The impact of vegetation disturbance around water holes on rodent abundance and diversity in the north of Kruger National Park, South Africa.

Many studies have demonstrated a causal relationship between disturbance and species diversity
and furthermore between losses in diversity and declines in ecosystem function, resilience and
resistance. Our study supports this and additionally the notion that monitoring of small mammal
diversity can be used as a quick and inexpensive indicator of ecosystem integrity. The movement
of herbivores to and from waterholes results in an increasing gradient in their grazing, browsing and
trampling impacts towards waterholes, creating circular zones of impact known as piospheres. An
increase in artificial waterholes in the past has resulted in an overlap in these impacted areas,
creating a homogenised, disturbed habitat. The aim of our study was to determine if the vegetation
structure and composition is indeed impacted in the piosphere and whether this affects rodent
diversity and abundance. We tested an open waterhole and one which had been closed for about
two years. We found similar number of rodents at both waterholes. However the open waterhole
had a lower diversity of rodents than the closed waterhole and was dominated by the multimammate
mouse, Mastomys natalensis, which in other studies has been associated with disturbed areas.