The impact of indigenous ungulate herbivory over five years (2004–2008) on the vegetation of the Little Karoo, South Africa

  • MT Hoffman
  • CF Madden
  • K Erasmus
  • N Saayman
  • JC Botha

Abstract

This study investigated the impact of rainfall and herbivory by indigenous herbivores over five years (2004–2008) on the vegetation of the Sanbona Wildlife Reserve (SWR), a 54 000 ha privately owned conservation area in the Little Karoo. Changes in floristic composition, species richness, aerial plant cover and grazing capacity were determined using drop-point surveys in fenced and open (i.e. grazed plots in four dominant vegetation types. Annual and seasonal rainfall totals, herbivore stocking rate and herbivore utilisation patterns were also measured. Ordination analyses showed that fenced plots did not develop a fundamentally different successional trajectory from open plots over time. There were also no significant differences in species richness, plant cover and grazing capacity between fenced and open plots in all vegetation types. This lack of indigenous herbivore impact is ascribed to the relatively low stocking rates that were maintained on SWR during most of the study period. Species richness, plant cover and grazing capacity also did not differ significantly between years in all vegetation types except for the highly disturbed Old Land sites. The  xisting monitoring programme provides a useful tool for assessing the impact of indigenous herbivores and should be supported at local and provincial levels.

Keywords: monitoring; non-equilibrium dynamics; rangeland ecology; stocking rates; vegetation change

African Journal of Range & Forage Science 2009, 26(3): 169–179

Author Biographies

MT Hoffman
Plant Conservation Unit, Botany Department, University of Cape Town, Private Bag X3, Rondebosch 7701, South Africa
CF Madden
Plant Conservation Unit, Botany Department, University of Cape Town, Private Bag X3, Rondebosch 7701, South Africa
K Erasmus
Sanbona Wildlife Reserve, PO Box 149, Montagu 6720, South Africa
N Saayman
Department of Agriculture: Western Cape, Private Bag X1, Elsenburg 7607, South Africa
JC Botha
Department of Agriculture: Western Cape, Worcester 7849, South Africa
Section
Articles

Journal Identifiers


eISSN: 1727-9380
print ISSN: 1022-0119