Competitive and facilitative relationships among three shrub species, and the role of browsing intensity and rooting depth in the Succulent Karoo, South Africa
2003; Wiley; Volume: 14; Issue: 5 Linguagem: Inglês
10.1658/1100-9233(2003)014[0761
ISSN1654-1103
Autores Tópico(s)Forest ecology and management
ResumoJournal of Vegetation ScienceVolume 14, Issue 5 p. 761-772 Competitive and facilitative relationships among three shrub species, and the role of browsing intensity and rooting depth in the Succulent Karoo, South Africa Peter J. Carrick, Peter J. Carrick Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK; Present address: Institute for Plant Conservation, Botany Department, University of Cape Town, Private Bag, Ronde-bosch, 7701, South Africa; E-mail p.j.carrick.97@cantab.netSearch for more papers by this author Peter J. Carrick, Peter J. Carrick Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK; Present address: Institute for Plant Conservation, Botany Department, University of Cape Town, Private Bag, Ronde-bosch, 7701, South Africa; E-mail p.j.carrick.97@cantab.netSearch for more papers by this author First published: 09 April 2003 https://doi.org/10.1111/j.1654-1103.2003.tb02208.xCitations: 37AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Abstract Abstract. The nearest-neighbour technique is used to infer competition and facilitation between the three most abundant species in a semi-arid region of western South Africa. Relationships among the shrubs Leipoldtia schultzei and Ruschia robusta, which are leaf-succulent members of the Mesembryanthemaceae ('mesembs') and Hirpicium alienatum a non-succulent Asteraceae, were compared on two adjacent sites with different histories of browsing intensity. Competition was more prevalent and more important than facilitation. The only evidence for facilitation was found at the heavily-browsed site where the palatable Hirpicium was larger under the unpalatable Leipoldtia. Generally the prevalence and importance of competition was reduced at the heavily-browsed site. Strong evidence was obtained for intraspecific competition in each of the three species; also, competition was evident between the two mesembs, where Leipoldtia was competitively dominant over Ruschia, although neither species inhibited Hirpicium. Minimal competition between the mesembs and the asteraceous shrub was interpreted in terms of differentiation in rooting depth, and competition within the mesembs, in terms of overlap in rooting depth. The mesembs had the bulk of their roots in the top 5 cm of soil, while the asteraceous shrub had the bulk of its roots, and all its fine roots, at greater depths. The shallow-rooted morphology of the mesembs is well adapted to utilize small rainfall events, which occur frequently in the Succulent Karoo, and do not penetrate the soil deeply. Modifications of existing methods are applied for analysing nearest-neighbour interactions. Citing Literature Volume14, Issue5October 2003Pages 761-772 RelatedInformation
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