Northern South Africa Research Articles

Predicting Spatial Patterns of Sindbis Virus (SINV) Infection Risk in Finland Using Vector, Host and Environmental Data.

Pogosta disease is a mosquito-borne infection, caused by Sindbis virus (SINV), which causes epidemics of febrile rash and arthritis in Northern Europe and South Africa. Resident grouse and migratory birds play a significant role as amplifying hosts and various mosquito species, including Aedes cinereus, Culex pipiens, Cx. torrentium and Culiseta morsitans are documented vectors. As specific treatments are not available for SINV infections, and joint symptoms may persist, the public health burden is considerable in endemic areas. To predict the environmental suitability for SINV infections in Finland, we applied a suite of geospatial and statistical modeling techniques to disease occurrence data. Using an ensemble approach, we first produced environmental suitability maps for potential SINV vectors in Finland. These suitability maps were then combined with grouse densities and environmental data to identify the influential determinants for SINV infections and to predict the risk of Pogosta disease in Finnish municipalities. Our predictions suggest that both the environmental suitability for vectors and the high risk of Pogosta disease are focused in geographically restricted areas. This provides evidence that the presence of both SINV vector species and grouse densities can predict the occurrence of the disease. The results support material for public-health officials when determining area-specific recommendations and deliver information to health care personnel to raise awareness of the disease among physicians.

Perceived impacts of climate change on rural poultry production: a case study in Limpopo Province, South Africa

ABSTRACT Rural farming households in developing countries frequently contend with multiple challenges, including a lack of resources, food insecurity, and poverty. Climate change threatens to compound existing challenges, particularly in such rural subsistence economies with limited adaptive capacity. We aim to establish farmers' perspectives on likely impacts of climate change on their rural poultry production in northern South Africa. A baseline questionnaire-based study was conducted across 106 households in the town of Musina, South Africa. Most households lacked reliable and adequate sources of income and had, for example, days when they had to skip meals as a coping strategy. With such poverty, coupled with poor access to scientific information on agricultural production, these farmers typically have limited capacity to adapt to shocks such as climate variability and change. Farmers reported a reduction in poultry productivity in recent years, coinciding with increased ambient temperatures. There are concerns that recent and ongoing warming trends will have negative impacts on the future growth and wellbeing of birds. However, the farmers in our study perceived their poultry as hardy and well adapted to survive any future climatic changes and may be uninclined to take adaptive action at this stage.

Expanding the known geographical distribution range of Kalanchoe waterbergensis (Crassulaceae subfam. Kalanchooideae) in northern South Africa

The natural geographical distribution range of Kalanchoe waterbergensis van Jaarsv. (Crassulaceae subfam. Kalanchooideae), previously documented only from the type locality, is extended by about 80km in a northeasterly direction in the Waterberg in northern South Africa.

The floristics and phytogeography of Kalanchoe Adans. (Crassulaceae subfam. Kalanchooideae) in the Waterberg Biosphere Reserve, northern South Africa

Aspects of the floristics and phytogeography of species of Kalanchoe Adans. (Crassulaceae subfam. Kalanchooideae) in the Waterberg, Limpopo province, northern South Africa, are discussed. In 2001 the Waterberg, which covers an area of 654,033ha (1,616,150.74 acres), was recognised as a Biosphere Reserve. It is shown that after eastern southern Africa (KwaZulu-Natal, Mpumalanga, eastern Limpopo, South Africa; Eswatini (formerly) Swaziland; southern Mozambique), the Waterberg has the most diverse Kalanchoe flora in southern Africa. A floristic synopsis of, and an identification key to, the kalanchoes of the Waterberg is presented. All the species are described and illustrated.

Population and genetic structure of a male-dispersing strepsirrhine, Galago moholi (Primates, Galagidae), from northern South Africa, inferred from mitochondrial DNA.

