Assessing the potential role of microorganisms in the production of seedlings for the restoration of Albany Thicket
- Authors: Mpama, Nelisa
- Date: 2017
- Subjects: Vesicular-arbuscular mycorrhizas , Rhizobacteria , Restoration ecology South Africa Albany , Microorganisms
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/64555 , vital:28558
- Description: The role of microorganisms in restoration of the Albany Thicket has not been well documented, although the benefits to plants of these various interactions has been well documented. Microorganisms are chief ecological engineers and assist in resolving environmental problems and act to restore degraded ecosystem function by forming mutual relationships with the roots of the plants. The aim of this study was to assess the potential of microorganisms for the improved biomass production of selected woody and succulent seedlings used in mesic thicket restoration. Three tree species were selected for propagation in this study namely; Mystroxylon aethiopicum Scutia myrtina and Aloe ferox. Soil samples were collected from a degraded and intact thicket site from Bathurst, South Africa. Soils were evaluated for number of arbuscular mycorrhizal (AM) spores, mycorrhizal infectivity potential and nutrient availability both before and after seedling propagation. Pasteurized soil from the degraded site was used in a pot trial. Ten replicates seedling for plant species were planted and subjected to four treatments which included inoculation with AM fungi and the rhizobacterium, Enterobacter sp., alone and in combination; the fourth treatment was an un-inouclated control. Plant growth parameters were recorded at regular intervals where appropriate and seedlings were harvested after 24 weeks for biomass measurements and AM colonisation assessments. Although generally low (< 1 spore per gram) the density of AM fungal spores was significantly higher in soils from the intact site when compared with soils from the degraded site. The mycorrhizal potential of the soils was however not significantly different. Mystroxylon aethiopicum seedling shoot height, canopy diameter and shoot biomass showed a significant increase when inoculated with AM fungi while S. myrtina seedlings showed increased shoot height when inoculated with both AM fungi and Enterobacter sp. Aloe ferox seedlings did not respond to microbial inoculation. The concentration of soil P and Na increased in treatments with Enterobacter sp. alone and in combination with AM fungi. Mystroxylon aethiopicum and S. myrtina seedlings showed a dependency on microbial inoculants indicating the importance of inoculation in the nursery before planting out into the field. Overall AM fungal inoculants applied to seedlings can be used to compensate for nutrient deficiency in soils. Although the Enterobacter isolate used was known to have various plant growth promoting capabilities. It is recommended that other rhizobacterial isolates be investigated. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2017
- Full Text:
- Authors: Mpama, Nelisa
- Date: 2017
- Subjects: Vesicular-arbuscular mycorrhizas , Rhizobacteria , Restoration ecology South Africa Albany , Microorganisms
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/64555 , vital:28558
- Description: The role of microorganisms in restoration of the Albany Thicket has not been well documented, although the benefits to plants of these various interactions has been well documented. Microorganisms are chief ecological engineers and assist in resolving environmental problems and act to restore degraded ecosystem function by forming mutual relationships with the roots of the plants. The aim of this study was to assess the potential of microorganisms for the improved biomass production of selected woody and succulent seedlings used in mesic thicket restoration. Three tree species were selected for propagation in this study namely; Mystroxylon aethiopicum Scutia myrtina and Aloe ferox. Soil samples were collected from a degraded and intact thicket site from Bathurst, South Africa. Soils were evaluated for number of arbuscular mycorrhizal (AM) spores, mycorrhizal infectivity potential and nutrient availability both before and after seedling propagation. Pasteurized soil from the degraded site was used in a pot trial. Ten replicates seedling for plant species were planted and subjected to four treatments which included inoculation with AM fungi and the rhizobacterium, Enterobacter sp., alone and