Showing papers in "South African Journal of Science in 2010"

Medicinal Plants of South Africa

Abstract: Medicinal plants in South Africa contribute to both the health and livelihood of many indigenous populations. The study of ethnobotany in the country is important not only as a means to preserve indigenous plant knowledge, but also to serve the natural products economic sector. The significance of materia medica in South African society remains an inherent part of many cultures, with an estimated 70% of the population using plants for medicinal purposes.

A critical review of studies of South African youth resilience, 1990-2008 : review article

Abstract: Given the growing emphasis in research and service provision on strengths rather than deficits, the focus on youth support in the South African Children's Act of 2005 and the lack of educational, therapeutic and other resources for most South Africans, insight into, and transdisciplinary commitment to, resilience is crucial. Resilience, or the phenomenon of 'bouncing back' from adversity, is common to societies that grapple with threatened well-being. Increasingly, international resilience studies have suggested that the capacity to rebound is nurtured by multiple resources that protect against risk and that these resources are rooted in culture. In this paper, we critically reviewed 23 articles that focus on South African youth resilience, published in academic journals between 1990 and 2008. By broadly comparing South African findings to those of international studies, we argued for continued research into the phenomenon of resilience and for a keener focus on the cultural and contextual roots of resilience that are endemic to South Africa. Although international resilience research has begun to match the antecedents of resilience to specific contexts and/or cultures, South African research hardly does so. Only when this gap in youth resilience research is addressed, will psychologists, service providers, teachers and communities be suitably equipped to enable South African youth towards sustained resilience.

The evolution of fire and invasive alien plant management practices in fynbos

Abstract: The history and development of fire and invasive alien plant management policies in fynbos during the 20th century are reviewed. Fire was initially condemned outright as a destructive force, but as its vital role became better understood, management policies switched from protection to active burning in 1968. During the 1970s, large, coordinated research programmes were established, resulting in a solid basis of knowledge on which to develop fire management policies. Despite policies of prescribed burning, wild fires remain the dominant feature of the region, fortunately driving a variable fire regime that remains broadly aligned with conservation objectives. The problem of conserving fire-adapted fynbos is complicated by invading alien trees that are also fire-adapted. Research results were used to demonstrate the impacts of these invasions on water yields, leading to the creation of one of the largest alien plant control programmes globally. Despite improvements in control methods, alien trees, notably pines, continue to spread almost unchecked. Biological control offered some hope for controlling pines, but was ruled out as too high a risk for these commercially-important trees. Failure to address this problem adequately will almost certainly result in the severe degradation of remaining fynbos ecosystems.

A critical review of studies of South African youth resilience, 1990–2008

Abstract: Given the growing emphasis in research and service provision on strengths rather than deficits, the focus on youth support in the South African Children’s Act of 2005 and the lack of educational, therapeutic and other resources for most South Africans, insight into, and transdisciplinary commitment to, resilience is crucial. Resilience, or the phenomenon of ‘bouncing back’ from adversity, is common to societies that grapple with threatened well-being. Increasingly, international resilience studies have suggested that the capacity to rebound is nurtured by multiple resources that protect against risk and that these resources are rooted in culture. In this paper, we critically reviewed 23 articles that focus on South African youth resilience, published in academic journals between 1990 and 2008. By broadly comparing South African findings to those of international studies, we argued for continued research into the phenomenon of resilience and for a keener focus on the cultural and contextual roots of resilience that are endemic to South Africa. Although international resilience research has begun to match the antecedents of resilience to specific contexts and/or cultures, South African research hardly does so. Only when this gap in youth resilience research is addressed, will psychologists, service providers, teachers and communities be suitably equipped to enable South African youth towards sustained resilience.

The evolution of fire management practices in savanna protected areas in South Africa

Abstract: The history and development of ecologically-based fire management policies in savanna protected areas during the 20th century are reviewed. Research on fire in savannas began in the 1950s, and from the 1980s onwards, managers of savanna protected areas experimented on large scales with different management approaches. New ecological paradigms that embraced variability in space and time, and management goals that broadened from single-species to biodiversity conservation, precipitated significant changes to management approaches in the 1990s. Many lessons have been learnt in the process, allowing for the derivation of general principles regarding both the effects of fire and managerial ability to influence fire regimes on a large scale. Significant challenges remain; these include dealing with increasing CO2 concentrations in the atmosphere, and with interactions between fire and increasing elephant numbers in protected areas. The ability of savanna managers to deal with these challenges in the context of an imperfect understanding will be determined by how well, and how fast, they can learn from experience.

