Skip header navigation

University of Stirling

×

Article

The Role of Forest Elephants in Shaping Tropical Forest-Savanna Coexistence

Citation
Cardoso AW, Malhi Y, Oliveras I, Lehmann D, Ndong JE, Dimoto E, Bush E, Jeffery K, Labriere N, Lewis SL, White LTJ, Bond W & Abernethy K (2019) The Role of Forest Elephants in Shaping Tropical Forest-Savanna Coexistence. Ecosystems. https://doi.org/10.1007/s10021-019-00424-3

Abstract
Forest edges that border savanna are dynamic features of tropical landscapes. Although the role of fire in determining edge dynamics has been relatively well explored, the role of mega-herbivores, specifically elephants, has not received as much attention. We investigated the role of forest elephants in shaping forest edges of the forest–savanna mosaic in Lopé National Park, Gabon. Using forty camera traps, we collected 1.2 million images between May 2016 and June 2017. These images were classified by over 10,000 volunteers through an online citizen science platform. These data were combined with a 33-year phenology dataset on elephant-favoured fruiting tree species, and field measurements of elephant browsing preferences and damage. Our results showed a strong relationship between forest elephant density at the forest edge and fruit availability. When fruit availability was high, elephant density at the edge reached values nearly double the highest densities ever reported in any other part of the landscape (7.5 elephants km−2 in this study vs the previous highest estimate of 4 elephants km−2). The highest elephant densities occurred at the end of the dry season, but even outside of this high density period elephant density at the forest edge (2.4 elephants km−2) was more than double what other studies estimate for forest interiors with low human hunting pressure (1 elephant km−2). We found forest elephants to be selective browsers, but their browsing was non-destructive (in contrast to savanna elephants) and had little effect on tree size demography. Elephant paths acted as firebreaks during savanna burning, making them inadvertent protectors of the fire-sensitive forest and contributing to the stabilising feedbacks that allow forest and savanna to coexist in tropical landscapes.

Keywords
ecosystem engineer; alternative stable states; forest elephants; Loxodonta cyclotis; fire; forest–savanna mosaic; Gabon

Notes
Output Status: Forthcoming/Available Online

Journal
Ecosystems

StatusPublished
Author(s)Cardoso, Anabelle W; Malhi, Yadvinder; Oliveras, Imma; Lehmann, David; Ndong, Josué Edzang; Dimoto, Edmond; Bush, Emma; Jeffery, Kathryn; Labriere, Nicolas; Lewis, Simon L; White, Lee T J; Bond, William; Abernethy, Katharine
FundersCommonwealth Scholarship Commission, University of Stirling, H2020 European Research Council, Jackson Foundation, Agence Nationale Des Parcs Nationaux, Oppenheimer Fund and Hertford College Mortimer May Scholarship
Publication date online31/07/2019
Date accepted by journal14/07/2019
URLhttp://hdl.handle.net/1893/29993
PublisherSpringer Science and Business Media LLC
ISSN1432-9840
eISSN1435-0629

Research programmes

Research centres/groups

Research themes

Scroll back to the top