A critical evaluation of inter-jurisdictional rules in the South African value-added tax system
- Authors: Schneider, Ferdinand Dirk
- Date: 2017
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/7971 , vital:21329
- Description: This study analysed the current inter-jurisdictional rules in the South African Value-Added Tax (VAT) system, identified shortcomings, and proposed legislative amendments or additions to address these shortcomings. The research was conducted within an interpretative post positivism paradigm, applied a qualitative research methodology, and a doctrinal research method. A detailed review of the literature was conducted to establish the theoretical basis of a good tax system and the theory underpinning indirect and consumption taxation. The literature review also included an in-depth analysis of the South African VAT system and its treatment of resident and non-resident businesses with a South African physical or economic reach, and its treatment of local and cross-border transactions, including imported services. The literature review also considered the international VAT treatment of these transactions. To obtain a wider range of expert opinions regarding shortcomings in inter-jurisdictional rules in the South African VAT system, data was collected through structured interviews with South African and global VAT and indirect tax experts, using a questionnaire that was specifically designed for this purpose. This study proposed amendments and additions to the VAT Act, dealing with the VAT registration of non-resident suppliers; addressing various issues relating to the interjurisdictional VAT rate; proposing measures in connection with imported services; and legislating the intention of the legislator to tax final utilisation or consumption. The study finally recommended the introduction of a general place of supply rule linked to residency; specific place of supply rules for electronic, broadcasting, and telecommunication services; and zero rating provisions for electronic, broadcasting, and telecommunication services provided to non-resident suppliers by resident suppliers for services initiated outside South Africa.
- Full Text:
- Authors: Schneider, Ferdinand Dirk
- Date: 2017
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/7971 , vital:21329
- Description: This study analysed the current inter-jurisdictional rules in the South African Value-Added Tax (VAT) system, identified shortcomings, and proposed legislative amendments or additions to address these shortcomings. The research was conducted within an interpretative post positivism paradigm, applied a qualitative research methodology, and a doctrinal research method. A detailed review of the literature was conducted to establish the theoretical basis of a good tax system and the theory underpinning indirect and consumption taxation. The literature review also included an in-depth analysis of the South African VAT system and its treatment of resident and non-resident businesses with a South African physical or economic reach, and its treatment of local and cross-border transactions, including imported services. The literature review also considered the international VAT treatment of these transactions. To obtain a wider range of expert opinions regarding shortcomings in inter-jurisdictional rules in the South African VAT system, data was collected through structured interviews with South African and global VAT and indirect tax experts, using a questionnaire that was specifically designed for this purpose. This study proposed amendments and additions to the VAT Act, dealing with the VAT registration of non-resident suppliers; addressing various issues relating to the interjurisdictional VAT rate; proposing measures in connection with imported services; and legislating the intention of the legislator to tax final utilisation or consumption. The study finally recommended the introduction of a general place of supply rule linked to residency; specific place of supply rules for electronic, broadcasting, and telecommunication services; and zero rating provisions for electronic, broadcasting, and telecommunication services provided to non-resident suppliers by resident suppliers for services initiated outside South Africa.
- Full Text:
A critical realist dialectical understanding of learning pathways associated with two scarce skill environmental occupations within a transitioning systems frame
- Authors: Ramsarup, Presha
- Date: 2017
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/5937 , vital:20992
- Description: Policy, environmental, social and economic factors are all driving South Africa's transition to sustainable development and a greener economy. Various policies have been developed to foster sustainable development in the post-apartheid era in South Africa (i.e. since 1994) and there are various projections on potential job creation for a green economy. However, there is a problem related to both the achievement of sustainable development and green economy objectives: South Africa is said to lack adequately qualified people to implement these goals resulting in what is termed 'scarce skills' in the environmental and sustainable development sector. This problem has, in turn, prompted various skills development studies in the environmental sector, including a national Environmental Sector Skills Plan produced in 2010. All these studies point to a reactive skills development system that provides inadequate learning pathways for existing and newly emerging green occupations, which provided the impetus for a more proactive, transformative praxis oriented system of skills development that supports environmental learning pathways in South Africa. A second problem is that the concept of 'learning pathway' is poorly defined in the South African environmental education and wider education and training policy context. This term is often used in policy discourse within the notion of 'seamless learning pathways' and is only vaguely defined. This study set out to investigate selected occupationally directed environmental learning pathways in the South African National Qualifications Framework (NQF) and green transitioning context. In attempting to characterise the nature of the environmental pathway, the study utilised critical realist metatheory which serves as an underlabourer for domain specific theory of transitioning societies and systems, life-course transitions and career development. This theoretical work allowed the characterisation of environmental learning pathways as educational and occupational progression. The study investigated the nature of learning and work transitions across the life- course of selected environmental professionals in two key occupational categories - environmental engineer and environmental scientist - both of which have been defined as scarce skills in South Africa. This enabled a nuanced examination of the formation of what emerged as 'boundaryless' career stories of professionals engaged in these two occupations. The study also sought to engage with a methodological problem in learning pathways research, notably that studies are generally framed either at the micro level career story, emphasising agency of individuals (voluntarism), or at the policy level, emphasising structural aspects of the skills development system (determinism). This study sought to bridge the macro-micro problem drawing on critical realist retroductive analysis; this facilitated the shift from a focus on events and experiences that can be empirically observed (captured in case study approaches) to the causal mechanisms influencing environmental learning pathways in these two scarce skill occupations (discussed and analysed using dialectical critical realism), shedding light on how systemic and structural dynamics and mechanisms shape and influence the emergence of learning pathways as experienced in scarce skill occupations in the environmental sector. The opening chapters of the thesis provide an historical view of how the South African education and training system, itself in a transitioning process, has had to grapple with how to respond to and meaningfully take up the new emerging environmental / sustainable development mandate, which is increasingly framed within a multi-levelled transitioning social-ecological system perspective in post-apartheid South Africa. These transitioning systems are shaped by substantive policy imperatives for societal transformation, social justice, sustainable development and equity. Since 1994, various transformations have been taking place, often in paradoxical forms, in both the environmental and educational sectors, shaping a complex multi-levelled transitioning systems perspective for the study. This background work on transitioning systems provides the foundation for the first data chapter, which provides a descriptive outline of key supply side systemic elements as these pertain to environmental learning pathways more broadly (qualifications; occupational framing; career systems; sector skills planning). It also points to the lack of adequate mechanisms for analysing demand for environmental occupations, and highlights some of the contradictions in the supply- demand relation as these pertain to newly emerging environmental occupations. This helps to explain the empirical findings of previous environmental sector studies on the slow and reactive defining of environmental education and training for environmental occupations within the transforming education and training system in South Africa. The next two chapters, using case-based qualitative data, present the analysis of the two scarce skill occupations investigated - environmental engineer and environmental scientist. These chapters outline the dominant institutional educational pathway and the key supply platforms that support these pathways (career guidance; qualifications, occupational framings, skills planning) and the learning and work transitions of professionals within the occupation. The chapters highlight the factors and causal mechanisms influencing these learning pathways and thus provide insight into the multi-level dynamics that underpin learning pathways. The final chapter uses dialectical critical realism to outline generative mechanisms influencing the construction of the learning pathways. It also highlights key absences that are shaping the emergence (or not) of environmental learning pathways, thus pointing to opportunities for how the NQF might respond to the two scarce skill occupations under study, and to the emergence of environmental learning pathways more broadly within the framework of society-in-transition. Through this, the study links the career stories as analysed within the framework of learning pathways and skills system transitioning literature, to generative mechanisms and system development elements. The study concludes with providing occupational and systemic insights into absences and disjunctures that characterise the emergence (or not) of occupationally oriented environmental learning pathways. It also provides insight into what leads to these absences, and how they are kept in place and suggests possibilities and openings for transformative praxis within a multi-levelled transitioning system framework. The study makes the following contributions: At a theoretical level, the study has shown that environmental learning pathways need to be viewed as a complex phenomenon that is emergent in open systems and constituted by dialectically interdependent planes. A deeper understanding of environmental learning pathways is driven by both educational and occupational progression. It utilises key contemporary ideas around learning and work transitions but links them to the broader analyses of transitioning societies influencing the environmental sector, indicating the significance of how environmental education and training system development is situated within the wider transitioning process oriented towards social-ecological sustainability, social justice and greener economies. This study has further identified green skills as an important focus in research work on transitioning societies. At a methodological level, the study has shown how macro-micro and laminated system research can be useful in studying transitioning systems. As a laminated systems study with a focus on transitioning societies, it provides a baseline for further systems study on green work and green skills. At a practical level, the study has made actual contributions to the conceptualisation of learning pathways in the South African NQF context, to building and informing future green skill developments in the South African post-school system, the environmental sector and to informing conceptualising in the emergent Green Skills project.
- Full Text:
- Authors: Ramsarup, Presha
- Date: 2017
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/5937 , vital:20992
- Description: Policy, environmental, social and economic factors are all driving South Africa's transition to sustainable development and a greener economy. Various policies have been developed to foster sustainable development in the post-apartheid era in South Africa (i.e. since 1994) and there are various projections on potential job creation for a green economy. However, there is a problem related to both the achievement of sustainable development and green economy objectives: South Africa is said to lack adequately qualified people to implement these goals resulting in what is termed 'scarce skills' in the environmental and sustainable development sector. This problem has, in turn, prompted various skills development studies in the environmental sector, including a national Environmental Sector Skills Plan produced in 2010. All these studies point to a reactive skills development system that provides inadequate learning pathways for existing and newly emerging green occupations, which provided the impetus for a more proactive, transformative praxis oriented system of skills development that supports environmental learning pathways in South Africa. A second problem is that the concept of 'learning pathway' is poorly defined in the South African environmental education and wider education and training policy context. This term is often used in policy discourse within the notion of 'seamless learning pathways' and is only vaguely defined. This study set out to investigate selected occupationally directed environmental learning pathways in the South African National Qualifications Framework (NQF) and green transitioning context. In attempting to characterise the nature of the environmental pathway, the study utilised critical realist metatheory which serves as an underlabourer for domain specific theory of transitioning societies and systems, life-course transitions and career development. This theoretical work allowed the characterisation of environmental learning pathways as educational and occupational progression. The study investigated the nature of learning and work transitions across the life- course of selected environmental professionals in two key occupational categories - environmental engineer and environmental scientist - both of which have been defined as scarce skills in South Africa. This enabled a nuanced examination of the formation of what emerged as 'boundaryless' career stories of professionals engaged in these two occupations. The study also sought to engage with a methodological problem in learning pathways research, notably that studies are generally framed either at the micro level career story, emphasising agency of individuals (voluntarism), or at the policy level, emphasising structural aspects of the skills development system (determinism). This study sought to bridge the macro-micro problem drawing on critical realist retroductive analysis; this facilitated the shift from a focus on events and experiences that can be empirically observed (captured in case study approaches) to the causal mechanisms influencing environmental learning pathways in these two scarce skill occupations (discussed and analysed using dialectical critical realism), shedding light on how systemic and structural dynamics and mechanisms shape and influence the emergence of learning pathways as experienced in scarce skill occupations in the environmental sector. The opening chapters of the thesis provide an historical view of how the South African education and training system, itself in a transitioning process, has had to grapple with how to respond to and meaningfully take up the new emerging environmental / sustainable development mandate, which is increasingly framed within a multi-levelled transitioning social-ecological system perspective in post-apartheid South Africa. These transitioning systems are shaped by substantive policy imperatives for societal transformation, social justice, sustainable development and equity. Since 1994, various transformations have been taking place, often in paradoxical forms, in both the environmental and educational sectors, shaping a complex multi-levelled transitioning systems perspective for the study. This background work on transitioning systems provides the foundation for the first data chapter, which provides a descriptive outline of key supply side systemic elements as these pertain to environmental learning pathways more broadly (qualifications; occupational framing; career systems; sector skills planning). It also points to the lack of adequate mechanisms for analysing demand for environmental occupations, and highlights some of the contradictions in the supply- demand relation as these pertain to newly emerging environmental occupations. This helps to explain the empirical findings of previous environmental sector studies on the slow and reactive defining of environmental education and training for environmental occupations within the transforming education and training system in South Africa. The next two chapters, using case-based qualitative data, present the analysis of the two scarce skill occupations investigated - environmental engineer and environmental scientist. These chapters outline the dominant institutional educational pathway and the key supply platforms that support these pathways (career guidance; qualifications, occupational framings, skills planning) and the learning and work transitions of professionals within the occupation. The chapters highlight the factors and causal mechanisms influencing these learning pathways and thus provide insight into the multi-level dynamics that underpin learning pathways. The final chapter uses dialectical critical realism to outline generative mechanisms influencing the construction of the learning pathways. It also highlights key absences that are shaping the emergence (or not) of environmental learning pathways, thus pointing to opportunities for how the NQF might respond to the two scarce skill occupations under study, and to the emergence of environmental learning pathways more broadly within the framework of society-in-transition. Through this, the study links the career stories as analysed within the framework of learning pathways and skills system transitioning literature, to generative mechanisms and system development elements. The study concludes with providing occupational and systemic insights into absences and disjunctures that characterise the emergence (or not) of occupationally oriented environmental learning pathways. It also provides insight into what leads to these absences, and how they are kept in place and suggests possibilities and openings for transformative praxis within a multi-levelled transitioning system framework. The study makes the following contributions: At a theoretical level, the study has shown that environmental learning pathways need to be viewed as a complex phenomenon that is emergent in open systems and constituted by dialectically interdependent planes. A deeper understanding of environmental learning pathways is driven by both educational and occupational progression. It utilises key contemporary ideas around learning and work transitions but links them to the broader analyses of transitioning societies influencing the environmental sector, indicating the significance of how environmental education and training system development is situated within the wider transitioning process oriented towards social-ecological sustainability, social justice and greener economies. This study has further identified green skills as an important focus in research work on transitioning societies. At a methodological level, the study has shown how macro-micro and laminated system research can be useful in studying transitioning systems. As a laminated systems study with a focus on transitioning societies, it provides a baseline for further systems study on green work and green skills. At a practical level, the study has made actual contributions to the conceptualisation of learning pathways in the South African NQF context, to building and informing future green skill developments in the South African post-school system, the environmental sector and to informing conceptualising in the emergent Green Skills project.
