Included here is the Sahel, a belt of semi-arid land that runs the length of the Sahara Desert’s southern margin. It forms a narrow zone some 400 km wide extending from the Red Sea coast of Sudan to the Atlantic coasts of Mauritainia and Senegal, and represents one of the hottest places on Earth.

Sahelian Semi-Desert Grassland

These semi-desert grasslands are typically dominated by Cenchrus biflorus but several species found in the wooded grasslands can also be found here. However, in northern Sahel close to the Sahara desert grasses such as Panicum turgidum and Stipagrostis pungens often become the main species.

Sahelian Panicum laetum-Echinochloa colona Grassland

Grassland dominated by Echinochloa colona and the endemic Panicum laetum (Poaceae) appears to be widespread in the western parts of this BioProvince. They appear very versitile being able to develop on sandy-silty, loamy and clayey soils and can tolerate water-saturation or repeated inundation during the wet season - they can also develop on dry non-inundated soils. Most of the associates are annual species whereas perennials are virtually absent. On the Sahelian peneplain in Burkina Faso, two sub-association or communities have been recognized – one characterized by Schoenofeldia gracilis and the other by Eragrostis pilosa. The former has its centre of occurrence on this peneplain and with good fodder value is often grazed. Other characteristic species include Aristida funiculata, A. mutabilis and Cleome scaposa, while the many other associates include Alysiocarpus ovalifolius, Dactyloctenium aegyptium, Spermacoce chaetocephala and the endemic Indigofera senegalensis (Fabaceae). The Eragrostis pilosa community appears to be confined to the Sahelian parts of the Burkina Faso and certain stands are regularly flooded during the rainy season. In such areas Schoenofeldia grassland is usually absent, but many associate species are common to both grasslands. Trees are rare but Acacia seyal, A. tortilis subsp. raddiana and Ziziphus mauritiana can be foundscattered throughout these grasslands.

References

Brenan, J. P. M. 1978. Some aspects of the phytogeography of tropical Africa. Annals of the Missouri Botanical Garden, 65: 437-474.

Cook, C. D. K. 1968. The vegetation of the Kainji Reservoir site in Northern Nigeria, Vegetatio, 15: 225-243.

Kassas, M. 1957. On the ecology of the Red Sea coastal land. Journal of Ecology, 45: 187-203.

Monod, Th. 1986. Sahel Zone north of the equator. In: Ecosystems of the World 12B - Hot Deserts and Arid Shrubland, B. Eds. M. Evenari, I. Noy-Meir and D. W. Goodall. Elsevier.

Müller, J. V. 2008. Grassland communities on the Sahelian peneplain in Burkina Faso. Feddes Repertorium, 119: 42-62.

White, F. 1983. The Vegetation of Africa. UNESCO.