A dynamic analysis of trade and biodiversity loss in semi-arid Southern Africa: The role of grazing activities

This paper assesses a specific ecosystem - rangelands, in semi-arid Southern Africa with a focus on livestock production. It modelled the dynamics of the composite of rangelands and different livestock grazing activities. A stylised model is developed to examine the extent to which trade may affect biodiversity of Southern African rangelands and their ecosystem functions. Bringing together the ecology of the rangeland and economic objective of maximising social welfare from the use of the rangeland services, the paper derived conditions for optimal levels of the composite of the rangeland. Trade influences however, as per scale, composition and technique effects, may increase the pressure on the rangeland and upset these optimal levels leading to negative impacts on the rangeland biodiversity and its ecosystem functions.