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Chapter 6 - Forms of Savanna: From Woodland to Grassland

from Part II - The Savanna Garden: Grassy Vegetation and Plant Dynamics

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 covers factors governing the prevalence of savanna and grassland formations. Savannas are climatically defined by the duration and intensity of the dry season. The tree canopy potentially closes above 650 mm in mean annual rainfall, but is widely variable. Above 1000 mm either a savanna woodland or a forest/grassland mosaic may prevail. Soil fertility based on bedrock geology coupled with rainfall underlies a division between arid/eutrophic and mesic/dystrophic savanna forms, not represented on other continents. Corresponding vegetation distinctions exist between fine-leaved and broad-leaved savannas. Water redistribution within landscapes contributes to local variation in tree canopy cover. Several factors contribute to the lack of tree cover in grasslands, but especially soils. The savanna biome is more widespread in Africa than in other continents. Characteristic tree and grass species are described in an appendix.

Keywords

arid/eutrophic savannasbroad-leaved woodlandsgrasslandssoil moisturefire regimesriver corridors
Type
Chapter
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Only in Africa
The Ecology of Human Evolution
 , pp. 69 - 96
Publisher: Cambridge University Press
Print publication year: 2021

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References

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