Browsing by Subject "Karoo"

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    A population dynamics model for analysing the effect of rainfall seasonality on vegetation in the Karoo
    (2025) Govender, Serayen; Altwegg, Andreas
    The flora of the Cape Floristic Region is amongst the most diverse and unique on the planet, due mainly to the unique climate of this region. The effects of climate change are threatening many sensitive ecosystems around the world and so it is important to understand how factors of climate change may affect the Cape Floristic Region. This paper investigates the effect of changing rainfall seasonality on certain important species of plants in the Cape Floristic Region. The species are selected from different biomes and I focus on two growth forms, namely reseeder and resprouter. Data from an experiment conducted between two biomes in the Cape Floristic Region is used to model the growth of the two growth forms post- fire. Rainfall in this experiment is artificially manipulated on replicated plots at the two experiment sites. The population growth is modelled using state-space models, incorporating both an ecological process model and an observation model. This allows us to account for errors both in the observation of the data as well as in the natural variability in the biological state process that generated the data in order to account for both measurement and process error. My results suggest that increased summer rainfall in the Cape Floristic Region has a positive effect on the populations of reseeder species in both biomes and has little effect on the populations of resprouter species. A multivariate state-space model is also proposed to investigate the effects of interactions of species growth, within the replicated plots.
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    Corbelled Buildings as heritage resources: in the Karoo, South Africa
    (2018) Hancock, Caroline; Townsend, Stephen
    The primary aim of this study was to determine who claims the corbelled buildings in the Karoo as their heritage and why. Through the use of vernacular architecture and heritage identification theory, interviews and research it is clear that the buildings are significant and a heritage resource. Their significance lies in their historical, social, aesthetic, symbolic and cultural values, as well as their unique vernacular construction and limited distribution. The corbelled buildings as vernacular buildings are part of the natural landscape which the local community associate as part of their identity and heritage. The buildings also possess academic and historical potential as they have the potential through further archaeological and vernacular architectural research, to provide more information on the northern frontier during the late 18th and early 19th centuries, a time that is not well recorded or documented. The buildings were built in 19th century along the ‘open’ northern frontier where there was intermingling and creolisation of people from different economic and social groups. As a result, they cannot be claimed by a single group of people in the present. The vast range in types and styles of corbelled buildings indicate that they were built by most people living in the area. They can therefore, be claimed by everyone who lives in the area today. They can also be claimed as national heritage as they possess values that are common to the whole country.
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    Sedimentology and ichnology of the Mafube dinosaur track site (Lower Jurassic, eastern Free State, South Africa): a report on footprint preservation and palaeoenvironment
    (2016) Sciscio, Lara; Bordy, Emese M; Reid, Mhairi; Abrahams, Miengah
    Footprint morphology (e.g., outline shape, depth of impression) is one of the key diagnostic features used in the interpretation of ancient vertebrate tracks. Over 80 tridactyl tracks, confined to the same bedding surface in the Lower Jurassic Elliot Formation at Mafube (eastern Free State, South Africa), show large shape variability over the length of the study site. These morphological differences are considered here to be mainly due to variations in the substrate rheology as opposed to differences in the trackmaker’s foot anatomy, foot kinematics or recent weathering of the bedding surface. The sedimentary structures (e.g., desiccation cracks, ripple marks) preserved in association with and within some of the Mafube tracks suggest that the imprints were produced essentially contemporaneous and are true dinosaur tracks rather than undertracks or erosional remnants. They are therefore valuable not only for the interpretation of the ancient environment (i.e., seasonally dry river channels) but also for taxonomic assessments as some of them closely resemble the original anatomy of the trackmaker’s foot. The tracks are grouped, based on size, into two morphotypes that can be identified as Eubrontes -like and Grallator -like ichnogenera. The Mafube morphotypes are tentatively attributable to large and small tridactyl theropod trackmakers, possibly to Dracovenator and Coelophysis based on the following criteria: (a) lack of manus impressions indicative of obligate bipeds; (b) long, slender-digits that are asymmetrical and taper; (c) often end in a claw impression or point; and (d) the tracks that are longer than broad. To enable high-resolution preservation, curation and subsequent remote studying of the morphological variations of and the secondary features in the tracks, low viscosity silicone rubber was used to generate casts of the Mafube tracks.