Since the turn of the twentieth century, and in particular since the 1920s, grave concern has mounted over the evident degradation of the semi-arid and arid rangelands of South and southern Africa. Climate change, desert encroachment, soil erosion, salinization of the few irrigated lands and, above all, overstocking by domestic livestock, were thought to be responsible for changes in the apparent production potential of the land. This led to a number of research programmes being set up by the Department of Agriculture, all designed to obtain some predictive understanding of the biology of organisms in the southern African arid and semi-arid rangelands, particularly the karoo. The karoo covers 35% of South Africa, and extends into neighbouring Namibia, and, as such, represents a significant proportion of southern Africa. Despite the accumulation of a large amount of knowledge on vegetation, grazing effects and the management of rangelands in the karoo over several decades, there still remained a serious gap in understanding the dynamics of vegetation and plant–animal interactions in this region.

The various ‘Biome Projects’ (see, for example, Scholes and Walker, 1993), set up by the South African National Programme for Ecosystem Research from the early 1970s, were designed to develop some understanding of ecosystem functioning in the major biomes and inland waters in South Africa. Research within the biome projects focussed on climate and soils, adaptive physiology and behaviour, reproductive biology, population dynamics, species interactions and community processes, and the protection of biodiversity and ecosystem modelling. Projects were funded mostly by the National Programme for Ecosystem Research, the Department of Environment Affairs and Tourism and the Department of Agriculture through the universities, nature conservation organizations and NGOs.