Browsing by Subject "Biodiversity"

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An exploratory study of biodiversity, ecological and extinction reporting among JSE-listed entities
(University of the Witwatersrand, Johannesburg, 2021) Da Mata, Dino Marco; Maroun, Warren
The purpose of this research is to explore the level of biodiversity, ecological and extinction reporting among 50 Top JSE-listed entities and the possible determinants of biodiversity, ecological and extinction reporting. This is important because unprecedented biodiversity loss is a major ecological and business risk affecting South African organisations. The thesis is grounded in an interpretive approach to collecting and analysing data and employs a mixed- methods approach. Qualitative content and thematic analysis were used to evaluate what content companies disclose in their integrated reports and to gauge the level of biodiversity, ecological and extinction reporting over the 2018 to 2020 reports. This was followed by the use of quantitative methods to test for associations between identified determinants and the level of reporting. The findings show that, overall, the level of disclosures have increased since 2018. Unfortunately, most of the disclosures are still vague, generic or focus on positive information. The findings also showed that there is a significant relationship between the typeof industry and the level of biodiversity, ecological and extinction reporting. Interestingly, the study found that secondary listed JSE companies have a much higher level of biodiversity, ecological and extinction reporting. The research found that there is a significant relationship between the level of reporting and if the company has a biodiversity partnership or has disclosed the importance of biodiversity. Suggesting that companies are beginning to understand the need to protect biodiversity and prevent further biodiversity loss. This change in mindset is, unfortunately, occurring at a slow pace and more needs to be done by companies, stakeholders and society in general. This thesis is the first study to explore biodiversity, ecology and extinction elements concurrently. It is also the first South African study to explore biodiversity, ecological and extinction reporting across a range of industries
Anthropological contributions to historical ecology: 50 questions, infinite prospects
(Public Library of Science, 2017-02) Armstrong, C.G.; Shoemaker, A.C.; McKechnie, I.; Ekblom, A.; Szabó, P.; Lane, P.J.; McAlvay, A.C.; Boles, O.J.; Walshaw, S.; Petek, N.; Gibbons, K.S.; Morales, E.Q.; Anderson, E.N.; Ibragimow, A.; Podruczny, G.; Vamosi, J.C.; Marks-Block, T.; LeCompte, J.K.; Awâsis, S.; Nabess, C.; Sinclair, P.; Crumley, C.L.
This paper presents the results of a consensus-driven process identifying 50 priority research questions for historical ecology obtained through crowdsourcing, literature reviews, and in-person workshopping. A deliberative approach was designed to maximize discussion and debate with defined outcomes. Two in-person workshops (in Sweden and Canada) over the course of two years and online discussions were peer facilitated to define specific key questions for historical ecology from anthropological and archaeological perspectives. The aim of this research is to showcase the variety of questions that reflect the broad scope for historical-ecological research trajectories across scientific disciplines. Historical ecology encompasses research concerned with decadal, centennial, and millennial human-environmental interactions, and the consequences that those relationships have in the formation of contemporary landscapes. Six interrelated themes arose from our consensus-building workshop model: (1) climate and environmental change and variability; (2) multi-scalar, multi-disciplinary; (3) biodiversity and community ecology; (4) resource and environmental management and governance; (5) methods and applications; and (6) communication and policy. The 50 questions represented by these themes highlight meaningful trends in historical ecology that distill the field down to three explicit findings. First, historical ecology is fundamentally an applied research program. Second, this program seeks to understand longterm human-environment interactions with a focus on avoiding, mitigating, and reversing adverse ecological effects. Third, historical ecology is part of convergent trends toward transdisciplinary research science, which erodes scientific boundaries between the cultural and natural.
Determinants of seasonal changes in availability of food patches for elephants (Loxodonta africana) in a semi-arid African savanna
(PeerJ Inc., 2017-06) Clegg, B.W.; O'Connor, T.G.
