Vegetation mapping in the St Lucia estuary using very high-resolution multispectral imagery and LiDAR

The original publication is available at https://www.sciencedirect.com/journal/south-african-journal-of-botanyCITATION: Luck-Vogel, M. et al. 2016. Vegetation mapping in the St Lucia estuary using very high-resolution multispectral imageray and LiDAR. South African Journal of Botany, 107:188-199. https://doi.org/10.1016/j.sajb.2016.04.010This paper examines the value of very high-resolution multispectral satellite imagery and LiDAR-derived digital elevation information for classifying estuarine vegetation types. Satellite images used are fromtheWorldView-2, RapidEye, and SPOT-6 sensors in 2mand 5mresolution, respectively, acquired between 2010 and 2014. Ground truthing reference is a GIS-derived vegetation map based on field data from 2008. Supervised maximum likelihood classification produced satisfactory overall accuracies between 64.3% and 77.9% for the SPOT-6 and the WorldView-2 image, respectively,while the RapidEye-based classifications produced overall accuracies between 55.0% and 66.8%. The reasons for the misclassifications are mainly based on the highly dynamic environmental conditions causing discrepancies between the field data and satellite acquisition dates rather than technical issues. Dynamics in water levels and salinity caused rapid change in vegetation communities. Further, weather impacts such as floods and wind events caused water turbidity and led to bias in the reflective properties of the satellite images and thus misclassifications. These results show, however, that the spatial and spectral resolution of modern very high-resolution imagery is sufficient to satisfactory map estuarine vegetation and to monitor small-scale change. They emphasise, however, the importance of synchronisation of ground truthing data with actual image acquisition dates in these highly dynamic environments in order to achieve high classification accuracies. The results also highlight the importance of ancillary data for accurate interpretation of observed classification discrepancies and vegetation dynamics.Publishers versio

South African universities and human development : Towards a theorisation and operationalisation of professional capabilities for poverty reduction

This paper reports on a research project investigating the role of universities in South Africa in contributing to poverty reduction through the quality of their professional education programmes. The focus here is on theorising and the early operationalisation of multi-layered, multi-dimensional transformation based on ideas from Amartya Sen's capability approach. Key features of a professionalism oriented to public service, which in South Africa must mean the needs and lives of the poor, are outlined. These features include: the demand from justice; the expansion of the comprehensive capabilities both of the poor and professional capability formation to be able to act in ‘pro-poor’ ways; and, praxis pedagogies which shape this connected process. This theorisation is then tentatively operationalised in a process of selecting transformation dimensions

Molecular tools for bathing water assessment in Europe:Balancing social science research with a rapidly developing environmental science evidence-base

The use of molecular tools, principally qPCR, versus traditional culture-based methods for quantifying microbial parameters (e.g., Fecal Indicator Organisms) in bathing waters generates considerable ongoing debate at the science-policy interface. Advances in science have allowed the development and application of molecular biological methods for rapid (~2 h) quantification of microbial pollution in bathing and recreational waters. In contrast, culture-based methods can take between 18 and 96 h for sample processing. Thus, molecular tools offer an opportunity to provide a more meaningful statement of microbial risk to water-users by providing near-real-time information enabling potentially more informed decision-making with regard to water-based activities. However, complementary studies concerning the potential costs and benefits of adopting rapid methods as a regulatory tool are in short supply. We report on findings from an international Working Group that examined the breadth of social impacts, challenges, and research opportunities associated with the application of molecular tools to bathing water regulations

The effect of crop rotation on soil health in the north-western Free State region, South Africa

Soil health is an important aspect of sustainable agriculture. By maintaining soil health, crop yields can be consistently successful without negatively affecting the environment. The objective of this study was to evaluate the effects that different cropping systems have on soil health in the north-western Free State region. The cropping systems focused on maize production, with soybean and cover crop included as rotational crops and monitored for three consecutive seasons. Soil samples were taken seasonally and their physical, chemical and biological properties, as well as the subsequent soil health score, were measured using the Haney Soil Health Test (HSHT). Results from the HSHT were statistically analysed and showed that there was no statistically significant interaction effect between cropping systems and season on soil properties, nor on the subsequent soil health score. These findings suggest that soybean and cover crop rotations with maize have the potential to naturally maintain soil health in a condition similar to those subjected to an artificially fertilised monoculture of maize. In addition, season variation influenced soil health irrespective of cropping system. Therefore, including soybean and cover crops in cropping systems with maize can be a means of promoting sustainable agriculture in the north-western Free State region, when seasonal variation and inherent soil properties are considered.</p

Assessing the Impacts of COVID-19 on the Aquaculture Industry in South Africa, Using the Marine Mussel Farming Sector as A Case Study

