Evidence that residues of tebuthiuron arboricide present in soil of Mokala National Park can be phytotoxic to woody and grass species

Mokala National Park (MoNP) has a history of arboricide use through South African National Parks (SANPs) having bought commercial game farmland for its establishment in 2007. Tebuthiuron arboricide is known to have been applied for controlling bush densification during the period 1996 to 2004. Persistent negative impacts on MoNP vegetation, which are ascribed to the historical arboricide use, have prompted this investigation from 2016 to 2017. Bioassay experiments employing as test plants the tree species Vachellia erioloba and Vachellia tortilis, the shrub species Senegalia mellifera and the grass Tragus berteronianus were conducted in a glasshouse. Growth responses of these species were assessed upon their exposure to a tebuthiuron concentration range that simulated expected levels in MoNP soil soon and long after application. Chemical analysis as well as bioassay with the test species Lycopersicon esculentum (tomato) were performed on soil samples collected from three depths (0−30, 30−60 and 60−90 cm) of the soil profile at two sites in MoNP where tebuthiuron was applied in the past. The three woody test species showed differential, negative growth response to tebuthiuron, and even growth of the grass species (T. berteronianus) was affected at the higher concentrations. Evidence provided by the tomato bioassay and analysis performed on soil samples collected in situ points to the putative presence of tebuthiuron, more than a decade after the last use of arboricides for controlling bush densification. CONSERVATION IMPLICATIONS : If the reported evidence of the presence of phytotoxic residue of tebuthiuron in soil of MoNP would be substantiated through further research, such findings could at least partly explain the failure of natural recruitment of vegetation in those areas where the woody component was degraded because of arboricide application more than a decade ago.Villa Crop Protection (Pty) Ltd provided partial financial support.http://www.koedoe.co.zaam2023Plant Production and Soil Scienc

Pollution impacts on the aquatic ecosystems of the Kruger National Park, South Africa

The Kruger National Park (KNP) is a savanna ecosystem situated in the middle reaches of five large, dynamic and biologically diverse transboundary river systems. The KNP has been at the forefront of applied river ecosystems research for over 30 years. Meanwhile each of its rivers has a unique set of challenges from both a river flow and water quality manage- ment perspective. These have often arisen from anthropogenic changes in the catchments of the park. The resultant challenges give rise to an array of effects that bear upon the parks’ ability to maintain the viability of aquatic ecosystems in a large and bio-diverse landscape. This paper sets the scene through a synopsis of the investments made by the KNP to improve river management practices and the present status-quo of these aquatic systems. Moreover, it details through particular case studies where emergent impacts of diffuse pol- lution sources have affected the aquatic biotic processes within the park and downstream. Issues are framed within a conservation management context with respect to broad ecosystem health and species of conservation concern. Comparisons are also made to other aquatic ecosystems within the KNP where the impacts of diffuse pollution effects are as yet unapparent.The Land-Use and Water Quality Task Group of the International Water Association is acknowledged for constructive inputs to the development of this manuscript and providing sponsorship to present it at the 3rd Regional Conference on Diffuse Pollution, Chiang Mai, Thailand, November 2018.http://www.elsevier.com/locate/sciafam2019Paraclinical Science

Reflecting on research produced after more than 60 years of exclosures in the Kruger National Park

All data, in this case works of literature reviewed have been summarised in Online Appendix 2.Herbivores are a main driver of ecosystem patterns and processes in semi-arid savannas, with their effects clearly observed when they are excluded from landscapes. Starting in the 1960s, various herbivore exclosures have been erected in the Kruger National Park (KNP), for research and management purposes. These exclosures vary from very small (1 m2) to relatively large (almost 900 ha), from short-term (single growing season) to long-term (e.g. some of the exclosures were erected more than 60 years ago), and are located on different geologies and across a rainfall gradient. We provide a summary of the history and specifications of various exclosures. This is followed by a systematic overview of mostly peer-reviewed literature resulting from using KNP exclosures as research sites. These 75 articles cover research on soils, vegetation dynamics, herbivore exclusion on other faunal groups and disease. We provide general patterns and mechanisms in a synthesis section, and end with recommendations to increase research outputs and productivity for future exclosure experiments. CONSERVATION IMPLICATIONS : Herbivore exclosures in the KNP have become global research platforms, that have helped in the training of ecologists, veterinarians and field biologists, and have provided valuable insights into savanna dynamics that would otherwise have been hard to gain. In an age of dwindling conservation funding, we make the case for the value added by exclosures and make recommendations for their continued use as learning tools in complex African savannas.South African Environment Observation Network (SAEON).http://www.koedoe.co.zaam2023Paraclinical Science

Earliest evidence for the ivory trade in southern Africa : isotopic and ZooMS analysis of seventh-tenth century AD ivory from KwaZulu-Natal

