Electronic Theses and Dissertations (Masters)

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A comparative analysis of mining environmental management programme reports following a change to the one environmental system
(University of the Witwatersrand, Johannesburg, 2022) Mathe, Lebogang; Watson, I.
The mining fraternity has recently seen a shift in terms of environmental requirements under the ambit of the Mineral and Petroleum Resources Development Act 28 of 2002 (MPRDA) to the National Environmental Management Act 107 of 1998 (NEMA). The objective was to ensure a streamlined environmental compliance and to put emphasis on integrated environmental management. The One Environmental System (OES) was introduced which denotes that all environmental related projects or activities, including mining, are regulated through an ambit of one system. NEMA is recognised as an overarching law which provides for co-operative environmental governance; therefore, all environmental related activities are regulated under its ambit and EIA regulations. In this research report, the Environmental Management Programme (EMP) reports and Environmental Authorisations that were issued under the MPRDA and the 2014 NEMA regulations respectively, were analysed using the respective regulations to compare the environmental management measures outlined in the reports to achieve better environmental results. The aim of the research was to assess whether the Environmental Authorisations granted in terms of NEMA reflect better environmental results as compared to those issued under the MPRDA. Better environmental results mean improved management plans with clearer assessment of impacts, more detailed mitigation measures with specific, achievable, relevant and time bound actions that do not pose harmful effects on the environment and communities. A mixed method of analysis was implemented which included a review and comparison of legislation, evaluation and scoring of 20 EMPs (10 submitted under MPRDA and 10 submitted under NEMA) and interviews with key informants, namely competent authorities and the Environmental Assessment Practitioners (EAPs) were conducted to support the findings of the reports. In conclusion, the reports analysed presented a significant improvement and better environmental results under NEMA. The interviews conducted with authorities and the EAPs have also substantiated the observations made in terms of Environmental Management Programme reports and Environmental Authorisations submitted. The findings indicated that there were similarities in the MPRDA and NEMA regulations as 4 | P a g e regards some environmental requirements. However, the MPRDA lacked to outline a detailed description of environmental requirements needed to manage environmental impacts. Thus, applicants provided limited information in terms of the management of impacts. NEMA has provided additional requirements, including baseline environmental information, specialist reports and public participation amongst others; these contributed to improved environmental results. The study revealed that the reports submitted under NEMA provided better environmental management measures as compared to the reports submitted under MPRDA.
An ethnobotanical study of indigenous knowledge of the medicinal plants used by traditional healers in the rural communities of Nkomazi Local Municipality, Mpumalanga province
(University of the Witwatersrand, Johannesburg, 2024) Khoza, Nompendulo; Dukhan, Shalini; Ramalepe, Phillemon; Risenga, Ida
Traditional medicine continues to significantly impact many people’s lives amid all the advancements in modern medicine. Many rural communities in Mpumalanga province depend on indigenous traditional medicines to manage various ailments. The available research on the traditional usage of medicinal plants among rural communities in Mpumalanga is highly fragmented and under-researched. The decline of medicinal plant populations has led stakeholders to take various initiatives to counteract over-exploitation, including cultivation as a viable conservation approach. However, the scientists' inadequate understanding of the acceptance of cultivated medicinal plants by traditional healers is one of the issues contributing to the failure of medicinal plant cultivation programs. Consequently, this study aimed to document medicinal plants utilised by the Nkomazi Local Municipality's traditional healers and assess opportunities and constraints for medicinal plant conservation in the Nkomazi Local Municipality. The ethnobotanical data was obtained through semi-structured questionnaires and guided field walks with traditional healers. Individual interviews were conducted with ten traditional healers from eight villages across Nkomazi during field visits between July 2021 and February 2022. The study employed qualitative and quantitative approaches to understand traditional healers' perspectives concerning the ethnobotanical significance and medicinal plant conservation. The study found that the indigenous knowledge of medicinal plants in the Nkomazi Local Municipality is diverse, encompassing 111 species from 59 different families employed to treat 70 ailments. Most of the reported medicinal plants for this study are of Least Concern. Additionally, the top fourteen most reported species in the Nkomazi Local Municipality included commercially valuable plants such as Psidium guajava, Ricinus communis, Sclerocarya birrea, Aloe ferox, Aloe maculata, Leonotis leonurus, and Moringa oleifera. Most of the Nkomazi Local Municipality's traditional healers did not know about protected plant species and the National Environmental Management Act (NEMA). Traditional healers were aware of the decline in wild populations of medicinal plants, which they attributed to various factors such as overharvesting. Diviner’s and herbalist perception of using cultivated plants did not differ significantly (𝜒2=0.4762, df=1, P= 0. 490). The study provided a comprehensive inventory of medicinal plants utilised by Nkomazi traditional healers and essential data for future assessments of the use local use of indigenous medicinal plants.
