School of Animal, Plant and Environmental Sciences (ETDs)

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Subject: search.filters.subject.UCTDSubject: search.filters.subject.SDG-9: Industry, innovation and infrastructure

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Now showing 1 - 4 of 4
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    Higher Education Sustainability: Investigating the barriers and opportunities to sustainable infrastructural development in tertiary education institutions
    (University of the Witwatersrand, Johannesburg, 2024-03) Buthelezi, Nontobeko Lynda Valerie; Engelbrecht, Francois; Reid, Memory
    The research investigates sustainability initiatives in South African higher education, focusing on the refurbishment of water heating systems at the University of the Witwatersrand, Johannesburg. It examines the economic and environmental impacts of adopting greener technologies, highlighting the importance of stakeholder engagement. Using a mixed methods approach, the study combines qualitative interviews to understand stakeholder perspectives with quantitative analysis of costs and carbon emissions. The findings reveal that the new water heating system significantly reduces emissions—6.6 times less than the traditional system—resulting in a 9.71 kg monthly carbon footprint versus 64.296 kg with old geysers. Financial analysis shows an 81% cost reduction in water heating expenses due to the switch from grid electricity to natural gas, achieving a 4.16% return on investment. The research underscores the challenges in securing broad stakeholder support and the importance of a holistic sustainability approach that integrates economic, environmental, and social factors. It highlights the potential of such initiatives to reduce environmental impact, save costs, and drive innovation, providing insights for future sustainability efforts in higher education.
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    Assessment of the Environmental Authorisation Processes and Mining Right Applications for Improved Environmental Outcomes
    (University of the Witwatersrand, Johannesburg, 2023) Antoniades, Maria; Watson, Ingrid
    This study investigates alignment of South African mining right and environmental authorisation application processes to determine their adequacy in catering for optimised early mine planning seeking to achieve enhanced environmental outcomes. First the legislative requirements for mining right and environmental authorisation applications are evaluated. Results are critically analysed, including an assessment of process alignments and disjunctions. Secondly, integration of the application study processes in practice are investigated. The practical implications of the application requirements are qualitatively examined through key informant and case study analysis. It is shown that integrated planning is not a legislated requirement nor readily adopted by proponents. Environmental planning conforms to technical outputs as tick-box exercises rather than being iterative and co-operative. Workstreams misalignments result in poor planning to the detriment of environmental outcomes. Finally, a practical guidance is presented for early integrated study processes aimed at meaningful project design through parallel planning to optimise environmental results.
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    Effects and consequences of natural and artificial light at night on small mammals in peri-urban Johannesburg, South Africa
    (University of the Witwatersrand, Johannesburg, 2024) Oosthuizen, Tasha; Pillay, Neville; Oosthuizen, Marietjie
    Studies investigating artificial light at night (ALAN) have increased over recent years. However, research examining the influence of ALAN on southern African small mammal species are lacking and even information on their basic biology is scarce. To close this knowledge gap, I investigated the effect of ALAN on different facets of animal behaviour in African small mammals. Firstly, I evaluated the impact of the natural (lunar cycle) and ALAN on the community composition and species abundance in two populations of small mammals. I chose two field sites: one facing Johannesburg (exposed to ALAN) and one facing away. I conducted mark-recapture trapping to ascertain the occurrence and abundance of small mammals. The Light site had both a higher species composition and a higher animal abundance when compared to the composition and abundance of the Dark site. The lunar cycle had an effect; on nights with a full moon, the species composition and animal abundance of both study sites declined, while on new moon nights, the opposite occurred, with an increase in both the species composition and abundance on the Light and Dark sites. The absence of a negative ALAN effect on the Light site can potentially be ascribed to the availability of microhabitats for small mammals to escape illumination, leaving them seemingly unaffected. Next, I