Megafaunal effects on vegetation structure throughout a densely wooded African landscape

Andrew B. Davies, Angela Gaylard, Gregory P. Asner

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

Megafauna strongly affect vegetation structure and composition, often leading to management concern. However, the extent of their influence across large scales and varying ecosystems remains largely unknown. Using high resolution airborne Light Detection and Ranging (LiDAR), we investigated landscape-scale changes in vegetation height and three-dimensional (3D) structure across landscapes of varying elephant densities and presence over time, and in response to surface water distribution and terrain variability in the heavily managed thicket biome of the Addo Elephant National Park, South Africa. Elephants caused up to a fourfold reduction in vegetation height and altered the vertical profile, but increased vegetation height variability. Vegetation height also increased with elevation and distance from water, particularly in areas that elephants had long occupied at high densities. Slope had opposing effects on vegetation height, with height increasing with slope in areas long exposed to elephants, but decreasing where elephants had only recently been granted access. Our results suggest that elephants are the primary agents of vegetation change in this ecosystem, but that the strength of their effects varies across the landscape, enabling management to use water and terrain as mitigation tools. We further highlight the necessity of landscape-level experimental studies on megafaunal effects to untangle mechanisms and establish causality.

Original languageEnglish (US)
Pages (from-to)398-408
Number of pages11
JournalEcological Applications
Volume28
Issue number2
DOIs
StatePublished - Mar 2018
Externally publishedYes

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elephant
vegetation structure
vegetation
ecosystem
landscape structure
biome
effect
vertical profile
water use
national park
mitigation
experimental study
surface water

Keywords

  • Addo Elephant National Park
  • Carnegie Airborne Observatory
  • elephants
  • herbivory
  • LiDAR
  • Loxodonta africana
  • South Africa
  • thicket

ASJC Scopus subject areas

  • Ecology

Cite this

Megafaunal effects on vegetation structure throughout a densely wooded African landscape. / Davies, Andrew B.; Gaylard, Angela; Asner, Gregory P.

In: Ecological Applications, Vol. 28, No. 2, 03.2018, p. 398-408.

Research output: Contribution to journalArticle

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