The habitats of Galago moholi are suspected to be largely fragmented, while the species is thought to be expanding further into the southernmost fringe of its range, as well as into human settlements. To date, no intraspecific molecular genetic studies have been published on G. moholi. Here we estimate the genetic diversity and connectivity of populations of G. moholi using two mitochondrial gene regions, the cytochrome C oxidase subunit I gene (COI) and the displacement loop of the control region (D-loop). Samples from five localities in northern South Africa were obtained from archived collections. The two mitochondrial DNA gene regions were amplified and sequenced to provide population summary statistics, differentiation [proportion of the total genetic variation in a population relative to the total genetic variance of all the populations (FST), differentiation within populations among regions (ΦST)], genetic distance and structure. There was discernible genetic structure among the individuals, with two COI and six D-loop haplotypes belonging to two genetically different groups. There was population differentiation among regions (FST = 0.670; ΦST = 0.783; P < 0.01). However, there were low levels of differentiation among populations, as haplotypes were shared between distant populations. Adjacent populations were as divergent from each other as from distant populations. The results suggest that genetic introgression, most likely due to past migrations or recent unintentional translocations that include the animal trade, may have led to connectivity among populations.

Archaeology and archaeometallurgy in Limpopo Province, South Africa: case studies of the Early Iron Age sites of Mutoti and Thomo

Decades of archaeological research have established the chronology of the history of culture by farmers in northern South Africa from the beginning of the first millennium AD to the recent past. Th...

Hydroclimatic trends during 1950–2018 over global land

Global hydroclimatic changes from 1950 to 2018 are analyzed using updated data of land precipitation, streamflow, and an improved form of the Palmer Drought Severity Index. The historical changes are then compared with climate model-simulated response to external forcing to determine how much of the recent change is forced response. It is found that precipitation has increased from 1950 to 2018 over mid-high latitude Eurasia, most North America, Southeast South America, and Northwest Australia, while it has decreased over most Africa, eastern Australia, the Mediterranean region, the Middle East, and parts of East Asia, central South America, and the Pacific coasts of Canada. Streamflow records largely confirm these precipitation changes. The wetting trend over Northwest Australia and Southeast South America is most pronounced in austral summer while the drying over Africa and wetting trend over mid-high latitude Eurasia are seen in all seasons. Coupled with the drying caused by rising surface temperatures, these precipitation changes have greatly increased the risk of drought over Africa, southern Europe, East Asia, eastern Australia, Northwest Canada, and southern Brazil. Global land precipitation and continental freshwater discharge show large interannual and inter-decadal variations, with negative anomalies during El Nino and following major volcanic eruptions in 1963, 1982, and 1991; whereas their decadal variations are correlated with the Interdecadal Pacific Oscillation (IPO) with IPO’s warm phase associated with low land precipitation and continental discharge. The IPO and Atlantic multidecadal variability also dominate multidecadal variations in land aridity, accounting for 90 % of the multidecadal variance. CMIP5 multi-model ensemble mean shows decreased precipitation and runoff and increased risk of drought during 1950–2018 over Southwest North America, Central America, northern and central South America (including the Amazon), southern and West Africa, the Mediterranean region, and Southeast Asia; while the northern mid-high latitudes, Southeast South America, and Northwest Australia see increased precipitation and runoff. The consistent spatial patterns between the observed changes and the model-simulated response suggest that many of the observed drying and wetting trends since 1950 may have resulted at least partly from historical external forcing. However, the drying over Southeast Asia and wetting over Northwest Australia are absent in the 21st century projections.

Drawing attention via diversity in thematic map design, as demonstrated by student maps of Northern South Africa

ABSTRACT In today’s information age, thematic maps increasingly appear in all kinds of media and publications and many users control the map design process themselves. Due to wider prevalence of data, teaching the principles of thematic cartography is gaining interest. Students need to understand the power of thematic maps to reveal geographic patterns and relations, and should learn how to create convincing maps. In this paper, student maps featuring socio-economic themes for Northern South Africa show how attention can be drawn to information hidden in data. Seven students each prepared a black-and-white traditional thematic map and a coloured infographics-style map, which were later enhanced by a well-trained cartographer. Through these maps, we demonstrate that the power of thematic maps depends on the chosen cartographic representation and that diversity of visualization options matters when telling a story with a map. Discussion of the maps illustrates the relevance and challenge of thematic maps for society, the need to develop map literacy, and the possibility to accommodate new visualization trends, like narrative data visualization, in thematic cartography teaching. The emphasis should be on using multivariate data and allowing infographics characteristics, thus fostering creativity and preparing students for a role in interdisciplinary data journalism teams.