- Full Text:
A perfect end: a study of syllable codas in South African Sign Language
- Köhlo, Mikhaela Demitria Katebe
- Authors: Köhlo, Mikhaela Demitria Katebe
- Date: 2017
- Subjects: South African Sign Language , South African Sign Language Phonology , Linguistics , Grammar, Comparative and general Syllable
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/36127 , vital:24492
- Description: Coda constraints are common in spoken languages. German, for example, can only have voiceless obstruents in the coda position (Lombardi 1999). Most sign language research has been on other sign languages, most notably American Sign Language (ASL). This research serves to contribute to syllable theory and has a methodology that allows for cross-linguistic research, strengthening the understanding of sign languages in general, and enhancing the description of SASL in particular. It is well known that syllables in spoken languages require a vowel nucleus to be well-formed. Sandler and Lillo-Martin (2006) provide evidence of sign languages requiring movement to be considered well-formed: even seemingly stationary signs such as WHO, which occurs at the chin, will have finger wiggling as some form of movement. It is thus natural to assume that movement is akin to vowels in syllable theory (Brentari 1998). Thus, locations are similar to consonants. However, the visual nature of sign allows for simultaneity - holds do not occur by themselves. Next to location, handshapes are phonetically complex features that may impact the constraints at coda position. To my knowledge, there is no formal research on the coda constraints of sign language syllables. The data examined here comes from a video dictionary of approximately 175 words. From this dictionary, a database of coded locations and handshapes are recorded for both the onset and the coda. From this, a consonant inventory is made and patterns are identified. Each source of data is analysed individually based on Brentari’s (1998) Prosodic Model. Patterns that are noticed are then looked at using Brentari’s (1998) framework to account for what phonological rules are dictating constraints. However, as a hearing researcher cannot claim native knowledge of a sign language, the conclusions drawn from the data will be tested using native SASL signers for negative judgement. The preliminary findings of the research suggest that there are constraints on the coda location and handshape of a sign and that this may be a result of the natural classes of handshape and location prohibiting certain onset-coda combinations. The onset and coda on monosyllabic signs mirror each other’s location, while the handshape cannot change in repeated and many monosyllabic signs. These constraints provide more understanding into the rich phonological nature of sign languages.
- Full Text:
- Authors: Köhlo, Mikhaela Demitria Katebe
- Date: 2017
- Subjects: South African Sign Language , South African Sign Language Phonology , Linguistics , Grammar, Comparative and general Syllable
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/36127 , vital:24492
- Description: Coda constraints are common in spoken languages. German, for example, can only have voiceless obstruents in the coda position (Lombardi 1999). Most sign language research has been on other sign languages, most notably American Sign Language (ASL). This research serves to contribute to syllable theory and has a methodology that allows for cross-linguistic research, strengthening the understanding of sign languages in general, and enhancing the description of SASL in particular. It is well known that syllables in spoken languages require a vowel nucleus to be well-formed. Sandler and Lillo-Martin (2006) provide evidence of sign languages requiring movement to be considered well-formed: even seemingly stationary signs such as WHO, which occurs at the chin, will have finger wiggling as some form of movement. It is thus natural to assume that movement is akin to vowels in syllable theory (Brentari 1998). Thus, locations are similar to consonants. However, the visual nature of sign allows for simultaneity - holds do not occur by themselves. Next to location, handshapes are phonetically complex features that may impact the constraints at coda position. To my knowledge, there is no formal research on the coda constraints of sign language syllables. The data examined here comes from a video dictionary of approximately 175 words. From this dictionary, a database of coded locations and handshapes are recorded for both the onset and the coda. From this, a consonant inventory is made and patterns are identified. Each source of data is analysed individually based on Brentari’s (1998) Prosodic Model. Patterns that are noticed are then looked at using Brentari’s (1998) framework to account for what phonological rules are dictating constraints. However, as a hearing researcher cannot claim native knowledge of a sign language, the conclusions drawn from the data will be tested using native SASL signers for negative judgement. The preliminary findings of the research suggest that there are constraints on the coda location and handshape of a sign and that this may be a result of the natural classes of handshape and location prohibiting certain onset-coda combinations. The onset and coda on monosyllabic signs mirror each other’s location, while the handshape cannot change in repeated and many monosyllabic signs. These constraints provide more understanding into the rich phonological nature of sign languages.
- Full Text:
A review of the development and enactment of a radio programme on rainwater harvesting in expanding social learning interactions: a case of the Imvotho Bubomi Learning Network in the Nkonkobe Municipality, Eastern Cape, South Africa
- Authors: Lupele, Chisala
- Date: 2017
- Subjects: Imvotho Bubomi Learning Network , Amanzi for Food , Radio in education -- South Africa -- Eastern Cape , Educational broadcasting -- South Africa -- Eastern Cape , Radio stations -- South Africa -- Eastern Cape , Community radio -- South Africa -- Eastern Cape , Environmental education -- South Africa , Water conservation -- Study and teaching -- South Africa , Rhodes University. Environmental Learning Research Centre
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/12991 , vital:21786
- Description: The use of radio and associated information and communications technologies (ICTs) has not been widely explored as a process of environmental education over the years. If environmental education is to involve many people, the use of radio and associated ICTs, particularly in community radio, needs to be researched because radio has multilayered functions. This study examines how practitioners in an agricultural Community of Practice (CoP), namely the Imvotho Bubomi Learning Network in the Nkonkobe Municipality, Eastern Cape, South Africa developed a radio programme on rainwater harvesting for the promotion of food security. The study probes the expansion and social learning of the network and into the public sphere after broadcasts. The study draws on research data generated in the Amanzi for Food project which was funded by the Water Research Commission of South Africa and was led by the Rhodes University Environmental Learning Research Centre. Using interviews, radio programme transcripts and observations, the study found that through using their prior knowledge from a training of trainers’ course on rain water harvesting and drawing on everyday experience of rainwater harvesting the CoP members had an expansion in their mutual engagement, joint enterprise, diversity, shared repertoire and identity into a knowledge community. This learning process developed through a successive elaboration of social ecological and social articulations related to the expansive functioning of the CoP; and experience of the benefits of rainwater harvesting as radio programme listeners deliberated how the different practices related to their existing knowledge and experience. The study also found that these expansive processes of social learning occurred across the spectrum of smallholder farmers and homestead food growers in a stimulated radio listening focus group discussion. The study concludes that agriculture practitioners involved in education for sustainable development could expand their knowledge sharing platforms by giving more attention to community radio as a means of both involving participants and engaging learning communities in local environment and sustainability concerns.
- Full Text:
- Authors: Lupele, Chisala
- Date: 2017
- Subjects: Imvotho Bubomi Learning Network , Amanzi for Food , Radio in education -- South Africa -- Eastern Cape , Educational broadcasting -- South Africa -- Eastern Cape , Radio stations -- South Africa -- Eastern Cape , Community radio -- South Africa -- Eastern Cape , Environmental education -- South Africa , Water conservation -- Study and teaching -- South Africa , Rhodes University. Environmental Learning Research Centre
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/12991 , vital:21786
- Description: The use of radio and associated information and communications technologies (ICTs) has not been widely explored as a process of environmental education over the years. If environmental education is to involve many people, the use of radio and associated ICTs, particularly in community radio, needs to be researched because radio has multilayered functions. This study examines how practitioners in an agricultural Community of Practice (CoP), namely the Imvotho Bubomi Learning Network in the Nkonkobe Municipality, Eastern Cape, South Africa developed a radio programme on rainwater harvesting for the promotion of food security. The study probes the expansion and social learning of the network and into the public sphere after broadcasts. The study draws on research data generated in the Amanzi for Food project which was funded by the Water Research Commission of South Africa and was led by the Rhodes University Environmental Learning Research Centre. Using interviews, radio programme transcripts and observations, the study found that through using their prior knowledge from a training of trainers’ course on rain water harvesting and drawing on everyday experience of rainwater harvesting the CoP members had an expansion in their mutual engagement, joint enterprise, diversity, shared repertoire and identity into a knowledge community. This learning process developed through a successive elaboration of social ecological and social articulations related to the expansive functioning of the CoP; and experience of the benefits of rainwater harvesting as radio programme listeners deliberated how the different practices related to their existing knowledge and experience. The study also found that these expansive processes of social learning occurred across the spectrum of smallholder farmers and homestead food growers in a stimulated radio listening focus group discussion. The study concludes that agriculture practitioners involved in education for sustainable development could expand their knowledge sharing platforms by giving more attention to community radio as a means of both involving participants and engaging learning communities in local environment and sustainability concerns.
- Full Text:
A sociological analysis of the lives and livelihoods of child support grant caregivers in Queenstown, South Africa
- Authors: Ntantiso, Ziyanda
- Date: 2017
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: http://hdl.handle.net/10962/7925 , vital:21325
- Description: The post-apartheid state in South Africa has initiated and implemented a large-scale social assistance programme in the form of social grants, including the child support grant. The grant system is meant to provide recipients, who comprise mainly people from poor black households, with the capacity to reduce levels of poverty in their households. The grant with the largest number of recipients is the child support grant, and it is given to the caregiver of a child eligible to receive the grant. Though the value of the monthly grant is minimal, the prevailing literature suggests that it does contribute in some way to enhancing the welfare of the recipients. This thesis focuses on child support grant recipients in the town of Queenstown in the Eastern Cape, and particularly those recipients for whom the grant is the crucial source of income. The main objective of the thesis is to understand and analyse the lives and livelihoods of child support grant recipients (all women) in Queenstown, South Africa. In this regard, the vast majority of caregivers of grant children are women and they often rely exclusively on the grant in taking care of themselves and the children. The thesis does not seek to determine any direct causal relationship between the child grant and poverty reduction, as much of the existing literature seeks to do. It focuses instead on the lives of the grant recipients, including the many challenges they face, as well as how they use the grant to pursue livelihoods in a manner which may at least inhibit the prospects of entering into deeper levels of poverty. The thesis demonstrates that, despite their deprived conditions of material existence, the female caregivers in Queenstown display significant agency in caring for their grant children.
- Full Text:
- Authors: Ntantiso, Ziyanda
- Date: 2017
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: http://hdl.handle.net/10962/7925 , vital:21325
- Description: The post-apartheid state in South Africa has initiated and implemented a large-scale social assistance programme in the form of social grants, including the child support grant. The grant system is meant to provide recipients, who comprise mainly people from poor black households, with the capacity to reduce levels of poverty in their households. The grant with the largest number of recipients is the child support grant, and it is given to the caregiver of a child eligible to receive the grant. Though the value of the monthly grant is minimal, the prevailing literature suggests that it does contribute in some way to enhancing the welfare of the recipients. This thesis focuses on child support grant recipients in the town of Queenstown in the Eastern Cape, and particularly those recipients for whom the grant is the crucial source of income. The main objective of the thesis is to understand and analyse the lives and livelihoods of child support grant recipients (all women) in Queenstown, South Africa. In this regard, the vast majority of caregivers of grant children are women and they often rely exclusively on the grant in taking care of themselves and the children. The thesis does not seek to determine any direct causal relationship between the child grant and poverty reduction, as much of the existing literature seeks to do. It focuses instead on the lives of the grant recipients, including the many challenges they face, as well as how they use the grant to pursue livelihoods in a manner which may at least inhibit the prospects of entering into deeper levels of poverty. The thesis demonstrates that, despite their deprived conditions of material existence, the female caregivers in Queenstown display significant agency in caring for their grant children.