Assessing habitat selection of grassland rodents in the Cradle of Humankind
(University of the Witwatersrand, Johannesburg, 2024) Pinto, Catiuscia-Jade; Mackay, Megan; Pillay, Neville
Habitat selection is a decision-making process undertaken by animals to select an appropriate environment suitable for fulfilling their survival and reproductive needs. These decisions are driven by a complex of biotic and abiotic factors. Habitat selection relies on how an animal interacts with its environment and is species-specific. The vegetation structure and composition influence how smaller animals, such as rodents, obtain food and cover, and are thus critical for their survival. The aim of my study was to assess the population demography and habitat selection of nocturnal rodents in two grassland sites located within the Cradle of Humankind Nature Reserve, Krugersdorp, Gauteng Province, South Africa. I obtained rodent data using Capture-Mark-Recapture (CMR) methods, and vegetation data were obtained through randomised quadrate sampling. The following six rodent species were sampled, Gerbilliscus leucogaster, Lemniscomys rosalia, Mastomys coucha, Micaelamys namaquensis, Mus minutoides and Otomys angoniensis. Rodent abundance differed between summer and winter, with winter showing a higher abundance, but richness and diversity indices did not differ significantly between sites or seasons. The three most common species, G. leucogaster, M. coucha and O. angoniensis, were selected for further population demography analyses. The demography of G. leucogaster, was mostly associated with the season since seasonal fluctuations were observed in their population size (higher in summer), reproductive activity (more active in summer) and body condition (higher in winter). Mastomys coucha was the most abundant species in the study, since it had the highest number of sampled individuals in both summer and winter, although its demography was not influenced by external factors (e.g.,, season, vegetation height, vegetation cover) recorded in both summer and winter. Otomys angoniensis had a positive relationship with vegetation height and rodents’ body condition. The three species were able to coexist with one another due to differences in foraging strategies, reproductive strategies, spatial and dietary partitioning, which help to facilitate habitat selection and illustrate that habitat selection is species specific. Key words: Rodents, habitat selection, Gerbilliscus leucogaster, Mastomys couch
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.
Biodiversity stewardship in south africa - an assessment of the klipkraal biodiversity stewardship programme and its potential for conservation
(University of the Witwatersrand, Johannesburg, 2024) Butler, Kirsten
The importance of conservation in agriculture has become more apparent over the last couple of years, however it involves complex social-ecological relationships and as agriculture is a critical industry for human survival, biodiversity conservation in the industry is a major challenge worldwide. In South Africa, biodiversity stewardship programmes, which involve agreements between landowners and conservation authorities to secure land in biodiversity priority areas, are becoming a prominent method of conservation in agriculture. Yet there is a lack of research on the conservation benefits and whether they show improvements in the area’s biodiversity. This study focussed on the Klipkraal biodiversity stewardship programme which consists of two privately owned functional cattle farms in a peri-urban area of the southern grasslands of Gauteng making up 2 656 hectares of land of which 1 600 hectares are natural vegetation, and the remaining area is cultivated land used for farming maize and soya. The study sought to answer the question: what is the ecological state of the area and does this programme have potential for conservation in the long-term? The aim of this study was to assess the potential conservation benefits and sustainability of the Klipkraal biodiversity stewardship programme. The study involved both qualitative and quantitative data collection, including landcover mapping, field surveying to assess the vegetation state and mammal diversity and distribution of the site, and interviews with key stakeholders. The landcover mapping allowed for a visual representation of the various landcover types and percentage coverage of each of the six landcover types found in the study area. Vegetation assessments at five different sites resulted in an understanding of the vegetation structure, composition and cover across the two farms and from this it was established that the vegetation structure and species diversity differ, but the species composition is similar throughout the study site. An anthropogenic disturbance score was allocated to each site and the highest rated anthropogenic scores correlated with the sites consisting of the highest exotic species. The mammal assessments showed that the varying vegetation structure allows for specialist species to occupy a range of habitats within the site and also indicated that there are barriers to the movement of large mammals within the site. The results of the vegetation and mammal assessment which suggest a diverse range of vegetation units, habitats, and mammal diversity, emphasise that the area is important for conservation. The interviews revealed the multiple challenges involved in the Klipkraal Biodiversity Stewardship Programme and requirements in order for the programme to be successful in the long term. These include a need for willingness of landowners to put their time and resources into conservation efforts on their properties, a need for constant monitoring of management strategies, the importance of expanding the stewardship areas to ensure conservation of the entire area and not just isolated fragments of the area. However, key challenges in expanding the programme were also revealed, such as scepticism by landowners in entering land agreements with the government and in Gauteng, many areas of conservation interest are made of multiple small properties that are owned by different landowners which means a lot of effort is required in getting each landowner to sign up. Insight was also given into the roles of the various stakeholders and the relationship between the Gauteng Department of Agriculture and Rural Development (GDARD) and the landowners, and it was indicated that GDARD’s role is to provide guidance, education and resources when available to the landowners in order to manage their protected area. This study can be used as a baseline study for GDARD to measure the progress in conservation in terms of the landcover and ecological aspects at the site and to monitor any changes in landowner-GDARD dynamics.