It depends on the rain: Smallholder farmers’ perceptions on the seasonality of feed gaps and how it affects livestock in semi-arid and arid regions in Southern Africa

The risk of climate-induced feed gaps, i.e. seasonal deficiencies in forage quantity and quality, is a major constraint for livestock in the dry regions of southern Africa. In South Africa particularly, the frequent occurrence of drought is a challenge for livestock farming and, coping strategies to mitigate feed gaps on smallholder farms are urgently needed. We chose the Limpopo province, of northern South Africa to study livestock farmers’ perceptions of the temporal patterns of feed gaps and their perceived impacts on livestock production across different agro-ecological zones (AEZ) and farm types (i.e., livestock only, mixed crop-livestock farms). We combined a semi-structured questionnaire on ninety farms with data from herbage analysis (mineral nutrient concentrations of grasses grazed in winter). Additionally, we explored the effect of seasonal feed availability on feed gaps, expressed as gross primary productivity (GPP), based on long-term simulated vegetation data. We found a close correlation between farmers’ perceived feed gaps and GPP (Pearson’s r = − 0.77, p < 0.01). Farmers’ perceptions of feed gaps are related to precipitation deficits that restrict rangeland productivity especially in winter and spring across the AEZ. Consequently, farmers considered that feed gaps occur mainly in winter (80%) followed by spring (30%) and autumn (20%). In addition, our analysis demonstrated that in winter the mineral concentration in rangeland biomass is inadequate to meet the livestock feed requirements. The percentages of farmers who perceived feed gaps and animal weight loss in the winter season did not differ significantly between farm types (p = 0.40) and AEZ (p = 0.41). Among livestock-only farmers, feed gaps were perceived to occur more in autumn (p < 0.01) whereas for mixed crop-livestock farmers the feed gap perception was greater in spring (p < 0.01). Farmers located in the drier zone perceived feed gaps more in spring (p < 0.05), leading to the significant perception of livestock weight loss for that period (p < 0.01). As strategies to deal with feed gaps, farmers rely on crop residues and/or reduction of livestock numbers. To improve the sustainability of the livestock system, our results show that feed gaps follow a strong seasonal pattern and they suggest that intervention strategies do not necessarily need to account for local climatic differences but rather for farm operation types.

Grass species richness decreases along a woody plant encroachment gradient in a semi-arid savanna grassland, South Africa

Savanna grasslands are undergoing rapid land cover transformation as a consequence of woody plant encroachment. It still remains unclear how increasing woody plant density and cover in savannas influences tree-grass-soil interactions. This study determined the effect of increasing tree density on grass species richness, evenness, diversity and assessed how nutrients change along an encroachment gradient of a shallow plinthic savanna soil. Vegetation was quantified and soil samples analysed from eighteen randomly distributed 10 m × 10 m plots along a tree density gradient spanning from open, transitioning into intermediate and intensively encroached savanna grassland in northern South Africa. We found that an increase in tree density along the encroachment gradient decreased grass richness (GR) by 53% in the intensively woody-encroached grassland. Higher tree density and canopy cover led to a 90% dominance of Panicum maximum grass species. Conversely, higher tree density increased concentrations of carbon, nitrogen, phosphorus and exchangeable calcium and magnesium in the topsoil layer. This study highlights that woody plant encroachment decreases grass species richness and composition, but increases nutrients in the uppermost layer of a plinthic savanna soil. Such information is critical to improve understanding of the mechanisms underlying tree-grass interactions in savannas.