- Full Text:
Abalone stock enhancement at Cape Recife, Eastern Cape Province of South Africa
- Authors: Witte, Warren
- Date: 2017
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/45695 , vital:25532
- Description: The potential for restocking depleted natural reefs with hatchery abalone, Haliotis midae, to support a commercial ranching venture in the Eastern Cape Province of South Africa was investigated. A baseline stock assessment and analysis of historical fishery data provided compelling evidence of significant declines in the abalone stock, attributed to uncontrolled illegal fishing over the last 20 years at the study site. A ranching pilot study was undertaken where small-scale replicated seeding experiments were set up which quantified the effect of seed size, density and habitat on survival and growth of hatchery-reared abalone. Thirty-six experimental plots were seeded with 8400 abalone spread evenly over two broad habitats. Mean retrievals of seeded abalone were 17% ranging from 4 - 42% after a minimum of eight months at large. Release density and large-scale habitat had no significant effect on seed survival, but smaller seed size (40.0 ±3.7mm shell length) achieved higher (F1, 22 = 4.64, p = 0.042) retrievals than larger seed size (53 ±3.7mm). Growth rates were an average of 30% higher in the shallow sites compared deeper sites (t1, 1091 = -2.79, p = 0.005). There was seasonal component in growth with a 0.55 ± 0.04 mm per month higher rate in summer than during winter (t1, 1091 = -12.45, p < 0.001). Abalone seed releases were also conducted on a larger scale, which focused on the economic potential for commercial-scale ranching. Over 160 sites were seeded with 1.4 million hatchery reared abalone or 30 metric tonnes. Seventeen sites underwent long-term monitoring of survival with repeated sampling events on sites over a period of up to 666 days. Nine of these sites were seeded with 140800 small abalone (29 – 40 mm), three sites with 25100 medium abalone (30 – 46 mm) and five sites with 14700 large abalone (60 – 84 mm). There was a significant difference in survival between the seed sizes (F4,6329 = 304.3, P < 0.001). The Generalized Linear Mixed Model (GLMM) calculation estimated the instantaneous apparent mortality rate for small, medium and large abalone at 1.19 yr-1 , -0.9 yr-1 and -0.67 yr-1 , which equated to a survival rate of 21%, 28% and 36% per year respectively. The weighted mortality rate calculated according to the seed size differential mortality and the number of seed released for those sizes was 1 yr-1 or 25% survival. In conjunction with a conservative somatic growth rate of 1.2mm.m-1 and plausible emigration rates, a range of biomass harvesting estimates were obtained. Movement and mortality were investigated using video analysis which showed that hatchery seed had the ability to move considerably once released onto natural reefs and confirmed that mortality immediately following releases was due to the heavy predation pressure as confirmed by shell collections. This project has demonstrated that potential exists for ranching in South Africa and highlights critical factors that need to be addressed if ranching is to be an economically viable operation.
- Full Text:
- Authors: Witte, Warren
- Date: 2017
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/45695 , vital:25532
- Description: The potential for restocking depleted natural reefs with hatchery abalone, Haliotis midae, to support a commercial ranching venture in the Eastern Cape Province of South Africa was investigated. A baseline stock assessment and analysis of historical fishery data provided compelling evidence of significant declines in the abalone stock, attributed to uncontrolled illegal fishing over the last 20 years at the study site. A ranching pilot study was undertaken where small-scale replicated seeding experiments were set up which quantified the effect of seed size, density and habitat on survival and growth of hatchery-reared abalone. Thirty-six experimental plots were seeded with 8400 abalone spread evenly over two broad habitats. Mean retrievals of seeded abalone were 17% ranging from 4 - 42% after a minimum of eight months at large. Release density and large-scale habitat had no significant effect on seed survival, but smaller seed size (40.0 ±3.7mm shell length) achieved higher (F1, 22 = 4.64, p = 0.042) retrievals than larger seed size (53 ±3.7mm). Growth rates were an average of 30% higher in the shallow sites compared deeper sites (t1, 1091 = -2.79, p = 0.005). There was seasonal component in growth with a 0.55 ± 0.04 mm per month higher rate in summer than during winter (t1, 1091 = -12.45, p < 0.001). Abalone seed releases were also conducted on a larger scale, which focused on the economic potential for commercial-scale ranching. Over 160 sites were seeded with 1.4 million hatchery reared abalone or 30 metric tonnes. Seventeen sites underwent long-term monitoring of survival with repeated sampling events on sites over a period of up to 666 days. Nine of these sites were seeded with 140800 small abalone (29 – 40 mm), three sites with 25100 medium abalone (30 – 46 mm) and five sites with 14700 large abalone (60 – 84 mm). There was a significant difference in survival between the seed sizes (F4,6329 = 304.3, P < 0.001). The Generalized Linear Mixed Model (GLMM) calculation estimated the instantaneous apparent mortality rate for small, medium and large abalone at 1.19 yr-1 , -0.9 yr-1 and -0.67 yr-1 , which equated to a survival rate of 21%, 28% and 36% per year respectively. The weighted mortality rate calculated according to the seed size differential mortality and the number of seed released for those sizes was 1 yr-1 or 25% survival. In conjunction with a conservative somatic growth rate of 1.2mm.m-1 and plausible emigration rates, a range of biomass harvesting estimates were obtained. Movement and mortality were investigated using video analysis which showed that hatchery seed had the ability to move considerably once released onto natural reefs and confirmed that mortality immediately following releases was due to the heavy predation pressure as confirmed by shell collections. This project has demonstrated that potential exists for ranching in South Africa and highlights critical factors that need to be addressed if ranching is to be an economically viable operation.
- Full Text:
An energy, water and disease disaster management module: a technoeconomic feasibility analysis
- Authors: Nicholson, Thomas J
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MSC
- Identifier: http://hdl.handle.net/10962/65167 , vital:28700
- Description: Intermittent energy and water supply are current challenges faced by many residents in South Africa. South Africa is one of the more water scarce countries in the world; this coupled with the lack of infrastructure makes it challenging to provide every citizen with their right to basic water and sanitation. With millennium development goal 7C not being addressed in many areas, residents experience sub-standard living conditions, which drastically increases the vulnerability of marginalised groups to epidemics. In the sustainable development goals improving sanitation and drinking water has been identified as one of the most effective and least expensive means of reducing fatalities and increasing public health. There is a need for a mobile laboratory that demonstrates power and water self-sufficiency, which is capable of on-site diagnosis and water treatment. The unit will have the ability to perform independent compliance monitoring of municipal water supply, treat inadequate water and provide surplus electricity to surrounding areas. A literature-based study was performed utilizing several scientific databases to identify current methods of power and water production in previous disaster management and humanitarian relief situations. Based on findings three example laboratories were theoretically designed; structural modelling, systems simulation and optimization and sensitivity analyses were performed with HOMER Pro, PackVol and SketchUp. A cost benefit analysis was performed with the social return on investment methodology. Novel human waste processing was performed with fly ash and simulated faeces. Bacterial species identification in ice samples was performed with the API 20E protocol and limited equipment as a proof of concept for field deployment. A hybrid system consisting of PV panels, a wind turbine and biomass generator showed promise for displaced humanitarian relief camps; with every 1 ZAR capital invested resulting in 3.13 ZAR social benefit. A system consisting of PV panels and a battery bank proved to have the least environmental impact and the grid supply laboratory showed a cheaper cost of energy alternative for needs provision. Fly ash showed potential as in nutrient recovery and as a fertility aid to soil. The units developed function as a means to increase disaster preparedness and humanitarian relief as well a means to improve quality of life for rural marginalize populations.
- Full Text:
- Authors: Nicholson, Thomas J
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MSC
- Identifier: http://hdl.handle.net/10962/65167 , vital:28700
- Description: Intermittent energy and water supply are current challenges faced by many residents in South Africa. South Africa is one of the more water scarce countries in the world; this coupled with the lack of infrastructure makes it challenging to provide every citizen with their right to basic water and sanitation. With millennium development goal 7C not being addressed in many areas, residents experience sub-standard living conditions, which drastically increases the vulnerability of marginalised groups to epidemics. In the sustainable development goals improving sanitation and drinking water has been identified as one of the most effective and least expensive means of reducing fatalities and increasing public health. There is a need for a mobile laboratory that demonstrates power and water self-sufficiency, which is capable of on-site diagnosis and water treatment. The unit will have the ability to perform independent compliance monitoring of municipal water supply, treat inadequate water and provide surplus electricity to surrounding areas. A literature-based study was performed utilizing several scientific databases to identify current methods of power and water production in previous disaster management and humanitarian relief situations. Based on findings three example laboratories were theoretically designed; structural modelling, systems simulation and optimization and sensitivity analyses were performed with HOMER Pro, PackVol and SketchUp. A cost benefit analysis was performed with the social return on investment methodology. Novel human waste processing was performed with fly ash and simulated faeces. Bacterial species identification in ice samples was performed with the API 20E protocol and limited equipment as a proof of concept for field deployment. A hybrid system consisting of PV panels, a wind turbine and biomass generator showed promise for displaced humanitarian relief camps; with every 1 ZAR capital invested resulting in 3.13 ZAR social benefit. A system consisting of PV panels and a battery bank proved to have the least environmental impact and the grid supply laboratory showed a cheaper cost of energy alternative for needs provision. Fly ash showed potential as in nutrient recovery and as a fertility aid to soil. The units developed function as a means to increase disaster preparedness and humanitarian relief as well a means to improve quality of life for rural marginalize populations.
- Full Text:
An Expanded Methodological View on Learning Pathways as Educational and Occupational Progression: A ‘Laminated Systems’ Perspective
- Ramsarup, Preesha, Lotz-Sisitka, Heila
- Authors: Ramsarup, Preesha , Lotz-Sisitka, Heila
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , bulletin
- Identifier: http://hdl.handle.net/10962/436344 , vital:73262 , ISBN bulletin , https://www.saqa.org.za/wp-content/uploads/2023/02/SAQA-Bulletin-2017-1.pdf#page=37
- Description: As shown across the collection of papers in this Bulletin, the central ques-tion that the South African Qualifications Authority (SAQA)-Rhodes Uni-versity research programme tried to explore was to understand the na-ture of environmental learning pathways and the systemic and agentive factors that shape their emergence. This was based on an emerging un-derstanding of the demand for environment and sustainable development occupations and greening of existing occupations (see Introduction, and Papers 1 and 7 in this Bulletin; Department of Environmental Affairs [DEA], 2010; International Labour Organisation [ILO], 2010; Rosenberg et al 2016).
- Full Text:
- Authors: Ramsarup, Preesha , Lotz-Sisitka, Heila
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , bulletin
- Identifier: http://hdl.handle.net/10962/436344 , vital:73262 , ISBN bulletin , https://www.saqa.org.za/wp-content/uploads/2023/02/SAQA-Bulletin-2017-1.pdf#page=37
- Description: As shown across the collection of papers in this Bulletin, the central ques-tion that the South African Qualifications Authority (SAQA)-Rhodes Uni-versity research programme tried to explore was to understand the na-ture of environmental learning pathways and the systemic and agentive factors that shape their emergence. This was based on an emerging un-derstanding of the demand for environment and sustainable development occupations and greening of existing occupations (see Introduction, and Papers 1 and 7 in this Bulletin; Department of Environmental Affairs [DEA], 2010; International Labour Organisation [ILO], 2010; Rosenberg et al 2016).
- Full Text:
An In-depth Case Study of Environmental Engineering Learning and Work Transitioning in Boundary-less Work
- Lotz-Sisitka, Heila, Ramsarup, Preesha
- Authors: Lotz-Sisitka, Heila , Ramsarup, Preesha
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , bulletin
- Identifier: http://hdl.handle.net/10962/436361 , vital:73264 , ISBN bulletin , https://www.saqa.org.za/wp-content/uploads/2023/02/SAQA-Bulletin-2017-1.pdf#page=37
- Description: Environmental issues are increasingly seen as complex, multi-faceted and integral to social and economic development. As societies grapple with the rapid and catastrophic effects of environmental degradation, occupa-tional and educational systems have to comprehend meaningfully, the implications. In a study on the ‘Green Skills’59 in South Africa’s economy, the International Labour Organisation (ILO, 2010:19) noted that “new skills and retraining needs for the greening sector should filter successfully through the ‘demand and supply’ process”. However, despite the National Qualifications Framework (NQF) commitment to responsive skills devel-opment and lifelong learning, several recent studies (including Depart-ment of Environmental Affairs [DEA], 2010; Human Sciences Research Council [HSRC], 2009) have highlighted many skills and competence-related issues within environmental provisioning. While there is a skills development focus and a greening focus, there is little articulated align-ment between the two (ILO, 2010), which highlights that the whole sys-tem of training provisioning for workplace learning and sustainability practices is poorly constituted and unresponsive to the rapidly changing nature of the sector.
- Full Text:
- Authors: Lotz-Sisitka, Heila , Ramsarup, Preesha
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , bulletin
- Identifier: http://hdl.handle.net/10962/436361 , vital:73264 , ISBN bulletin , https://www.saqa.org.za/wp-content/uploads/2023/02/SAQA-Bulletin-2017-1.pdf#page=37
- Description: Environmental issues are increasingly seen as complex, multi-faceted and integral to social and economic development. As societies grapple with the rapid and catastrophic effects of environmental degradation, occupa-tional and educational systems have to comprehend meaningfully, the implications. In a study on the ‘Green Skills’59 in South Africa’s economy, the International Labour Organisation (ILO, 2010:19) noted that “new skills and retraining needs for the greening sector should filter successfully through the ‘demand and supply’ process”. However, despite the National Qualifications Framework (NQF) commitment to responsive skills devel-opment and lifelong learning, several recent studies (including Depart-ment of Environmental Affairs [DEA], 2010; Human Sciences Research Council [HSRC], 2009) have highlighted many skills and competence-related issues within environmental provisioning. While there is a skills development focus and a greening focus, there is little articulated align-ment between the two (ILO, 2010), which highlights that the whole sys-tem of training provisioning for workplace learning and sustainability practices is poorly constituted and unresponsive to the rapidly changing nature of the sector.
