Spatial dynamics of elephant impacts on trees in Chobe national park, Botswana

Abstract

The African elephant (Loxodonta africana) regulates shifts between different savanna states, primarily through herbivory of woody vegetation. As a water-dependent herbivore, these impacts on trees are constrained by water availability, potentially leading to a gradient of degradation known as the piosphere effect. Transects evaluating vegetation status with increasing distance from the Chobe River were conducted in Chobe National Park, Botswana, to test whether predictions of the piosphere effect can be applied at multiple scales. Trends varied depending on the type of utilization, with debarking by elephants decreasing with distance from the Chobe River and branch herbivory showing a bimodal distribution. Results suggest that piosphere predictions may be applicable over greater distances, with important implications for monitoring species changes far from water points. Managers should consider this as they evaluate landscape stability and discuss provisioning of waterpoints in semi-arid habitats.