Kalahari vegetation: veld condition trends and ecological status of species

Abstract

Grazing intensity gradients were determined in the duneveld, river terrace and river bed habitats of the Kalahari Gemsbok National Park. Under increased grazing, a species composition characterised mostly by annual forbs and grasses results. In all three habitats the relatively heavily grazed areas were closest to the watering points, although this was less evident in the river terrace and river bed habitats. Monitoring degradation at a watering point over the long term, produced results similar to those observed from a single sampling period. The identification of grazing gradients within homogeneous habitats, is a prerequisite for the classification of plant species into different categories. The allocation of a species to a category is based on the changes in frequency along this grazing gradient and this approach is more acceptable than the classification of species commonly used. The use of terminology such as Decreasers and Increasers is discussed.

Keywords

• Decreaser, grazing gradients, Increaser, Kalahari, ordination, rainfall, veld condition.