- Full Text:
Analysis of a foundational biomedical curriculum: exploring cumulative knowledge-building in the rehabilitative health professions
- Authors: De Bie, Gabrielle
- Date: 2017
- Subjects: Medical education -- Curricula , Human anatomy -- Study and teaching -- Curricula , Physiology -- Study and teaching -- Curricula , Occupational therapy -- Study and teaching -- Curricula , Physical therapy -- Study and teaching -- Curricula , Medical rehabilitation -- Study and teaching -- Curricula , Knowledge, Theory of
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/18617 , vital:22361
- Description: This study was motivated by the researcher's experience that students in the rehabilitative health professional programmes were finding it difficult to access fundamental knowledge upon which their professional practices and clinical contexts are based. An important focus of the research was the extent to which cumulative knowledge-building was impacted after the foundational biomedical curriculum became an interdisciplinary programme. The study explored whether the organisation of the interdisciplinary foundational curriculum served the fundamental needs of the professions, and whether, as a matter of social justice, students' access to powerful knowledge was enabled by the form that the fundamental curriculum assumed. This curriculum study at a particular Faculty of Health Sciences foregrounds the structuring, organisation and differentiation of disciplinary knowledge, and reflects a twenty year period that included not only transitions in professional education but also extensive transformation in, and a different approach to, health delivery. At the institution, physiology and anatomy, the biomedical sciences basic to the health professions, underwent disciplinary merging and subsequent altered positioning in curricula. Medicine opted for a problem-based learning approach whereas the rehabilitation health sciences did not. Legitimation Code Theory (LCT) provided the means for analysis of the extent to which interdisciplinary organisation in the foundational curriculum for Physiotherapy and Occupational Therapy enabled integrative, cumulative building of knowledge for professional and clinical contexts. Specialisation and Semantics dimensions of Legitimation Code Theory were used to reveal the principles underpinning practices, contexts and dispositions of Anatomy and Physiology at the Faculty of Health Sciences over a twenty year period post democratisation in South Africa (1994 - 2013). Disciplinary positioning in curriculum prior- and post-merger, were compared and contrasted. LCT were used to characterise the distinctiveness of Physiotherapy and Occupational Therapy at the university including the kind of knowledge and the kind of knower that specialises the different professions, and what is valorised and legitimated for each kind of professional. Semantic gravity was used to explore the expected knowledge recontextualisations in diverse and complex clinical settings for each of the professions. Registered professionals who are clinical educators as well as curriculum designers for clinical studies were interviewed. Profession-specific course outlines were further data sources. The biomedical disciplines Anatomy and Physiology were characterised for their measures of distinction and their respective knowledge-knower structures. Analysis traced each discipline from its strongly classified form in autonomous curricula when there were separate learner-cohorts for physiotherapists and occupational therapists, to post-merger when the disciplines were framed as human biology in an integrated foundational curriculum for a joint cohort of students. Curricular documents for the twenty year period were analysed quantitatively and qualitatively to establish the positioning of Physiology and Anatomy before and after the disciplines merged to a single course of Human Biology. Teaching staff were interviewed for their understanding of what specialises the physiological and anatomical components of the Human Biology curriculum, what they considered as powerful knowledge for the professions, and who they envisaged as the ideal student-knower exiting the basic sciences platform to enter more advanced clinical studies. The degree of context-dependence for meaning-making in the different disciplinary domains and the condensation of meanings inherent in the respective practices and contexts, were analysed. The thesis argues that following the merger Anatomy is preferentially legitimated as powerful knowledge at the expense of Physiology; that the ideal of disciplinary integration is not reached, and that the segmental organisation and structuring of the curriculum negatively impacted on cumulative knowledge-building and application of professional knowledge in the clinical arena. After the merger the disciplines lost their shape, and in particular the hierarchical knowledge structure of Physiology collapsed. By not having access to the necessary disciplinary knowledge structures and their associated practices, students' ability for scaffolding and integrating knowledge into the clinical arena was constrained. The organisation of the current Human Biology curriculum does not facilitate cumulative learning, and in so doing may not contribute to the envisaged graduate professional who is required to practice within a complex and demanding healthcare work environment. The significance of this study conveys that interdisciplinary programmes should be carefully considered, and there is an added imperative in the health professions which ultimately realise treatment of patients. If, aside from interdisciplinary teaching, there are also merged cohorts of participant students, then a sound understanding of the epistemic requirements of each profession is required. Those involved in curriculum development in various fields need to take these recommendations into account to enable cumulative learning and enable epistemological access to powerful knowledge for an increasingly diverse student body.
- Full Text:
- Authors: De Bie, Gabrielle
- Date: 2017
- Subjects: Medical education -- Curricula , Human anatomy -- Study and teaching -- Curricula , Physiology -- Study and teaching -- Curricula , Occupational therapy -- Study and teaching -- Curricula , Physical therapy -- Study and teaching -- Curricula , Medical rehabilitation -- Study and teaching -- Curricula , Knowledge, Theory of
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/18617 , vital:22361
- Description: This study was motivated by the researcher's experience that students in the rehabilitative health professional programmes were finding it difficult to access fundamental knowledge upon which their professional practices and clinical contexts are based. An important focus of the research was the extent to which cumulative knowledge-building was impacted after the foundational biomedical curriculum became an interdisciplinary programme. The study explored whether the organisation of the interdisciplinary foundational curriculum served the fundamental needs of the professions, and whether, as a matter of social justice, students' access to powerful knowledge was enabled by the form that the fundamental curriculum assumed. This curriculum study at a particular Faculty of Health Sciences foregrounds the structuring, organisation and differentiation of disciplinary knowledge, and reflects a twenty year period that included not only transitions in professional education but also extensive transformation in, and a different approach to, health delivery. At the institution, physiology and anatomy, the biomedical sciences basic to the health professions, underwent disciplinary merging and subsequent altered positioning in curricula. Medicine opted for a problem-based learning approach whereas the rehabilitation health sciences did not. Legitimation Code Theory (LCT) provided the means for analysis of the extent to which interdisciplinary organisation in the foundational curriculum for Physiotherapy and Occupational Therapy enabled integrative, cumulative building of knowledge for professional and clinical contexts. Specialisation and Semantics dimensions of Legitimation Code Theory were used to reveal the principles underpinning practices, contexts and dispositions of Anatomy and Physiology at the Faculty of Health Sciences over a twenty year period post democratisation in South Africa (1994 - 2013). Disciplinary positioning in curriculum prior- and post-merger, were compared and contrasted. LCT were used to characterise the distinctiveness of Physiotherapy and Occupational Therapy at the university including the kind of knowledge and the kind of knower that specialises the different professions, and what is valorised and legitimated for each kind of professional. Semantic gravity was used to explore the expected knowledge recontextualisations in diverse and complex clinical settings for each of the professions. Registered professionals who are clinical educators as well as curriculum designers for clinical studies were interviewed. Profession-specific course outlines were further data sources. The biomedical disciplines Anatomy and Physiology were characterised for their measures of distinction and their respective knowledge-knower structures. Analysis traced each discipline from its strongly classified form in autonomous curricula when there were separate learner-cohorts for physiotherapists and occupational therapists, to post-merger when the disciplines were framed as human biology in an integrated foundational curriculum for a joint cohort of students. Curricular documents for the twenty year period were analysed quantitatively and qualitatively to establish the positioning of Physiology and Anatomy before and after the disciplines merged to a single course of Human Biology. Teaching staff were interviewed for their understanding of what specialises the physiological and anatomical components of the Human Biology curriculum, what they considered as powerful knowledge for the professions, and who they envisaged as the ideal student-knower exiting the basic sciences platform to enter more advanced clinical studies. The degree of context-dependence for meaning-making in the different disciplinary domains and the condensation of meanings inherent in the respective practices and contexts, were analysed. The thesis argues that following the merger Anatomy is preferentially legitimated as powerful knowledge at the expense of Physiology; that the ideal of disciplinary integration is not reached, and that the segmental organisation and structuring of the curriculum negatively impacted on cumulative knowledge-building and application of professional knowledge in the clinical arena. After the merger the disciplines lost their shape, and in particular the hierarchical knowledge structure of Physiology collapsed. By not having access to the necessary disciplinary knowledge structures and their associated practices, students' ability for scaffolding and integrating knowledge into the clinical arena was constrained. The organisation of the current Human Biology curriculum does not facilitate cumulative learning, and in so doing may not contribute to the envisaged graduate professional who is required to practice within a complex and demanding healthcare work environment. The significance of this study conveys that interdisciplinary programmes should be carefully considered, and there is an added imperative in the health professions which ultimately realise treatment of patients. If, aside from interdisciplinary teaching, there are also merged cohorts of participant students, then a sound understanding of the epistemic requirements of each profession is required. Those involved in curriculum development in various fields need to take these recommendations into account to enable cumulative learning and enable epistemological access to powerful knowledge for an increasingly diverse student body.
- Full Text:
Assessing selected ecosystem services in urban green spaces in Bulawayo, Zimbabwe
- Ngulani, Thembelihle Tshandapiwa
- Authors: Ngulani, Thembelihle Tshandapiwa
- Date: 2017
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/5856 , vital:20982
- Description: Urbanization has resulted in the building of numerous structures such as buildings and roads which reduces the amount of natural land. Urban space planning has taken this into consideration resulting in planned urban green spaces and remnant land within urban areas. Urban green spaces provide a number of ecosystem services which are beneficial to urban residents. This study sought to determine residents’ use and perception of urban green spaces in Bulawayo, the second largest city in Zimbabwe, and to quantify and value four selected ecosystem services, i.e. carbon sequestration by urban trees, urban heat island amelioration, spiritual services and firewood provision. All ecosystem services were valued using local a variety of direct or substitutive methods. Questionnaires were administered at green spaces to green space users to capture responses on reasons why they use green spaces and their perception of green spaces. Residents’ responses showed that they appreciate green spaces as multidimensional spaces which provide a number of benefits for cultural and provisioning services. The role of the green spaces in providing regulating services was not well appreciated by the residents as they did not directly experience these benefits. An association was revealed between primary purpose of visit to urban green spaces and household income. Residents in areas of medium and high density housing visited green spaces on a daily basis, whereas those in more affluent, low density housing areas visited green spaces less often, i.e. a few times a month Carbon sequestration rate was determined by measuring tree diameter within one year to determine increase in carbon sequestered. Bulawayo’s urban green spaces sequester 3 290 t/C/yr valued at approximately $13 000/yr. There was a significant difference in carbon sequestration by urban trees between formal and informal green spaces with formal green spaces sequestering more carbon. Indigenous trees were shown to sequester more carbon than exotic trees and trees with bigger stem diameter were determined sequester more carbon than trees with small diameter. The effect of urban green spaces on ambient temperature was determined by measuring ambient air temperature in green spaces and built up areas over six months. Urban green spaces in Bulawayo play a role in urban micro-climate regulation by reducing the ambient temperature in the green spaces as well as is built up areas. The mean difference between green spaces and surrounding urban areas was up to 60C, with larger green spaces generally showing larger differences. The green spaces extend their cooling effect to surrounding areas thus reducing the temperatures in surrounding residential areas thus reducing the energy demand used for indoor cooling. To determine why residents worship in green spaces, questionnaires were administered to congregation members to capture reasons why and how often they worship in green spaces, challenges faced by the congregants as well as assistance that can be given by the Bulawayo city council to improve the outdoor worship experience. Green spaces offer ideal places for worship in natural areas for congregants to be in touch with nature. The green spaces are also used by some congregations who ordinarily would worship in buildings but fail to do so due to lack of funds for rent or to purchase or construct a church building to use. The value of Bulawayo’s green spaces spiritual services was determined to be $92.50/ha/yr. Firewood provision was also determined by measuring tree diameter within one year to determine increase in fuelwood. The green spaces showed a significant difference in firewood production among sites. Formal green spaces were shown to produce more firewood as compared to informal green spaces and no difference was determined in growth rates between exotic and indigenous tree species. Bulawayo’s green spaces produce 1.9t/ha/yr of firewood with an ecosystem service value of $340 to $490 /ha/yr. These findings indicate the importance of urban green spaces in Bulawayo. They are multifunctional spaces, providing multiple ecosystem services. The local appreciation of the services provided by urban green spaces differs according to the type of service and location in the city. The value of services provided by green spaces is high, albeit not taken into account in planning decisions.