Age of the Archaean Murchison Belt and mineralisation, South Africa

Abstract The east-northeast-trending Murchison-Thabazimbi Lineament in northern South Africa is one of the world’s most important structures for its control on world-class mineral deposits, Proterozoic sedimentary basins and giant igneous intrusions. The deepest exposed Archaean parts of the lineament are the Murchison Belt. Bounded by granitoids, the belt comprises greenschist to amphibolite facies volcano-sedimentary strata with isoclinal folds and the 7 km thick meta-igneous Rooiwater Complex. The Rooiwater Complex is intruded by a northern regional granitoid dated at 2 929 ± 7 Ma by SHRIMP U-Pb on zircons. Using field relationships, published isotopic age data and new SHRIMP zircon dates we confirm the age Rooiwater Complex at 2 965 Ma, showing it to be contemporaneous with the Archaean volcanic and sedimentary formations, the meta-igneous Complex being the lower sequence in a ~2 980 to 2 960 Ma island arc. Despite being implicated as a source of gold for the world’s largest natural accumulation of gold in the Witwatersrand Basin, the absolute age of Sb-Au mineralisation in the Murchison Belt is poorly constrained. We have utilised SHRIMP U-Pb geochronology to date monazites from a Sb-Au ore sample from the granitoid-hosted Malati Pump orebody and determine ages for two different generations of monazite, both associated with ore minerals. The older age of 2 832 ± 23 Ma is from a minority of grains and is interpreted to date the primary Sb-Au mineralisation, about 120 Ma after belt formation. This age predates, or is possibly synchronous with, sedimentation of the upper-Witwatersrand Central Rand Group. The younger age of 1 968 ± 17 Ma from a majority of monazite grains is unrelated in time to known events and interpreted here as a cryptic hydrothermal reworking of the Sb-Au ores in this deposit.

Sindbis Virus Strains of Divergent Origin Isolated from Humans and Mosquitoes During a Recent Outbreak in Finland.

Sindbis virus (SINV) is a mosquito-borne avian hosted virus that is widely distributed in Europe, Africa, Asia, and Oceania. Disease in humans is documented mainly from Northern Europe and South Africa and associated with genotype I. In 2018 under extremely warm climatic conditions, a small outbreak of 71 diagnosed SINV infections was recorded in Finland. We screened 52 mosquito pools (570 mosquitoes) and 223 human sera for SINV with real-time RT-PCR and the positive samples with virus isolation. One SINV strain was isolated from a pool (n = 13) of genus Ochlerotatus mosquitoes and three strains from patient serum samples. Complete genome analysis suggested all the isolates to be divergent from one another and related to previous Finnish, Swedish, and German strains. The study provides evidence of SINV strain transfer within Europe across regions with different epidemiological characteristics. Whether these are influenced by different mosquito genera involved in the transmission remains to be studied.

Prevalence of vitamin D deficiency in Africa: A systematic review and meta-analysis

Summary Background Vitamin D deficiency is associated with non-communicable and infectious diseases, but the vitamin D status of African populations is not well characterised. We aimed to estimate the prevalence of vitamin D deficiency in children and adults living in Africa. Methods For this systematic review and meta-analysis, we searched PubMed, Web of Science, Embase, African Journals Online, and African Index Medicus for studies on vitamin D prevalence, published from database inception to Aug 6, 2019, without language restrictions. We included all studies with measured serum 25-hydroxyvitamin D (25[OH]D) concentrations from healthy participants residing in Africa. We excluded case reports and case series, studies that measured 25(OH)D only after a clinical intervention, and studies with only a meeting abstract or unpublished material available. We used a standardised data extraction form to collect information from eligible studies; if the required information was not available in the published report, we requested raw data from the authors. We did a random-effects meta-analysis to obtain the pooled prevalence of vitamin D deficiency in African populations, with use of established cutoffs and mean 25(OH)D concentrations. We stratified meta-analyses by participant age group, geographical region, and residence in rural or urban areas. The study is registered with PROSPERO, number CRD42018112030. Findings Our search identified 1692 studies, of which 129 studies with 21 474 participants from 23 African countries were included in the systematic review and 119 studies were included in the meta-analyses. The pooled prevalence of low vitamin D status was 18·46% (95% CI 10·66–27·78) with a cutoff of serum 25(OH)D concentration less than 30 nmol/L; 34·22% (26·22–43·68) for a cutoff of less than 50 nmol/L; and 59·54% (51·32–67·50) for a cutoff of less than 75 nmol/L. The overall mean 25(OH)D concentration was 67·78 nmol/L (95% CI 64·50–71·06). There was no evidence of publication bias, although heterogeneity was high (I2 ranged from 98·26% to 99·82%). Mean serum 25(OH)D concentrations were lower in populations living in northern African countries or South Africa compared with sub-Saharan Africa, in urban areas compared with rural areas, in women compared with men, and in newborn babies compared with their mothers. Interpretation The prevalence of vitamin D deficiency is high in African populations. Public health strategies in Africa should include efforts to prevent, detect, and treat vitamin D deficiency, especially in newborn babies, women, and urban populations. Funding Wellcome Trust and the DELTAS Africa Initiative.