Loss of biodiversity caused by impact of elephants (Loxodonta africana) on African woodlands may require a management response, but any action should be based on an understanding of why elephants choose to utilise trees destructively. Comprehension of elephant feeding behaviour requires consideration of the relative value of the plant groups they may potentially consume. Profitability of available food is partly determined by the time to locate a food patch and, therefore, as a foundation for understanding the influence of food availability on diet selection, key controls on the density of grass, forb, and browse patches were investigated across space and time in a semi-arid African savanna. Density of food patches changed seasonally because plant life-forms required different volumes of soil water to produce green forage; and woody plants and forbs responded to long-term changes in soil moisture, while grasses responded to short-term moisture pulses. Soil texture, structure of woody vegetation and fire added further complexity by altering the soil water thresholds required for production of green forage. Interpolating between regularly-timed, ground-based measurements of food density by using modelled soil water as the predictor in regression equations may be a feasible method of quantifying food available to elephants in complex savanna environments.
Expecto patronum
(2020) Edery, Kyle
Our natural world is currently undergoing a drastic and radical transformation! Human agency has led to the erosion of the very foundations of our livelihoods, economies, food security, health and quality of life. Ecosystems, which form our life support systems and our safety nets are shrinking and collapsing. At the heart of this collapse are pollinators, such as butterflies and bees, key species responsible for maintaining these vital ecosystems, whose very existence is being threatened by human activity. This thesis depicts a series of explorations, re-defining the environment and surface needed for pollinators in this new age of man vs nature, before manifesting and putting forth the creation of a version of an artificial envi-ronment. This version of an artificial environment is presented as a solution to sustain and revive endangered pollinators and the degrading context of the proposed site.This thesis looks at how architecture, in its physicality, can not only assist eco-systems and pollinators in their fight for survival but also act as a catalyst for a process of awakening and awareness. The intervention proposed in this thesis aims to create a space that negotiates between the two worlds of pollinators and humans, at the intersection of the built form and the natural environment. In doing so, this will ensure a space that benefits both people and pollinators, at their respective scales. The design of this new surface / artificial environment aims to aid pollinators year-round both naturally and through artificial means, while also showcasing their contribution to human life and research to aid their survival. The thesis demonstrates the demise of nature, illustrating the impact humanity, as a species, has had and continues to have on the natural world, primarily on the lives of pollinators. A focus on the demise of pollinators is addressed, as their brink of extinction stresses a fundamental link between the two causes of collapse and how by saving pollinators, nature in turn can be revived. By doing the above, this thesis will advocate for the creation of an artificial environment as an effective solution to sustain and revive South Africa’s endangered pollinators
Functional ecology of afrotropical freshwaters in the Republic of Congo, west-central Africa
(2024) Walsh, Gina
Characterising functional freshwater biodiversity patterns and understanding community determinants can aid in predicting changes and prioritising specific conservation management actions. Afrotropical freshwater systems support diverse ecological communities, including many taxonomically undescribed species, yet few studies have been undertaken in this region and they remain poorly understood. Additionally, an overwhelming amount of research on north temperate streams has given rise to widely used lotic conceptual models which are superimposed over freshwaters globally, though the theory governing the structure of Afrotropical lotic communities remains largely unexplored. In this thesis I explored different aspects of the biodiversity, trophic ecology and functional diversity of an Afrotropical system in the Republic of Congo (west Central Africa) through a series of field studies. I formally describe two new to science fish species collected in the region, and use fish functional traitbased approaches to explore the functional diversity of fish assemblages and test selected expectations of riverine conceptual models in this regional setting. Following, I used carbon and nitrogen stable isotopes (δ13C, δ15N) from samples collected along a continuum of a coastal river in the Republic of the Congo to show temporal and spatial patterns of trophic diversity and basal carbon resource use. In addition to uncovering new fish diversity, I established that whilst tenets of certain conceptual models such as the River Continuum Concept and the River Habitat Template were supported by fish trait-environment relationships, unique patterns of functional diversity also exist which are scale dependent and result in different functional strategies driving communities between upper and lower positions in the basin. At sub-basin scale, headwater zones harbour substantial functional diversity in relation to upstream catchment size, and results suggest that historical forest refugia may play a role in the high functional richness at high elevations of the region. Isotopic analysis revealed that river order and season are important drivers in consumer trophic strategies along a river continuum in the wet Afrotropics, and that riparian forest sources are key basal carbon resources supporting consumers. Isotopic work reiterated that headwaters are distinctive in terms of trophic and functional diversity. I discovered potential evidence for methanogenic pathways in lateral swamp forests that may subsidize instream food webs. The outcomes of this work demonstrate that existing river conceptual models only partially explain patterns of richness and functional diversity of river systems in this region, and highlights the importance of understanding mechanisms structuring regional functional diversity (e.g. nestedness and turnover) in efforts to conserve freshwater systems. It also emphasizes the need for swamp forest- and riparian specific policies in central Africa to be incorporated into freshwater conservation plans and strategies for forested regions of the Afrotropics.