Periodicities, ENSO effects and trends of some South African rainfall series: an update

Abstract: The precipitation data for some regions in South Africa were studied for the period 1900–1998. From the 11 regions examined, 8 in South Africa had maximum precipitations in the austral summer months (December, January, February, March), while 3 had maxima in autumn and winter. Annual values showed considerable year-to-year fluctuations (50% to 200% of the mean), while five-year running means showed long-term fluctuations (75% to 150% of the mean). A spectrum analysis indicated periodicities in the ranges 2–3 (quasi-biennial oscillation, QBO), 3–4 (quasi-triennial oscillation, QTO), 6–11, 17–21, 23–26, 32–35 and 55–66 years, some common to, and some different in different regions. The QBO and QTO accounted for a substantial fraction (30–50%) of the total variance. In five-year running means, the effects of QBO and QTO were suppressed considerably. The plots showed distinct peaks, but the spacings varied in a wide range, indicating that predictions based on extrapolation of single peaks are not likely to come true even for decadal averages. El Nino effects for the giant event of 1982/83 were as expected but those for 1997/98 were obscure, almost absent. Running means over 21 years did not indicate linear trends, upwards or downwards. Instead, considerable oscillations were seen, with magnitudes different in different regions (5–25%). On average, high values during 1915/16 decreased considerably (5–8%) up to 1935, oscillated upwards thereafter and recouped by 1980, but decreased considerably thereafter. : South Africa, rainfall, ENSO, periodicities, predictions, trends

Antibiotic-resistant Staphylococcus aureus isolated from milk in the Mafikeng Area, North West province, South Africa : research article

Abstract: The aim of this study was to isolate Staphylococcus aureus from samples of cow's milk obtained from different farm settings and to determine their antibiotic susceptibility patterns. Gram staining, oxidase, catalase, DNase, haemolysis and the MASTASTAPHTM rapid agglutination tests were employed for bacterial identification. A total of 28 milk samples were collected and screened for the presence of S. aureus. All the samples were contaminated with S. aureus. A total of 240 S. aureus isolates were obtained during this study. The levels of contamination with S. aureus were higher in milk obtained from the communal farms in Lokaleng and Mogosane (24.6% and 35.4%, respectively) compared to the commercial farms in Rooigrond and Molelwane (17.9% and 22.1%, respectively). A large percentage of the S. aureus isolates (39%-100%) from both communal farms was resistant to methicillin (MT), ampicillin (AP), penicillin G (PG), sulphamethoxazole (Smx), oxytetracycline (OT), erythromycin (E), nitrofurantoin (NI) and streptomycin (S), but not vancomycin (V). An even higher percentage (64.2% - 100%) of the isolates from both commercial farms was resistant to sulphamethoxazole and nitrofurantoin. A comparably smaller percentage (3.4% - 4.7%) of the isolates from both communal farms was resistant to vancomycin, but all isolates from commercial farm milk were susceptible to this drug. The predominant multiple antibiotic resistant phenotypes for isolates from the commercial farms were AP-Smx-NI and MT-AP-PG-OT-Smx-NI for Rooigrond and Molelwane farms, respectively, while those for isolates from the communal farms were MTAP- PG-Smx-E-NI-S and MT-AP-PG-OT-Smx-NI-S for Lokaleng and Mogosane, respectively. When comparing the percentage of antibiotic resistance, a significant positive correlation was observed between the isolates from the commercial farms (r = 0.966, p < 0.01). S. aureus is normally resident in humans, therefore, the S. aureus present in the cows may have resulted from transmission between the two species, emphasising the need to improve sanitary conditions in the milking environment.