in combination; the fourth treatment was an un-inouclated control. Plant growth parameters were recorded at regular intervals where appropriate and seedlings were harvested after 24 weeks for biomass measurements and AM colonisation assessments. Although generally low (< 1 spore per gram) the density of AM fungal spores was significantly higher in soils from the intact site when compared with soils from the degraded site. The mycorrhizal potential of the soils was however not significantly different. Mystroxylon aethiopicum seedling shoot height, canopy diameter and shoot biomass showed a significant increase when inoculated with AM fungi while S. myrtina seedlings showed increased shoot height when inoculated with both AM fungi and Enterobacter sp. Aloe ferox seedlings did not respond to microbial inoculation. The concentration of soil P and Na increased in treatments with Enterobacter sp. alone and in combination with AM fungi. Mystroxylon aethiopicum and S. myrtina seedlings showed a dependency on microbial inoculants indicating the importance of inoculation in the nursery before planting out into the field. Overall AM fungal inoculants applied to seedlings can be used to compensate for nutrient deficiency in soils. Although the Enterobacter isolate used was known to have various plant growth promoting capabilities. It is recommended that other rhizobacterial isolates be investigated. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2017
- Full Text:
Assessing the status of biological control as a management tool for suppression of invasive alien plants in South Africa
- Zachariades, Costas, Paterson, Iain D, Strathie, Lorraine W, Hill, Martin P, van Wilgen, Brian W
- Authors: Zachariades, Costas , Paterson, Iain D , Strathie, Lorraine W , Hill, Martin P , van Wilgen, Brian W
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59762 , vital:27646 , https://doi.org/10.4102/abc.v47i2.2142
- Description: Biological control of invasive alien plant (IAP) species is the use of introduced, highly selective natural enemies (usually herbivorous arthropods or pathogens) to control plants. It has been used in 130 countries as a valuable tool for the control of IAP species, with a total of over 550 biological control agents having been released (Winston et al. 2014). The benefits of biological control to natural ecosystems are significant (Van Driesch et al. 2010), with some specific examples of threatened indigenous species being protected by the action of biological control agents (Barton et al. 2007; Meyer, Fourdrigniez & Taputuarai 2011). Detailed analyses of programmes on biological control of IAPs have also clearly indicated that the risks of non-target effects from biological control agents are minimal (Fowler, Syrett & Hill 2000; Funasaki et al. 1988; Moran & Hoffmann 2015; Paynter et al. 2004; Pemberton 2000; Suckling & Sforza 2014). Less than 1% of all the agents released have a negative impact on non-target plant populations, and those that do could have been predicted to do so, and would not be released today (Suckling & Sforza 2014).
- Full Text:
- Authors: Zachariades, Costas , Paterson, Iain D , Strathie, Lorraine W , Hill, Martin P , van Wilgen, Brian W
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59762 , vital:27646 , https://doi.org/10.4102/abc.v47i2.2142
- Description: Biological control of invasive alien plant (IAP) species is the use of introduced, highly selective natural enemies (usually herbivorous arthropods or pathogens) to control plants. It has been used in 130 countries as a valuable tool for the control of IAP species, with a total of over 550 biological control agents having been released (Winston et al. 2014). The benefits of biological control to natural ecosystems are significant (Van Driesch et al. 2010), with some specific examples of threatened indigenous species being protected by the action of biological control agents (Barton et al. 2007; Meyer, Fourdrigniez & Taputuarai 2011). Detailed analyses of programmes on biological control of IAPs have also clearly indicated that the risks of non-target effects from biological control agents are minimal (Fowler, Syrett & Hill 2000; Funasaki et al. 1988; Moran & Hoffmann 2015; Paynter et al. 2004; Pemberton 2000; Suckling & Sforza 2014). Less than 1% of all the agents released have a negative impact on non-target plant populations, and those that do could have been predicted to do so, and would not be released today (Suckling & Sforza 2014).
