System In South Africa Research Articles

Blue carbon dynamics across a salt marsh-seagrass ecotone in a cool-temperate estuary

Abstract Background Seagrass and salt marsh ecosystems are recognised for their role in climate change mitigation and adaptation given their carbon storage potential. However, factors driving variability in blue carbon ecosystems are understudied, yet are important to account for. Aims Examine the variability of sediment organic carbon (SOC) and its drivers (seagrass morphometrics and sediment nutrients) at different spatial scales; > 1 km, ~ 150 m and ~ 10 m across the salt marsh-seagrass ecotone. Methods We collected the top 5 cm of sediment in the Olifants River Estuary, a cool-temperate system in South Africa. Using a line transect approach, we sampled across the salt marsh-seagrass ecotone (~ 10 m) in triplicate transects (~ 50 m apart) at three sampling sites (1–3 km) and analysed for SOC and elemental nutrient (nitrogen and phosphorus) content. Seagrass morphometrics (shoot density, leaf length and number per shoot) were measured. Results There was significant (P < 0.05) spatial heterogeneity in SOC stocks between sites (1–3 km) and between salt marshes and seagrass, but low variability at ~150 m. We detected a significant decrease in SOC from salt marsh towards the seagrass edge, with seagrass SOC remaining uniform. Nitrogen content was positively correlated with SOC in seagrass and salt marshes (P < 0.05), but seagrass morphometrics were not significant drivers of SOC. Conclusions The dynamics of blue carbon differ between salt marshes and seagrass, with spatial heterogeneity of SOC at scales > 1 km, suggesting that future BC assessments need to account for spatial heterogeneity to improve the accuracy of carbon removal estimates.

Potential of Wheat Straw for Biogas Production by Anaerobic Digestion in South Africa: A Review

Wheat straw (WS) is a promising substrate for biogas production by anaerobic digestion (AD) due to its high carbohydrate content. An estimated 0.603 million t yr−1 of WS are generated from wheat production systems in South Africa. This is equivalent to an energy potential of 11 PJ. Despite this, WS is still undervalued as a bioenergy resource in South Africa due to its structural complexity and low nitrogen content. WS disposal methods, such as use in livestock bedding, burning and burying into the soil, inter alia, are not sustainable and may contribute to global warming and climate change. The commercialization of the AD of WS needs to be further developed and promoted. Pre-treatment (i.e., physical, chemical, biological and hybrid methods) and anaerobic co-digestion (AcoD) are novel strategies that can support the conversion of WS into biogas and other value-added products. Current and future research should focus on optimizing pre-treatment and AcoD conditions towards industrialization of WS into valuable products. This paper focuses on the potential use of WS for biogas production in South Africa. The aim is to create information that will promote research and development, and encourage policy makers and stakeholders to participate and invest in WS biogas technology. Were WS biogas technology fully adopted, we believe that it would alleviate energy insecurity and environmental degradation, and sustain the livelihoods of citizens in South Africa.

An exploratory study on supplier acceptance of and engagement in a national tax lottery designed to improve tax compliance

Purpose: To determine business owners’ perceptions of and support for a national tax lottery system in South Africa. Motivation: Tax compliance in developing countries is a challenge for governments, which depend on tax revenue to provide public goods and services. A tax lottery system has been recommended for South Africa, where customers would demand receipts for purchases that serve as lottery tickets and create paper trails that would expose tax non-compliant businesses. Literature indicates that small businesses find the process burdensome, costly, and detrimental to competitiveness and growth, particularly when customers are lost to larger businesses that are better equipped to routinely supply receipts. Design: An exploratory approach, using an online survey of suppliers to gauge their perceptions of a South African tax lottery system was followed. Findings: Of the respondent, 51% expressed support for a tax lottery system, and thus, at an exploratory level, business owners in South Africa do not seem to support a tax lottery. This is an important finding, since suppliers play an integral role in the implementation of a tax lottery system. Further research should be conducted to determine the views of a more representative sample of suppliers, to determine whether they would play their part in administering such a system. Suppliers’ biggest concern was government corruption in implementing such a system. Contribution: This study contributes to the body of knowledge on tax lotteries, particularly from a developing country perspective; furthermore, few empirical studies take the supplier perspective and acceptance of a tax lottery into account.

