Biodiversity in African savannas: functional significance and implications for animal production
Proceedings of the 18th International Grassland Congress
Association Management Centre, Calgary, Canada
The African savanna biome supports a higher diversity of ungulate species than is found in any other biome or continent. This exceptional faunal diversity and herbivore biomass density is directly linked to the high spatial heterogeneity of African savanna ecosystems. The dependence of herbivore dietary tolerance on body size translates into important size-related differences between savanna ungulate species in terms of habitat specificity, geographical range, and the share of community resources exploited. Intact savanna ungulate communities, with species distributed across body size classes and feeding guilds (grazer/browser), have strong regulatory influences on savanna ecosystem structure and function. Replacement with livestock systems of low diversity and high biomass density within a narrow body size range has occurred through the removal of competitors, pathogens, and predators, and the widespread provisioning of water. Overgrazing by livestock, coupled with episodic droughts, has caused widespread rangeland degradation and loss of floristic and faunal diversity which, by current models, is unlikely to recover to ‘climax’ conditions even with destocking. In selected regions where potential still exists, African savanna biodiversity and human economic development will both be best served by the integration of sustainable wildlife utilization into multispecies animal production systems.
du Toit, J.T. & Cumming, D.H.M. 1999. Biodiversity in African savannas: functional significance and implications for animal production. Pages 233-240 in: J.G. Buchanan-Smith, L.D. Bailey and P. McCaughey (eds.) Proceedings of the XVIII International Grassland Congress, June 1997, Winnipeg and Saskatoon, Canada, vol. III, Association Management Centre, Calgary, Canada.