The extent of biodiversity and species reporting by the top 75 companies listed on the london stock exchange (ISE)
(University of the Witwatersrand, Johannesburg, 2023) Lai, Timothy; Ecim, Dusan; Maroun, Warren
Corporate activities have significantly contributed to the accelerating decline of biological diversity on a global scale, having contributed to resource exploitation, industrialisation, land-use changes and deforestation in their associated operations. In recent years, the loss of habitats, ecosystems and threatened species has been brought to the attention of the public, mostly as a result of adverse events caused by these organisations in the conduct of their operations. The real impacts and consequences of biodiversity loss, has however, largely remained under-reported resulting in the need for organisations to adopt greater levels of corporate accountability and transparency within their biodiversity reports. This study analyses the primary reports (i.e., annual reports) of the top 75 companies listed on the London Stock Exchange (LSE) across a three-year period (2018 – 2020). These reports are studied in order to assess the quality and quantity of the biodiversity and species extinction disclosures, with thepurpose of identifying any trends and patterns across the three years. This research also assesses the possible determinants driving biodiversity disclosures. A mixed method approach is utilised. The content in the primary reports is analysed and evaluated to identify biodiversity-related disclosures and categorises them according to the themes outlined in a detailed disclosure checklist developed using the existing professional and academic literature. Secondly, the quantum and quality of the biodiversity and species extinction related disclosures included in these reports will be determined using a standardised scoring system. This paper finds that the biodiversity and species extinction disclosure among the LSE-listed companies has remained low in both quality and quantity. Although there is considerable improvement in the biodiversity disclosures year-on-year, the disclosures remain limited in substance, lacking sufficient detail over the biodiversity-related matters conveyed to key stakeholders. This research provides insight into the environmental reporting practices of UK-listed companies and aims to identify the trends, patterns and weaknesses found within biodiversity reporting. This study expands on the limited volume of literature within the environmental accounting field, to ultimately aid the transformation in corporate reporting practices
Using the South African Diatom Index (SADI) to determine the present ecological status of the Crocodile River, Kruger National Park
(University of the Witwatersrand, Johannesburg, 2023-08) Thamae, Seeng; Snow, Gavin; Parrini, Francesca
The Crocodile River in the Mpumalanga Province of South Africa is a river of great economic significance, while providing support to the surrounding aquatic and riparian ecosystems through ecological processes of chemical, hydrological, and geomorphological nature. This river forms part of the Inkomati River Basin, which serves as a transboundary basin shared between the Republic of South Africa, Mozambique and Eswatini. The importance of the effective management of transboundary water resources, from an African perspective, cannot be stressed enough due to the water-scarce nature of the Southern African region, particularly South Africa. Incorporating Integrated Water Resources Management (IWRM) and Strategic Adaptive Management approaches into the governance of water resources can aid in the protection of both the quality and quantity of the country’s freshwater reserve. Good governance of water resources is essential in the conservation of aquatic and riparian ecosystem biodiversity, as well as meeting the basic human needs reserve, which is essential to meet people’s daily drinking, food preparation and personal hygiene requirements. The Crocodile River is not immune to pollution of anthropogenic origin, such as urbanisation, mining, agriculture, and industrial by-products. The above mentioned constitutes some of the direct and indirect results of large-scale stresses that are exerted on a river system, mainly owing to environmental factors such as landscape, demographic, atmospheric and hydrologic changes. A few practical examples of these factors