Hydrological and pedological effects of combining Italian alder and blackberries in an agroforestry windbreak system in South Africa

Abstract. The Western Cape in South Africa is a water-scarce region which will likely receive less rainfall and higher air temperatures under projected climate change scenarios. The integration of trees within agricultural systems provides an effective measure for improving water retention on agricultural land. Studying an established and irrigated agroforestry system (AFS) combining alder (Alnus cordata (Loisel.) Duby) as a linear windbreak with a blackberry (Rubus fructicosus L.) crop, we explore the water use dynamics of the intercrop as influenced by the windbreak element by combining methods from hydrology, soil science and forestry disciplines. Our objective is to explore whether the AFS positively impacts the water balance by combining measurement campaigns to characterise the spatial variability of various key system properties with continuous monitoring. The campaigns encompassed extensive soil sampling to determine soil characteristics (nutrient concentrations, hydraulic conductivity, texture, water retention) in the laboratory as well as terrestrial laser scans of the field site, especially of the windbreaks. The continuous measurements covered meteorological, soil water content and soil water potential observations over a 6-month period (in summer). These were applied to understand soil water dynamics during rainstorms and dry spells, including root water uptake as well as soil water storage. We recorded a total of 13 rainfall events delivering 2.5–117.6 mm of rainfall with maximum intensities of 4.1 to 82.6 mm h−1. Further analyses showed that infiltration is likely dominated by preferential flow, with root water uptake potentially occurring in two depth zones corresponding to different plant communities. While soil water content varied by depth and was influenced by physical and environmental factors, it was generally higher in the intercrop zone than within the windbreak-influenced zone. During dry spells, soil water content did not drop below the water content of the permanent wilting point (<-1500 kPa). Values corresponding to soil water tensions above 1000 kPa were recorded on several occasions; these were mitigated by irrigation and, thus, did not result in water stress. Nutrient distribution and soil physical properties differed near the windbreak in comparison to the blackberry crop, and the carbon sequestration potential is great in comparison to monoculture farming. We could demonstrate positive effects of the windbreak on the water balance and dynamics in the blackberry field site, even though questions remain as to the extent of these benefits and how they compared to disadvantageous aspects brought about by the presence of the trees (e.g. increased water usage). Irrigation did, in fact, shift the AFS from a water-limited regime to an energy-limited one.

Multivariate characterisation of a blackberry–alder agroforestry system in South Africa: hydrological, pedological, dendrological and meteorological measurements

Abstract. Trees established in linear formations can be utilised as windbreak structures on farms as a form of agroforestry system. We present an extensive data package collected from an active berry farm located near Stellenbosch, South Africa, considering hydrological, pedological, dendrological and meteorological measurements centred around an Italian alder (Alnus cordata (Loisel.) Duby) windbreak and a blackberry (Rubus fruticosus L. Var. “Waldo”) crop. Data were collected between September 2019 and June 2021. The data are available from Hassler et al. (2024) and include the following measurements (i) meteorological variables – solar radiation, precipitation characteristics, vapour pressure deficit, air temperature, humidity, atmospheric pressure, wind speed and direction, gust speed, and lightning strikes and distance recorded at 10 min intervals; (ii) hydrological measurements – soil moisture and matric potential in two profiles at 15 min intervals alongside soil samples at various depths describing soil texture, hydraulic conductivity, and water retention parameters; (iii) soil characteristics – a soil profile description accompanied by 60 topsoil samples describing carbon, nitrogen, and exchangeable base cation concentrations, as well as potential cation exchange capacity and descriptions of soil texture; and (iv) dendrological measurements – point cloud data for the studied windbreak trees and surrounding features, cylinder models of the windbreak trees with volume and biomass data, and foliage data as a product of an existing leaf creation algorithm. The described dataset provides a multidisciplinary approach to assess the impact and interaction of windbreaks and tree structures in agroforestry landscapes, aiding future work concerning water fluxes, nutrient distribution, microclimate and carbon sequestration. The dataset, including high-resolution time series and point cloud data, offers valuable insights for managing the windbreak's influence and serves as a unique training dataset for spatial analysis (https://doi.org/10.5880/fidgeo.2023.028, Hassler et al., 2024).

