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. https://doi.org/10.1093/biosci/bix014
  2. 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. https://doi.org/10.1093/biosci/bix014