« Previous AbstractSexual behaviour in Euplotes raikovi is accompanied by pheromone-induced modifications of ionic currents    Next AbstractScents in the stack: olfactometric proficiency testing with an emission simulation apparatus »

Oecologia

Title:		Regrowth and tannin production in woody and succulent karoo shrubs in response to simulated browsing
Author(s):		Stock WD; Le Roux D; Van der Heyden F;
Address:		"Department of Botany, University of Cape Town, Private Bag, 7700, Rondebosch, South Africa"
Journal Title:		Oecologia
Year:		1993
Volume:		96
Issue:		4
Page Number:		562 - 568
DOI:		10.1007/BF00320514
ISSN/ISBN:		1432-1939 (Electronic) 0029-8549 (Linking)
Abstract:		"Allocation of carbon to chemical defences has often been suggested to be a direct response to browsing or grazing by herbivores. This study quantitatively compares total polyphenol and tannin production in response to simulated browsing of three karoo shrubs in order to test this induced defence hypothesis. The three species studied responded to browsing either by rapid regrowth or by increasing polyphenol production in the remaining tissues. The patterns did not follow any phylogenetic relationships but were weakly associated with the palatability of each species. The highly palatable deciduous species Osteospermum sinuatum, which is capable of rapid regrowth, showed no or very low levels of constitutive and browsing-induced total polyphenols, condensed tannins and protein-precipitating tannins. The evergreen sclerophyllous species Pteronia pallens showed a limited regrowth capacity and had intermediate levels of polyphenols, while the evergreen succulent species Ruschia spinosa showed almost no regrowth over the study period. R. spinosa contained the highest constitutive and browsing-induced levels of polyphenols, condensed tannins and protein-precipitating tannins. In two of the species more than one anti-herbivore defence feature co-occur. P. pallens foliage contains both hepatotoxins and polyphenols while R. spinosa has both structural (spines) and chemical defences. Responses of karoo shrubs to simulated browsing are interpreted as the result of passive alterations in plant chemistry rather than as an active defence response to herbivores"
Keywords:		Clipping Herbivore-deterrents Induced defence Semi-arid shrubs;
Notes:		"PubMed-not-MEDLINEStock, W D Le Roux, D Van der Heyden, F eng Germany 1993/12/01 Oecologia. 1993 Dec; 96(4):562-568. doi: 10.1007/BF00320514"