DEVELOPMENT OF AN HERBACEOUS COVER IN A SUDANO-SAHELIAN SAVANNA IN NORTH CAMEROON IN RELATION TO AVAILABLE SOIL-WATER

Dynamics of annual communities are studied in Sudano-Sahelian savannas of the north of the Cameroon. The vegetation composition of three typ es of soil (a vertisol, a degraded vertisol and a ferruginous soil) un der two rainfall conditions is compared. The study supports the idea t hat intense fluctuations in water availability at the beginning of the rainy season determine which species germinate, grow and survive unde r conditions of water stress. However soil conditions can accentuate o r reduce the influence of the rainfall fluctuations while the land use history of each station tends to buffer the variations of the overall pattern determining potential vegetation.