Antibiotic-resistant Staphylococcus aureus isolated from milk in the Mafikeng Area, North West province, South Africa

Abstract: The aim of this study was to isolate Staphylococcus aureus from samples of cow’s milk obtained from different farm settings and to determine their antibiotic susceptibility patterns. Gram staining, oxidase, catalase, DNase, haemolysis and the MASTASTAPH TM rapid agglutination tests were employed for bacterial identification. A total of 28 milk samples were collected and screened for the presence of S. aureus . All the samples were contaminated with S. aureus . A total of 240 S. aureus isolates were obtained during this study. The levels of contamination with S. aureus were higher in milk obtained from the communal farms in Lokaleng and Mogosane (24.6% and 35.4%, respectively)compared to the commercial farms in Rooigrond and Molelwane (17.9% and 22.1%, respectively). A large percentage of the S. aureus isolates (39%–100%) from both communal farms was resistant to methicillin (MT), ampicillin (AP), penicillin G (PG), sulphamethoxazole (Smx), oxytetracycline (OT), erythromycin (E), nitrofurantoin (NI) and streptomycin (S), but not vancomycin (V). An even higher percentage (64.2% – 100%) of the isolates from both commercial farms was resistant to sulphamethoxazole and nitrofurantoin. A comparably smaller percentage (3.4% – 4.7%) of the isolates from both communal farms was resistant to vancomycin, but all isolates from commercial farm milk were susceptible to this drug. The predominant multiple antibiotic resistant phenotypes for isolates from the commercial farms were AP-Smx-NI and MT-AP-PG-OT-Smx-NI for Rooigrond and Molelwane farms, respectively, while those for isolates from the communal farms were MT-AP-PG-Smx-E-NI-S and MT-AP-PG-OT-Smx-NI-S for Lokaleng and Mogosane, respectively. When comparing the percentage of antibiotic resistance, a significant positive correlation was observed between the isolates from the commercial farms ( r = 0.966, p S. aureus is normally resident in humans, therefore, the S. aureus present in the cows may have resulted from transmission between the two species, emphasising the need to improve sanitary conditions in the milking environment.

An assessment of the atmospheric nitrogen budget on the South African Highveld

Abstract: Atmospheric reactive nitrogen concentrations on the South African Highveld have become a growing concern, with satellite images indicating very high nitrogen dioxide (NO 2 ) concentrations in the region. This study investigated the nitrogen budget on the Highveld through the analysis of the concentration of the atmospheric nitrogen species on a temporal scale as well as the atmospheric conversion, transport and removal of these species. Data were collected at Eskom’s Elandsfontein ambient air quality monitoring site, which is centrally located on the industrialised Highveld. A year’s dataset from 2005 and 2006 was analysed and it was found that nitrogen oxide (NO x ) concentrations were higher in winter as a result of stable atmospheric conditions, as well as prevalent westerly and north-westerly airflow, which transported emissions directly from the nearby power station sources to the monitoring site. Nitrate (NO 3 ) concentrations also peaked during winter, with a distinct biomass burning peak during August 2005. Diurnally, NO x concentrations indicated a tall-stack industrial source, where concentrations peaked at midday. The NO 3 concentrations were higher at night than during the day; during the day the NO 3 radical is rapidly photolysed and nitrates cannot be produced. Case studies indicated that the conversion rate of nitric oxide (NO) to NO 2 was highly variable as a result of varying atmospheric factors, which include time of day, dispersion, stability and regional atmospheric chemistry. These rates ranged from 11% to 59% per hour. Rates of dry deposition of NO, NO 2 and NO 3 were generally higher during winter as a result of higher atmospheric concentrations and increased atmospheric stability. Nitrogen was predominantly deposited as NO 2 throughout the year, except during spring when NO 3 deposition dominated. The total annual amount of nitrogen that was deposited to the Mpumalanga Highveld region was in the range of 6.7 kg/ha –13.1 kg/ha per year, which is well below the stipulated critical load value. Such deposition, therefore, should not pose significant threats to the natural environment on the Highveld. Between 4% and 15% of the total emitted nitrogen from power generation on the Highveld was deposited to the surface via wet and dry deposition. The remainder was advected out of the region.