EDNA State and Medium Affect DNA Degradation Patterns in Seminatural Systems of Southern African Waterholes

ABSTRACTEnvironmental DNA (eDNA) has evolved into a valuable asset of the ecologists' toolkit, enabling time‐ and cost‐efficient biodiversity assessments in a wide variety of ecosystems. Since eDNA can be isolated from a broad range of environmental substrates, its persistence times in those media are of decisive importance for drawing inferences about species presence. For the first time, we characterize eDNA persistence in water and sediment samples of seminatural waterholes in a savanna system in South Africa to gain a better understanding of eDNA decay in these waterbodies. Using mesocosm experiments, we tracked eDNA decay in two different DNA states (extracellular and membrane bound), during two different seasons (wet and dry), and from two different substrates (surface water and sediment). Extracellular DNA degraded rapidly in a first‐order exponential decay fashion and membrane‐bound DNA exhibited a slower decline with more intricate patterns, involving initial reduction followed by a subsequent increase in measured DNA concentrations. The latter we attribute to cell disassociation and cell lysis at 24–48 h after introduction into the environment. Higher stochasticity of membrane‐bound DNA capture in the dry season highlights the need for higher sampling efforts in natural systems in which eDNA is presumably more patchily distributed. Additionally, we observed longer eDNA persistence in sediments than in water samples, presumably due to better protection from nucleases. We could not reveal any effects of environmental parameters on eDNA decay, emphasizing that further research is needed to better understand eDNA dynamics in those waterbodies in order to exploit their full potential for eDNA‐based bioassessments in those systems.

Situating Ubuntu Philosophy in Pre-service Teacher Education

Ubuntu African philosophy and its values have been a subject of discussion by stakeholders due to its humanness and communal nature. It embodies African cultural values and belief systems that form the ways of life of indigenous people. These critical attributes of Ubuntu have necessitated its integration into pre-service teacher education to prepare Ubuntu-focused teachers who can contribute to decolonizing the education system in South Africa and beyond. However, efforts must be made to integrate Ubuntu values into pre-service teacher education. This paper reports on an investigation of the relevance of Ubuntu’s philosophy to pre-service teacher education. The investigation adopted the qualitative integrative literature review approach by selecting twenty-four articles from Scopus, EBSCO, and Google Scholar databases for review. The authors selected relevant articles using the relevant inclusion criteria and analyzed them under different themes to answer the two research questions formulated for this study. In order to increase teachers’ capacity to support the decolonization of education in Africa, the article suggests that the humanness and communalism approaches to education should be incorporated into pre-service teacher education curricula. That the quest for colonial knowledge over the years in South Africa and, indeed, Africa has been attributed to the Eurocentric and increased domination of African culture of togetherness and ethics of care. The paper also concludes that Ubuntu higher education can serve as a framework for decolonizing the African higher education system. The authors suggest that there is a need to formulate strategies for integrating important values of Ubuntu, like humanness, interconnectedness, and communalism, into the pre-service teacher education program.

What we know and do not know after the first decade of Homo naledi.

It has been just over 10 years since the first fossils attributed to Homo naledi were recovered from the Rising Star Cave system in South Africa's Cradle of Humankind. The hominin fossil evidence for H. naledi displays a distinctive combination of primitive and derived morphology, yet for a time-averaged fossil sample it is remarkable for its relatively low level of variation. Thus-unusually for palaeoanthropology-there has been little pushback against the decision to recognize a single novel taxon for all of the material recovered from the Rising Star Cave system. However, almost everything else claimed about H. naledi-its age, burial context and behaviour-has been controversial. Here we examine the strength of the evidence for these claims.

