Woody forage species in the Sahel: their biology and use.
The trees and shrubs of a Sahelian site in Senegal were studied for 7 consecutive yr, which included a period of exceptional aridity. The 5 dominant spp. represented 130 individual plants/ha. Their total above-ground biomass was close to 2 t/ha and all spp. were browsed by domestic animals. The av. annual production of leaves and fruit was 120 kg/ha of protein-rich (10-20%) DM, an indispensable complementary feed in the dry season. During the 1972-3 drought the number of individual plants of Guiera senegalensis, Commiphora africana and Acacia senegal was reduced by 50%, whereas Balanites aegyptiaca, Grewia bicolor and Boscia senegalensis showed a perfect adaptation to climatic fluctuations. The productivity of woody spp. was sharply reduced in 1972 (30 kg/ha) and in 1973. Under these conditions, 30 ha/head of cattle would have been necessary to ensure survival, whereas in normal conditions 7 ha would be required.