The Kalahari Transect is proposed as one of IGBPs Transects (see Koch et al. 1995 [IGBP Report 36]). It is located so as to span the gradient between the arid subtropics and the moist tropics in southern Africa, a zone potentially susceptible to changes in the global precipitation pattern. Its focus is the relationships between the structure and function of ecosystems and their large-scale biophysical and human drivers (climate, atmosphere and land use). The Kalahari Transect spans a strong climatic gradient in southern Africa, from the arid south to the humid north, while remaining on a single broad soil type, the deep sands of the Kalahari basin. The vegetation ranges over the length of the transect from shrubland through savannas and woodlands to closed evergreen tropical forest, with land uses ranging from migratory wildlife systems, through pastoralism, subsistence cropping to forestry. The objectives of the Kalahari Transect activity are to: build an active network of regional and international researchers around the issue of ecosystem structure and function in savanna woodlands undergoing climatic and land use change; quantify the current and future role of southern African savanna woodlands in the global carbon, water and trace gas budgets and the degree of dependence of these budgets on climate and land use change; develop a predictive understanding of future changes in southern African savannas and woodlands on sandy soils, including their capacity to deliver forage, timber and other products. A five year project is proposed, commencing in 1997. The project revolves around four themes: vegetation structure, composition and dynamics; biogeochemistry, trace gas emissions and productivity; resource use and management and water and energy balance. These themes define the minimum set of processes necessary for understanding of the Kalahari system.