This study investigated the impacts of COVID-19 on the aquaculture sector in South Africa. The study was conducted on the West Coast of the Western Cape, South Africa. A multiple-case study approach was followed, focusing on the marine mussel farming sub-sector in Saldanha Bay. Semi-structured interviews were conducted with the owners or managers of nine mussel farming enterprises, and with nine representatives of role players with responsibility or experience in aquaculture, agriculture, or enterprise development. The results of the study focussed on the impacts of COVID-19 on the aquaculture sector and role player organizations; COVID-19 support; initiatives for preparation, survival, and rebuilding; factors promoting resilience, survival, and rebuilding; and requirements to survive and rebuild the sector. The main impact on the aquaculture sector was the closure of markets, which led to cascading impacts on all aspects of the value chain. Role players were affected through impacts on programmes, projects, and staff. Various COVID-19 relief schemes were made available however these could not address all the needs of the sector. Enterprises prepare for the pandemic and the future through long term planning. The main factors contributing to resilience were subsidisation from shareholders, having reserve funds and multiple streams of revenue. The most critical requirements to survive and rebuild the sector was financial support and the opening of markets. The study recommends follow up assessments of the aquaculture industry to fully understand and quantify the effects of the prolonged pandemic and provide tailor-made solutions for each sub-sector to stabilise, revive and grow the aquaculture sector in the medium to long term. Aquaculture enterprises that have closed or are at risk of closure should be prioritised first before any investment in new ventures is considered. In addition, the development of an aquaculture industry-based Business Continuity Strategy and the Ocean Economy Master plan should be prioritised to assist enterprises until the pandemic is over, to prepare for normalisation of operations thereafter, and to prepare the sector and individual enterprises to be more resilient in case of future global crises and disasters

Opportunities and limitations of molecular methods for quantifying microbial compliance parameters in EU bathing waters

The debate over the suitability of molecular biological methods for the enumeration of regulatory microbial parameters (e.g. Faecal Indicator Organisms [FIOs]) in bathing waters versus the use of traditional culture-based methods is of current interest to regulators and the science community. Culture-based methods require a 24-48hour turn-around time from receipt at the laboratory to reporting, whilst quantitative molecular tools provide a more rapid assay (approximately 2-3h). Traditional culturing methods are therefore often viewed as slow and 'out-dated', although they still deliver an internationally 'accepted' evidence-base. In contrast, molecular tools have the potential for rapid analysis and their operational utility and associated limitations and uncertainties should be assessed in light of their use for regulatory monitoring. Here we report on the recommendations from a series of international workshops, chaired by a UK Working Group (WG) comprised of scientists, regulators, policy makers and other stakeholders, which explored and interrogated both molecular (principally quantitative polymerase chain reaction [qPCR]) and culture-based tools for FIO monitoring under the European Bathing Water Directive. Through detailed analysis of policy implications, regulatory barriers, stakeholder engagement, and the needs of the end-user, the WG identified a series of key concerns that require critical appraisal before a potential shift from culture-based approaches to the employment of molecular biological methods for bathing water regulation could be justified

Data_Sheet_2_Iterative mapping of marine ecosystems for spatial status assessment, prioritization, and decision support.PDF

South Africa has taken an iterative approach to marine ecosystem mapping over 18  years that has provided a valuable foundation for ecosystem assessment, planning and decision-making, supporting improved ecosystem-based management and protection. Iterative progress has been made in overcoming challenges faced by developing countries, especially in the inaccessible marine realm. Our aim is to report on the approach to produce and improve a national marine ecosystem map to guide other countries facing similar challenges, and to illustrate the impact of even the simplest ecosystem map. South Africa has produced four map versions, from a rudimentary map of 34 biozones informed by bathymetry data, to the latest version comprising 163 ecosystem types informed by 83 environmental and biodiversity datasets that aligns with the IUCN Global Ecosystem Typology. Data were unlocked through academic and industry collaborations; multi-disciplinary, multi-realm and multi-generational networks of practitioners; and targeted research to address key gaps. To advance toward a more transparent, reproducible and data-driven approach, limitations, barriers and opportunities for improvement were identified. Challenges included limited human and data infrastructure capacity to collate, curate and assimilate many data sources, covering a variety of ecosystem components, methods and scales. Five key lessons that are of relevance for others working to advance ecosystem classification and mapping, were distilled. These include (1) the benefits of iterative improvement; (2) the value of fostering relationships among a co-ordinated network of practitioners including early-career researchers; (3) strategically prioritizing and leveraging resources to build and curate key foundational biodiversity datasets and understand drivers of biodiversity pattern; (4) the need for developing, transferring and applying capacity and tools that enhance data quality, analytical workflows and outputs; and (5) the application of new technology and emerging statistical tools to improve the classification and prediction of biodiversity pattern. South Africa’s map of marine ecosystem types has been successfully applied in spatial biodiversity assessment, prioritization to support protected area expansion and marine spatial planning. These successes demonstrate the value of a co-ordinated network of practitioners who continually build an evidence base and iteratively improve ecosystem mapping while simultaneously growing ecological knowledge and informing changing priorities and policy.</p