Comparing the financial benefits of different grain production systems in South Africa’s summer rainfall region

There is growing evidence that soil degradation, among other factors, has led to both the decline and constraint of agriculture in southern Africa. Conservation and regenerative agriculture (CA/RA) have been proposed as a grain crop production system that could slow down, halt or even reverse some of these disturbing trends. But the question remains whether it is financially viable. We sought to find an answer to this question by comparing the financial returns of a CA/RA system over a 20-year period to its alternatives, namely conventional tillage (CT) and no-tillage (NT) production systems. The cumulative free cash flow (CFCF) of the average between the realistic and conservative CA/RA scenarios in year 20 is considerably higher than that of the other systems under investigation. The CFCF for CA/RA in year 20 in Mpumalanga is estimated to be R86 million, compared to -ZAR51 million for CT and about ZAR4 million for NT. That is a net difference between ZAR137 million (compared to CT) and ZAR82 million (compared to NT). In the Maluti area, the CFCF for the CA/RA production system is estimated at ZAR26 million, compared to -ZAR66 million for CT and -ZAR19 million for NT. In the North-West production area, the CFCF for the CA/RA production system is estimated at ZAR35 million, compared to -ZAR9 million for CT and about ZAR21 million for NT. The differences between the CFCF of the CA/RA system and the other systems represent the financial opportunity cost of not converting to the CA/RA system.

The current state of emergency medical services in South Africa: A review

Emergency medical services (EMS) are a vital component of the health system and provide pre-hospital emergency care and specialised transport for patients requiring access to health facilities, thereby contributing to universal health coverage and improving health outcomes. Evidence regarding the current state of EMS within South Africa to fulfil this role is lacking and was the motivation for this review. Our objective was to describe the current state of EMS in South Africa. A literature search was conducted using keywords, BOOLEAN operating terms, and eligibility criteria on Sabinet, EBSCOhost, Google Scholar, ProQuest, Medline, PubMed, and ScienceDirect databases to find articles related to the components of the EMS system in South Africa. The articles were critically assessed, and six themes emerged: leadership and governance; resources; preparedness (knowledge, attitude, and practices) of the emergency care provider; health and safety; training; and communications. Challenges were found in all themes at a provincial EMS level despite improvements in legislation, leadership, and governance from the National Department of Health. These themes demonstrate that all components in the EMS system are not functioning optimally and may be affecting its contribution to improving universal health coverage and health outcomes. The current state of EMS appears to be constrained and requires greater leadership and governance from the Provincial Departments of Health to improve poorly functioning components of the EMS system.

Across the professional lifespan: comparing the workforce trends of early career and established counselling psychologists in South Africa

ABSTRACT Counselling Psychologists (CPs) constitute a considerable proportion of psychologists in South Africa (SA), yet empirical knowledge on this workforce remains limited. Furthermore, changes within this workforce overtime have not been thoroughly examined. This study compares early career (<10 years) and established (>10 years) CPs relating to demographic characteristics, work settings, professional roles and activities, career satisfaction, and perspectives on efforts to demarcate the practice of CPs in SA. A total of 512 survey responses were analysed, with 39% representing early career CPs and 61% representing established CPs. Findings reveal significant differences between early career and established CPs across several domains, including age, race, geographic location, highest professional degree, languages spoken; current job-seeking status; satisfaction with income, employment opportunities, work-life balance and primary work settings; likelihood of emigration; and supervision frequency and format. Overall, the results suggest movement towards transformation within the CP profession in SA. Nevertheless, systemic issues continue to hinder the optimal utilisation and equitable distribution of CPs within the country. Advocacy and ongoing workforce analysis is thus essential to support, retain, and effectively utilise CPs as a valuable resource, especially in light of the ongoing debates surrounding the implementation of the National Health Insurance (NHI) system in SA.

