Determinants of the extent of indigenous large herbivore impact on herbaceous vegetation at watering points in the north-eastern lowveld, South Africa

Watering points in the semi-arid Kruger National Park, Klaserie Private Nature Reserve, Cleveland Game Park and four game ranches in the Klaserie district were studied. Herbaceous community composition and basal cover were measured in transects starting at, and radiating from the water. The community compositions were converted to herbaceous forage and fine fuel production potential scores and the extents of impact determined. A general linear model was used to analyse the extent of impact of indigenous large herbivores on these parameters at artificial watering points. Rainfall in the previous rainfall season, stocking rate and distance to the nearest neighbouring watering point had significant effects. Amounts of clay and sand in the A and B horizons of the soil were not important in determining the extent of impacts on herbaceous rangeland condition indices. Once watering points are placed at a density such that all areas on a property are within reach of foraging, water-dependent indigenous large herbivores, the effects of additional watering points are expected to be of little importance relative to those of rainfall and stocking rate. It is feasible to manage for reduced impacts on rangeland condition at watering points. A water provision system of clusters of watering points separated by large waterless areas is proposed.