Agriculture Reference
In-Depth Information
CHAPTER TWENTY-TWO
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L
ivestock Early Warning System
fo
r Africa's Rangelands
A
BDI JAMA, AND RAPHAEL MARAMBII
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Line
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0.0
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Norm
PgEn
Rangelands in Africa (i.e., grasslands, savannas, and woodlands, which
contain both grasses and woody plants) cover approximately 2.1
10
9
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 ex-
pansion of grazing territories, the traditional coping strategies of farmers,
ranchers, and pastoralists have become inappropriate. More uncertain-
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