Characterisation of Drought Using Hydrological and Meteorological Indices: A Case Study of Bethlehem, South Africa
(University of the Witwatersrand, Johannesburg, 2023) Tshabalala, Khanyisile; Evans, Mary; Masindi, Khuliso
The study aims to assess the severity and evolution of drought/s in Bethlehem using the hydrological: Streamflow Drought Index (SDI), Reconnaissance Drought Index (RDI), Effective Reconnaissance Drought Index (eRDI) and meteorological: Standardised Precipitation Index (SPI), Agricultural Standardised Precipitation Index (aSPI), and Precipitation Deciles (PD) indices. These indices were computed using the Drought Indices Calculator (DrinC). The RDI, eRDI, aSPI, and SPI identified three drought events between 1980 and 2017. The PD on the other hand, identified particular years between 1980 and 2017 that received below-normal to much below- normal precipitation. Further, the years identified to have received below normal to much below normal precipitation fell between the drought periods identified by the other indices, such as the 1980 – 1990 drought identified by the SPI, RDI, aSPI, and eRDI; the PD identified 1982, 198, 1985, and 1986 as specific years the received significantly low precipitation within the decade long drought. Of critical note is the absence of the SDI results, stream levels data was not available at the time the results presented in this report were computed. The unavailability of SDI values did not compromise or negatively affect the results presented in this study as the computed indices had a strong correlation, implying the reliability of the results presented in this report
Characterizing microclimates as potential thermal buffers for reptiles, birds, and mammals in an arid-zone environment
(University of the Witwatersrand, Johannesburg, 2023) Warner, Grace M.; Alexander, Graham J.; Fuller, Andrea
Aridification, increases in air temperatures and frequency of extreme weather events, such as heat waves, are predicted to intensify under climate change, suggesting dire consequences for dryland animals. Microhabitats may buffer dryland animals against the changing climate, yet microclimatic data remains scarce from Africa and arid regions. The distribution, abundance, and thermal buffering capacity of five microhabitat types (burrows, nests, rock crevices, tree hollows and vegetation) were investigated across three habitat types (dunes, plains, and mountains) in the Kalahari. The distribution and abundance of microhabitats were assessed via strip transects, while thermal buffering capacity was evaluated by comparing miniature black globe temperatures from 70 representative sheltered microhabitats with 12 localised exposed-site microhabitats. The data generated have provided a baseline measure of the abundance and distribution of microhabitats in the Kalahari and have produced a year-long fine-resolution microclimatic thermal dataset. Microhabitat types and abundance were found to differ per habitat type and across topographic gradients. Abiotic drivers, such as soil type and fire frequency, along with drivers such as biotic community composition, were highlighted as potential causes of these microhabitat distribution patterns. Burrows were the best buffered microhabitat across all tested temporal and spatial gradients, providing an average maximum decrease of -29.5 ˚C during the day, and an average maximum increase of 20.1 ˚C during the night. Well-buffered microhabitats were rare within the field-site, whereas some of the poorest buffering microhabitats (Vegetation) were abundant and widespread. Thus, competition for well-buffered microhabitats may increase under climate change, whilst the risk of traversing large distances between microhabitats may become too great for smaller animals as exposure risk to extreme temperatures increases. Furthermore, birds and large mammals may likely be at a high risk of extreme temperature exposure, as their size and structural adaptations may restrict them from access to well-buffered microhabitats. Therefore, the need for the concurrent assessments of microhabitat distribution, abundance and buffering capacity in future species vulnerability assessments is highlighted, as it is the combination of these factors that are likely to impact population viability under climate change.
Comparative Analysis of Water Hyacinth Efficiency as Biosorbent and Phyto remediating Plant for Removal of Lead (Pb) Water Contaminants
(University of the Witwatersrand, Johannesburg, 2023-08) Nwagbara, Victor Uzoma; Parrini, Francesca; Newete, Solomon
One of the major problems facing the modern society is the issues of water contamination. The ability of aquatic plants to serve as both heavy metal biomarkers and phytoremediators has been advocated for many years. The purpose of this study was therefore to compare the efficacy of water hyacith as a biosorbent and phytoremediating plant for removal of lead from contaminated waters. Dry and fresh water hyacinth biomass were exposed to Pb-contaminated water at different time intervals of 1, 7, 14 and 21 days. The results showed that with the increase of the exposure time, the Pb removal capacity of the plant biomass also increased. The Pb water concentration in day 1 and day 7 were significantly different from those in day 14 and day 21 which were not significantly different from each other. The average Pb removal from the Pb-treated waters for the different time exposure of 1, 7, 14 and 21 days in the fresh water hyacinth biomass were 40%, 56%, 78 % and 79%, respectively, the highest reduction being in the latter. The biomass of the freshwater hyacinth roots had the highest Pd concentration compared to the shoot. On The other hand the average Pb removal by the dry water hyacinth biomass were 78.9 %, 78.5%, 78.3 % and 78.3% for day 1, 7, 14 and 21 respectively, showing no significant difference between the different time series exposure. This suggests the instant adsorption of Pb by the dry plant material from the first day of exposure, after which the active sites for adsorption saturates to accommodate any further Pb ion uptake. There were some plant stresses such as leaf chlorosis, and significant decrease in biomass weight and length of leaf-2 petiole in the lead-treated fresh water hyacinth plants compared to the controls (Pb-free water hyacinth plant). Thus, this study confirms that the largest removal by the dry water hyacinth biomass, occurred in the first day as opposed to the last day (day 21) by the freshwater hyacinth biomass.