- Full Text:
Automation of source-artefact classification
- Sebokolodi, Makhuduga Lerato Lydia
- Authors: Sebokolodi, Makhuduga Lerato Lydia
- Date: 2017
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/4920 , vital:20743
- Description: The high sensitivities of modern radio telescopes will enable the detection of very faint astrophysical sources in the distant Universe. However, these high sensitivities also imply that calibration artefacts, which were below the noise for less sensitive instruments, will emerge above the noise and may limit the dynamic range capabilities of these instruments. Detecting faint emission will require detection thresholds close to the noise and this may cause some of the artefacts to be incorrectly detected as real emission. The current approach is to manually remove the artefacts, or set high detection thresholds in order to avoid them. The former will not be possible given the large quantities of data that these instruments will produce, and the latter results in very shallow and incomplete catalogues. This work uses the negative detection method developed by Serra et al. (2012) to distinguish artefacts from astrophysical emission in radio images. We also present a technique that automates the identification of sources subject to severe direction-dependent (DD) effects and thus allows them to be flagged for DD calibration. The negative detection approach is shown to provide high reliability and high completeness catalogues for simulated data, as well as a JVLA observation of the 3C147 field (Mitra et al., 2015). We also show that our technique correctly identifies sources that require DD calibration for datasets from the KAT-7, LOFAR, JVLA and GMRT instruments.
- Full Text:
- Authors: Sebokolodi, Makhuduga Lerato Lydia
- Date: 2017
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/4920 , vital:20743
- Description: The high sensitivities of modern radio telescopes will enable the detection of very faint astrophysical sources in the distant Universe. However, these high sensitivities also imply that calibration artefacts, which were below the noise for less sensitive instruments, will emerge above the noise and may limit the dynamic range capabilities of these instruments. Detecting faint emission will require detection thresholds close to the noise and this may cause some of the artefacts to be incorrectly detected as real emission. The current approach is to manually remove the artefacts, or set high detection thresholds in order to avoid them. The former will not be possible given the large quantities of data that these instruments will produce, and the latter results in very shallow and incomplete catalogues. This work uses the negative detection method developed by Serra et al. (2012) to distinguish artefacts from astrophysical emission in radio images. We also present a technique that automates the identification of sources subject to severe direction-dependent (DD) effects and thus allows them to be flagged for DD calibration. The negative detection approach is shown to provide high reliability and high completeness catalogues for simulated data, as well as a JVLA observation of the 3C147 field (Mitra et al., 2015). We also show that our technique correctly identifies sources that require DD calibration for datasets from the KAT-7, LOFAR, JVLA and GMRT instruments.
- Full Text:
Aza boron-pyridyl-isoindoline analogues
- Zhang, Hui, Wu, Yanping, Fan, Minhui, Xiao, Xuqiong, Mack, John, Kubheka, Gugu, Nyokong, Tebello, Lu, Hua
- Authors: Zhang, Hui , Wu, Yanping , Fan, Minhui , Xiao, Xuqiong , Mack, John , Kubheka, Gugu , Nyokong, Tebello , Lu, Hua
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/232912 , vital:50037 , xlink:href="https://doi.org/10.1039/C7NJ00707H"
- Description: Several aza boron-pyridyl-isoindoline analogues are synthesized through a facile and scale-up two step reaction using 1,2-naphthalenedicarbonitrile as a starting material. These analogues show broad envelopes of intense vibrational bands in the absorption spectra with moderate fluorescence quantum yields in solution and the solid-state. An analysis of the structure–property relationships is described based on X-ray crystallography, optical spectroscopy, and theoretical calculations.
- Full Text:
- Authors: Zhang, Hui , Wu, Yanping , Fan, Minhui , Xiao, Xuqiong , Mack, John , Kubheka, Gugu , Nyokong, Tebello , Lu, Hua
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/232912 , vital:50037 , xlink:href="https://doi.org/10.1039/C7NJ00707H"
- Description: Several aza boron-pyridyl-isoindoline analogues are synthesized through a facile and scale-up two step reaction using 1,2-naphthalenedicarbonitrile as a starting material. These analogues show broad envelopes of intense vibrational bands in the absorption spectra with moderate fluorescence quantum yields in solution and the solid-state. An analysis of the structure–property relationships is described based on X-ray crystallography, optical spectroscopy, and theoretical calculations.
