DOCUMENTING THE EFFECTS OF VELD BURNING ON SOIL AND VEGETATION CHARACTERISTICS IN GIANT'S CASTLE GAME RESERVE, KWAZULU-NATAL DRAKENSBERG

ABSTRACT

Prescribed veld burning is a commonly used management practice in the KwaZulu-Natal Drakensberg. It is implemented in order to maintain grassveld and decrease soil erodibility even though there is limited knowledge of the long-term effects on soil properties. Vegetation and soil characteristics of three sites in the KwaZulu-Natal Drakensberg are documented; comparing a site protected from the burning programme for four decades with two sites of different aspects within the normal biennial burning regime. Vegetation surveys and soil analyses show that regular burning lowers the plant diversity of woody and forb species while vegetation cover after burn recovery appears unaffected. Soil properties, namely organic matter, pH, aggregate size distribution, compressive and shear strength differ between the burn and no-burn sites. An increase in soil strength and aggregation probably reduces soil erodibility under burning but the effect is offset by a decrease in infiltration capacity. This casts some doubt on the overall effectiveness of decreasing soil erodibility though regular burning, particularly considering the surface exposure during vegetation recovery. Further studies on the long-term geomorphic effects including sediment yields are suggested.