A simulated history of Aloe dichotoma recruitment and its link to rainfall : insights from an isolated population near Kenhardt

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dc.contributor.advisorHoffman, Timmen_ZA
dc.contributor.advisorJack, Samen_ZA
dc.contributor.authorvan Blerk, Justinen_ZA
dc.date.accessioned2015-09-15T10:33:05Z
dc.date.available2015-09-15T10:33:05Z
dc.date.issued2013en_ZA
dc.description.abstractAloe dichotoma populations differ in their rates of recruitment and mortality across the species distribution in South Western Africa. Little is known about how recruitment and mortality rates are affected by local climate and ecological factors. Using repeat photography and a statistical recruitment model, the recruitment history of an emerging population of over 200 A. dichotoma individuals near Kenhardt was simulated. Historical rainfall data was used in order to assess the possible link between rainfall and recruitment. Recruitment patterns were found to be a combination of episodic events of varying length and magnitude superimposed over a background of low-rate continuous recruitment. The largest, most extended episodic recruitment period peaked in the mid-1970s and led to the establishment of most of the individuals in the Kenhardt population. These trees were generally between 150 and 250 cm in height (2013). Newly discovered juveniles below 100 cm in height were predominantly the result of relatively small and brief episodic recruitment events that occurred in the mid and late 2000s. Between episodic recruitment events, evidence for low-rate continuous recruitment is present, particularly in more recent years. Episodic periods of high-rate recruitment were found to be linked to high rainfall. The largest, most extended recruitment period coincided with the exceptionally high rainfall of the 1970s. The more recent episodic recruitment events also coincided with high rainfall spikes during the 2000s. While correlations between rainfall variables and recruitment were significant, many other factors may affect the strength of this relationship.en_ZA
dc.identifier.apacitationvan Blerk, J. (2013). <i>A simulated history of Aloe dichotoma recruitment and its link to rainfall : insights from an isolated population near Kenhardt</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Biological Sciences. Retrieved from http://hdl.handle.net/11427/14021en_ZA
dc.identifier.chicagocitationvan Blerk, Justin. <i>"A simulated history of Aloe dichotoma recruitment and its link to rainfall : insights from an isolated population near Kenhardt."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 2013. http://hdl.handle.net/11427/14021en_ZA
dc.identifier.citationvan Blerk, J. 2013. A simulated history of Aloe dichotoma recruitment and its link to rainfall : insights from an isolated population near Kenhardt. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - van Blerk, Justin AB - Aloe dichotoma populations differ in their rates of recruitment and mortality across the species distribution in South Western Africa. Little is known about how recruitment and mortality rates are affected by local climate and ecological factors. Using repeat photography and a statistical recruitment model, the recruitment history of an emerging population of over 200 A. dichotoma individuals near Kenhardt was simulated. Historical rainfall data was used in order to assess the possible link between rainfall and recruitment. Recruitment patterns were found to be a combination of episodic events of varying length and magnitude superimposed over a background of low-rate continuous recruitment. The largest, most extended episodic recruitment period peaked in the mid-1970s and led to the establishment of most of the individuals in the Kenhardt population. These trees were generally between 150 and 250 cm in height (2013). Newly discovered juveniles below 100 cm in height were predominantly the result of relatively small and brief episodic recruitment events that occurred in the mid and late 2000s. Between episodic recruitment events, evidence for low-rate continuous recruitment is present, particularly in more recent years. Episodic periods of high-rate recruitment were found to be linked to high rainfall. The largest, most extended recruitment period coincided with the exceptionally high rainfall of the 1970s. The more recent episodic recruitment events also coincided with high rainfall spikes during the 2000s. While correlations between rainfall variables and recruitment were significant, many other factors may affect the strength of this relationship. DA - 2013 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 2013 T1 - A simulated history of Aloe dichotoma recruitment and its link to rainfall : insights from an isolated population near Kenhardt TI - A simulated history of Aloe dichotoma recruitment and its link to rainfall : insights from an isolated population near Kenhardt UR - http://hdl.handle.net/11427/14021 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/14021
dc.identifier.vancouvercitationvan Blerk J. A simulated history of Aloe dichotoma recruitment and its link to rainfall : insights from an isolated population near Kenhardt. [Thesis]. University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 2013 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/14021en_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.titleA simulated history of Aloe dichotoma recruitment and its link to rainfall : insights from an isolated population near Kenhardten_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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