Design phase collaborative risk management factors: a case study of a green rating system in South Africa

PurposeWe explore the design risk factors and associated managerial practices driving collaborative risk management for design efficacy in green building projects. By illuminating project design risk as an important project risk category in its own right, the study contributes to our understanding of optimising design efficacies for collaborative project risk management.Design/methodology/approachThe study comprises exploratory interviews conducted with 27 industry project practitioners involved in the design and delivery/implementation of Green Star-certified building projects in South Africa.FindingsThe findings discursively highlight seven sources of design risk. We also identify seven specific collaborative risk management practices for design efficacy emerging from a consideration of how risk environments vary in the Green Star-certified projects, each with its own project design risk implications.Originality/valueThe study advances our understanding of how collaborations emerging from particular relational yet context-specific practices can be optimised to strengthen project risk management.

Accountability Leadership in South African Police Service

This study looks at how accountability leadership might help the South African Police Service (SAPS) become more effective and win back the public's trust. Principal Subjects: frameworks for accountability leadership theory (such as procedural justice theory and social learning theory). A growing body of research has examined several leadership philosophies, such as ethical and authentic leadership, to promote accountability. The SAPS faces several challenges in adopting accountable leadership, including resource restrictions, community participation, and leadership commitment. SAPS accountability mechanisms now in place (CPFs, IPIDs). Suggestions for enhancing accountability leadership methods (community involvement, openness, and training). gaps in the body of knowledge now available and potential future study areas. Principal arguments the SAPS has a promising structure in accountability leadership to address challenges of public trust and improve police performance. Implementing accountable leadership can be guided by combining theoretical frameworks with useful tactics. There are significant obstacles to overcome, but doing so with effective leadership, education, and community involvement can pay off. Methodological approach this study uses a literature review methodology, examining previous academic publications on police reform, accountable leadership, and the South African environment. Significance of this study intends to contribute to a more moral, efficient, and reliable SAPS by promoting accountability leadership. This may result in increased community policing, enhanced public safety, and a more respectable legal system in South Africa. Audience a wide range of people interested in police reform and enhancing public safety in South Africa are the intended audience for this study, including legislators, police leadership, academics, community organizations, and the general public.

Genome analysis of multidrug resistant Enterococcus faecium and Enterococcus faecalis circulating among hospitalized patients in uMgungundlovu District, KwaZulu-Natal, South Africa

BackgroundVancomycin-resistant enterococci (VRE) are important pathogens categorized as high-priority bacteria in the Global Priority List of Antibiotic-Resistant Bacteria to Guide Research, Discovery, and Development of New Antibiotics published by the World Health Organization. The aim of this study was to determine the risk factors, resistance, virulence, mobilomes associated with multidrug-resistant and clonal lineages of Enterococcus faecium and faecalis circulating among hospitalized patients following the health system in South Africa, using whole genome sequencing (WGS).MethodsA cross-sectional study was conducted during a two-month periods among hospitalized patients in 2017. Rectal swabs were collected from patients admitted to medical and surgical wards in an urban tertiary hospital, and a rural district hospital in uMgungundlovu district, South Africa. Enterococci were screened for vancomycin resistance on bile esculin azide agar supplemented with 6 mg/L of vancomycin and confirmation of VRE was done using ROSCO kits. Conventional and real-time PCR methods were used to ascertain the presence of VanA, VanB, VanC-2/3 and VanC-1 genes. All six multidrug-resistant Enterococcus faecalis and faecium selected were identified using multiplexed paired-end libraries (2 × 300 bp) with the Nextera XT DNA sample preparation kit (Illumina, San Diego, CA, USA) and genome sequencing was done using Illumina MiSeq instrument with 100× coverage at the National Institute of Communicable Diseases Sequencing Core Facility, South Africa. Antibiotic resistance genes, virulence factors, plasmids, integrons and CRISPR were characterized using RAST, ResFinder, VirulenceFinder, PlasmidFinder, PHAST and ISFinder respectively.ResultsSequencing analysis revealed that these strains harbouring numerous resistance genes to glycopeptides (vanC[100%], vex3[100%], vex2[83,33%] and vanG[16,66%]), macrolides, lincosamides, sterptogramine B (ermB[33,32%], Isa[16,66%], emeA[16,66%]) and tetracyclines (tetM[33,32%]) in both district and tertiary hospitals. Multidrug efflux pumps including MATE, MFS and pmrA conferring resistance to several classes of antibiotics were also identified. The main transposable elements observed were in the Tn3 family, specifically Tn1546. Four single sequence types (STs) were identified among E. faecium in the district hospital, namely ST822, ST636, ST97 along with a novel ST assigned ST1386, while one lineage, ST29 was detected in the tertiary hospital.ConclusionThe study reveals the genetic diversity and high pathogenicity of multidrug-resistant Enterococcus faecalis and faecium circulating among hospitalized patients. It underlines the necessity to implement routine screening of admitted patients coupled with infection control procedures, antimicrobial stewardship and awareness should be strengthened to prevent and/or contain the carriage and spread of multidrug resistant E. faecium and E. faecalis in hospitals and communities in South Africa.