assessed the locomotor activity of three species of commonly occurring rodents on the study area, one crepuscular (19 single-striped grass mice, Lemniscomys rosalia), one species with reportedly variable activity (19 angoni vlei rats, Otomys angoniensis) and one nocturnal (19 southern multimammate mice, Mastomys coucha). They were captured at a different location than the mark-recapture study sites and tested in captivity under natural (exposed to natural light and temperature changes), laboratory (standard laboratory conditions; 12h light:12h dark and constant temperature) and ALAN treatments. Lemniscomys rosalia exhibited crepuscular activity under all three experimental treatments, Otomys angoniensis was mostly nocturnal with some diurnal activity. The temporal activity profiles of the two species that showed some activity during the light hours were unaffected by ALAN. Mastomys coucha displayed strictly nocturnal activity during the natural and laboratory treatments, but during ALAN treatments the temporal activity profiles of some animals shifted so that they were active during the start of the day. Lemniscomys rosalia and O. angoniensis were more active under the natural treatment, whilst M. coucha was more active in the laboratory treatment. When exposed to 2 Lux ALAN presented remotely, there was no effect on the level of activity in O. angoniensis, L. rosalia showed a reduction of about 20% in its activity, whereas M. coucha reduced its activity by more than 50%. Finally, I studied how ALAN impacted the foraging behaviour of the three species under four treatments (during the day, at night, 2 Lux ALAN and 10 Lux ALAN). Foraging behaviour differed in the three species under different light conditions. Lemniscomys rosalia was risk-averse when feeding during the diurnal and nocturnal (no light at night) treatments. Otomys angoniensis showed irregular responses in their foraging behaviour under all foraging treatments. Mastomys coucha showed no differences when feeding under any of the nocturnal treatments, but it was inactive under the diurnal treatment. Overall, my study revealed that the effect of ALAN is not similar for all small mammalian species and appear to depend on both the spatial and temporal niches that the different species occupy. Strictly nocturnal animals seem to be affected the most, whereas animals that are active during the day showed lesser responses. Given the rapid increase in urbanisation and anthropogenic disturbances, more and more species are exposed to ALAN. Species that prefer darker, more secluded habitats appear to be more vulnerable and at higher risk of local extinctions as a result of disturbances, such as ALAN and habitat transformation. My study highlights that ALAN affects both nocturnal and diurnal rodents to the extent that it can have fitness consequences, including changed active times, foraging efficiency, movement patterns and susceptibility to predation. Finally, the disruption of rodent behaviour can have cascading effects for ecosystems and my study also emphasises the importance of safeguarding our night skies to protect biodiversity.
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    Seasonal abundance and diversity of mites in Coffea arabica L. at Beaver Creek Coffee Estate, South Africa
    (University of the Witwatersrand, Johannesburg, 2023) Chikomo, Nontobeko Natasha; Situngu, Sivuyisiwe
    The presence of multiple species of mites inside the leaf domatia of Coffea arabica is well documented by various studies. This study examined the influence of seasonal changes on the abundance and diversity of mites in the leaf domatia of Coffea arabica. The study furthermore documented the species of predatory mites that were associated with coffee. The results of the study showed that there was a significant variation in the abundance of mites due to changes in season. Mite counts were significantly higher in spring followed by autumn and lowest in summer. There was no correlation between the number of mites and temperature and relative humidity. Therefore, this study could not establish what drives the seasonal changes in the mite populations and we postulate that this was because we did not measure the microclimate of the individual trees we sampled. This would have given us more accurate data on the temperature and relative humidity experienced by these mites. The Shannon-Weiner Diversity Index was found to be highest in summer and lowest in winter. The Phytoseiidae, Tydeidae, Stigmaeidae, and Tenuipalpidae were found to be the predominant families in this study. This study is one of the few studies in South Africa to directly investigate the effects of seasonal changes in mite abundance, and could potentially open avenues for further research, particularly on what seasonal parameters drive the mite population changes. We recommend that future studies use Ibuttons to get a true measure of the climatic variables that are experienced by the mites sampled at a tree level