Eco-art for a transformative climate culture
(University of the Witwatersrand, Johannesburg, 2022) Warrington-Coetzee, Hannelie; Voge, Coleen; Manderson, Lenore
Human”‘development” since the industrial revolution has unequivocally attributed to a code red of climate disasters, according to the recent IPCC Sixth Assessment Report of the Intergovernmental Panel on Climate Change report (IPCC, 2022a). To selectively unlearn or de-grow the unsustainable industrial culture crisis, humanity needs seriously to consider and act to transform (e.g., through ecocitizenship) in support of governments, scientists, and other civic actions in our journey to sustainable futures. Using a transdisciplinary praxis approach, artists can provide various forms of transformative possibilities, including transgressive interventions at a grassroots level, deliberately designed to provoke and inspire change. This research interrogates how eco-art deeply engages audiences to identify the key characteristics of such potentially radically transformative artworks. Humans have a narrowing window to transform our relationship to the Earth’s resources and reverse or slow temperature rise. The ‘near term’ (2022 – 2030) will determine and define the extent of various climate transformation pathways (IPCC, 2022, p. 7). Relational eco-art creates spaces for meaningful dialogue to design opportunities for transcendence to ecological citizenship. Art also holds a potential revolutionary connection tool that can unite science and society in incidences of immersion and change to spur further creations and change. These works, which visually articulate diverse types of knowledge, are described in the literature as situated in the fecund middle, a hidden third zone in which components are rhizomatically connected. Here I use fecundity to refer to intellectual productivity. The study aimed to establish which characteristics in eco-art can contribute significantly more to sustainable eco-cultural development and what form and opportunities such transformative interventions manifest. The ways in which artists position their work to contribute to cultural climate change adaptation is interrogated in transdisciplinary praxis. In doing so, I interrogate previously published work of a select group of artists. This is not an inquiry into the methodology of transdisciplinary research, but, drawing on the artists’ praxis, I argue and expand on how the value of collaboration of scholars and artists working in these liminal spaces can reach new audiences. Two datasets are interrogated to analyse the approaches in art related to the environment, one eco-art characteristic derived from the author’s public art praxis, and the second, a broader interrogation of 50 international eco-artworks. By comparing and contrasting the two datasets, characteristics of intentionality, often built into the artworks, were identified. Six key characteristics were isolated, described and further interrogated to discover how they may create opportunities for society to build and foster potential cultural climate change solutions
Employee Sentiments Concerning Workplace Greening
(University of the Witwatersrand, Johannesburg, 2023-09) Khorommbi, Phumudzo; Moolla, Raeesa
For centuries, people have continuously impacted the environment, resulting in an exponential rise in environmental problems and deterioration. In the quest to find solutions, business organisations have employed or tried to institute greening programmes, such as promoting waste at source and installing solar panels. However, it is essential for people, specifically in occupational settings, to see this as a need - for greening programmes to be effective. To this end, this study aimed to identify the elements that drive individuals to conduct environmentally responsible behaviours at work. This qualitative study collected data by administering surveys to research participants. Information related to eco-helping, eco-initiatives and eco-civic engagement was collected by administering surveys to local contractors at the PepsiCo site in Kempton Park, Johannesburg. The survey amassed 70 responses during October 2023. The study found that gender was an important indicator of pro-environmental behaviour, and that age affected a person’s inclination to act pro-environmentally. As this study relied on proclamations of good environmental intentions from participants, future studies should test this hypothesis in the field to quantify its success.
Evaluating the Effectiveness of Green Drop Audit Criterion in Relation to Its Link to Enforcement Protocol in South Africa
(University of the Witwatersrand, Johannesburg, 2022-08) Tshongweni, Olwethu Lenox; Tutu, Hlanganani; Richards, Heidi L.