- Full Text:
Azide-derivatized gold nanosphere “clicked” to indium and zinc phthalocyanines for improved nonlinear optical limiting
- Bankole, Owolabi M, Nyokong, Tebello
- Authors: Bankole, Owolabi M , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188249 , vital:44738 , xlink:href="https://doi.org/10.1016/j.molstruc.2017.01.088"
- Description: We report on the conjugation of azide-derivatized gold nanoparticles (AuNPs) to alkyne moieties of ZnPc and InPc via azide-alkyne Huisgen cycloaddition reaction to form phthalocyanines-AuNPs (MPc-AuNPs) conjugates. The detailed structural characterizations of the composites were in good agreement with the expected results. The nonlinear absorption coefficients and other nonlinear optical limiting parameters were almost two times larger for the conjugates compared to free phthalocyanines. We established direct relationship between improved photophysical characterizations and enhanced nonlinear effects of reverse saturable absorption mechanisms favoured by excited triplet absorption of the phthalocyanines in the presence of AuNPs. The combination of InPc with AuNPs resulted in the lowest limiting intensity value of 0.06 J/cm2, hence the best performance in terms of optical limiting.
- Full Text:
- Authors: Bankole, Owolabi M , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188249 , vital:44738 , xlink:href="https://doi.org/10.1016/j.molstruc.2017.01.088"
- Description: We report on the conjugation of azide-derivatized gold nanoparticles (AuNPs) to alkyne moieties of ZnPc and InPc via azide-alkyne Huisgen cycloaddition reaction to form phthalocyanines-AuNPs (MPc-AuNPs) conjugates. The detailed structural characterizations of the composites were in good agreement with the expected results. The nonlinear absorption coefficients and other nonlinear optical limiting parameters were almost two times larger for the conjugates compared to free phthalocyanines. We established direct relationship between improved photophysical characterizations and enhanced nonlinear effects of reverse saturable absorption mechanisms favoured by excited triplet absorption of the phthalocyanines in the presence of AuNPs. The combination of InPc with AuNPs resulted in the lowest limiting intensity value of 0.06 J/cm2, hence the best performance in terms of optical limiting.
- Full Text:
Back to good health
- Authors: Machanick, Philip
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/61144 , vital:27984 , http://dx.doi.org/10.18489/sacj.v29i3.565
- Description: From introduction: We have a bumper issue, with eleven research papers and one letter to the editor. 2016 was a difficult year for academia in South Africa with highly disruptive protests. 2017 was mostly better from that point of view, though the protest movement has not completely gone away. This issue contains some papers that were submissions to special issues that were not ready in time and hence to some extent is a catch-up issue. In previous issues this year, 29(1), published in July, contained nine research papers, of which five were extended papers from the 2016 SAICSIT annual conference. There was also a special issue on ICT in Education published in October, 29(2), which had five research papers. Two papers from the ICT in Education special issue spilled over to this issue. Overall, we have published 25 research papers this year, compared with four in 2016, fourteen in 2015 and nineteen in 2014. Numbers are therefore looking healthy again; I hope the underlying causes of protest are addressed so we do not have to endure another year like 2016. In the remainder of this editorial, I give an update on the effects of indexing in Scopus, list papers in this issue and end with changes in the editorial team.
- Full Text:
- Authors: Machanick, Philip
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/61144 , vital:27984 , http://dx.doi.org/10.18489/sacj.v29i3.565
- Description: From introduction: We have a bumper issue, with eleven research papers and one letter to the editor. 2016 was a difficult year for academia in South Africa with highly disruptive protests. 2017 was mostly better from that point of view, though the protest movement has not completely gone away. This issue contains some papers that were submissions to special issues that were not ready in time and hence to some extent is a catch-up issue. In previous issues this year, 29(1), published in July, contained nine research papers, of which five were extended papers from the 2016 SAICSIT annual conference. There was also a special issue on ICT in Education published in October, 29(2), which had five research papers. Two papers from the ICT in Education special issue spilled over to this issue. Overall, we have published 25 research papers this year, compared with four in 2016, fourteen in 2015 and nineteen in 2014. Numbers are therefore looking healthy again; I hope the underlying causes of protest are addressed so we do not have to endure another year like 2016. In the remainder of this editorial, I give an update on the effects of indexing in Scopus, list papers in this issue and end with changes in the editorial team.