Association of genetic polymorphism at tumor necrosis factor-α gene promoter - 1031T/C and parasitic infections among children in Northern South Africa

Intestinal parasitic diseases are common in developing countries including South Africa and have been documented to be the most common in children under the age of five. The present study aimed to identify any potential association that may exist between TNF-α promoter gene polymorphism and parasitic infections. A total of 199 blood samples were evaluated from children who were part of the MAL-ED study cohort. The DNA was used to investigate polymorphism in the promoter region of the TNF-α gene at position -1031T/C. The polymorphisms were detected by polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) assay. The TC genotype at position -1031 was significantly higher in healthy controls children than in children who were infected with Entamoeba species (59.9% vs 29.4%, P = 0.015) and Entamoeba coli (59.1% vs 30.8%, P = 0.046), indicating that TC genotype may be protective against Entamoeba infections and Entamoeba coli infections. The CC genotype at position -1031 was more common among children with parasite and diarrhea and the results was statistically significant (P = 0.04). This study has revealed that the CC genotype may be is a risk factor for symptomatic parasitic infections while the TC genotype might be protective of Entamoeba infections among children in Dzimauli community.

Historical and contemporary range expansion of an invasive mussel, Semimytlius algosus, in Angola and Namibia despite data scarcity in an infrequently surveyed region.

Understanding the spread of invasive species in many regions is difficult because surveys are rare. Here, historical records of the invasive marine mussel, Semimytilus algosus, on the shores of Angola and Namibia are synthesised to re-construct its invasive history. Since this mussel was first discovered in Namibia about 90 years ago, it has spread throughout the western coast of southern Africa. By the late 1960s, the species was well established across a range of 1005 km of coastline in southern Angola and northern Namibia. Although only coarse spatial resolution data are available since the 1990s, the distribution of S. algosus clearly increased substantially over the subsequent decades. Today, the species is distributed over 2785 km of coastline, appearing in southern Namibia in 2014, whence it spread across the border to northern South Africa in 2017, and in northern Angola in 2015. Conspicuously, its current range appears to be relatively contiguous across at least 810 km of shore in southern Angola and throughout Namibia, with isolated, spatially disjunct occurrences towards the southern and northern limits of its distribution. Despite there being few occurrence records that are unevenly distributed spatially and temporally, data for the distributional patterns of S. algosus in Angola and Namibia provide invaluable insights into how marine invasive species spread in developing regions that are infrequently monitored.

Ochna maguirei (Ochnaceae), a new species with corky bark from northern South Africa

Specimens of an undescribed species of Ochna were found mixed among specimens of O. pretoriensis and O. holstii. It differs from these two species on the basis of leaf shape and its corky bark. It differs from O. schweinfurthiana, a tropical African species with corky bark, on the basis of leaf shape and by producing its flowers simultaneously and amongst the leaves, rather than being hysteranthous. Differences from O. puberula and O. oxyphylla are discussed. A key is provided to separate the new species from O. holstii and the new species is described and named in honour of Brian Maguire. Ochna maguirei occurs from the Magaliesberg to the Southpansberg and is restricted to quartzite. Twenty populations occur over an area of approximately 550 km × 210 km giving an EOO of about 100,000 km2. Although the AOO is likely to be between 500 and 2000 km2, the number of populations is over 10. A population census at the Makapansgat locality suggests that the species is resilient to fire and that the population has remained equally fit for 21 years. Thus, on the basis of estimated EOO, AOO and population size and the lack of threats to its habitat, a provisional threat status of Least Concern is recommended.

Facilitation or Competition? Effects of Lions on Brown Hyaenas and Leopards

Intra-guild interactions related to facilitation and competition can be strong forces structuring ecological communities and have been suggested as particularly prominent for large carnivores. The African lion (Panthera leo) is generally thought to be a dominant predator where it occurs and can be expected to have broad effects on sympatric carnivore communities. We used data from two small game reserves in northern South Africa to relate the presence of African lions to abundance, habitat use, diet, and prey selection of two sympatric large carnivores, brown hyaenas (Parahyaena brunnea) and leopards (Panthera pardus). Our results offered some support for the facilitative effects of lions on brown hyaenas, and competitive effects on leopards. However, differences between populations living without and with lions were restricted to broad diet composition and appear not to have permeated into differences in either prey selection, abundance or habitat use. Therefore, we suggest that the potential effects of lions on the predator–prey interactions of sympatric predators may have been context dependent or absent, and subsequently argue that lions may not necessarily influence the predator–prey dynamics in the landscapes they live in beyond those caused by their own predatory behaviour.