Identifying critical assumptions and risks in air quality management planning using Theory of Change approach

Governments across the world have been developing legislation and policy implementation instruments to address air pollution issues. Air Quality Management Plans (AQMPs) have emerged as a key instrument, with most developed countries having established effective AQMPs. These take a variety of forms depending on the overarching national framework for environmental regulations. The uptake of AQMPs in low and middle-income countries, however, has been less broad and, even in those that have adopted AQMPs, their effectiveness and efficiency have been limited, especially in urban areas. South Africa has adopted AQMPs and is recognised as having one of the most mature and complex air quality management legal frameworks in the world. Yet South Africa is still facing serious air quality challenges, especially in those areas that have been declared as priority areas. This paper, therefore, aims to identify critical assumptions and risks as a basis to evaluate the effectiveness of AQMPs as a policy instrument through the application of Theory of Change (ToC) approach. This study has resulted in the development of the ToC map, identification of 15 critical assumptions and associated causal narrative framework. In addition, this paper identified key risks underpinning the AQMP development and implementation process in South Africa. The identified critical assumptions embedded within different components of the ToC framework are not the only assumptions relating to this policy instrument, however, they are the fundamentally important ones that may significantly impact the success or failure of the AQMP system in South Africa if not managed. This study suggests that in order to further understand the challenges relating to the effective development and implementation of AQMPs, it is important that further research be conducted to test the validity of these critical assumptions which will provide solutions towards avoiding or mitigating risks associated with them.

Measuring the performance and maturity of the plastic recycling value chain system: implications and prospects

The sustainability of plastic materials and products requires the continuous improvement of the circular pathways for the material. A key strategy in the circularity of plastic is plastic recycling. Improving the circular pathways requires an understanding of the maturity level of the plastic recycling system. This study evaluated the maturity of the plastic recycling system in South Africa across the plastic value chain. Both secondary and primary data were collected, analysed and cross-validated. The results put the maturity of the country’s system at “Visionary” (Level 3) for the value chain stages of primary plastic production, product manufacturing and recycling, whereas waste generation, collection and handling, sorting and recyclate market were rated as “Structured” (Level 2). Furthermore, a set of initiatives to advance the maturity of the system to the desired level of “Connected and Dynamic” (Level 5) were identified. The paper provides a benchmark of performance and determines the stages of the system requiring additional attention. This is aimed at providing insight into policymaking to advance plastic recycling and circularity.

Digital Transformation of Medical Libraries

The prospects presented by digital transformation holds the potential of greatly increasing the capacity of medical libraries, which in turn it will make it possible for these libraries to provide better services and increasing accessibility. But how can digital technologies be adopted in transforming medical libraries' services and operations, in the digital transformation era? This study looked at the opportunities and challenges associated with implementing digital technologies in medical libraries through digital transformation. The study thus reviewed literature on digital transformation of medical libraries services, as a way to support healthcare systems in South Africa. The chapter revealed that digital transformation has the potential to enhance libraries processes, practices, performance, and to stay relevant in their increasingly competitive environment.