Photocatalytic degradation of methyl red dye

Abstract: Silica nanoparticles (SiO2 NPs) are active in the photocatalytic degradation of methyl red dye (MR). SiO2 NPs and SiO2 NPs that have been doped with either silver (Ag NPs) and/or gold nano- particles (Au NPs) were prepared. The particle size and morphology of the catalysts were assessed by transmission electron microscopy (TEM) imaging. The rate of photocatalytic degradation of MR was found to increase from SiO2 NPs, SiO2 NPs coated with both Au NPs and Ag NPs, SiO2 NPs coated with Ag NPs, SiO2 NPs coated with Au NPs, Ag + -doped SiO2 NPs to Au 3+ -doped SiO2 NPs. : silica nanoparticles, photocatalysis, photo- degradation, gold, silver

Land-cover change in the Kruger to Canyons Biosphere Reserve (1993-2006): a first step towards creating a conservation plan for the subregion.

Abstract: This paper is a first step towards a conservation plan for the Kruger to Canyons Biosphere Reserve (K2C) on the South African Central Lowveld, quantifying the historical land-cover trends (1993–2006). During the analysis period, 36% of the biosphere reserve (BR) underwent land-cover change. Settlement areas increased by 39.7%, mainly in rural areas, becoming denser, particularly along roadways. Human-Impacted Vegetation increased by 6.8% and Intact Vegetation declined by 7.3%, predominantly around settlement areas, which is testament to the interdependency between rural communities and the local environment. However, settlement expansion exceeded the rate of rangeland growth; in the long term, this may raise questions for sustainable resource extraction. Similarly, the block losses of intact vegetation are of concern; issues of fragmentation arise, with knock-on effects for ecosystem functioning. In the economic sector, agriculture increased by 51.9%, while forestry and mining declined by 7.1% and 6.3%, respectively. The future of these three sectors may also have significant repercussions for land-cover change in the BR. The identification of historical drivers, along with the chance that existing trends may continue, will have important implications for biodiversity protection in this landscape. Applied within a conservation-planning framework, these land-cover data, together with economic and biodiversity data, will help reconcile the spatial requirements of socio-economic development with those of conservation.

Salinity and temperature tolerance of the invasive freshwater gastropod Tarebia granifera

Abstract: Invasive aquatic species, such as the gastropod Tarebia granifera , can cause ecological isturbances and potentially reduce biodiversity by displacing indigenous invertebrates. In South Africa, T. granifera was first recorded in an estuarine environment in the St Lucia Estuary. Its tolerance to salinity and temperature was investigated through the experimental manipulation of these factors. T. granifera can tolerate temperatures between 0 oC and 47.5 oC, allowing it to survive high temperature extremes. The species may also survive cold snaps and invade higher altitude areas. More remarkably, this snail survives high salinity for a relatively long time, as LS 50 (lethal salinity for 50% of the population) was reached at 30 psu over 65–75 days. However, higher salinity adversely affected the T. granifera population. Snails acclimated to freshwater conditions and suddenly transferred to 30 psu experienced 100% mortality within 48 h. Snail activity also declined with increasing salinity. T. granifera’ s environmental tolerance and parthenogenetic characteristics are the keys to successful introduction and establishment. Therefore, the management of T. granifera may prove diffcult in the short to medium term. The present findings constitute a contribution to the knowledge of biological invasions in Africa and to the understanding of estuarine invasions by T. granifera .

Evidence-based policymaking: A review

Abstract: The process of facilitating the uptake of evidence, for example, scientific research findings, into the policymaking process is multifaceted and thus complex. It is therefore important for scientists to understand this process in order to influence it more effectively. Similarly, policymakers need to understand the complexities of the scientific process to improve their interaction with the scientific sphere. This literature review addresses those factors that influence the uptake of scientific evidence into policymaking, the barriers to using science in policymaking, as well as recommendations for improved science–policymaking interaction. A visual diagram of the gears of a car is used to convey the message of the complexities around the engagement between science and policymaking. It is concluded that the issue of evidence-based policymaking remains unresolved and questions for future research on the science–policy interface are raised.

