Pastoralism is the dominant system of production and way of life for people in the Gourma region of Mali. Pastoralism has, however, been in deep crisis for decades. As elsewhere in Sahel, this crisis hits the subsistence economy, which is centred on animal production associated with cereal cropping and harvesting of natural products. It also affects the social, political and cultural life of the Sahelian peoples.

The population of the Gourma region has been decreasing since the 1960s, in marked contrast to rural and urban populations further south in the country. This trend reflects the depth and duration of the pastoral crisis. Changes in the livestock population have probably been even larger, but are not so well documented. The few data that are available are either dubious estimates, or are difficult to interpret because of the effects of herds moving into and out of the Gourma between seasons (Boudet et al. 1971; Gallais 1975; Ag Mahmoud 1980; IEMVT 1989).

There are few permanent water sources in the Gourma and therefore the region is mainly a wet-season grazing area for herds and flocks that rely on permanent water sources elsewhere during the dry season – and in particular in the Macina flood plain of the Niger river to the south-west. The Gourma has also recently become a refuge for pastoralists who traditionally lived further north and east in the Azaouad, Adrar and Houassa regions (Marie 1977).

The cattle population of the Gourma has steadily declined since the early 1970s . According to Government estimates (DNE 1966, 1971, 1976, 1984, 1988), between 1971 and 1988 the cattle population in the Gourma declined by 79% and the population of sheep and goats declined by 8%. In the Gourma Rharous district the corresponding figures were 82% and 21%. This decline in the Gourma region contrasts with the pattern for Mali as a whole, in which livestock populations are fluctuating but not declining consistently.

These trends have been confirmed by local ground and aerial surveys. In the early 1970s Boudet et al. (1971) and Gallais (1975) estimated the maximum number of livestock using the Gourma to be 1200000 cattle, 2000000 smallstock and 30000 camels. Aerial-survey estimates for 1983–84 (Milligan 1983; Bourn and Wint 1985) gave much lower figures; 357000 cattle and 581000 small ruminants during the 1983 dry season (resident herds) and 500000 cattle and 1100000 smallstock during the 1984 rainy season (resident herds plus some transhumant herds). A survey of resident herds in May 1987 over the southern half of the Gourma (RIM 1987) indicated a further 51% decrease in numbers of cattle and a 30% increase in small ruminants between the 1983 and 1987 dry seasons – suggesting that livestock owners are rebuilding their herds with small ruminants. A ground survey in Gourma Rharous district (Diallo and Djiteye 1991) confirmed these low dry season stocking rates, but found evidence that the cattle population was beginning to increase.

These changes in livestock population and herd structure are related to a decline in the nutritional status of livestock as a result of the degradation of rangeland resources (Grouzis 1991). The decline in feed availability follows a long series of low rainfall and drought years that began in the Gourma in the late 1960s. Annual rainfall has been below average throughout the region for two decades (Nicholson et al. 1988), and this climatic drying explains the decline in rangeland productivity and the associated structural and floristic changes that have taken place. But these changes have more often been blamed on livestock – with drought being considered merely an aggravating factor. Pastoralism has been accused of being the motor of desertification in Sahel, the actor of its crisis (Stebbing 1935; Wade 1974; Sinclair and Fryxell 1985; Lamprey 1988).

This paper discusses the impact of the pastoral economy on the Sahelian ecosystem. It presents data from rangeland monitoring started in 1984 in the Gourma and the results of experiments aimed at quantifying some of the processes by which livestock affect rangeland and their environment.