West Sudanian savanna

West Sudanian savanna
Name	West Sudanian savanna
Biogeographic realm	Afrotropical
Biome	Tropical and subtropical grasslands, savannas, and shrublands
Area km2	1,020,000
Countries	Burkina Faso; Benin; Ghana; Ivory Coast; Mali; Mauritania; Niger; Nigeria; Senegal; Togo; Guinea

West Sudanian savanna is a broad belt of tropical savanna and woodland stretching across West Africa between the Sahel and the Guinean forest-savanna mosaic. The ecoregion spans parts of national territories including Mali, Niger, Nigeria, Burkina Faso, Ghana, Togo, Benin, Ivory Coast, Guinea, Senegal, and Mauritania. It forms a transitional landscape that connects the ecological gradients of the Sahara Desert margin with the forests of the Gulf of Guinea.

Geography and boundaries

The ecoregion occupies river basins and plateaus, incorporating parts of the Niger River basin, the Volta River system, and tributaries of the Senegal River. It abuts the Sahelian Acacia savanna to the north and the Guinean Forests of West Africa to the south, bordering protected areas such as W National Park, Pendjari National Park, and Comoé National Park. Major urban centers within or near the ecoregion include Kano, Ouagadougou, Niamey, Kumasi, and Accra. Topography ranges from the Fouta Djallon highlands' flanks to lowland floodplains like the Inner Niger Delta.

Climate and soils

Rainfall is strongly seasonal, governed by the northward and southward movement of the Intertropical Convergence Zone and influenced by the Harmattan wind and Gulf of Guinea moisture. Annual precipitation ranges roughly from 600 to 1200 mm, producing a marked wet season and a pronounced dry season that shapes vegetation and fire regimes. Soils include ferruginous laterites, leached oxisols, and alluvial deposits along floodplains of the Niger River Delta and Volta River Basin, supporting agriculturally productive zones such as parts of the Sahel Belt and the Sudanian zone of former colonial agrarian systems.

Flora and vegetation types

Vegetation is a mosaic of wooded savanna, grassland, gallery forests, and riparian woodlands featuring species such as Isoberlinia doka, Combretum nigricans, and Vitellaria paradoxa (shea tree). Gallery forests along rivers host genera like Ficus and Terminalia, while grasslands are dominated by Andropogon gayanus and Hyparrhenia species that respond to seasonal rains and traditional fire practices associated with communities like the Dogon and Fulani. Agroforestry systems integrating Parkia biglobosa (locust bean) and Adansonia digitata (baobab) reflect long-standing human management seen in regions influenced by pre-colonial polities such as the Mali Empire and the Ghana Empire.

Fauna and biodiversity

The ecoregion supports large mammal assemblages including African elephant, Loxodonta africana populations formerly linked by corridors to the W-Arly-Pendjari Complex, and carnivores like Panthera leo and Lycaon pictus in declining numbers. Ungulates include Syncerus caffer (African buffalo), Hippotragus equinus (roan antelope), Gazella rufifrons (red-fronted gazelle), and seasonal migrants that follow riverine productivity such as populations associated with the Inner Niger Delta. Avifauna includes migratory species connecting to the Palearctic flyway, with wetlands used by Ardea goliath (goliath heron) and Anas ducks, while reptiles and amphibians show affinities with the Guinean forest fringe. Endemic and near-endemic taxa reflect historical fragmentation linked to Pleistocene climatic shifts and the distributional histories studied by institutions like the Muséum national d'Histoire naturelle.

Human populations and land use

Human presence is dense in parts of the ecoregion, with ethnolinguistic groups including the Mande peoples, Voltaic peoples, Fulani, Hausa, and Gurma engaging in mixed livelihoods. Land use mosaics combine rainfed agriculture of crops such as Sorghum bicolor, Zea mays (maize), Oryza glaberrima (African rice) in inland deltas, and agro-pastoralism with transhumant herding routes linked to markets in cities like Bamako, Kumasi, Kano, and Bobo-Dioulasso. Colonial-era infrastructures, missionary stations, and postcolonial development projects by organizations such as the African Development Bank and Food and Agriculture Organization have shaped irrigation schemes, road corridors, and shifting cultivation patterns across the landscape.

Conservation and threats

Conservation efforts occur via national parks, transboundary initiatives like the W-Arly-Pendjari Complex, and programs by international NGOs such as WWF and IUCN. Primary threats include agricultural expansion, overgrazing by livestock associated with transhumance networks, recurrent fires, deforestation for fuelwood and charcoal feeding urban demands from cities like Abuja and Lagos, and poaching linked to regional trade routes. Climate change projections suggest shifts in the Intertropical Convergence Zone and altered precipitation regimes that may intensify desertification processes observed in studies by the Intergovernmental Panel on Climate Change and regional research centers like the International Institute for Environment and Development. Conservation strategies emphasize landscape-scale corridor restoration, community-based natural resource management exemplified by initiatives in the Sahel, and integration of indigenous tenure arrangements in national policy frameworks.

Category:Ecoregions of Africa