Herbivore and human impacts on woody species dynamics in Maputaland, South Africa

Abstract

Maputaland's woodlands are under utilisation pressure inside and outside conserved areas, due to mounting densities of mammals in the former, and increasing human utilisation of vegetation in the latter. Conservation of this biodiversity hotspot requires a better understanding of vegetation dynamics. To this purpose, woodland vegetation structure was evaluated at three sites through size class distribution analysis and grain determination, a forestry concept here applied to woodlands. Three sites represented animal disturbance, human disturbance, and no disturbance, under their respective utilisation regimes for comparable periods.Results showed clear utilisation patterns with woodlands over-utilised by man in rural areas, and damaged by large herbivores in confined conserved areas. Worryingly, common species occurrence changed subsequent to the three land use forms applied. The woodlands were mostly fine-grained forest-like vegetation units, and followed fine-grained forests dynamics closely. The grain model performed successfully for the region's woodlands and proved a good tool to improve vegetation dynamics understanding. 2In general, people and herbivores led to local extirpation of species and threatened both ecological structure and function of Maputaland's woodlands. However, the fine grain status was considered positive, as it facilitated future management options by reducing time frames and scale of management actions to be applied.

Woody Vegetation Utilisation in Tembe Elephant Park, Kwazulu-Natal, South Africa

“…3;2014 than a year in terms of canopy volume removal (defoliation), observed levels of use are close to levels measured elsewhere that were followed by a retrogression sequence with significant associated vegetation changes. As elephant impact is also considered significant in Tembe (Gaugris & van Rooyen, 2011;Gaugris et al, 2012), a clear danger exists of forcing Tembe's vegetation into a phase of rapid changes. Subsequent to the present study field work in 2004, larger carnivores (Lions and wild dogs) were reintroduced in Tembe, which should be a key step to restore natural limits to herbivore populations' growth.…”