- Full Text:
Back to nowhere
- Authors: Fundakubi, Zukile Anthony
- Date: 2017
- Subjects: Creative writing (Higher education) South Africa , South African fiction (English) 21st century , Short stories, South African (English) 21st century , Xhosa fiction 21st century , Short stories, Xhosa 21st century , Detective and mystery stories 21st century
- Language: English , Xhosa
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/5071 , vital:20763
- Description: My writing contains elements of hard-boiled detective fiction and crime writing. My stories, written in isiXhosa and English and a mixture of both, transplant these genres into a South African township setting where gang violence dominates and life is cheap. They are driven by uniquely South African characters, brutal crime scenes and fear-inspiring suspense, but none the less still full of humour. I want my work to entertain the reader while also looking realistically and critically at the problem of crime in our townships. I draw on influences of African and Latin American writers to create South African crime fiction in a realistic urban setting, with dynamic characters and sharp dialogue. , Le ngqokelela yamabali iqulathe amabali angobomi babantu abasezilokishini nabo bahlala ezilalini. Nangona umfundi angahle awafumanisa ehlekisa amanye elusizi, injongo yombhali asikukuhlekisa nakunyanzelisa imfundiso koko ikuzoba ubomi bababantu, bephila kwezi ndawo neengxaki abajongene nazo. Imeko yaba bantu kumakhaya ngamakhaya yiyo ebangele ukuba umbhali abelane nomfundi ngokuqhubekayo ebomini. , This thesis is presented in two parts: English and isiXhosa
- Full Text:
- Authors: Fundakubi, Zukile Anthony
- Date: 2017
- Subjects: Creative writing (Higher education) South Africa , South African fiction (English) 21st century , Short stories, South African (English) 21st century , Xhosa fiction 21st century , Short stories, Xhosa 21st century , Detective and mystery stories 21st century
- Language: English , Xhosa
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/5071 , vital:20763
- Description: My writing contains elements of hard-boiled detective fiction and crime writing. My stories, written in isiXhosa and English and a mixture of both, transplant these genres into a South African township setting where gang violence dominates and life is cheap. They are driven by uniquely South African characters, brutal crime scenes and fear-inspiring suspense, but none the less still full of humour. I want my work to entertain the reader while also looking realistically and critically at the problem of crime in our townships. I draw on influences of African and Latin American writers to create South African crime fiction in a realistic urban setting, with dynamic characters and sharp dialogue. , Le ngqokelela yamabali iqulathe amabali angobomi babantu abasezilokishini nabo bahlala ezilalini. Nangona umfundi angahle awafumanisa ehlekisa amanye elusizi, injongo yombhali asikukuhlekisa nakunyanzelisa imfundiso koko ikuzoba ubomi bababantu, bephila kwezi ndawo neengxaki abajongene nazo. Imeko yaba bantu kumakhaya ngamakhaya yiyo ebangele ukuba umbhali abelane nomfundi ngokuqhubekayo ebomini. , This thesis is presented in two parts: English and isiXhosa
- Full Text:
Bearers of Memory: Georges Senga’s Assani’s ‘Cette maison n’est pas a vendre et a vendre
- Mukendi, Jean-Sylvain Tshilumba
- Authors: Mukendi, Jean-Sylvain Tshilumba
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147182 , vital:38600 , https://artthrob.co.za/2017/06/06/bearers-of-memory-georges-senga-assanis-cette-maison-nest-pas-a-vendre-et-a-vendre/
- Description: Dedicated to the work of emerging international photographers, the upper gallery of the new Market Photo Workshop relocated building is showcasing Georges Senga Assani’s latest series ‘Cette maison n’est pas à vendre et à vendre’ which translates as ‘This house is not for sale, and for sale’. The Lubumbashi-based photographer has been wandering his surroundings, alert to the passage of time and history. Immutable concepts like history and time leave traces. Time enforces memory, history bequeaths and infuses collective memory.
