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Adaptation of a decreaser and an increaser grass species to defoliation in semi?arid grassveld
Author
Danckwerts, J.E.
Stuart?Hill, G.C.
Publisher
Journal of the Grassland Society of Southern Africa
Publication Year
1987
Body

Grasses have developed through natural selection to deter, escape and tolerate herbivory, and to escape and tolerate fire. In the semi?arid grassveld of the Eastern Cape, the species Themeda triandra and Sporobolus fimbriatus have been classified as Decreaser and Increaser II plants respectively. Both species have well?developed escape and tolerance mechanisms, although T. triandra readily tolerates defoliation only during the dormant season, while S. fimbriatus is adapted to tolerating defoliation throughout the year. Furthermore, T. triandra has only moderately developed deterrents to herbivory, in contrast to S. fimbriatus, where deterrents are well developed. It follows that the Decreaser species T. triandra is adapted to relatively frequent fire and no more than modest herbivory, while the Increaser II species, S. fimbriatus, is adapted to heavy herbivore usage, but infrequent fire.

Language
English
Resource Type
Text
Document Type
Journal Issue/Article
Collection
Southern Africa Collection
Journal Name
Journal of the Grassland Society of Southern Africa
Keywords
Africa