Relief, sols et végétation d'une savane soudano-sahélienne du Mali Central

The relief forms, soils and vegetation of the Saye region in the Sudano-Sahelian zone of central Mali were classified in order to establish an ecological basis for sampling fodder phytomass. From the interpretation of aerial photographs (1 : 50000) 4 topographical units were recognized: summit, slope, terrace and depression. Descriptions and analyses of 21 pedons identified the soils from summits and slopes as tropical ferruginous, those from terraces as hydromorphic pseudo-gley and soils in the depressions as hydromorphic gley. The vegetation is composed of 12 communities following the toposequence. They are dominated in descending order by Acacia albida, Borassus aethiopium, Hyphaene thebaica, Piliostigma reticulatum (in sandy depressions), Acacia seyal, Balanites aegyptiaca, Boscia senegalensis, Vitellaria paradoxa, Pterocarpus lucens, Mitragyna inermis (channel), Mitragyna inermis and Piliostigma reticulatum. A map was produced from pan-chromatic and false colour infrared aerial photographs using the geographical information system (G.I.S.) program Terrasoft. This map will be used to calculate the global phytomass in the region.