Grassland communities on a Sahelian peneplain in Burkina Faso

Abstract

AbstractA detailed phytosociological analysis of grassland communities of a Sahelian peneplain in Burkina Faso (West Africa) is presented. The floristic structure of the vegetation was documented with 113 relevés, which were classified manually and in addition ordinated to characterize main floristic gradients. The topographical situation from high‐lying areas of the peneplain with erosion of material to low‐lying areas with accumulation of material turned out to be the most important differentiating factor in the data set.All grassland communities are dominated by annual grasses and have large distribution ranges. They colonize sandy‐silty, loamy to clayey soils and can be water‐saturated or repeatedly inundated during the rainy season, while dry, non‐inundated habitats are also colonized. Many grasses are valuable fodder plants and are appreciated by livestock – the peneplain is economically highly important as a grazing ground. Whereas exozoochorous annual species are constantly present companions, perennial herbaceous species are almost completely missing.Stands were grouped into one alliance Panico laeti‐Echinochloion colonae and only two phytocoenoses: a rankless Schoenefeldia gracilis ‐community (with two subcommunities: a typical subcommunity with a large ecological amplitude from sandy‐silty to loamy soils, and an Aristida funiculata ‐subcommunity on sandy, dry, non‐inundated soils) and Eragrostietum pilosae. The Eragrostietum pilosae grows in the low‐lying areas of the peneplain and connects between communities of seasonally inundated lakes and the grasslands on the upper parts of the pene‐ plain. Following the topography, the two plant communities form a large transition (zonation complex). It is widespread across the study area and contains the diagnostic species of both plant communities.The plant communities are compared with other Sahelian grass‐dominated plant communities, and with plant communities from the Sahara and the (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)