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Chapter 13 - How Large Herbivores Transform Savanna Ecosystems

from Part III - The Big Mammal Menagerie: Herbivores, Carnivores and Their Ecosystem Impacts

Published online by Cambridge University Press:  09 September 2021

Norman Owen-Smith
Norman Owen-Smith
Affiliation:
University of the Witwatersrand, Johannesburg
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Summary

This chapter looks more broadly at interactions. Total herbivore biomass and consequent consumption of vegetation depends on the basic soil fertility. Mean levels underestimate local offtake, particularly in drought years. Heavy grazing suppresses the spread of fires so that more vegetation gets digested than incinerated. Browsing on tree seedlings can counteract woody plant expansion following heavy grazing. Elephants cause large tree mortality by toppling and debarking and can transform savanna woodlands into open grasslands or shrub coppice, especially on fertile soils. Termites promote the decomposition of vegetation not consumed by herbivores or incinerated by fires and contribute to nutrient cycling. Sodium is available through different routes. Large herbivores amplify the spatial heterogeneity inherent in savannas in various ways.

Keywords

herbivore biomassprimary productiongrazing lawnnutrient cyclingspatial heterogeneitybush encroachmentfire suppressionbrowsing hedgeselephant impactstermitessodium restrictions
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Chapter
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Only in Africa
The Ecology of Human Evolution
 , pp. 199 - 219
Publisher: Cambridge University Press
Print publication year: 2021

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References

Suggested Further Reading

Owen-Smith, N. (1988) Megaherbivores. The Influence of Very Large Body Size on Ecology. Cambridge University Press, Cambridge.Google Scholar

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