The Green and Blue Drop programs are incentive-based regulatory systems based on the Department of Water and Sanitation's (DWS) realization that rewarding positive behaviour is more efficient and effective than penalizing undesirable behaviour. The Green Drop was developed for the Wastewater Quality Management Regulation certification program. In contrast, the Blue Drop was developed for the certification program for the Drinking Water Quality Management Regulation (Burgess, 2021). Most municipalities have accepted them and have raised awareness about the need for better efficiency in the wastewater sector. The Sand River, in Polokwane wastewater treatment works (WWTWs), was chosen as the research area for this study. This particular river was selected based on the premise of continuous non-compliance of the wastewater treatment plant and the resulting pressure it puts on the Sand River by compromising its quality, with the DWS not having a successful way of regulating and enforcing the water user to abide by the rules of the license that has been issued. This study aims to evaluate the effectiveness of the Green Drop Program audits and assessments about their link to the regulatory system within the DWS. Additionally, a risk assessment and cumulative risk rating are used to assess wastewater discharge into the Sand River in the Limpopo Province. Based on the observation made during the study, it appears that within the DWS organizational arrangements, the lack of coordination among the sectors (compliance monitoring, water quality management, the green drop program, and enforcement), lack of accountability, and the regulatory requirement of cooperation within DWS sectors have hindered implementation. Some of the non-compliance factors may be due to the misuse of funds meant for infrastructure development and difficulties relating to capacity, procurement, and management of the WWTWs. Moreover, DWS's absence of interactive data management systems and business processes contributes to non-compliance. The Polokwane WWTW, directly linked to the Sand River, is overloaded and needs to comply with the Water Use Licence (WUL) conditions. For example, the 21 August 2022, this facility was found to be non-compliant by 69.01%, collectively with administration and technical conditions of the WUL issued to the facility (DWS, 2022c). In addition, this investigation discovered that the Polokwane facility, which has been operating outside of regulations for the past four years, therefore, as calculated in equation 7 could be responsible for 72.3% of the hazards to people's health, the quality of the river's water, and the aquatic ecosystem life in the Sand River in a single month. As much as some municipalities do not perform according to the desired standards, there have been a few noticeable, well-performing ones reported in the green drop report released in 2022. These include Langebaan WWTW (90%), Riebeek Valley WWTW (97%), Gansevallei WWTW (84%), and Wellington WWTW (95%), and this illustrates that the Green Drop Certification is achievable if the municipalities follow and adhere to the Water Use Authorization (WUA) issued them (DWS, 2022b). The DWS must integrate the internal structures or link sectors responsible for monitoring and regulating municipal water service facilities and incentivize performing facilities to improve their performance. Additionally, facilities with minor compliance issues, such as water quality, must be referred to the Water Quality Management (WQM) unit for further investigation and recommendations. However, those non-compliances of authorized wastewater treatment facilities that require regulatory attention must be referred to the compliance monitoring sector through the system for compliance monitoring. Lastly, those facilities that are not authorized must be directed to enforcement for further action. Therefore, using the Integrated Regulatory Information System (IRIS) as the umbrella body for both database and work-based information has an imperative role that can curb some of the issues faced by the DWS. Standard operating procedures (SOPs) should guide all interactions between these systems.
Evaluation of the JSE’s environmental reporting requirements of South African listed companies
(University of the Witwatersrand, Johannesburg, 2024) Hariram, Viratha; Schwaibold, Ute
Through its mandatory environmental reporting requirements, the Johannesburg Stock Exchange (JSE) plays a pivotal role in the private sector to align to Environmental, Social and Governance frameworks and disclose information of a company’s environmental priorities and performance in addressing areas of concern. While there are attempts to safeguard the environment from damage and degradation, it is unclear if this framework is suitable at appropriately addressing the environmental areas of concern facing South Africa. In order to evaluate the JSE’s environmental requirements on listed companies, this study aimed to identify the local and global environmental priorities via the South African State of Environment Outlook Report (local view), National Development Plan (local view) and Sustainable Development Goals (global view) and thereafter determine if the Global Reporting Initiative, the only set of mandatory environmental requirements of the JSE, was adequately addressing the indicators they outlined. Furthermore, using a scoring system from zero to four, the study evaluated the alignment of ten randomly selected JSE listed companies against the requirements of the Global Reporting Initiative to note their level of adherence and alignment to the South African State of Environment Outlook Report, National Development Plan and Sustainable Development Goals. The results indicate that the Global Reporting Initiative (GRI) covers 73% of environmental priorities discussed in the South African State of Environment Outlook Report, National Development Plan and Sustainable Development Goals. Of the total 74 indicators of environmental concern identified from the three reports, the GRI did not require disclosure for 20 indicators. Only three indicators that were required to be disclosed by the GRI had scored a four on the rating scale due to it being an integrated disclosure that takes into account one or more other related environmental categories. The evaluation of the sampled listed company’s adherence to the GRI via their sustainability reports and integrated annual reports indicated that none of the companies had provided sufficient disclosures to meet the requirements of the GRI. 80% of the sampled listed companies made a strong alignment to the Sustainable Development Goals in their sustainability reports and / or integrated annual reports. A shortcoming of the JSE that was stated by all four sustainability experts interviewed was the lack of enforcement for listed companies to make quality and comprehensive disclosures or accountability expected from listed companies. There is no formal process of review or consequences for listed companies who do not comply.