Pyrethroid resistance in a major African malaria vector Anopheles arabiensis from Mamfene, northern KwaZulu-Natal, South Africa

Abstract: A population of Anopheles arabiensis, a major malaria vector in South Africa, was collected during 2005 from inside sprayed houses in Mamfene, northern KwaZulu-Natal, South Africa, using window exit traps. None of these specimens (n = 300 females) was found to be infected with Plasmodium falciparum. Insecticide susceptibility assays on 2–3 day old F1 progeny using WHO susceptibility kits revealed 100% susceptibility to bendiocarb, resistance to deltamethrin (95.91%) was suspected, while resistance to permethrin (78.05%) was confirmed. The knockdown resistant (kdr) genotype was not found in the surviving mosquitoes. Biochemical analysis using enzyme assays showed elevated levels of monooxygenase that correlated with the permethrin bioassay data. While elevated levels of non-specific esterase were found in some families (11/12 for α- and 6/12 for -esterases), the data did not show any correlation with the permethrin bioassay. Analysis of permethrin and bendiocarb tolerant lines, selected in the laboratory to characterise biochemical resistance profiles, showed increased levels of non-specific esterase and monooxygenase activity in the case of the permethrin-selected cohorts, and elevated glutathione S-trans

Imaging spectroscopy (hyperspectral remote sensing) in southern Africa: an overview

Abstract: Recent developments in imaging spectroscopy have seen a dramatic improvement in the characterisation of terrestrial features due to the high spectral resolution of the sensors used. For example vegetation species discrimination, stress detection and foliar chemistry mapping can now be achieved using these high spectral resolution sensors, a task that was almost impossible with coarse resolution satellite sensors. In spite of its capabilities, imaging spectroscopy is still in its early stages of development and application in southern Africa. This overview will attempt to briefly describe the science and analysis techniques, as well as review trends and challenges in the South African imaging spectroscopy landscape. It therefore is not intended as a pure research paper, but merely to illustrate the potential of and developments in imaging spectroscopy. This is pertinent to the South African scientific community where the technology is still in its infancy, especially given that the first-ever spaceborne South African imaging spectrometer, the Multi-Sensor Micro-Satellite Imager Satellite (MSMISat) is being developed for launch in the near future.

Synthesis of zeolite-P from coal fly ash derivative and its utilisation in mine-water remediation

Abstract: Solid residues resulting from the active treatment of acid mine drainage with coal fly ash were successfully converted to zeolite-P under mild hydrothermal treatment conditions. Scanning electron microscopy showed that the zeolite-P product was highly crystalline. The product had a high cation exchange capacity (178.7 meq / 100 g) and surface area (69.1 m 2 /g) and has potential application in waste-water treatment. A mineralogical analysis of the final product identified zeolite-P, as well as mullite and quartz phases, which indicated incomplete dissolution of the fly ash feedstock during the ageing step. Further optimisation of the synthesis conditions would be required to attain complete utilisation of the feedstock. The zeolite-P was tested for decontamination potential of circumneutral mine water. High removal efficiency was observed in the first treatment, but varied for different contaminants. The synthesised zeolite-P exhibited a high efficiency for the removal of heavy metal cations, such as aluminium, iron, manganese, zinc, copper and nickel, from contaminated mine water, even with repeated use. For potassium, calcium, strontium and barium, the removal was only efficient in the first treatment and decreased rapidly with subsequent treatments, indicating preferential adsorption of the other metals. A continuous release of sodium was observed during decontamination experiments, which decreased with subsequent treatments, confirming that sodium was the main exchangeable charge-balancing cation present in the zeolite-P product.

South Africa's diminishing coal reserves

Abstract: South Africa’s coal reserves have been significantly reduced since 2003 and a re-assessment based on the complete statistical history of production from southern Africa has indicated that the present remaining reserve for the entire subcontinent comprises only about 15 billion tonnes or gigatonnes (Gt). South African coal geologists should therefore be mindful of experience in Britain, where reserves were grossly overestimated by conventional techniques and remained a large multiple of future production until very shortly before the effective collapse of the industry in the 1980s. The southern African historical analysis has shown that an impressive leap in coal production occurred between 1975 and 1985, from about 69 million tonnes per year (Mt/yr) to 179 Mt/yr. By 1989, the cumulative production had reached 4 Gt. Despite this doubling since to just over 8 Gt, the underlying pattern has been one of faltering growth. Hubbertarian analysis predicts a peak in production rate of about 284 Mt/yr in 2020, at which stage approximately half (12 Gt) of the total resource (23 Gt) will be exhausted. The Waterberg Coalfield (Ellisras Basin) in South Africa may be a remaining large resource, but structural complexity, finely interbedded coal-shale strata at large depths, low grades, high ash content and water scarcity are likely to inhibit its major development. Given South Africa’s heavy dependence on coal for power generation and electricity supply, an anticipated peak production in 2020 will cause problems for future economic growth.