- Full Text:
- Authors: Ngulani, Thembelihle Tshandapiwa
- Date: 2017
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/5856 , vital:20982
- Description: Urbanization has resulted in the building of numerous structures such as buildings and roads which reduces the amount of natural land. Urban space planning has taken this into consideration resulting in planned urban green spaces and remnant land within urban areas. Urban green spaces provide a number of ecosystem services which are beneficial to urban residents. This study sought to determine residents’ use and perception of urban green spaces in Bulawayo, the second largest city in Zimbabwe, and to quantify and value four selected ecosystem services, i.e. carbon sequestration by urban trees, urban heat island amelioration, spiritual services and firewood provision. All ecosystem services were valued using local a variety of direct or substitutive methods. Questionnaires were administered at green spaces to green space users to capture responses on reasons why they use green spaces and their perception of green spaces. Residents’ responses showed that they appreciate green spaces as multidimensional spaces which provide a number of benefits for cultural and provisioning services. The role of the green spaces in providing regulating services was not well appreciated by the residents as they did not directly experience these benefits. An association was revealed between primary purpose of visit to urban green spaces and household income. Residents in areas of medium and high density housing visited green spaces on a daily basis, whereas those in more affluent, low density housing areas visited green spaces less often, i.e. a few times a month Carbon sequestration rate was determined by measuring tree diameter within one year to determine increase in carbon sequestered. Bulawayo’s urban green spaces sequester 3 290 t/C/yr valued at approximately $13 000/yr. There was a significant difference in carbon sequestration by urban trees between formal and informal green spaces with formal green spaces sequestering more carbon. Indigenous trees were shown to sequester more carbon than exotic trees and trees with bigger stem diameter were determined sequester more carbon than trees with small diameter. The effect of urban green spaces on ambient temperature was determined by measuring ambient air temperature in green spaces and built up areas over six months. Urban green spaces in Bulawayo play a role in urban micro-climate regulation by reducing the ambient temperature in the green spaces as well as is built up areas. The mean difference between green spaces and surrounding urban areas was up to 60C, with larger green spaces generally showing larger differences. The green spaces extend their cooling effect to surrounding areas thus reducing the temperatures in surrounding residential areas thus reducing the energy demand used for indoor cooling. To determine why residents worship in green spaces, questionnaires were administered to congregation members to capture reasons why and how often they worship in green spaces, challenges faced by the congregants as well as assistance that can be given by the Bulawayo city council to improve the outdoor worship experience. Green spaces offer ideal places for worship in natural areas for congregants to be in touch with nature. The green spaces are also used by some congregations who ordinarily would worship in buildings but fail to do so due to lack of funds for rent or to purchase or construct a church building to use. The value of Bulawayo’s green spaces spiritual services was determined to be $92.50/ha/yr. Firewood provision was also determined by measuring tree diameter within one year to determine increase in fuelwood. The green spaces showed a significant difference in firewood production among sites. Formal green spaces were shown to produce more firewood as compared to informal green spaces and no difference was determined in growth rates between exotic and indigenous tree species. Bulawayo’s green spaces produce 1.9t/ha/yr of firewood with an ecosystem service value of $340 to $490 /ha/yr. These findings indicate the importance of urban green spaces in Bulawayo. They are multifunctional spaces, providing multiple ecosystem services. The local appreciation of the services provided by urban green spaces differs according to the type of service and location in the city. The value of services provided by green spaces is high, albeit not taken into account in planning decisions.
- Full Text:
Biogeomorphic aspects of lichen colonisation in part of western Dronning Maud Land, Antarctica
- Authors: Ayres, Gabrielle Alexzena
- Date: 2017
- Subjects: Lichen communities -- Queen Maud Land , Lichens -- Ecology -- Queen Maud Land , Polar regions , Ecology -- Polar regions , Antarctica , Ecology -- Antarctica
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/19713 , vital:22477
- Description: Ice-free regions in Antarctica provide natural laboratories for investigating and modelling change in landscapes and ecosystems. The terrestrial ecosystems in western Dronning Maud Land are potentially critical to improve current understanding of polar ecosystems, however, they remain poorly represented and under-protected. Lichen habitats were used to elucidate geomorphic-biological feedbacks that shape the landscape’s topography and biodiversity, which in turn promote environmental heterogeneity. Environmental parameters acting on two landforms were measured to determine the colonisation and growth of lichens in niche habitats. The habitats were identified and characterised, and topographic heterogeneity was found to control lichen colonisation. Micro-topographical niches provide the most stable environments for colonisation, and are preferred habitats. Lichen-habitat interactions were species specific, and closely related to insolation and moisture availability. The bidirectional relationships between rock weathering and lichen colonisation was ascertained. Results showed that lichens are good indicators of landform heterogeneity, but also promote landform heterogeneity. Given the habitat preferences of specific lichen species, they provide proxy to evaluating environmental responses, especially environmental change. The findings of this research are to be used as baseline data for future studies exploring ecosystem development in emerging landforms.
- Full Text:
- Authors: Ayres, Gabrielle Alexzena
- Date: 2017
- Subjects: Lichen communities -- Queen Maud Land , Lichens -- Ecology -- Queen Maud Land , Polar regions , Ecology -- Polar regions , Antarctica , Ecology -- Antarctica
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/19713 , vital:22477
- Description: Ice-free regions in Antarctica provide natural laboratories for investigating and modelling change in landscapes and ecosystems. The terrestrial ecosystems in western Dronning Maud Land are potentially critical to improve current understanding of polar ecosystems, however, they remain poorly represented and under-protected. Lichen habitats were used to elucidate geomorphic-biological feedbacks that shape the landscape’s topography and biodiversity, which in turn promote environmental heterogeneity. Environmental parameters acting on two landforms were measured to determine the colonisation and growth of lichens in niche habitats. The habitats were identified and characterised, and topographic heterogeneity was found to control lichen colonisation. Micro-topographical niches provide the most stable environments for colonisation, and are preferred habitats. Lichen-habitat interactions were species specific, and closely related to insolation and moisture availability. The bidirectional relationships between rock weathering and lichen colonisation was ascertained. Results showed that lichens are good indicators of landform heterogeneity, but also promote landform heterogeneity. Given the habitat preferences of specific lichen species, they provide proxy to evaluating environmental responses, especially environmental change. The findings of this research are to be used as baseline data for future studies exploring ecosystem development in emerging landforms.
- Full Text:
Biotic and abiotic factors promoting the development and proliferation of water hyacinth (eichhornia crassipes (Mart.) Solms-Laub.) in the Wouri Basin (Douala-Cameroon) and environs, with implications for its control
- Voukeng, Sonia Nadege Kenfack
- Authors: Voukeng, Sonia Nadege Kenfack
- Date: 2017
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/7644 , vital:21281
- Description: The Wouri River, situated in the Wouri Basin, is one of the main rivers of the Littoral Region in the city of Douala in Cameroon. It is a source of income and food for the population living around these areas. Since the 1990s, the fishing, transportation, irrigation and sand extraction activities have been impeded by the invasion of aquatic plants, specifically water hyacinth (Eichhornia crassipes [Mart.] Solms-Laubach: Pontederiaceae). Introduced in 1997 to the shore of Lake Chad, water hyacinth has invaded almost 114 ha of the Wouri Basin. Furthermore, Douala, the economic capital of the Cameroon and location for more than 70% of the country’s industries, uses the Wouri River and its tributaries to deposit its effluent and waste, which has worsened the problem of water hyacinth. This thesis examined the ecological and socio-economic impacts of water hyacinth in the Wouri Basin and its possible control. An increase in the nutrients in the water has provided water hyacinth with appropriate conditions for its fast growth during both the rainy and dry seasons. The availability of nutrients in these areas is enhanced by the constant, daily tidal fluctuation of water, providing enough water to the plant for easy nutrient uptake. A survey of the impacts of water hyacinth on aquatic plant communities in the Wouri Basin showed that this plant is able to out-compete native species. Assessment of the impact of water hyacinth on the abundance and diversity of plant communities indicated that at some invaded sites, 65% of the vegetation consisted of water hyacinth. Species found in association with water hyacinth with a high level of abundance-dominance were Pistia stratiotes L. (Araceae) (another invader), Commelina benghalensis L. (Commelinaceae) and Echinochloa pyramidalis (Lam.) Hitchc. & Chase (Poaceae). This component of the study also showed that habitats rich in water hyacinth were poor in diversity, while habitats without water hyacinth were rich in diversity, thus raising awareness of the importance of monitoring invasive aquatic weeds along the Wouri Basin, and of implementing correct control management of all invasive aquatic weeds. Communities living along the invaded rivers are well aware of the range of problems caused by the weed; because as the rivers and water bodies used for fishing, transportation, and sand extraction are progressively invaded by the weed, the riparian population is the first to feel the impact. The impact on people has been noticeable, with an increase in diseases, such as malaria, cholera, diarrhoea, typhoid, filariasis, schistosomiasis, scabies and yellow fever increasing the need for a medicine and hospitalization. Economic losses due to the management of invasive aquatic weeds were recorded, and the Ministry of Environment spent an estimated US$1 200 000 between 2010 and 2015 to manage this scourge. In 2016, an amount of US$160 000 was transferred to these regions to manage invasive aquatic weeds, especially water hyacinth, although manual clearing is still the only method used to control this weed. Isolation of fungi from diseased water hyacinth plants in the Wouri Basin revealed several fungal species, most of which have been isolated from water hyacinth species in water bodies elsewhere, which showed a higher diversity during the dry season than during the rainy season. These fungi included Acremonium zonatum (Sawada). W. Gams (Hypocreaceae), Alternaria eichhorniae Nag Raj & Ponnappa (Pleosporaceae), Chaetomium sp., Colletotrichum sp., Curvularia pallescens Boedjin (Pleosporaceae), Curvalaria sp., Epicoccum nigrum Link (Pleosporaceae), Fusarium sp., Pithomyces chartarum fBerk. & M. A. Curtis) M. B. Ellis (Montagnulaceae), to a lesser extent Myrothecium roridum Tode ex Fr. (Incertae sedis) and Nigrospora sp. Although never released in Cameroon, arthropod biological control agents (Neochetina eichhorniae Warner (Coleoptera, Curculionidae) and N. bruchi Hustache (Coleoptera, Curculionidae)) were present, but their populations were relatively low. The slow spread of the insect population was explained by several factors, among them the tidal fluctuation of water, which has an impact on the population growth of the weevils. Whilst adults may be able to survive tidal fluctuations, larvae are severely impacted by them, contributing to the slow success of biological control. In this study, a significant increase in pathogen-induced disease severity and incidence was noted when Neochetina eichhorniae weevils were present, possibly because larvae tunnelling on the petiole created openings for the penetration of fungal spores. This study highlights the negative impacts of water hyacinth, on the environment, people, and thus economy of Cameroon. The presence of biological control agents and pathogens offers Cameroon the possibility of initiating and properly implementing the biological control option, or an integrated management solution, to manage water hyacinth in the Wouri Basin, and in the rest of Cameroon.
- Full Text:
- Authors: Voukeng, Sonia Nadege Kenfack
- Date: 2017
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/7644 , vital:21281
- Description: The Wouri River, situated in the Wouri Basin, is one of the main rivers of the Littoral Region in the city of Douala in Cameroon. It is a source of income and food for the population living around these areas. Since the 1990s, the fishing, transportation, irrigation and sand extraction activities have been impeded by the invasion of aquatic plants, specifically water hyacinth (Eichhornia crassipes [Mart.] Solms-Laubach: Pontederiaceae). Introduced in 1997 to the shore of Lake Chad, water hyacinth has invaded almost 114 ha of the Wouri Basin. Furthermore, Douala, the economic capital of the Cameroon and location for more than 70% of the country’s industries, uses the Wouri River and its tributaries to deposit its effluent and waste, which has worsened the problem of water hyacinth. This thesis examined the ecological and socio-economic impacts of water hyacinth in the Wouri Basin and its possible control. An increase in the nutrients in the water has provided water hyacinth with appropriate conditions for its fast growth during both the rainy and dry seasons. The availability of nutrients in these areas is enhanced by the constant, daily tidal fluctuation of water, providing enough water to the plant for easy nutrient uptake. A survey of the impacts of water hyacinth on aquatic plant communities in the Wouri Basin showed that this plant is able to out-compete native species. Assessment of the impact of water hyacinth on the abundance and diversity of plant communities indicated that at some invaded sites, 65% of the vegetation consisted of water hyacinth. Species found in association with water hyacinth with a high level of abundance-dominance were Pistia stratiotes L. (Araceae) (another invader), Commelina benghalensis L. (Commelinaceae) and Echinochloa pyramidalis (Lam.) Hitchc. & Chase (Poaceae). This component of the study also showed that habitats rich in water hyacinth were poor in diversity, while habitats without water hyacinth were rich in diversity, thus raising awareness of the importance of monitoring invasive aquatic weeds along the Wouri Basin, and of implementing correct control management of all invasive aquatic weeds. Communities living along the invaded rivers are well aware of the range of problems caused by the weed; because as the rivers and water bodies used for fishing, transportation, and sand extraction are progressively invaded by the weed, the riparian population is the first to feel the impact. The impact on people has been noticeable, with an increase in diseases, such as malaria, cholera, diarrhoea, typhoid, filariasis, schistosomiasis, scabies and yellow fever increasing the need for a medicine and hospitalization. Economic losses due to the management of invasive aquatic weeds were recorded, and the Ministry of Environment spent an estimated US$1 200 000 between 2010 and 2015 to manage this scourge. In 2016, an amount of US$160 000 was transferred to these regions to manage invasive aquatic weeds, especially water hyacinth, although manual clearing is still the only method used to control this weed. Isolation of fungi from diseased water hyacinth plants in the Wouri Basin revealed several fungal species, most of which have been isolated from water hyacinth species in water bodies elsewhere, which showed a higher diversity during the dry season than during the rainy season. These fungi included Acremonium zonatum (Sawada). W. Gams (Hypocreaceae), Alternaria eichhorniae Nag Raj & Ponnappa (Pleosporaceae), Chaetomium sp., Colletotrichum sp., Curvularia pallescens Boedjin (Pleosporaceae), Curvalaria sp., Epicoccum nigrum Link (Pleosporaceae), Fusarium sp., Pithomyces chartarum fBerk. & M. A. Curtis) M. B. Ellis (Montagnulaceae), to a lesser extent Myrothecium roridum Tode ex Fr. (Incertae sedis) and Nigrospora sp. Although never released in Cameroon, arthropod biological control agents (Neochetina eichhorniae Warner (Coleoptera, Curculionidae) and N. bruchi Hustache (Coleoptera, Curculionidae)) were present, but their populations were relatively low. The slow spread of the insect population was explained by several factors, among them the tidal fluctuation of water, which has an impact on the population growth of the weevils. Whilst adults may be able to survive tidal fluctuations, larvae are severely impacted by them, contributing to the slow success of biological control. In this study, a significant increase in pathogen-induced disease severity and incidence was noted when Neochetina eichhorniae weevils were present, possibly because larvae tunnelling on the petiole created openings for the penetration of fungal spores. This study highlights the negative impacts of water hyacinth, on the environment, people, and thus economy of Cameroon. The presence of biological control agents and pathogens offers Cameroon the possibility of initiating and properly implementing the biological control option, or an integrated management solution, to manage water hyacinth in the Wouri Basin, and in the rest of Cameroon.