Towards decolonisation of primary school education in South Africa

Background: Despite the end of apartheid in South Africa in 1994, most black schools in the country still embrace coloniality through policies and practices. This leads to disempowerment, loss of identity, inequalities and inferiority in the learners, which are nurtured till their adulthood. It is therefore important to decolonise the inherited curriculum and recognise African identity, culture and system as valuable for Africans.Aim: This article aims to explore coloniality within the primary school education system in South Africa and aims to motivate curriculum transformation that will divest coloniality in Africa.Setting: This article centres around South African Primary schools.Methods: This article employs a desktop approach and a systematic literature review. To collect the data, the study selected articles from different search engines such as EBSCO, Science Direct and Google Scholar. This enables the synthetisation of previous works to provide knowledge on the topic. The decoloniality theory underpins the study.Results: Primary school education in South Africa is influenced by coloniality; hence, there is a need for transformation.Conclusion: The primary school curriculum in South Africa needs to be revised in a decolonised manner to suit a multi-racial or ethnic South Africa for the realisation of an equitable and just future for Africans.Contribution: This article provides knowledge about coloniality within the context of primary schools in South Africa and further recommends curriculum transformation to a truly African manner. It thus aligns with the journal’s theme and scope, which is the interrogation of coloniality in South African primary schools.

Distribution, abundance, population structures, and potential impacts of the invasive snail, Tarebia granifera in aquatic ecosystems of north-eastern South Africa.

Aquatic ecosystems globally have been invaded by molluscs. Tarebia granifera is a highly successful invader, often becoming the dominant aquatic invertebrate species in an invaded ecosystem. Resultingly, it has been suggested that T. granifera may have severe negative impacts on these invaded ecosystems. Limited information is available regarding the population structures and densities of T. granifera, particularly in invaded countries such as South Africa, and information on this could assist in developing management and control strategies for this invasive species. The present study aimed to assess the current distribution, densities, and population structures of T. granifera in invaded habitats on the Limpopo and Phongolo River systems in South Africa. This was accomplished by collecting aquatic molluscs from sites across these systems. Water quality parameters were measured at each site and water samples were collected for chemical nutrient analyses. The density of snails was determined for each site and the population size and structure as well as birth rate was calculated for T. granifera. Tarebia granifera was found to be the dominant molluscan species in habitats where it was present and all size classes from newborn to mature adults were found throughout at some of the highest densities globally. Worryingly, native molluscan species, were often absent or in much lower densities than reported in literature at sites where T. granifera was present, suggesting a negative effect on the native molluscan density and diversity. Contrary to most previous studies, there were no significant correlations between T. granifera and the selected water quality parameters. Higher densities and newborn recruitment of T. granifera were observed in the spring than in autumn, likely in response to shifts in environmental conditions. This study provides crucial insights into the population structure, densities, and impacts of T. granifera in invaded habitats, particularly for relatively newly invaded regions such as southern Africa.

Comparing the effectiveness of the African Growth and Opportunity Act (AGOA) and Forum on China-Africa Cooperation (FOCAC) in South Africa: An application of Keynes' Macroeconomic Theory

This study applies Keynesian macroeconomic theory in the ARDL model to compare the growth effects of the US's AGOA and China's FOCAC multilateral trading systems in South Africa from the first quarter of 2001 to the fourth quarter of 2022. The study uses South Africa's net exports with the corresponding partner as a proxy for each multilateral trading system. This quantification stems from the fact that South Africa's trade with the US and China has significantly improved since the establishment of AGOA and FOCAC in 2000. Our findings show that none of the multilateral trading systems contribute significantly to South Africa's economic growth. Rather, they appear to be used as strategic initiatives to gain access to mineral resources and facilitate the movement of mining machinery and other inputs into South Africa. To some extent, they are used as market-seeking initiatives, particularly FOCAC. It is worth noting, however, that the mineral resource preferences of these systems vary: while China prioritizes mineral products, the US prioritizes precious metals. This suggests that China and the US scramble for natural resources in South Africa, and possibly Africa in general, is complementary rather than competitive.