Will the real custodian of natural resource management please stand up

Abstract: South Africa is the custodian of an immense wealth of biodiversity resources, and is estimated to be the third most biodiverse country in the world. At the ecosystem level this biodiversity supports the production of goods and services used by us all ; water, air, soil fertility, wood, food, etc. At a more local level the harvesting of numerous natural resources provides consumptive products for millions of poor South Africans, as well as income for equally significant numbers. Consumption of and trade in these resources is the very mainstay of their well-being, and crucial in preventing deeper poverty levels.

South Africa’s gold production and reserves

Abstract: The recent underground mass death of more than 80 ‘illegal miners’ or zama-zamas (chance-takers) highlights the parlous state of South Africa’s gold-mining industry. Also attracting notice and comment recently is the official acknowledgement 1 that South Africa (S.A.) has fallen into second place after China in the world ranking of gold production. At the same time, S.A. continues to claim a first-place country ranking in the world list of gold ‘reserves’, with a (suspiciously round and, since 2001, unchanging) quantity of 36 000 tonnes (or about 40% of the global total) still in the ground. 1 How credible is this latter claim? A critical examination of the full history of gold production from the Witwatersrand, based on figures from the Chamber of Mines of South Africa, 2

Recent advances in sex identification of human skeletal remains in South Africa

Abstract: We review methods of sex estimation from human skeletal remains in South Africa within the forensic context. Sex is one of the key variables in obtaining a biological profile of the individual or population whose remains are analysed. Sex estimation based on the morphological characteristics of skeletal elements is population specific and thus the establishment of regional criteria is one of the imperatives for modern forensic anthropology. A literature review was carried out wherein the available methods of sex identification (morphological, metrical, geometric morphometrics and molecular) from South African skeletal material were critically examined. The approaches to sex estimation based on bone morphology have a long and productive history in South Africa. A number of approaches providing accurate results on the local populations have been developed. Research in molecular sex determination methods is still in its infancy in South Africa and the first innovative studies appeared only in recent years. While each of the four methods analysed is bounded by a number of constraints, they seem to complement each other and provide the best results when applied in conjunction with each other.

Anti-inflammatory and antibacterial profiles of selected compounds found in South African propolis

Abstract: Propolis is a complex resinous substance manufactured by honey bees to scaffold and protect the hive against pathogens. Although it has been widely used for its medicinal properties, it is unknown whether the activity depends on the concentrations of specific constituents or on potentiation between these. This study describes (1) the individual topical anti-inflammatory activities of selected flavonoids commonly found in propolis, and (2) their antibacterial activities, alone or in combination with the non-flavonoid caffeic acid phenethyl ester (CAPE). For the anti-inflammatory activities, the reduction in croton oil-induced oedema in a mouse model, after topical application of quercetin and galangin for 3 h, was more than 50%, while after 6 h of treatment the reduction was less then 50%. By contrast, the suppressive activity of luteolin was about 30% and 50%, for treatments of 3 h and 6 h, respectively. The maximum inhibition of the growth of Staphylococcus aureus by each of CAPE, eriodictyol and quercetin was about 20%, while luteolin was inactive. When combined with CAPE, potentiation of the antibacterial effect was observed in the case of luteolin, but antagonism was observed when combined with either eriodictyol or quercetin. The propolis flavonoids each appear to have significant anti-inflammatory activity while their antibacterial activities are somewhat weaker and significant only when luteolin was combined with CAPE.

Hybrid wildebeest (Artiodactyla: Bovidae) provide further evidence for shared signatures of admixture in mammalian crania

Abstract: The genus Connochaetes, Lichtenstein, 1814, contains two extant species, the blue wildebeest (C. taurinus, Burchell, 1823) and the black wildebeest (C. gnou, Zimmermann, 1780). In recent years, forced sympatry in confined areas within South Africa has led to interbreeding between these taxa and to fertile hybrid offspring. Here we report on a series of cranial characteristics of a hybrid wildebeest population culled at Spioenkop Dam Nature Reserve, KwaZulu-Natal, South Africa. Dental, sutural and horn morphological anomalies occur at high frequency within these animals. Similar cranial morphological anomalies have been shown in other mammalian hybrids and this study provides further evidence that such anomalies may characterise hybridisation more broadly across phylogenetically divergent mammalian groups, although the anomalies appear to differ in their expression across taxa. An increased ability to identify hybrids may also have important applications in the conservation of the endemic black wildebeest.