- Full Text:
Bird-Monk Seding
- Authors: Rampolokeng, Lesego
- Date: 2017
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/5049 , vital:20758
- Description: This novella is made up of interlinked stories from a rural township in the North West province. The stories of this surface-tranquil place are told through descriptive passages, vignettes, snatches of dialogue, profiles and picture-postcards, all organically interwoven and entwined, and rendered in non-linear fashion. They are set in shebeens, shops, farmlands and the dusty empty spaces of the South African landscape, peopled by police, tourists, and prostitutes of all sorts. The pervasiveness of violence in all forms has the fictional narrator reflecting on the violence of his own past. A smattering of musicians' musings gleaned from interviews and album liner-notes helps him navigate his way through this morass, the rage and frustration that simmers beneath it all.
- Full Text:
- Authors: Rampolokeng, Lesego
- Date: 2017
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/5049 , vital:20758
- Description: This novella is made up of interlinked stories from a rural township in the North West province. The stories of this surface-tranquil place are told through descriptive passages, vignettes, snatches of dialogue, profiles and picture-postcards, all organically interwoven and entwined, and rendered in non-linear fashion. They are set in shebeens, shops, farmlands and the dusty empty spaces of the South African landscape, peopled by police, tourists, and prostitutes of all sorts. The pervasiveness of violence in all forms has the fictional narrator reflecting on the violence of his own past. A smattering of musicians' musings gleaned from interviews and album liner-notes helps him navigate his way through this morass, the rage and frustration that simmers beneath it all.
- Full Text:
Birds as major predators of fishes in the East Kleinemonde Estuary
- Cowley, Paul D, Whitfield, Alan K, Terörde, Anja I
- Authors: Cowley, Paul D , Whitfield, Alan K , Terörde, Anja I
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/443271 , vital:74104 , https://hdl.handle.net/10520/EJC-c2893c53c
- Description: This study provides a quantitative account of fish predation by piscivorous birds in the temporarily open/closed East Kleinemonde Estuary and represents the first global attempt to simultaneously relate such consumption to production by a fish community in the same estuary. Cormorants and herons were the dominant predators and seasonal variations in the avifaunal community composition were noted. Based on comprehensive counts over three years, the piscivorous bird population was estimated to have consumed a maximum of 4 414 kg of fish in 1994, 2 400 kg in 1995/96 and 2 960 kg in 2004/05. In 1995/96 fish production in the East Kleinemonde Estuary (55.89 g m−2 a−1) was estimated at 9 780 kg and maximum bird predation amounted to 25% of annual fish production within the system over the same period, assuming that all birds counted on the estuary foraged there and that the diet of these birds comprised only fish. The above 1995/96 figures, together with an estimate of fish predation by the dominant piscivorous fish Lichia amia of 696 kg suggests that birds are probably the single most important natural predator of fishes within this estuary. An unusual mass invasion by marine Cape Cormorants Phalacrocorax capensis during July 1994 was responsible for large-scale predation of fish (2 155 kg) and resulted in the population of estuary-associated marine fishes declining from approximately 63 300 to about 18 600 individuals during the 1994 closed phase. Given that little or no marine fish recruitment was possible while the estuary mouth was closed, piscivorous birds are likely to have a higher predatory impact on populations of juvenile marine fishes in small temporarily closed estuaries than in larger permanently open systems.
- Full Text:
- Authors: Cowley, Paul D , Whitfield, Alan K , Terörde, Anja I
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/443271 , vital:74104 , https://hdl.handle.net/10520/EJC-c2893c53c
- Description: This study provides a quantitative account of fish predation by piscivorous birds in the temporarily open/closed East Kleinemonde Estuary and represents the first global attempt to simultaneously relate such consumption to production by a fish community in the same estuary. Cormorants and herons were the dominant predators and seasonal variations in the avifaunal community composition were noted. Based on comprehensive counts over three years, the piscivorous bird population was estimated to have consumed a maximum of 4 414 kg of fish in 1994, 2 400 kg in 1995/96 and 2 960 kg in 2004/05. In 1995/96 fish production in the East Kleinemonde Estuary (55.89 g m−2 a−1) was estimated at 9 780 kg and maximum bird predation amounted to 25% of annual fish production within the system over the same period, assuming that all birds counted on the estuary foraged there and that the diet of these birds comprised only fish. The above 1995/96 figures, together with an estimate of fish predation by the dominant piscivorous fish Lichia amia of 696 kg suggests that birds are probably the single most important natural predator of fishes within this estuary. An unusual mass invasion by marine Cape Cormorants Phalacrocorax capensis during July 1994 was responsible for large-scale predation of fish (2 155 kg) and resulted in the population of estuary-associated marine fishes declining from approximately 63 300 to about 18 600 individuals during the 1994 closed phase. Given that little or no marine fish recruitment was possible while the estuary mouth was closed, piscivorous birds are likely to have a higher predatory impact on populations of juvenile marine fishes in small temporarily closed estuaries than in larger permanently open systems.
- Full Text:
Boundary making and boundary crossing in learning pathways access and progression: Voices from the workplace
- Lotz-Sisitka, Heila, Mohanoe, M Nthabiseng, Ramsarup, Preesha, Olvitt, Lausanne L
- Authors: Lotz-Sisitka, Heila , Mohanoe, M Nthabiseng , Ramsarup, Preesha , Olvitt, Lausanne L
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , bulletin
- Identifier: http://hdl.handle.net/10962/436374 , vital:73265 , ISBN bulletin , https://www.saqa.org.za/wp-content/uploads/2023/02/SAQA-Bulletin-2017-1.pdf#page=37
- Description: In the South African Qualifications Authority and Rhodes University (SAQA-Rhodes) partnership research it was found that ‘researching the boundary’is an important unit of analysis in learning pathways research (see Papers 1 and 2 in this Bulle-tin). The researchers have argued that this focus has rele-vance for discussions on articulation, as articulation is a boundary crossing practice39. However, to understand boundary crossing processes, it is important to understand what the boundaries are in learning pathways research and to understand how these boundaries were developed. Bounda-ries in learning pathways are both social and material and are constructed by people’s actions and practices, and can only be resolved through people’s actions and practices. This pa-per–Paper 5–considers the manner in which social-material factors are ‘boundary makers’ in learning pathways, affecting access, mobility, progression and articulation possibilities, with specific reference to articulation between workplace experi-ences and contexts on one hand, and education and training systems on the other. The paper argues for a perspective on the social-material that includes the Critical Realist concept of ‘absence’(Bhaskar, 1993) as an important shaping force in learning pathways research (see Paper 4, in this Bulletin). By identifying ‘boundary making’processes and factors, as articu-lated through ‘voices in the workplace’[one perspective on this issue], the paper identifies key areas for ‘boundary cross-ing’practices in the South African National Qualifications Framework (NQF) system and its associated sub-systems.
- Full Text:
- Authors: Lotz-Sisitka, Heila , Mohanoe, M Nthabiseng , Ramsarup, Preesha , Olvitt, Lausanne L
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , bulletin
- Identifier: http://hdl.handle.net/10962/436374 , vital:73265 , ISBN bulletin , https://www.saqa.org.za/wp-content/uploads/2023/02/SAQA-Bulletin-2017-1.pdf#page=37
- Description: In the South African Qualifications Authority and Rhodes University (SAQA-Rhodes) partnership research it was found that ‘researching the boundary’is an important unit of analysis in learning pathways research (see Papers 1 and 2 in this Bulle-tin). The researchers have argued that this focus has rele-vance for discussions on articulation, as articulation is a boundary crossing practice39. However, to understand boundary crossing processes, it is important to understand what the boundaries are in learning pathways research and to understand how these boundaries were developed. Bounda-ries in learning pathways are both social and material and are constructed by people’s actions and practices, and can only be resolved through people’s actions and practices. This pa-per–Paper 5–considers the manner in which social-material factors are ‘boundary makers’ in learning pathways, affecting access, mobility, progression and articulation possibilities, with specific reference to articulation between workplace experi-ences and contexts on one hand, and education and training systems on the other. The paper argues for a perspective on the social-material that includes the Critical Realist concept of ‘absence’(Bhaskar, 1993) as an important shaping force in learning pathways research (see Paper 4, in this Bulletin). By identifying ‘boundary making’processes and factors, as articu-lated through ‘voices in the workplace’[one perspective on this issue], the paper identifies key areas for ‘boundary cross-ing’practices in the South African National Qualifications Framework (NQF) system and its associated sub-systems.
- Full Text:
Browsing as a demographic bottleneck in a semi-arid savanna: the effect of size and age on compensatory responses of Vachellia karroo seedlings after simulated herbivory
- Authors: Perumal, Lavinia
- Date: 2017
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/4899 , vital:20741
- Description: Savannas are characterised by a continuous grass layer with scattered trees at varying densities. This vegetation structure is determined by several interacting factors, including fire, herbivory, resource competition and atmospheric CO2 concentration. The preservation of savanna biomes is important and a shift towards a woody biome threatens savanna globally. Bush encroachment which describes the shift towards domination of savannas by C3 woody plants, is especially acute in southern Africa. In semi-arid rangelands, encroachment progresses to dense thickets dominated by thorny and unpalatable bushes and trees. There is evidence that bush encroachment is driven by a reduction in fire and browsing events as well as their interaction. Despite browsing having strong effects on African savannas its isolated role in maintaining tree-grass coexistence has not received as much attention as the role of fire. Therefore the overall aim of this study was to examine the effects of browsing on seedlings of a commonly encroaching species, Vachellia karroo. Browsing was hypothesized to be a demographic release bottleneck for bush encroachment in a semiarid (MAP ~550mm) savanna in the Eastern Cape of South Africa, where fire has been historically rare. In a single study I explored the fate of V. karroo seedlings (less than a year old) following browsing in sub canopy and inter canopy microhabitats. Additionally, I explored how the fate of a seedling changed under high and low tree cover. Firstly, I investigated the type, intensity and frequency of herbivory, from both small and large herbivores, which seedlings were subjected to. Results revealed that browsing was severe and frequent with the majority of seedlings browsed more than twice over a 12 month period. Large browsers such as kudu and impala caused high seedling mortality (46%) while smaller browsers such as invertebrates were more effective at suppressing growth. Microhabitat had little impact on seedling survival, but significantly influenced plant compensatory growth. Reduced seedling growth following browsing was observed in the sub-canopy in comparison to seedling growth in full sunlight in the intercanopy, suggesting V.karroo may be shade intolerant. Secondly, the effect of tree cover on browsed seedlings was determined by quantifying browsing frequency and intensity at high and low tree cover. No differences in browsing intensity and frequency were observed between high and low tree cover. However, high tree cover due to bush encroachment limited seedling above ground growth. The aim of the second study was to investigate how V.karroo survival and growth were influenced by its age and size following simulated browsing. I explored this aim through field and greenhouse experiments. I was particularly interested in testing how plant sensitivity to varying defoliation intensities of repeated browsing varied with plant age (known ages of 6, 12, 16 and 30 weeks). There were large differences in mortality between the different age groups. Furthermore, age interacted with repeated browsing and negatively influenced seedling survival and regrowth. Older seedlings (16 and 30 week old) had greater survival and higher browsing frequencies resulted in greater mortality and reduced growth. The threshold age after which seedlings become more tolerant to herbivory occurs at an age of 28 weeks. Seedlings less than six weeks old experiencing intense (100 % defoliation)browsing had a very low probability (33%) of survival following just a single defoliation. Interestingly, all 16 week old seedlings regrew most of their foliage following a moderate (50%) defoliation with some plants overcompensating for leaf loss. The field study revealed two distinct demographic stages based on age and size (seedlings< 9 mm and saplings >9 mm in stem basal diameter (SBD)). Browsing had a strong negative effect on seedlings, resulting in reduced investment in leaf biomass. These findings suggest plant size and age can be used as robust predictors of a plants vulnerability to browsing. An increase in tree cover requires successful transitions of seedlings to saplings (also known as release). The results of this study suggest that in semi-arid savannas, browsing can impact tree cover through imposing a release bottleneck for tree seedlings and to lesser extent saplings. By limiting tree growth plants are kept in a disturbance trap and will therefore be exposed to not only browsers but fire. These findings also have important implications for tree-grass coexistence dynamics, suggesting that specific size and browsing thresholds should be considered in savanna management.
