Rangelands in Africa (i.e., grasslands, savannas, and woodlands, which contain both grasses and woody plants) cover approximately 2.1 × 109 ha. Africa’s livestock population of about 184 million cattle, 3.72 million small ruminants (sheep and goats), and 17 million camels extract about 80% of their nutrition from these vast rangelands (IPCC, 1996). Rangelands have a long history of human use and are noted for great variability in climate and frequent drought events. The combination of climatic variability, low ecological resilience, and human land use make rangeland ecosystems more susceptible to rapid degeneration of ecosystems. From a land-use perspective, there are differences between West Africa and East Africa in rangelands use. In arid and semiarid areas of West Africa (rainfall 5–600 mm), millet (or another crop) is planted over a unimodal (one peak in rainfall per year) rainy season (three to four months); then fields remain fallow during the dry season, ranging from eight to nine months. Livestock eat crop residues. Land use is dominated by cultivation, with livestock playing a subsidiary role in the village economy. In East Africa, by contrast, areas with higher rainfall (up to 600 mm) are inhabited by pastoralists rather than farmers. In dry parts, cultivation occurs mainly where irrigation is possible or where water can otherwise be sequestered and stored for cropping. Rainfall is bimodal (two peaks in rainfall per year) in most rangelands, resulting in two growing seasons. As much as 85% of the population live and depend on rangelands in a number of countries in Africa. With emerging problems associated with the increasing population, the changes in key production areas, and the prevalence of episodic droughts and insecurity due to climatic change and ecological degradation and expansion of grazing territories, the traditional coping strategies of farmers, ranchers, and pastoralists have become inappropriate. More uncertainties require new innovations in characterizing, monitoring, analyzing, and communicating the emergence of drought to allow pastoral communities to cope with a rapidly changing environment. To this end, the United States Agency for International Development (USAID) awarded the Texas A&M University System an assessment grant to develop a Livestock Early Warning System (LEWS) as part of the Global Livestock Collaborative Research Support Program.
Malaria predictions based on seasonal climate forecasts in South Africa: A time series distributed lag nonlinear model