Factors affecting mammal utilisation of non-wildlife railway underpasses within the Greater Kruger, South Africa
(University of the Witwatersrand, Johannesburg, 2023) de Villiers, Hannah; Parrini, Francesca; Teren, Gabriella
Railways are an integral component of sustainable transport systems, but cause significant impacts to biodiversity, primarily through wildlife-train collisions and the habitat fragmentation created in the landscape. Crossing structures (CSs) for wildlife are the key mitigation measure for these adverse impacts, which will be critical throughout Africa, where 55,000 km of new railway lines are predicted to cut through hundreds of protected areas. For the first time in southern Africa, mammal usage of railway underpasses that were not designed to facilitate wildlife movement was studied using camera traps in the Greater Kruger National Park, South Africa. This study demonstrates that 70% of the terrestrial medium and large mammals species present in the area used at least one non-wildlife CS during the study period, with a total of 1,823 usage events by 33 species. Twelve medium to large African mammal species used underpasses regularly, improving the permeability of the railway line for these species. A viaduct design was characterised by almost four times the usage rate of a typical box culvert and was used by twice as many species, including megaherbivores and mesoherbivores, whereas box culverts supported a smaller number of species, of which the majority were predators. Species most affected by rail collisions in the study area were mostly herbivorous and seldom used non-wildlife underpasses. These results indicate that a railway line with only drainage culverts and the occasional viaduct is not effective in providing adequate safe crossing structures for megaherbivores and ungulate mesoherbivores. Contrary to expectations, vegetation and environmental factors influenced mammal usage of box culverts more than structural dimensions. Ensuring that there is high visibility through the structure, with less herbaceous cover and more woody cover outside of entrances, is likely to enhance culvert usage by most trophic groups. In a savanna context where faunal diversity is high and no single species is a target for mitigation, a range of underpass designs including larger viaducts, located in different types of vegetation cover, thereby combining the range of requirements of different guilds, is recommended.
Functional feeding groups of mayfly nymphs (Ephemeroptera) in South African rivers of the North West and Limpopo Provinces
(University of the Witwatersrand, Johannesburg, 2024-02) Bossman, Esi H.; Harrison, James du G.; Woodford, Darragh J.
Researchers, primarily in the Northern hemisphere, have extensively studied mouthpart morphology and dietary variability in Ephemeroptera (colloquially called mayflies). Ephemeroptera are key primary consumers in rivers around the world and are used as aquatic biomonitoring indicators due to interspecific variation in ecological tolerances that make them good indicator taxa. Cummins (1973, 1974) created a functional feeding groups (FFG) classification system, based on northern hemisphere macroinvertebrates, as a universal tool to functionally categorise organisms based on their primary feeding mode within their habitat. The FFG classification system is useful in identifying interrelations between structural and functional components of an ecosystem. The aim of this study was to contribute knowledge on FFGs for particular mayfly species, in the southern African savanna biome, through mouthpart morphology and gut content analysis. Four study sites were sampled from the Magaliesberg (M) and Waterberg (W) catchments. There were three species studied, namely Afroptilum parvum (Family Baetidae), Afronurus barnardi (Family Heptageniidae) and Elassoneuria sp. (Family Oligoneuriidae). These species’ mouthparts were dissected and their macro- and microstructures were prepared for viewing with Scanning Electron Microscopy (SEM) and light microscopy. Micrographs and images showed variation in mouthpart morphology between all three species, with special attention to the labia and maxilla microstructures. The identification and description of microstructures that differentiate mayfly species (and the adaptations of these appendages to facilitate food uptake and ingestion) are important to address knowledge gaps regarding mayfly mouthpart morphology. A Principal Component Analysis (PCA) showed distinct grouping of the three species, with mandibles and maxillary palps showing the most variation between species. After analysis, the following feeding groups were assigned: Afroptilum parvum is a collector-gatherer feeder, Afronurus barnardi is a brusher-scraper feeder and Elassoneuria sp. is a filter feeder. This study showed, in part, that the Cummins’ (1973, 1974) classification categories were too broad for classifying organisms from a South African savanna stream. However, it is a good foundational starting point for region specific FFG classification systems. Thus, it is recommended to use the classification system Cummins created as a starting point for classifying organisms into FFGs with an initial definition that can be expanded upon to create individual classification systems for different localities.