- Full Text:
- Authors: Perumal, Lavinia
- Date: 2017
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/4899 , vital:20741
- Description: Savannas are characterised by a continuous grass layer with scattered trees at varying densities. This vegetation structure is determined by several interacting factors, including fire, herbivory, resource competition and atmospheric CO2 concentration. The preservation of savanna biomes is important and a shift towards a woody biome threatens savanna globally. Bush encroachment which describes the shift towards domination of savannas by C3 woody plants, is especially acute in southern Africa. In semi-arid rangelands, encroachment progresses to dense thickets dominated by thorny and unpalatable bushes and trees. There is evidence that bush encroachment is driven by a reduction in fire and browsing events as well as their interaction. Despite browsing having strong effects on African savannas its isolated role in maintaining tree-grass coexistence has not received as much attention as the role of fire. Therefore the overall aim of this study was to examine the effects of browsing on seedlings of a commonly encroaching species, Vachellia karroo. Browsing was hypothesized to be a demographic release bottleneck for bush encroachment in a semiarid (MAP ~550mm) savanna in the Eastern Cape of South Africa, where fire has been historically rare. In a single study I explored the fate of V. karroo seedlings (less than a year old) following browsing in sub canopy and inter canopy microhabitats. Additionally, I explored how the fate of a seedling changed under high and low tree cover. Firstly, I investigated the type, intensity and frequency of herbivory, from both small and large herbivores, which seedlings were subjected to. Results revealed that browsing was severe and frequent with the majority of seedlings browsed more than twice over a 12 month period. Large browsers such as kudu and impala caused high seedling mortality (46%) while smaller browsers such as invertebrates were more effective at suppressing growth. Microhabitat had little impact on seedling survival, but significantly influenced plant compensatory growth. Reduced seedling growth following browsing was observed in the sub-canopy in comparison to seedling growth in full sunlight in the intercanopy, suggesting V.karroo may be shade intolerant. Secondly, the effect of tree cover on browsed seedlings was determined by quantifying browsing frequency and intensity at high and low tree cover. No differences in browsing intensity and frequency were observed between high and low tree cover. However, high tree cover due to bush encroachment limited seedling above ground growth. The aim of the second study was to investigate how V.karroo survival and growth were influenced by its age and size following simulated browsing. I explored this aim through field and greenhouse experiments. I was particularly interested in testing how plant sensitivity to varying defoliation intensities of repeated browsing varied with plant age (known ages of 6, 12, 16 and 30 weeks). There were large differences in mortality between the different age groups. Furthermore, age interacted with repeated browsing and negatively influenced seedling survival and regrowth. Older seedlings (16 and 30 week old) had greater survival and higher browsing frequencies resulted in greater mortality and reduced growth. The threshold age after which seedlings become more tolerant to herbivory occurs at an age of 28 weeks. Seedlings less than six weeks old experiencing intense (100 % defoliation)browsing had a very low probability (33%) of survival following just a single defoliation. Interestingly, all 16 week old seedlings regrew most of their foliage following a moderate (50%) defoliation with some plants overcompensating for leaf loss. The field study revealed two distinct demographic stages based on age and size (seedlings< 9 mm and saplings >9 mm in stem basal diameter (SBD)). Browsing had a strong negative effect on seedlings, resulting in reduced investment in leaf biomass. These findings suggest plant size and age can be used as robust predictors of a plants vulnerability to browsing. An increase in tree cover requires successful transitions of seedlings to saplings (also known as release). The results of this study suggest that in semi-arid savannas, browsing can impact tree cover through imposing a release bottleneck for tree seedlings and to lesser extent saplings. By limiting tree growth plants are kept in a disturbance trap and will therefore be exposed to not only browsers but fire. These findings also have important implications for tree-grass coexistence dynamics, suggesting that specific size and browsing thresholds should be considered in savanna management.
- Full Text:
Changes in household food security, nutrition and food waste along an agro-ecological gradient and the rural-urban continuum in mid-sized South African towns
- Authors: Chakona, Gamuchirai
- Date: 2017
- Subjects: Food security -- South Africa , Women -- South Africa -- Nutritiona , Urban women -- South Africa -- Nutrition , Rural women -- South Africa -- Nutrition , Wild foods -- South Africa , Food supply -- South Africa , Malnutrition in children -- South Africa , Grants-in-aid -- South Africa , Household ecology -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/6484 , vital:21127
- Description: The lack of dietary diversity is a severe problem experienced by most poor households globally. Most poor communities are at high risk of inadequate intake of micronutrients resulting from diets dominated by starchy staples. The present study considered the diets, dietary diversities and food security of women of reproductive age between 15-49 years, households and communities along the rural-urban continuum in three mid-sized towns situated along an agro-ecological gradient in South Africa. A 48-hour dietary recall was performed across two seasons (twice in summer and once in winter) and focus group discussions were held to gather all information including food abundance, seasons of food scarcity as well as coping strategies which households employ during periods of food shocks. Households were further asked to quantify any type of food waste that they could have generated in the previous 48 hours. Nutritional status of children under the age of five in all three towns was also measured using height-for-age (HAZ) and mid-upper arm circumference (MUAC) as indicators of stunting and wasting respectively. The household surveys were conducted with 554 women randomly selected in rural, peri-urban and urban locations of Richards Bay, Dundee and Harrismith. For nutritional status, the sample consisted of 216 children who were randomly selected from the sampled households in rural, peri-urban and urban locations of the study sites. Household Dietary Diversity Scores (HDDS) and Women’s Dietary Diversity Scores (WDDS) were calculated from the food items consumed by each household and each woman over a two-day period, respectively. Household food access was also measured for each household using Household Food Insecurity Access Scale (HFIAS). The mean WDDS and HDDS for the wettest site of Richards Bay (3.8±0.29 and 8.44±1.72, respectively) was significantly higher than at Dundee (3.4±0.30 and 7.76±1.63, respectively) and Harrismith (3.5±0.27 and 7.83±1.59, respectively) which were not different from one another. The mean HFIAS for Dundee (9.39±7.13) was significantly higher than that in Richards Bay (5.57±6.98) and Harrismith (6.43±6.59) which were not significantly different from one another. Dietary diversity scores were also significantly higher in urban locations than in peri-urban and rural ones whilst HFIAS was significantly lower in the urban locations than peri-urban and rural locations. There was lower dependence on food purchasing in Richards Bay compared to Dundee and Harrismith where the majority of the population was purchasing most of their food. The majority of Richards Bay households were involved in subsistence agriculture and also produced a surplus for sale, as well as collecting wild foods, which improved food security, unlike Dundee and Harrismith. Food insecurity was higher in rural and peri-urban areas compared to urban areas. In all towns, food was always available throughout the year but was beyond the reach of many households. In urban areas food was readily available and only limited by access, whereas rural populations have limited access to affordable food and face higher prices. The peri-urban populations were more food insecure because of high levels of poverty, unemployment and lack of access/entitlements to land. Periurban dwellers are therefore more sensitive to changes in incomes and food prices because they lack safety nets to absorb income or price shocks as they purchase more, rather than growing their own food. Household dietary diversity was significantly negatively correlated with household food access, that is households with low HDDS had higher HFIAS scores. Due to high levels of food insecurity, a greater percentage of children under the age of five years were stunted (35 %) and wasted (18 %). There were no significant differences in stunting along the agro-ecological gradient, along the rural-urban continuum and sex of child. However, significant differences were observed in child wasting along the agro-ecological gradient with Harrismith having more wasted children than the other two towns, which were not significantly different from each other. Significant differences were also observed between MUAC and sex of child where male children had higher MUAC than females. Wasting was significantly negatively associated with HDDS, with children from households with low HDDS tending to have large MUAC thus showing an inverse association among HDDS and obesity. However, further studies are needed to confirm this finding. In general food insecurity was closely associated with low wealth, food expenditure, large household size and limited access to land. The study did not find any significant role in the use of wild foods and social grants in improving food security for those households who were consuming wild foods and those receiving social grants. Although a greater percentage of households were food insecure, significant amounts of unprepared food (495±179 g per household) were wasted in Richards Bay alone in 48 hours mainly because the food had passed the best before date or had visibly gone bad. The amount of food waste was closely significantly negatively associated with household size. In general, the prevalence of food insecurity and wasting followed the agro-ecological gradient, with households in Richards Bay where the area.
- Full Text:
- Authors: Chakona, Gamuchirai
- Date: 2017
- Subjects: Food security -- South Africa , Women -- South Africa -- Nutritiona , Urban women -- South Africa -- Nutrition , Rural women -- South Africa -- Nutrition , Wild foods -- South Africa , Food supply -- South Africa , Malnutrition in children -- South Africa , Grants-in-aid -- South Africa , Household ecology -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/6484 , vital:21127
- Description: The lack of dietary diversity is a severe problem experienced by most poor households globally. Most poor communities are at high risk of inadequate intake of micronutrients resulting from diets dominated by starchy staples. The present study considered the diets, dietary diversities and food security of women of reproductive age between 15-49 years, households and communities along the rural-urban continuum in three mid-sized towns situated along an agro-ecological gradient in South Africa. A 48-hour dietary recall was performed across two seasons (twice in summer and once in winter) and focus group discussions were held to gather all information including food abundance, seasons of food scarcity as well as coping strategies which households employ during periods of food shocks. Households were further asked to quantify any type of food waste that they could have generated in the previous 48 hours. Nutritional status of children under the age of five in all three towns was also measured using height-for-age (HAZ) and mid-upper arm circumference (MUAC) as indicators of stunting and wasting respectively. The household surveys were conducted with 554 women randomly selected in rural, peri-urban and urban locations of Richards Bay, Dundee and Harrismith. For nutritional status, the sample consisted of 216 children who were randomly selected from the sampled households in rural, peri-urban and urban locations of the study sites. Household Dietary Diversity Scores (HDDS) and Women’s Dietary Diversity Scores (WDDS) were calculated from the food items consumed by each household and each woman over a two-day period, respectively. Household food access was also measured for each household using Household Food Insecurity Access Scale (HFIAS). The mean WDDS and HDDS for the wettest site of Richards Bay (3.8±0.29 and 8.44±1.72, respectively) was significantly higher than at Dundee (3.4±0.30 and 7.76±1.63, respectively) and Harrismith (3.5±0.27 and 7.83±1.59, respectively) which were not different from one another. The mean HFIAS for Dundee (9.39±7.13) was significantly higher than that in Richards Bay (5.57±6.98) and Harrismith (6.43±6.59) which were not significantly different from one another. Dietary diversity scores were also significantly higher in urban locations than in peri-urban and rural ones whilst HFIAS was significantly lower in the urban locations than peri-urban and rural locations. There was lower dependence on food purchasing in Richards Bay compared to Dundee and Harrismith where the majority of the population was purchasing most of their food. The majority of Richards Bay households were involved in subsistence agriculture and also produced a surplus for sale, as well as collecting wild foods, which improved food security, unlike Dundee and Harrismith. Food insecurity was higher in rural and peri-urban areas compared to urban areas. In all towns, food was always available throughout the year but was beyond the reach of many households. In urban areas food was readily available and only limited by access, whereas rural populations have limited access to affordable food and face higher prices. The peri-urban populations were more food insecure because of high levels of poverty, unemployment and lack of access/entitlements to land. Periurban dwellers are therefore more sensitive to changes in incomes and food prices because they lack safety nets to absorb income or price shocks as they purchase more, rather than growing their own food. Household dietary diversity was significantly negatively correlated with household food access, that is households with low HDDS had higher HFIAS scores. Due to high levels of food insecurity, a greater percentage of children under the age of five years were stunted (35 %) and wasted (18 %). There were no significant differences in stunting along the agro-ecological gradient, along the rural-urban continuum and sex of child. However, significant differences were observed in child wasting along the agro-ecological gradient with Harrismith having more wasted children than the other two towns, which were not significantly different from each other. Significant differences were also observed between MUAC and sex of child where male children had higher MUAC than females. Wasting was significantly negatively associated with HDDS, with children from households with low HDDS tending to have large MUAC thus showing an inverse association among HDDS and obesity. However, further studies are needed to confirm this finding. In general food insecurity was closely associated with low wealth, food expenditure, large household size and limited access to land. The study did not find any significant role in the use of wild foods and social grants in improving food security for those households who were consuming wild foods and those receiving social grants. Although a greater percentage of households were food insecure, significant amounts of unprepared food (495±179 g per household) were wasted in Richards Bay alone in 48 hours mainly because the food had passed the best before date or had visibly gone bad. The amount of food waste was closely significantly negatively associated with household size. In general, the prevalence of food insecurity and wasting followed the agro-ecological gradient, with households in Richards Bay where the area.
