Examining patterns of coexistence in the Cape genus Tetraria (Cyperaceae) from a phylogenetic perspective : tracing the history of community assembly processes

dc.contributor.advisorVerboom, George Anthonyen_ZA
dc.contributor.authorSlingsby, Jasperen_ZA
dc.date.accessioned2017-10-30T14:03:06Z
dc.date.available2017-10-30T14:03:06Z
dc.date.issued2004en_ZA
dc.date.updated2017-03-10T10:52:50Z
dc.description.abstractThe coexistence of species is fundamentally important in maintaining high species diversity in a defined area, and is partly responsible for the remarkable diversity of the Cape Floristic Region. The ecological attributes that determine the community assembly processes of competitive interactions and ecological sorting are subject to phylogenetic constraint and niche conservatism, suggesting that patterns of coexistence should be phylogenetically structured. This study compares patterns of coexistence against phylogenetic and ecological divergence in the genus Tetraria (Cyperaceae), and related sedges in the tribe Schoeneae, at different spatial and phylogenetic scales in multiple communities across the Cape Fynbos Biome. The investigation is based on coexistence data inferred from plot data from 13 phytosociological studies, ecological distances based on plant functional traits, and phylogenetic distances based on a molecular phylogeny of the species in question. Species coexisting in plots are significantly less related than expected on the basis of chance, and plots of phylogenetic distance against coexistence show triangular relationships, implying coexistence between closely related species is restricted, but that coexistence levels between more distantly related species may vary greatly. Quantification of these triangular relationships was problematic due to the small sample sizes and the low power of the nonparametric tests used. The pattern is more pronounced when a closely related subset of the species was used in a separate analysis, suggesting that phylogenetic scale is important. Coexisting species are significantly more closely related at the study than at the plot scale, implying relaxation of the effects of competitive interactions at coarser spatial scales. Significant positive correlation between ecological and phylogenetic divergence implies that phylogenetic constraint and niche conservatism has a strong effect on the ecological attributes of the study species. These results provide support for the hypothesis that the patterns of coexistence among species' in the genus Tetraria, and related sedges in the tribe Schoeneae, are influenced by phylogenetic constraint and niche conservatism on ecological attributes.en_ZA
dc.identifier.apacitationSlingsby, J. (2004). <i>Examining patterns of coexistence in the Cape genus Tetraria (Cyperaceae) from a phylogenetic perspective : tracing the history of community assembly processes</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Biological Sciences. Retrieved from http://hdl.handle.net/11427/25929en_ZA
dc.identifier.chicagocitationSlingsby, Jasper. <i>"Examining patterns of coexistence in the Cape genus Tetraria (Cyperaceae) from a phylogenetic perspective : tracing the history of community assembly processes."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 2004. http://hdl.handle.net/11427/25929en_ZA
dc.identifier.citationSlingsby, J. 2004. Examining patterns of coexistence in the Cape genus Tetraria (Cyperaceae) from a phylogenetic perspective : tracing the history of community assembly processes. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Slingsby, Jasper AB - The coexistence of species is fundamentally important in maintaining high species diversity in a defined area, and is partly responsible for the remarkable diversity of the Cape Floristic Region. The ecological attributes that determine the community assembly processes of competitive interactions and ecological sorting are subject to phylogenetic constraint and niche conservatism, suggesting that patterns of coexistence should be phylogenetically structured. This study compares patterns of coexistence against phylogenetic and ecological divergence in the genus Tetraria (Cyperaceae), and related sedges in the tribe Schoeneae, at different spatial and phylogenetic scales in multiple communities across the Cape Fynbos Biome. The investigation is based on coexistence data inferred from plot data from 13 phytosociological studies, ecological distances based on plant functional traits, and phylogenetic distances based on a molecular phylogeny of the species in question. Species coexisting in plots are significantly less related than expected on the basis of chance, and plots of phylogenetic distance against coexistence show triangular relationships, implying coexistence between closely related species is restricted, but that coexistence levels between more distantly related species may vary greatly. Quantification of these triangular relationships was problematic due to the small sample sizes and the low power of the nonparametric tests used. The pattern is more pronounced when a closely related subset of the species was used in a separate analysis, suggesting that phylogenetic scale is important. Coexisting species are significantly more closely related at the study than at the plot scale, implying relaxation of the effects of competitive interactions at coarser spatial scales. Significant positive correlation between ecological and phylogenetic divergence implies that phylogenetic constraint and niche conservatism has a strong effect on the ecological attributes of the study species. These results provide support for the hypothesis that the patterns of coexistence among species' in the genus Tetraria, and related sedges in the tribe Schoeneae, are influenced by phylogenetic constraint and niche conservatism on ecological attributes. DA - 2004 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 2004 T1 - Examining patterns of coexistence in the Cape genus Tetraria (Cyperaceae) from a phylogenetic perspective : tracing the history of community assembly processes TI - Examining patterns of coexistence in the Cape genus Tetraria (Cyperaceae) from a phylogenetic perspective : tracing the history of community assembly processes UR - http://hdl.handle.net/11427/25929 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/25929
dc.identifier.vancouvercitationSlingsby J. Examining patterns of coexistence in the Cape genus Tetraria (Cyperaceae) from a phylogenetic perspective : tracing the history of community assembly processes. [Thesis]. University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 2004 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/25929en_ZA
dc.language.isoengen_ZA
dc.publisher.departmentDepartment of Biological Sciencesen_ZA
dc.publisher.facultyFaculty of Scienceen_ZA
dc.publisher.institutionUniversity of Cape Town
dc.subject.otherBotanyen_ZA
dc.subject.otherSystematicsen_ZA
dc.titleExamining patterns of coexistence in the Cape genus Tetraria (Cyperaceae) from a phylogenetic perspective : tracing the history of community assembly processesen_ZA
dc.typeBachelor Thesis
dc.type.qualificationlevelHonours
dc.type.qualificationnameBSc (Hons)en_ZA
uct.type.filetype
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
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