Rozen-Rechels, David
- Department of Wildlife, Fish and Environmental Studies, Swedish University of Agricultural Sciences
- École Normale Supérieure (ENS)
Research article2017Peer reviewedOpen access
Determinants of patchiness of woody vegetation in an African savanna
Veldhuis, Michiel P.; Rozen-Rechels, David; le Roux, Elizabeth; Cromsigt, Joris P. G. M.; Berg, Matty P.; Olff, Han
Abstract
QuestionsHow is woody vegetation patchiness affected by rainfall, fire and large herbivore biomass? Can we predict woody patchiness and cover over large-scale environmental gradients?LocationHluhluwe-iMfolozi Park, South Africa.MethodsWe quantified variation in local patchiness as the lacunarity of woody cover on satellite-derived images. Using Random Forest regression we analysed how both average woody cover and its patchiness depend on annual rainfall, fire frequency and grazer and browser metabolic biomass densities.ResultsFire frequency and rainfall were the clearest predictors, whereas effects of large herbivores on woody vegetation were smaller and more complex. Under low rainfall conditions (500mmyr(-1)) trees had less total cover and were more regularly spaced across the landscape (lower patchiness). Woody cover and vegetation patchiness increased with rainfall whereas fire frequency decreased woody cover and further increased patchiness.ConclusionThese results suggest a switch from competition between neighbouring trees under low rainfall conditions towards benefits among neighbours with increasing fire frequencies. Whereas overall woody cover and its patchiness are two independent aspects of savanna woody vegetation patterns, both need to be investigated to obtain a good understanding of the functioning and diversity of savanna ecosystems.
Keywords
Browser; Clustering; Fire; Grazer; Landscape heterogeneity; Normalized lacunarity; Rainfall; Vegetation patchiness; Woody cover
Published in
Journal of Vegetation Science
2017, volume: 28, number: 1, pages: 93-104
SLU Authors
Le Roux, Elizabeth
- Department of Wildlife, Fish and Environmental Studies, Swedish University of Agricultural Sciences
- Nelson Mandela Metropolitan University
- Department of Wildlife, Fish and Environmental Studies, Swedish University of Agricultural Sciences
Cromsigt, Joris
- Department of Wildlife, Fish and Environmental Studies, Swedish University of Agricultural Sciences
- Nelson Mandela Metropolitan University
- Department of Wildlife, Fish and Environmental Studies, Swedish University of Agricultural Sciences
Global goals (SDG)
UKÄ Subject classification
Ecology
Publication identifier
- DOI: https://doi.org/10.1111/jvs.12461
Permanent link to this page (URI)
https://res.slu.se/id/publ/77592