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Children and wild foods in the context of deforestation in rural Malawi
- Maseko, Heather N, Shackleton, Charlie M, Nagoli, J, Pullanikkatil, Deepa
- Authors: Maseko, Heather N , Shackleton, Charlie M , Nagoli, J , Pullanikkatil, Deepa
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182101 , vital:43800 , xlink:href="https://doi.org/10.1007/s10745-017-9956-8"
- Description: There is growing recognition of the contribution of wild foods to local diets, nutrition, and culture. Yet disaggregation of understanding of wild food use by gender and age is limited. We used a mixed methods approach to determine the types, frequencies, and perceptions of wild foods used and sold by children in four villages in southern Malawi that have different levels of deforestation. Household and individual dietary diversity scores are low at all sites. All households consume one or more wild foods. Across the four sites, children listed 119 wild foods, with a wider variety at the least deforested sites than the most deforested ones. Older children can name more wild foods than younger ones. More children from poor households sell wild foods than from well-off households. Several reasons were provided for the consumption or avoidance of wild foods (most commonly taste, contribution to health, limited alternatives, hunger, availability, local taboos).
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- Authors: Maseko, Heather N , Shackleton, Charlie M , Nagoli, J , Pullanikkatil, Deepa
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182101 , vital:43800 , xlink:href="https://doi.org/10.1007/s10745-017-9956-8"
- Description: There is growing recognition of the contribution of wild foods to local diets, nutrition, and culture. Yet disaggregation of understanding of wild food use by gender and age is limited. We used a mixed methods approach to determine the types, frequencies, and perceptions of wild foods used and sold by children in four villages in southern Malawi that have different levels of deforestation. Household and individual dietary diversity scores are low at all sites. All households consume one or more wild foods. Across the four sites, children listed 119 wild foods, with a wider variety at the least deforested sites than the most deforested ones. Older children can name more wild foods than younger ones. More children from poor households sell wild foods than from well-off households. Several reasons were provided for the consumption or avoidance of wild foods (most commonly taste, contribution to health, limited alternatives, hunger, availability, local taboos).
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Comparative fish ecology in three periodically connected rivers in the upper Zambezi and Okavango ecoregions
- Authors: Taylor, Geraldine Claire
- Date: 2017
- Subjects: Fishes Ecology Zambia Zambezi District , Floodplain ecology Zambia Zambezi District , Stable isotopes , Fishes Food Zambia Zambezi District , Fishes Mortality Zambia Zambezi District , Fish populations Zambia Zambezi District , Fishes Growth
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/65055 , vital:28660 , DOI https://doi.org/10.21504/10962/65055
- Description: The Upper Zambezi, Kavango and Kwando rivers are three periodically interlinked floodplain rivers which share the same Upper Zambezian floodplain ichthyofauna. The aim of this thesis was to compare the biology and ecology of the fish communities in these three rivers. The objective was to test the hypothesis that fish community composition and assemblage structure, fish diets, food web structure and trophic dynamics, fish growth rates and total mortality are influenced by the differing flood magnitudes of the three rivers, in support of the flood pulse concept. To understand the abiotic characteristics of each river, water temperature, flood regime, total dissolved inorganic nitrogen concentrations and water quality parameters were measured and compared between rivers. Water temperatures varied seasonally, and seven day moving averages peaked above 30 °C in January, and fell to between 16 and 19 °C in June. The Zambezi River had the largest flood (6.14 m), followed by the Kavango River (3.80 m), while the Kwando River had the smallest flood (0.65 m). Total dissolved inorganic nitrogen concentrations were low in the Kavango and Zambezi Rivers (0.2 - 0.6 mg/l), and slightly higher in the Kwando River (<1 mg/l). Conductivity, total dissolved solids and total dissolved inorganic nitrogen concentrations decreased with the flood (dilution effect). Using biomass catch per unit effort data from experimental gillnets, fish community composition and assemblage structure was described, and differed between rivers in all hydrological seasons. In the Zambezi and Kavango rivers, fish assemblages varied with hydrological season as a result of the homogenising influence of the flood pulse, while in the Kwando River fish assemblages did not differ seasonally as flood pulses were small and often irregular. Differences in community composition were attributed to the abundance of Hydrocynus vittatus, a large bodied open water predator, in the Zambezi and Kavango rivers, and its relative absence in the Kwando River. Based on the results of the community composition, six focus species were chosen that were abundant and representative of the various feeding modes and life history strategies of the fish community. These were the striped robber Brycinus lateralis, sharptooth catfish Clarias gariepinus, blunttooth catfish Clarias ngamensis, African pike Hepsetus cuvieri, silver catfish Schilbe intermedius and purpleface largemouth Serranochromis macrocephalus. Stomach contents analysis was then used to compare the feeding ecology of the six example species between rivers. Clarias gariepinus, C. ngamensis and S. intermedius were piscivorous in the Zambezi and Kavango rivers, and preyed upon more invertebrates in the Kwando River, while Hepsetus cuvieri and S. macrocephalus were piscivorous in all three rivers. Differences in diets were attributed to seasonal prey abundance, with prey fishes abundant during falling and low water when the Zambezi and Kavango rivers were sampled, while invertebrates were abundant during rising and high water when the Kwando River was sampled. Prey mastication by B. lateralis made prey identification difficult. For other predators, the usefulness of stomach contents analysis for dietary descriptions was restricted by the high proportion of empty stomachs. As a result, whole ecosystem stable isotope analysis was used to gain a holistic understanding of the food web structure and fish feeding ecology of the three rivers. The Zambezi and Kavango river food webs were supported by C enriched resources such as C4 and C3 riparian vegetation from the floodplain, while the Kwando River food web was based on C depleted resources such as filamentous algae and aquatic macrophytes. The Zambezi River food web had a restricted nitrogen range, with reduced food chain length and the predators in this river did not occupy such elevated trophic positions compared to in the Kavango and Kwando river food webs. This was attributed to the overfishing of the primary and tertiary consumers in the Zambezi River, a phenomenon known to reduce food chain length. Focussing on predator communities, in the Zambezi and Kavango rivers, H. vittatus isotopic niche width was large and overlapped significantly with most other predators, while in the Kwando River predator niches were more distinct. This supported previously proposed hypotheses by describing H. vittatus as a dominant predator which excludes all other fishes by predation or competition. Despite the dominance of H. vittatus, C. gariepinus occupied the position of top predator in all three rivers, and information on the habitat use, feeding habits and trophic niches of the serranochromine cichlids added understanding of their ecology. Lastly, age was determined using sectioned sagittal otoliths for C. gariepinus, C. ngamensis, S. intermedius and S. macrocephalus and using whole asteriscus otoliths for B. lateralis and H. cuvieri, and growth was modelled using the von Bertalanffy growth equation. Growth performance was high in the Zambezi and Kavango rivers, and lower in the Kwando River, most likely in response to the varying flood magnitudes. Total mortality rates, estimated using Hoenig’s maximum-age based equation, were high in the Zambezi River as a result of the high fishing pressure on this river. Overall floodplain fish ecology in the Zambezi, Kavango and Kwando rivers was influenced by the flood pulse, as was predicted by the flood pulse concept. Periodic and equilibrium life history strategists were found to adapt either to the pulsing environments of the Zambezi and Kavango rivers, or to the more stable environment of the Kwando River, and large bodied, long lived periodic strategists such as C. gariepinus tended to be highly plastic and able to thrive in most conditions. Data also suggested that Zambezi River food web structure and fish mortality rates have been impacted by overfishing, for which more information is needed to conserve and manage this system. , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2018
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- Authors: Taylor, Geraldine Claire
- Date: 2017
- Subjects: Fishes Ecology Zambia Zambezi District , Floodplain ecology Zambia Zambezi District , Stable isotopes , Fishes Food Zambia Zambezi District , Fishes Mortality Zambia Zambezi District , Fish populations Zambia Zambezi District , Fishes Growth
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/65055 , vital:28660 , DOI https://doi.org/10.21504/10962/65055
- Description: The Upper Zambezi, Kavango and Kwando rivers are three periodically interlinked floodplain rivers which share the same Upper Zambezian floodplain ichthyofauna. The aim of this thesis was to compare the biology and ecology of the fish communities in these three rivers. The objective was to test the hypothesis that fish community composition and assemblage structure, fish diets, food web structure and trophic dynamics, fish growth rates and total mortality are influenced by the differing flood magnitudes of the three rivers, in support of the flood pulse concept. To understand the abiotic characteristics of each river, water temperature, flood regime, total dissolved inorganic nitrogen concentrations and water quality parameters were measured and compared between rivers. Water temperatures varied seasonally, and seven day moving averages peaked above 30 °C in January, and fell to between 16 and 19 °C in June. The Zambezi River had the largest flood (6.14 m), followed by the Kavango River (3.80 m), while the Kwando River had the smallest flood (0.65 m). Total dissolved inorganic nitrogen concentrations were low in the Kavango and Zambezi Rivers (0.2 - 0.6 mg/l), and slightly higher in the Kwando River (<1 mg/l). Conductivity, total dissolved solids and total dissolved inorganic nitrogen concentrations decreased with the flood (dilution effect). Using biomass catch per unit effort data from experimental gillnets, fish community composition and assemblage structure was described, and differed between rivers in all hydrological seasons. In the Zambezi and Kavango rivers, fish assemblages varied with hydrological season as a result of the homogenising influence of the flood pulse, while in the Kwando River fish assemblages did not differ seasonally as flood pulses were small and often irregular. Differences in community composition were attributed to the abundance of Hydrocynus vittatus, a large bodied open water predator, in the Zambezi and Kavango rivers, and its relative absence in the Kwando River. Based on the results of the community composition, six focus species were chosen that were abundant and representative of the various feeding modes and life history strategies of the fish community. These were the striped robber Brycinus lateralis, sharptooth catfish Clarias gariepinus, blunttooth catfish Clarias ngamensis, African pike Hepsetus cuvieri, silver catfish Schilbe intermedius and purpleface largemouth Serranochromis macrocephalus. Stomach contents analysis was then used to compare the feeding ecology of the six example species between rivers. Clarias gariepinus, C. ngamensis and S. intermedius were piscivorous in the Zambezi and Kavango rivers, and preyed upon more invertebrates in the Kwando River, while Hepsetus cuvieri and S. macrocephalus were piscivorous in all three rivers. Differences in diets were attributed to seasonal prey abundance, with prey fishes abundant during falling and low water when the Zambezi and Kavango rivers were sampled, while invertebrates were abundant during rising and high water when the Kwando River was sampled. Prey mastication by B. lateralis made prey identification difficult. For other predators, the usefulness of stomach contents analysis for dietary descriptions was restricted by the high proportion of empty stomachs. As a result, whole ecosystem stable isotope analysis was used to gain a holistic understanding of the food web structure and fish feeding ecology of the three rivers. The Zambezi and Kavango river food webs were supported by C enriched resources such as C4 and C3 riparian vegetation from the floodplain, while the Kwando River food web was based on C depleted resources such as filamentous algae and aquatic macrophytes. The Zambezi River food web had a restricted nitrogen range, with reduced food chain length and the predators in this river did not occupy such elevated trophic positions compared to in the Kavango and Kwando river food webs. This was attributed to the overfishing of the primary and tertiary consumers in the Zambezi River, a phenomenon known to reduce food chain length. Focussing on predator communities, in the Zambezi and Kavango rivers, H. vittatus isotopic niche width was large and overlapped significantly with most other predators, while in the Kwando River predator niches were more distinct. This supported previously proposed hypotheses by describing H. vittatus as a dominant predator which excludes all other fishes by predation or competition. Despite the dominance of H. vittatus, C. gariepinus occupied the position of top predator in all three rivers, and information on the habitat use, feeding habits and trophic niches of the serranochromine cichlids added understanding of their ecology. Lastly, age was determined using sectioned sagittal otoliths for C. gariepinus, C. ngamensis, S. intermedius and S. macrocephalus and using whole asteriscus otoliths for B. lateralis and H. cuvieri, and growth was modelled using the von Bertalanffy growth equation. Growth performance was high in the Zambezi and Kavango rivers, and lower in the Kwando River, most likely in response to the varying flood magnitudes. Total mortality rates, estimated using Hoenig’s maximum-age based equation, were high in the Zambezi River as a result of the high fishing pressure on this river. Overall floodplain fish ecology in the Zambezi, Kavango and Kwando rivers was influenced by the flood pulse, as was predicted by the flood pulse concept. Periodic and equilibrium life history strategists were found to adapt either to the pulsing environments of the Zambezi and Kavango rivers, or to the more stable environment of the Kwando River, and large bodied, long lived periodic strategists such as C. gariepinus tended to be highly plastic and able to thrive in most conditions. Data also suggested that Zambezi River food web structure and fish mortality rates have been impacted by overfishing, for which more information is needed to conserve and manage this system. , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2018
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