Heterogeneity in African savanna elephant distributions and their impacts on trees in Kruger National Park, South Africa. Issue 10 (6th April 2021)

• Record Type: Journal Article
• Authors: Abraham, Joel O.; Goldberg, Emily R.; Botha, Judith; Staver, A. Carla
• Is Part Of: Ecology and evolution. Volume 11:Issue 10(2021)
• Page Start: 5624
• Page End: 5634
• Publication Date: 2021-04-06
• Subjects: elephant impacts -- landscape heterogeneity -- Loxodonta Africana -- management legacies -- savanna vegetation -- surface water -- tree damage; Ecology -- Periodicals; Evolution -- Periodicals; 577.05
• DOI: 10.1002/ece3.7465
• Languages: English
• ISSNs: 2045-7758

Abstract

Abstract: Though elephants are a major cause of savanna tree mortality and threaten vulnerable tree species, managing their impact remains difficult, in part because relatively little is known about how elephant impacts are distributed throughout space. This is exacerbated by uncertainty about what determines the distribution of elephants themselves, as well as whether the distribution of elephants is even informative for understanding the distribution of their impacts. To better understand the factors that underlie elephant impacts, we modeled elephant distributions and their damage to trees with respect to soil properties, water availability, and vegetation in Kruger National Park, South Africa, using structural equation modeling. We found that bull elephants and mixed herds differed markedly in their distributions, with bull elephants concentrating in sparsely treed basaltic sites close to artificial waterholes and mixed herds aggregating around permanent rivers, particularly in areas with little grass. Surprisingly, we also found that the distribution of elephant impacts, while highly heterogeneous, was largely unrelated to the distribution of elephants themselves, with damage concentrated instead in densely treed areas and particularly on basaltic soils. Results underscore the importance of surface water for elephants but suggest that elephant water dependence operates together with other landscape factors, particularly vegetation community composition and historical management interventions, to influence elephant distributions. Abstract : Elephant conservation must strike the balance between protecting elephants and managing the impacts they have on savanna ecosystems, especially on trees, but we still know relatively little about how elephant impacts are distributed in space. In this study, we found that elephant impacts were largely unrelated to the distribution of elephants themselves and were instead concentrated in densely treed areas and particularly on basaltic soils. As such, we need to shift our focus away from describing patterns of elephant landscape use and instead need to consider characteristics of trees themselves and their role in tolerating elephant damage.