‘Objects with Objectives’: Applied puppetry from practice into theory

This article draws on the dialogue between puppetry and applied drama that arose from the AHRC Objects with Objectives Research Network in 2017–18 to explore a tentative theory of applied puppetry. A range of theoretical approaches to applied drama are examined in the light of practical examples of applied puppetry using case studies from Northern Ireland, South Africa and Australia. Morton (2013) highlights how, in performance ‘tension between the material puppet and the imagined puppet’ gives rise to a kind of ‘double vision’ (Tillis 1992), a concept that the article considers alongside Gallagher’s (2005) distinction between body image and body schema, Brecht’s (1974) V-effekt, Meyerhold’s (1998) distinction between the materiality and agency of the actor and Boal’s (1992) idea of metaxis. The article concludes that the distancing and conductive qualities of applied puppetry often work in parallel and that the puppet can be seen as the site of metaxis when used in an applied context.

Joint modeling of precipitation and temperature under influences of El Niño Southern Oscillation for compound event evaluation and prediction

Compound precipitation and temperature events have received much attention in recent decades owing to their amplified impacts on agriculture, economy and public health. Due to the relationship between precipitation and temperature, both of which are affected by El Niño–Southern Oscillation (ENSO) in large regions across the globe, joint modeling of their variability under influences of ENSO is desirable for understanding compound events. In this study, a statistical approach is proposed for the evaluation and prediction of compound precipitation and temperature events (with a focus on compound dry and hot events) under influences of ENSO by constructing the joint distribution of precipitation, temperature, and the ENSO indicator. The joint probability of precipitation and temperature is compared with the conditional probability given different states of ENSO for June–July-August (JJA) and December–January-February (DJF) over global land areas. Results show that ENSO affects the risk of compound dry and hot events in regions including southern Canada, northern South America, southeast Asia, south Africa, and part of Australia. The conditional distribution of precipitation and temperature given ENSO enables the probabilistic prediction of compound events. The strong El Niño event during DJF 2015–2016 significantly affects risks of the compound dry and hot event and provides useful early warning information for large regions including northern South America and south Africa. This study provides useful insights for improved understanding and early warning of compound dry and hot events to reduce their negative impacts.

Mosquito community composition and abundance at contrasting sites in northern South Africa, 2014-2017.

Most data on species associations and vector potential of mosquitoes in relation to arboviral infections in South Africa date back from the 1940s to late 1990s. Contextual information crucial for disease risk management and control, such as the sampling effort, diversity, abundance, and distribution of mosquitoes in large parts of South Africa still remains limited. Adult mosquitoes were collected routinely from two horse farms in Gauteng Province; two wildlife reserves in Limpopo Province, at Orpen Gate in Kruger National Park (KNP) and Mnisi Area in Mpumalanga Province between 2014-2017, using carbon dioxide-baited light and tent traps. Mosquito diversity and richness are greater in untransformed natural and mixed rural settings. In untransformed wilderness areas, the most dominant species were Culex poicilipes, Anopheles coustani, and Aedes mcintoshi, while in mixed rural settings such as the Mnisi area, the two most abundant species were Cx. poicilipes and Mansonia uniformis. However, in peri-urban areas, Cx. theileri, Cx. univittatus, and Cx. pipiens sensu lato were the most dominant. Aedes aegypti, Ae. mcintoshi, Ae. metallicus, Ae. vittatus, Cx. pipiens s.l., Cx. theileri, and Cx. univittatus had the widest geographical distribution in northern South Africa. Also collected were Anopheles arabiensis and An. vaneedeni, both known malaria vectors in South Africa. Arbovirus surveillance and vector control programs should be augmented in mixed rural and peri-urban areas where the risk for mosquito-borne disease transmission to humans and domestic stock is greater.