Land degradation in African pastoral systems and the destocking controversy

Abstract

The discussion about rangeland degradation in African pastoral systems has so far largely been based on the conventional theory of ‘carrying capacity’. This paper argues that the carrying capacity concept and the related ‘destocking policy’ as a management strategy to increase productivity and to protect rangelands from degradation are of little applicability in African pastoral systems. They ignore the spatial and temporal variability in primary biomass production, as well as the effect of spatial and temporal fluctuations in forage quality on animal production. A case study from Northern Kenya shows that the rapid decrease in forage quality in the dry season is the crucial factor determining livestock production and pastoral land use patterns. The results of a principal component analysis indicate that rangeland degradation does not occur in most of the range units considered because grazing is limited to a short time span in a year. In contrast, the few range units with a good potential are susceptible to degradation when formerly mobile pastoral households become sedentary and overuse these key resources. An example from Marsabit District, Northern Kenya, shows that carrying capacity figures overestimate the potential livestock-supporting capacities. Destocking rangelands would result in a serious decline in the productivity of pastoral production systems and is not likely to halt rangeland degradation. It is concluded that land use policy interventions in Northern Kenya should not focus on the manipulation of absolute livestock numbers, but rather on the optimal distribution of animal abundance in space and time.