Bridging the science-policy interface : a new era for South African research and the role of knowledge brokering : research article

Abstract: Government departments and agencies are faced with issues of increasing socio-ecological complexities around environmental sustainability and global change, which require them to make decisions that have the potential to impact greatly on society and economies. As a result, they are under increasing pressure to develop policies that consider a wide spectrum of scientific and indigenous knowledge. It is acknowledged that in South Africa, as elsewhere, a gap typically exists between the scientific or research community and the policymaking community, due to a number of underlying reasons at both ends. This gap often results in a unidirectional 'push of evidence' by researchers to policymakers, with a hope that policymakers will take up these findings and use them in policy identification, formulation or implementation. To support the uptake of evidence in policy, it is also important to stimulate an environment of 'evidence pull' by the policy community from the research community, as well as increasing the dialogue between these communities. A model of knowledge brokering is proposed in this paper as a means to bridge this gap between science and policy and, thereby, ensure the uptake of evidence in policy development and implementation. This model looks at the need for institutional mechanisms, such as knowledge-brokering offices, both within research organisations and government departments. It also highlights the importance of researchers involving policymakers from the onset of their research process, with a continuous dialogue between the two parties, both during and after the research, as a means of increasing the likelihood of research uptake.

Determining the relationship between invasive alien species density and a country’s socio-economic status

Abstract: We explored the relationships between various socio-economic variables and the prevalence and density of invasive alien species (IAS) on a global scale using country-level data sets. We did this by testing the hypothesis that the abundance and distribution of populations of IAS are correlated with various socio-economic indicators, with the direction of causality being that the state of IAS is determined by socio-economic conditions. We found a positive and statistically significant relationship between the prevalence and density of IAS and the human development index (HDI), the satisfaction with life index and the gross domestic product (GDP) among all the countries tested. Additionally, the density of IAS increased significantly with human-population density, total geographic area, GDP and HDI. We also found a positive relationship between the density of IAS and the top 10 road networks of the world. This provides some insight into the development of renewed policies and management strategies for invasive species across both continents and countries. We do caution, however, that the results are likely to be influenced by the sampling factor, whereby affluent countries have more resources to measure and monitor IAS than poorer countries and hence have better records of such, which then indicates a stronger relationship with the level of development.

Evidence for opal phytolith preservation in the Langebaanweg 'E' Quarry Varswater Formation and its potential for palaeohabitat reconstruction

Abstract: At the end of the Miocene epoch, C4 grasslands began to expand at the expense of tree-, shrub- and forb-dominated C3 ecosystems. While C4 grasses were spreading throughout most regions of the world, C3 grasses may have been spreading along South Africa’s southwest coast. Stable isotope analyses of hypsodont fossil ungulates from ‘E’ Quarry, a well-known Late Miocene/Early Pliocene fossil locality near the town of Langebaanweg, suggest that the local environment might have included a substantial C3 grass component. Besides this indirect evidence, little is known about the evolution, nature and importance of grass in the ‘E’ Quarry biome. As a preliminary step towards addressing these questions, we initiated a trial investigation to assess whether sediments at the site are conducive to the preservation of phytoliths, an important tool in the reconstruction of palaeohabitats. Results indicate that fossil phytoliths are sufficiently well preserved to allow a comprehensive analysis of the ‘E’ Quarry phytolith assemblage.

