Reconstructing the late pleistocene palaeoenvironment of the Richtersveld using fossil charcoal

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dc.contributor.advisorHoffman, Timmen_ZA
dc.contributor.advisorFebruary, Edmund Cen_ZA
dc.contributor.authorCronin, Kateen_ZA
dc.date.accessioned2015-09-30T13:24:40Z
dc.date.available2015-09-30T13:24:40Z
dc.date.issued2013en_ZA
dc.description.abstractThe Succulent Karoo is recognised as an important biodiversity hotspot and many of the key plant lineages that characterise the biome are thought to have originated during the Pleistocene epoch. However, due to the paucity of palaeobiological proxy data available for the Succulent Karoo, relatively little is known about its environmental history and how an important core of this region, Namaqualand and its subregion the Richtersveld, may have responded to Pleistocene changes. Recent excavations at Spitzkloof Rockshelter A in the Richtersveld have provided a rare source of palaeoenvironmental data in the form of fossil wood charcoal assemblages that span a sequence from the last glacial maximum (LGM) to ~14 500 yrs BP. The present study analysed the fossil charcoal deposits from the rockshelter in order to reconstruct woody species assemblage patterns as a proxy for late Pleistocene palaeoclimate. Identification of the fossil charcoal specimens was achieved by anatomical comparison with transverse section photomicrographs of identified reference specimens of woody taxa currently growing at the site. Patterns in the charcoal data set were sought by assessing the changes in woody species assemblages over time. An assessment of the environmental correlates of the contemporary distributions of taxa found in the archaeological sequence provided the basis for palaeoenvironmental reconstruction. Based on the current generalisation for glacial climates in the winter rainfall zone (WRZ), it was hypothesised that the study region experienced an increase in rainfall at the LGM, and a steady aridification towards the terminal Pleistocene. However, Spitzkloof's charcoal records provide little evidence to suggest that the LGM supported a more mesic vegetation community than more recent time-periods. Instead, results suggest that the region experienced fairly limited climatic change as there is compelling evidence for the persistence of Succulent Karoo elements – namely Stoeberia arborea, Hermannia disermifolia and Lycium spp. - throughout the late Pleistocene. The localised appearance at the terminal Pleistocene (~14 ka) of all of the most abundant taxa at the site today is interpreted as a consequence of terminal Pleistocene changes in sea-level and CO2 concentration within a persistent context of minimal climatic change. These results have important implications for the applicability of a generalised WRZ model of climate change to the Succulent Karoo and for hypothetical predictions of future climate change impacts in the biome.en_ZA
dc.identifier.apacitationCronin, K. (2013). <i>Reconstructing the late pleistocene palaeoenvironment of the Richtersveld using fossil charcoal</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Biological Sciences. Retrieved from http://hdl.handle.net/11427/14119en_ZA
dc.identifier.chicagocitationCronin, Kate. <i>"Reconstructing the late pleistocene palaeoenvironment of the Richtersveld using fossil charcoal."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 2013. http://hdl.handle.net/11427/14119en_ZA
dc.identifier.citationCronin, K. 2013. Reconstructing the late pleistocene palaeoenvironment of the Richtersveld using fossil charcoal. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Cronin, Kate AB - The Succulent Karoo is recognised as an important biodiversity hotspot and many of the key plant lineages that characterise the biome are thought to have originated during the Pleistocene epoch. However, due to the paucity of palaeobiological proxy data available for the Succulent Karoo, relatively little is known about its environmental history and how an important core of this region, Namaqualand and its subregion the Richtersveld, may have responded to Pleistocene changes. Recent excavations at Spitzkloof Rockshelter A in the Richtersveld have provided a rare source of palaeoenvironmental data in the form of fossil wood charcoal assemblages that span a sequence from the last glacial maximum (LGM) to ~14 500 yrs BP. The present study analysed the fossil charcoal deposits from the rockshelter in order to reconstruct woody species assemblage patterns as a proxy for late Pleistocene palaeoclimate. Identification of the fossil charcoal specimens was achieved by anatomical comparison with transverse section photomicrographs of identified reference specimens of woody taxa currently growing at the site. Patterns in the charcoal data set were sought by assessing the changes in woody species assemblages over time. An assessment of the environmental correlates of the contemporary distributions of taxa found in the archaeological sequence provided the basis for palaeoenvironmental reconstruction. Based on the current generalisation for glacial climates in the winter rainfall zone (WRZ), it was hypothesised that the study region experienced an increase in rainfall at the LGM, and a steady aridification towards the terminal Pleistocene. However, Spitzkloof's charcoal records provide little evidence to suggest that the LGM supported a more mesic vegetation community than more recent time-periods. Instead, results suggest that the region experienced fairly limited climatic change as there is compelling evidence for the persistence of Succulent Karoo elements – namely Stoeberia arborea, Hermannia disermifolia and Lycium spp. - throughout the late Pleistocene. The localised appearance at the terminal Pleistocene (~14 ka) of all of the most abundant taxa at the site today is interpreted as a consequence of terminal Pleistocene changes in sea-level and CO2 concentration within a persistent context of minimal climatic change. These results have important implications for the applicability of a generalised WRZ model of climate change to the Succulent Karoo and for hypothetical predictions of future climate change impacts in the biome. DA - 2013 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 2013 T1 - Reconstructing the late pleistocene palaeoenvironment of the Richtersveld using fossil charcoal TI - Reconstructing the late pleistocene palaeoenvironment of the Richtersveld using fossil charcoal UR - http://hdl.handle.net/11427/14119 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/14119
dc.identifier.vancouvercitationCronin K. Reconstructing the late pleistocene palaeoenvironment of the Richtersveld using fossil charcoal. [Thesis]. University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 2013 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/14119en_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.otherBiological Sciencesen_ZA
dc.titleReconstructing the late pleistocene palaeoenvironment of the Richtersveld using fossil charcoalen_ZA
dc.typeBachelor Thesis
dc.type.qualificationlevelHonours
dc.type.qualificationnameBSc (Hons)en_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
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