include changing population dynamics and resultant land-use requirements, accompanied by compromised riparian vegetations arising from the altered land-use. All this necessitates the regular monitoring of the quality of water in this river system. The outcome of regular river monitoring is essential to the protection of this resource through regulation and policy. The use of physico-chemical parameters to determine the health of the Crocodile River has assisted in identifying compromised aquatic and riparian ecosystems and ultimately recommending relevant mitigation strategies necessary in maintaining an acceptable standard of water quality. Incorporating biomonitoring techniques, wherein aquatic microorganisms are used to infer water quality, as a tool to assess the health of a river ecosystem has proven useful, mainly due to the sensitivity of periphyton assemblages (algae, cyanobacteria, diatoms) to changing river conditions, based on nutrients and physico-chemical parameters. The use of these organisms, in bio-assessments of aquatic ecosystems has been key to overall river health monitoring. This study highlights how diatoms, through their published ecological data, can contribute to the Resource Directed Measures method of determining the Present Ecological Status of a river, using the Crocodile (East) River as a case study. The current study was developed to assess the ecological category of the Crocodile River, along the southern boundary of the Kruger National Park. Four sampling sites were identified for the study, from which water samples were collected during September 2019, October 2019, and March 2020 sampling sessions. The basis of this was to investigate the changes in diatom communities and dominant microphytobenthos (MPB) groups (based on the tolerance to fluctuating environmental conditions amongst the various species) in response to the spatio-temporal changes in the quality and quantity of water at the four sites throughout the study period. These results were then compared to past studies to determine if there has been a change in river health over the past decade. Physico-chemical variables were measured in situ using a YSI Professional Plus (Pro Plus) multi-parameter instrument, which included temperature, pH, electrical conductivity, and dissolved oxygen. The benthic microalgal biomass of cyanobacteria, green algae and diatoms was quantified from the fluorescent signatures of the groups in situ using a bbe BenthoTorch. The bbe BenthoTorch is a hand-held apparatus that uses in situ quantification of chlorophyll-a fluorescence as an index of benthic algal biomass. The diatoms present in the samples were later prepared and isolated for microscopic identification and individual counts. The Relative Abundance (RA%) of dominant diatom species and the ecological category of each sampling site was determined using OMNIDIA software based South African Diatom Index (SADI). Ecological categories using the SADI range from A (good quality) to E (bad quality). Data analyses include the use of ordination plots (CCA and PCA) to evaluate the response of the dominant diatom species to changing environmental variables and the interspecific relationships between the diatom species in each assemblage, based on their ecological requirements. The study revealed that the ecological status of the Crocodile River when compared to previous studies had remained the same; C (moderate quality). This finding supports the use of the South African Diatom Index (SADI) in determining the Present Ecological State of the Crocodile River, in the Kruger National Park. There have been similar studies in other river systems within the Kruger National Park, wherein diatoms (specifically diatom-based index scores) were used to infer the water quality, at the time, in comparison to historic / benchmark water quality parameters. These studies were conducted in the Olifants, Letaba and the Sabie rivers of the park. The viability of these studies is motivated by benthic diatoms being particularly sensitive to changes in water quality, making them an ideal indicator of river health that is complementary to the current suite of biomonitoring tools. This method has immense potential in South Africa, provided that more focus is placed on diatoms and investment made in capacitating researchers and diatom taxonomists with the skills to perpetuate this vast field of study.