Heat-related health impacts: the responses of local governments to current and emerging heat extremes in the Gauteng province
(University of the Witwatersrand, Johannesburg, 2024) Riley, Bradley; Vogel, Coleen
In recent years, particularly during the last few summer seasons across the globe, there has been growing attention to the impacts of heat on human health due to unprecedented extreme heat and heatwave events. Cities and urban areas are especially at risk due to enhanced urbanisation and anthropogenic activities, leading to increased heat-related deaths and hospitalisation. Although many cities globally have developed adaptation approaches to address the current and emerging heat risks, heat adaptation strategies and planning in an African context have been poorly recognised despite the continent warming at double the rate of global temperatures. The high vulnerability of African cities due to poverty and poor socio-economic conditions, coupled with these temperature extremes, puts African societies at the forefront of future heat-related health impacts. South Africa is one African country that has recognised these growing heat risks and provided frameworks in their national and municipal policy and planning instruments. However, implementing and mainstreaming heat action across institutional structures remains a challenge. This study investigated the extent of current heat responses within three metropolitan municipalities in the Gauteng Province, South Africa, in the cities of Tshwane, Ekhuruleni and Johannesburg; to advance heat action within the local government and institutional structures of the province. In this mixed-methods research design, local officials from the municipality’s Environmental Health Department in each metro were interviewed, and a perception-informed assessment of vulnerability to heat-related health impacts was developed using Principal Component Analysis. Through interviews with the local Environmental Health Officials, it was revealed that extreme heat is not a priority within the Department, as heat action is neither mandated nor budgeted for, leading to a misalignment between policy and implementation. The ability of the Department to unlock its full potential for heat action is constrained by many challenges, highlighted by three central themes: (1) Resource capacity and the ripple effects, (2) Policy-implementation gap and (3) Interdepartmental coordination. Despite this, the Department has the potential to unlock many opportunities for future heat responses, highlighted by four central themes: (1) Existing systems: connecting the dots, (2) Power in unity: embracing a collaborative approach, (3) Mandated heat action and (4) Specialised heat action units. Additionally, this study demonstrated how a heat vulnerability assessment tool could be created using heat-specific socio-economic variables. This reveals the spatial distribution of vulnerability throughout the metro’s and highlights high levels of vulnerability within rural and informal settlements due to poverty, lack of access to resources and services and poor living conditions in these areas. Such an approach can offer valuable insights into the populations and areas most susceptible and at risk of heat-related health impacts, which can aid in developing targeted heat action responses and plans. Finally, this study contributes
Home range establishment of translocated African elephants (Loxodonta africana) in a savanna environment
(University of the Witwatersrand, Johannesburg, 2023-09) Ngorima, Patmore; Parrini, Francesca; Boyers, Melinda; Mariotti, Elena
Data from nine female African elephants translocated to Hurungwe Safari Area that had been collared was used to estimate home range patterns. Monthly home ranges for each elephant were estimated using the 50% and 95% Kernel Density Estimates (KDEs) method for a period of 20 months following translocation. At the population level, a linear regression model was used to test for the effect of months from release on the home range patterns. The findings revealed that the 95% home range of the elephants increased over time, while the 50% home range decreased since their initial release. I went further to compare the individual differences using the generalised additive model. The results showed some individual differences in patterns of exploration, with some displaying more linear home range patterns than others. Over and above, a considerably positive and relevant relationship between time and variation in the extent of the home range was observed.
Modelling current and future distributions of Warburgia species at continental (Africa) and local (South Africa) scales Samista Kim
(University of the Witwatersrand, Johannesburg, 2024) Rooplal, Samista Kim; Thompson, D.I.; Glennon, K.L.; Witkowski, E.T.F.
Warburgia is a genus of trees and shrubs that is greatly valued in Africa for its use in traditional medicine. The genus contains four species, one of which has two subspecies: Warburgia elongata, W. salutaris, W. stuhlmannii, W. ugandensis subsp. longifolia and Wugandensis subsp. ugandensis. Individuals are harvested primarily for their bark, which contains pharmacological compounds that are used to treat various ailments. Due to the high demand, species within the genus are overharvested throughout their range and have consequently become threatened by extinction. Warburgia salutaris, the pepper-bark tree, is the only species of the genus that naturally occurs in South Africa. Like its congeners, Wasalutaris is heavily exploited for its bark and has been listed as IUCN Endangered in South Africa. This dissertation, therefore, assesses the distributions of Warburgia species in eastern and southern Africa to identify new, potentially suitable areas to increase population numbers to aid in the conservation of the genus. The aim of the first part of the study was to assess the eastern and southern African distributions of Warburgia species. Species distribution models (SDMs) were created for the four Warburgia species and two subspecies, and the geographic distributions and key environmental predictors were identified for each taxon. Environmental niche analyses were also performed to understand whether the two subspecies of W. ugandensis should be considered as a single species in accordance with the ecological species concept. The second part of the study aimed to assess how the current South African distribution of W. salutaris will be affected by future climate change. An SDM was produced to assess the current distribution of W. salutaris in South Africa and identify its key predictor climate variables. The SDM was then extrapolated into the future (2070) using two climate change scenarios, RCP 4.5 and RCP 8.5, which are greenhouse gas emission scenarios that predict future climates under a probable and extreme scenario, respectively. Ecological niche analyses were also used to assess the degree to which W. salutaris’ climatic niche will change in response to the two climate change scenarios. Results showed that the distributions of Warburgia species are restricted and primarily influenced by climatic variables that likely impact their seeds’ and seedlings’ sensitivity to water stress and desiccation. Ecological niche modelling results show that the