Food production needs fuel too: perspectives on the impact of biofuels in southern Africa

Abstract: Southern Africa is faced with the complex challenge of achieving sustainable economic development and food and energy security while protecting the environment. The region is currently experiencing an energy crisis, a result in part because of global increases in crude oil prices and limited generating capacity in some countries. We examined the potential of biofuels to address the aforesaid problems and their role in the agroecological and socioeconomic systems in the region, highlighting the challenges to be overcome before biofuels can become an integral part of the regional socioeconomic dynamics. Major hurdles to biofuels establishment include relatively poor awareness of the potential and opportunities presented by biofuels, technology challenges, food insecurity vulnerability associated with the use of grains such as maize as feedstocks, potential conflict in resource allocation between food and fuel crops, and good governance and its impact on stability of food supply. Resource allocation and the balance between the need for food security and fuel is discussed in the context of selection of a crop matrix that does not compromise food security or limit development of the biofuels sector. While the use of maize for ethanol might enhance producer prices, it may contribute to high food inflation and political unrest. Sweet sorghum on the other hand, presents an opportunity to provide food and bioethanol without compromising food security. Biofuels have great potential in southern Africa, but there is a need to establish and nurture the development of capacity, in the value chain from production to consumption, to realise the benefits of biofuels in the region.

Marine environmental monitoring programmes in South Africa: a review

Abstract: South Africa uniquely lies at the junction of two major currents, the Agulhas and the Benguela The waters overlying the continental shelf exhibit exceptionally high short-, medium- and long-term (days to inter-decadal) variability compared with most other shelf areas, and strongly contrasting oceanographic conditions are observed on the east and west coasts South Africa is rich in fisheries resources and associated environmental data collected over more than a century The South African marine scientific community has a history of multidisciplinary studies of marine foodwebs, from the driving forces such as wind, currents and solar heating, to the top predators, with the development of kelp bed, sub-tidal reefs and estuarine ecosystem studies in the 1970s; the Benguela Ecology Programme, which ran through four successive five-year stages, focused on the pelagic marine resources Various approaches have been used to observe the continental shelf at different time and space scales, including: macroscale but frequent satellite imagery, mesoscale environmental and fishery surveys, dedicated crossshelf transects in key areas, measurements of dynamic processes, use of moored buoys and coastal weather stations, and integrated monitoring approaches, including modelling and simulation studies Between 30 and 50 years of comprehensive marine data now exist, which are proving useful in the application of an ecosystem approach to fisheries monitoring and management, as decadal changes become discernible These observations need to continue; even though the single-species stock assessment and operational management procedures have not yet formally used environmental factors for fisheries management advice, they help us to understand the factors affecting fish population fluctuations and early life histories and to identify large-scale regime shifts where marine trophic structure and functioning alter to a new state

Cobalt(II) removal from synthetic wastewater by adsorption on South African coal fly ash : research article

Abstract: Advanced wastewater-treatment techniques such as adsorption are essential in the removal of non-biodegradable toxic wastes from water. In this study, the use of South African coal fly ash, an industrial byproduct, has been investigated as a potential replacement for the current costly adsorbents used for removing heavy metals from wastewater. We utilised coal fly ash for the adsorption of cobalt(II) ions from synthetic petrochemical wastewater and characterised its performance. A two-level three-factor full-factorial design was successfully employed for experimental design and analysis of the results. The combined effects of pH, initial concentration and adsorbent dose on cobalt(II) removal were assessed using response surface methodology. Although the focus was on removal of cobalt(II), the adsorption was carried out in the presence of phenol and other heavy metal ions using the batch technique. The applicability of the Freundlich and Langmuir models to the equilibrium data was tested. Consequently, the equilibrium data was found to conform more favourably to the Freundlich isotherm than to the Langmuir isotherm; in this case, the coal fly ash had a maximum adsorption capacity of 0.401 mg/g for cobalt(II). We conclude that South African coal fly ash, as a natural, abundant and low-cost adsorbent, might be a suitable local alternative for elimination of cobalt(II) from aqueous solutions.

Contemporary spatio-temporal patterns of snow cover over the Drakensberg

Abstract: Sixteen years of low-resolution Landsat 5 and 7 satellite images were used to construct Boolean images of snow cover over the Drakensberg through a GIS. Contemporary patterns of snow cover, including altitudinal variations, were determined for individual months and various seasons. The seasonal occurrence and spatial influence of various snow-producing weather systems were determined through remote sensing and the consultation of daily climate data and synoptic charts. A proportional relationship was found between altitude of snow-covered pixels and the number of occurrences that pixels were covered in snow. The highest incidence and most widespread snow cover occurred from June to August; spring snow occurred preferentially in the central and southern Drakensberg regions. Cold fronts and associated cut-off lows accounted for about 80% of snow cover over the Drakensberg.