Current Research

Current research investigates the interactions that elephants have with other large herbivores in southern African savannas. Elephants play a critical role in the environment by altering vegetation structure and composition, depositing nutrients, and through direct interactions with other species. While these actions help maintain biodiversity, there are concerns that as elephant populations continue to increase, their impacts may begin to have negative effects on other organisms. The Intermediate Disturbance Hypothesis (IDH) suggests that species diversity will be highest in areas with intermediate levels of disturbance due to a balance between competition and colonization. While this hypothesis has been used to justify elephant management by some governments, little is actually known about the effects of elephant density on biodiversity. This project is addressing this issue by testing the applicability of the Intermediate Disturbance Hypothesis to elephants and other large herbivores in southern Africa, using density as a proxy for disturbance. It is not enough, however, just to know if IDH patterns of diversity exist. If effective management is to be achieved, an understanding of the mechanisms underlying the disturbance-diversity relationship must be obtained. This research both quantifies the pattern of diversity and disturbance as well as investigates the processes causing this pattern through a combination of literature-based and field-based research.

The 2008 Assessment of South African Elephant Management emphasized the urgent need to study the effects of elephants and elephant density on biodiversity, and especially to evaluate the mechanisms of elephant impacts, in order to promote effective conservation. There is a dire need to understand the impact of increasing densities of elephants on species diversity. This project is helping to provide this knowledge as we investigate the applicability of the Intermediate Disturbance Hypothesis to elephants and other large herbivores by quantifying patterns of species diversity across a range of elephant densities and analyzing species interactions to investigate environmental and biotic mechanisms underlying diversity trends. A better understanding of the influence of elephants on other species will enable more effective management decisions in an area where biodiversity conservation is essential for economic growth and local livelihoods.