KwaGandaganda, Ndondondwane and Wosi were major Early Farming Community settlements in what is today the KwaZulu-Natal province of South Africa. These sites have yielded, among other remains, abundant evidence of ivory and ivory working dating to the seventh–tenth centuries ad, pre-dating by approximately 200 years the better-known ivory artefacts from sites in the Limpopo River Valley and surrounding regions. We report the results of carbon, nitrogen and strontium isotope analysis to explore the origins and procurement of this ivory, in combination with Zooarchaeology by Mass Spectrometry (ZooMS) to identify the species of animals from which it was derived. All of the ivory studied using ZooMS was elephant, despite the presence of hippopotamus remains on all three sites. Some ivory was probably obtained from elephant herds that lived close to the sites, in the densely wooded river valleys favoured by both elephants and early farmers. Other material came from savannah environments further afield. Ivory found at these three sites was drawn from different catchments, implying a degree of landscape/resource partitioning even at this early stage. These communities clearly invested substantial effort in obtaining ivory from across the region, which speaks to the importance of this commodity in the economy of the time. We suggest that some ivory items were for local use, but that some may have been intended for more distant markets via Indian Ocean trade

Drowning in data, thirsty for information and starved for understanding: A biodiversity information hub for cooperative environmental monitoring in South Africa

The world is firmly cemented in a notitian age (Latin: notitia, meaning data) – drowning in data, yet thirsty for information and the synthesis of knowledge into understanding. As concerns over biodiversity declines escalate, the volume, diversity and speed at which new environmental and ecological data are generated has increased exponentially. Data availability primes the research and discovery engine driving biodiversity conservation. South Africa (SA) is poised to become a world leader in biodiversity conservation. However, continent-wide resource limitations hamper the establishment of inclusive technologies and robust platforms and tools for biodiversity informatics. In this perspectives piece, we bring together the opinions of 37 co-authors from 20 different departments, across 10 SA universities, 7 national and provincial conservation research agencies, and various institutes and private conservation, research and management bodies, to develop a way forward for biodiversity informatics in SA. We propose the development of a SA Biodiversity Informatics Hub and describe the essential components necessary for its design, implementation and sustainability. We emphasise the importance of developing a culture of cooperation, collaboration and interoperability among custodians of biodiversity data to establish operational workflows for data synthesis. However, our biggest challenges are misgivings around data sharing and multidisciplinary collaboration

The association between central obesity and psychological distress in a group of urban Africans : the SABPA study

Thesis (PhD (Human Movement Science))--North-West University, Potchefstroom Campus, 2012.Introduction: Obesity plays an important role in the development of the metabolic syndrome, with central obesity being included as a required prerequisite in the most recent definition of the metabolic syndrome by the International Diabetes Federation (IDF). The following components were included in the Joint Statement Consensus (JSC) definition: raised blood pressure (systolic BP ? 130 or diastolic BP ? 85 mm Hg), raised triglycerides (Trig)( ? 1.7 mmol/L) and lowered high–density lipoprotein cholesterol (HDL)(< 1.03 mmol/L in males and < 1.29 mmol/L in females), raised fasting glucose (? 5.6 mmol/L), and central obesity. Population– and country–specific definitions for waist circumference is recommended, although the IDF cut points are to be used for non–Europeans until more data are available. Aim: Consequently, the aim of the study was to determine a population–specific waist circumference (WC) cut off, comparing the new proposed waist circumference model (NPM) with the current cut offs proposed by the Joint Statement Consensus (JSC). Association between the new proposed cut off and perception of own health in a group of urban African teachers was also investigated. Method: WC, sphygmomanometer blood pressure, fasting bloods (glucose, HDL and triglycerides) and ultrasound carotid intima–media thickness (CIMT) were obtained for 171 black urban teachers from the sympathetic activity and ambulatory blood pressure in Africans (SABPA) study. Perception of own health was determined via the General Health Questionnaire–28 (GHQ–28). Gender–separate receiver operating curve (ROC) analyses were performed for each of the metabolic syndrome components to determine a new population–specific waist circumference cut off. Subsequently Logistic Regression and Neural Networks analyses were performed in order to validate the NPM. Thereafter the association between the NPM and perception of own health was considered. Results: The respective blood pressure cut offs corresponded best with WC pathology, and a NPM was proposed with the new WC cut off for the males be set at 90 cm as opposed to the current 94 cm; whilst the female cut off be set at 98 cm as opposed to the existing cut off of 80 cm. Thereafter ROC analyses (not adjusting for covariates), Logistic Regression and Neural Networks statistics (both adjusting for a priori confounders, age, BMI and physical activity) validated that the NPM model was comparable to the JSC model. Both models correlated with CIMT, an indicator of structural vascular disease. When comparing the JSC and NPM WC models, only the NPM model was associated with perception of own poorer health. Conclusion: A new population and ethnicity–specific WC cut off was recommended (NPM). Subsequently the NPM was validated via Logistic Regression and Neural Networks statistical analyses. The NPM was comparable with the JSC cut offs which are currently in use in predicting structural vascular disease via CIMT. It is proposed that the NPM cut offs be used in this population due to the strong association between blood pressure and the proposed WC cut offs, validated by Logistic Regression and Neural Networks statistical analyses. Furthermore, associations were demonstrated between the NPM and perception of own health in a group of urban Africans.Doctora