Abstract

The Nkuhlu large-scale long-term exclusion experiment in Kruger National Park was designed to study the long-term effects of large herbivores on vegetation. One treatment excludes elephants, another excludes all herbivores larger than hares and another one comprises an open, control area. Vegetation monitoring was implemented in 2002 when a baseline survey was conducted prior to exclusion. Monitoring was repeated 5 years after exclusion. Data from the surveys were analysed to establish how structure and composition of woody vegetation had changed 5 years after herbivore exclusion. The analysis showed that neither plant assemblage nor mean vegetation height had changed significantly since exclusion. However, both species richness and density of woody plants increased 5 years after exclusion of all large herbivores, but not after the exclusion of elephants alone. One already common species, Dichrostachys cinerea, became more common after excluding all large herbivores compared with either no exclusion or elephant exclusion, possibly leading to competitive suppression of other species. Species other than D. cinerea tended to either increase or decrease in density, but the changes were insufficient to induce significant shifts in the overall assemblage of woody plants. The results indicate that after 5 years of exclusion, the combined assemblage of large herbivores, and not elephants alone, could induce changes in species richness and abundances of woody plants, but the effect was so far insufficient to induce measureable shifts in the assemblages of woody plants. It is possible that assemblages will change with time and increasing elephant numbers may amplify future changes.

Keywords

assemblage; browse; elephant; long-term exclusion; species richness

Published in

Austral Ecology
2012, Volume: 37, number: 1, pages: 56-66
Publisher: WILEY-BLACKWELL

SLU Authors

• Löfroth, Therese

  • Department of Wildlife, Fish and Environmental Studies, Swedish University of Agricultural Sciences
    

• Hjältén, Joakim

  • Department of Wildlife, Fish and Environmental Studies, Swedish University of Agricultural Sciences
    

Sustainable Development Goals

Protect, restore and promote sustainable use of terrestrial ecosystems, sustainably manage forests, combat desertification, and halt and reverse land degradation and halt biodiversity loss


UKÄ Subject classification

Environmental Sciences related to Agriculture and Land-use


Publication identifier

DOI: https://doi.org/10.1111/j.1442-9993.2011.02249.x

Permanent link to this page (URI)

https://res.slu.se/id/publ/56443