climatic niches of W. ugandensis subsp. longifolia and W. ugandensis subsp. ugandensis are identical and should therefore be considered as a single species according to the ecological species concept. The South African distribution of W. salutaris is fragmented and restricted. The species’ current and future distribution is influenced by its sensitivity to frost and the fact that it produces seeds that are susceptible to drying out. SDMs predicted that the distribution of W. salutaris will shrink in eastern Limpopo and in parts of Mpumalanga, but increase in eastern KwaZulu-Natal by 2070 under both climate change scenarios. Overall, this species was predicted to contract from the Indian Ocean coastal belt and grassland biomes and expand into the savanna biome. This study has expanded our knowledge of the distributions and environmental drivers of Warburgia species. It was found that in general, Warburgia species have restricted ranges that are likely governed by their sensitivity to desiccation at the seed and seedling stages. Climate change is anticipated to negatively impact the populations of many plant species, especially those in Sub-Saharan Africa. While the environmental niche of W. salutaris will remain stable, its geographical distribution was predicted to expand further in the savanna biome along the eastern coast of South Africa in response to climate change. Results from this study support pursuing different conservation techniques, including propagating Warburgia populations around the Great Lakes of Africa and Mt. Kenya and in western Limpopo and eastern KwaZulu-Natal for W. salutaris only. This study therefore emphasizes the importance of using SDMs as a baseline to inform effective conservation efforts for important medicinal plant species
Personality profiles of the Namaqua rock mouse (Micaelamys namaquensis), the Mozambique thicket rat (Grammomys cometes) and the woodland dormouse (Graphiurus murinus)
(University of the Witwatersrand, Johannesburg, 2023-09) Mampa, Nthabiseng; Linhsan, Emmanuel Do; Madikiza, Kim
Personality is the variation in behaviour amongst individuals, which arises as a result of genetic differences and exposure to different environments. Although the term is usually associated with humans, multiple studies have found evidence for personality in other non-human taxa such as rodents, fish, reptiles, and primates, which ultimately showed that personality is ubiquitous. Personality determines how individuals react in different situations throughout their life, such as when they encounter stressors, interact with their conspecifics, prey and predators, how they select seeds and the distance to which they disperse, when displaying aggression, and when facing novel objects, their propensity to take risks, among other behaviours. Personality traits are most described using terms such as bold and shy, aggressive, docile, and avoidant. These terms relate to individual coping style, temperament, and correlated traits. Given the importance of personality, this study was aimed at studying personality in the woodland dormouse, Mozambique thicket rat and Namaqua rock mouse, in order to understand personality and how it varies among species and within species, i.e., between sexes. In consideration of the importance of genetic factors in the development of personality, it was expected that there would be differences among the three rodent species despite being exposed to similar environmental conditions. It was also expected that there would be differences between males and females within each species due to the influence of sex hormones on personality. Two standardised personality tests were conducted, namely the open-field and the novel object test to measure boldness, shyness, exploration, and avoidance when facing novelty by observing the frequency and duration of the behavioural responses exhibited during these tests. The study showed that rodents react to novelty by showing both shy and bold behavioural responses. However, the three species differ from each other in boldness and shyness. Males and females also showed differences in their behavioural responses to novelty. Overall, this study highlighted two strategies used for survival in nature. In consideration of this, it would be beneficial to preserve pristine forests to protect keystone structures that are crucial for preserving diversity in species and personality types. However, more studies on long-term trapping and correlation with personality tests could reveal more information on the personality profiles and their subsequent consequences.
Quantifying and Mapping Urban Ecosystem Services in Johannesburg, South Africa
(University of the Witwatersrand, Johannesburg, 2024) Friemond, Joseph
Modern cities face a wide range of challenges such as flooding and heat stress, which are driven by urbanisation and exacerbated by the impacts of climatic change. The ecosystem services provided by green spaces in cities have become a crucial element in addressing these challenges by supporting climate change mitigation and adaptation. The first step in maintaining and improving the supply of these services is their quantification and mapping. However, large knowledge gaps exist in South Africa and Johannesburg relating to the provision of urban ecosystem services. This study aimed to quantify the supply of three important urban ecosystem services (carbon storage, runoff retention and cooling) and map their distribution across the wards of Johannesburg. Carbon storage was quantified through field sampling of four urban forest types (roadside trees, parks, gardens and nature reserves) and the use of biomass equations. InVEST's urban flood risk mitigation model was used to quantify runoff retention, while cooling was quantified by deriving land surface temperatures from Landsat satellite imagery, which were then used as inputs for a cooling indicator. All three services were mapped across the wards of Johannesburg and then normalised for comparison. The results revealed that Johannesburg's urban forest stores 2.4 million tonnes of carbon, with significant differences in carbon storage between forest types. Johannesburg’s ecosystem services provide great value in mitigating urban challenges, retaining 20.9 million m3 of runoff during a 50 mm storm, and providing cooling services across most of the city. However, the supply of these services is unequal, with large spatial disparities between the northern and southern regions in the city. Numerous wards receive critically low supply of these services, making them vulnerable to the impacts of climatic change. The northern- central wards have optimal supply of all three services, highlighting synergies between services. Ultimately, these three services have immense value in the Johannesburg context and play key roles in supporting the city’s climate change mitigation and adaptation, through the multi-functional delivery of ecosystem services from urban green infrastructure. By mapping these services at the ward scale, our findings can be used to accurately inform authorities and decision makers of priority areas for intervention, as well as key areas for conservation
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

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