Grasslands of the World.pdf - Disasters and Conflicts - UNEP

Other grasslands 421
The Sahelian grazing lands have suffered much damage in the past fifty
years, through an increasing human population, excessive advance of cropping
into very marginal areas and serious deforestation, mainly for firewood, all
exacerbated by recurrent droughts . The great drought of 1968 was particularly
serious, as were others in the early 1980s.
The Sudanian zone , with from 500 mm to 1 100 mm/yr rainfall , is mainly
on ferruginous tropical soils, with colluvions in depressions. Agricultural activity
is more intense and the chance of crops succeeding is much more reliable.
Millet is still important on light soils in the drier parts, along with cowpea and
groundnut, with sorghum on heavier soils. The range of crops widens as rainfall
increases: maize is grown and cotton is a cash crop. Stock-rearing is sedentary,
with some migration away from cropland in the growing season. Areas with
between 800 and 1 400 mm/yr precipitation is “parkland”, where much of the
original forest has been cleared for cropping but trees that yield useful products
have been protected; it is characterized by Vitellaria paradoxa (shea butter),
Parkia biglobosa, Lannea acida and Sclerocaraya birrea. The herbaceous layer
was dominated by Andropogon gayanus , which is becoming scarce because of
clearing and in cultivated areas has been replaced by vast areas of poor, unpalatable
grasses. Forage quality is generally poorer than in the Sahel .
In the subhumid Sudano-Guinean zone , the rains last five to seven months,
and agriculture is oriented to tubers (yams, cassava) and fruits. This is the
wooded savannah (savane arborée - analogous to the miombo of centralsouthern
Africa) and open forest (forêt claire). The tree layer is dominated by
Daniella olivieri and Isoberlina doka, and associated grasses are Hyperaemia
spp. , Schizachryium rupestre , S. semi-herbe and Diheteropogon hagerupii .
The southern, humid parts of West Africa are not grazing areas. Tsetse flies
(Glossina spp. ), the vectors of trypanosomiasis, are a major hindrance to the
expansion of animal husbandry; ticks are also a serious problem. Root crops
are important for subsistence, and many tree crops are grown, including oilpalm
and cacao.
There are two main stock-rearing ethnic groups, the Tuareg and the Fulani
(Peul). Tuareg live on the desert fringe , and are divided into many groups: some
are still exclusively transhumant herders; others are part of a pastoral economy,
staying in villages or camps close to their fields . Exclusive herders occupy land
that is unsuitable for crops , to the north of the agropastoralists.
Fulani (Plate 11.3) are cattle breeders, but small ruminants (Plate 11.4) provide
meat for a family while cattle are capital, investment and prestige. There
are both stock-rearing and agropastoralist groups; agropastoralist Fulani occupy
the southern Sahelian space. Transhumant groups sow millet near the fringe
of cultivation during their migration. As tsetse fly challenge is reduced through
tree and bush clearing , Fulani are increasingly settling, notably in Nigeria.
Transhumance systems traverse the land of farming communities and their
herds may graze the stovers and fallows of farming groups. Many agricultural