- Full Text:
- Authors: Mukendi, Jean-Sylvain Tshilumba
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147182 , vital:38600 , https://artthrob.co.za/2017/06/06/bearers-of-memory-georges-senga-assanis-cette-maison-nest-pas-a-vendre-et-a-vendre/
- Description: Dedicated to the work of emerging international photographers, the upper gallery of the new Market Photo Workshop relocated building is showcasing Georges Senga Assani’s latest series ‘Cette maison n’est pas à vendre et à vendre’ which translates as ‘This house is not for sale, and for sale’. The Lubumbashi-based photographer has been wandering his surroundings, alert to the passage of time and history. Immutable concepts like history and time leave traces. Time enforces memory, history bequeaths and infuses collective memory.
- Full Text:
Being young, black, woman academics on an Accelerated Development Programme in an Historically White University in South Africa: a narrative analysis
- Mohoto, Nkoe Lieketso Paballo
- Authors: Mohoto, Nkoe Lieketso Paballo
- Date: 2017
- Subjects: New generation academic professionals Programme (South Africa) , College teachers, Black -- South Africa , Women college teachers, Black -- South Africa -- Case studies , Rhodes University
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/13202 , vital:21813
- Description: The national program for the development of next and new generation academic professionals (NGAP) aims to help Universities to diversify their academic teaching staff to be more reflective of the national demographics of the country. Through NGAP and policies of redress, a Historically White University would predictably introduce young black women into their academic teaching staff. This is a category of the population who would have been most affected by the exclusionary hiring policies that would have generally been in use in historically white universities before 1995, the year following the first democratic elections. The selection of staff according to criteria that has historically been used to exclude them is a policy which is widely considered to be a useful and necessary way to institute redress. While this half thesis does not disagree with this social and moral imperative, I find interest in the lack of focus on the emotional, psychological, spiritual and otherwise personal toll of the implementation of such a policy on those who are introduced through it and related policies. I believe there is a need to problematise the highly normative environments in which staff (to benefit from redress) are required to function. This half thesis examines the narrated experiences of three such staff members at Rhodes University with specific interest in their everyday experiences in an institution which has historically been tailored for (and in many cases is still run by) white, older male academics. The thesis indicates that the emotional and psychological effects and 'taxes' of being on an accelerated development programme may be worth noting and appreciating in order to think about the retention of black woman academics. The findings show that the complexity of younger black women's experiences within historically white universities such as Rhodes University requires equally complex and multifaceted strategies and programmes. These programmes should not only support these academics but also undermine existing exclusionary institutional cultures in order to facilitate true, deep transformational practice in historically white universities such as Rhodes University.
- Full Text:
- Authors: Mohoto, Nkoe Lieketso Paballo
- Date: 2017
- Subjects: New generation academic professionals Programme (South Africa) , College teachers, Black -- South Africa , Women college teachers, Black -- South Africa -- Case studies , Rhodes University
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/13202 , vital:21813
- Description: The national program for the development of next and new generation academic professionals (NGAP) aims to help Universities to diversify their academic teaching staff to be more reflective of the national demographics of the country. Through NGAP and policies of redress, a Historically White University would predictably introduce young black women into their academic teaching staff. This is a category of the population who would have been most affected by the exclusionary hiring policies that would have generally been in use in historically white universities before 1995, the year following the first democratic elections. The selection of staff according to criteria that has historically been used to exclude them is a policy which is widely considered to be a useful and necessary way to institute redress. While this half thesis does not disagree with this social and moral imperative, I find interest in the lack of focus on the emotional, psychological, spiritual and otherwise personal toll of the implementation of such a policy on those who are introduced through it and related policies. I believe there is a need to problematise the highly normative environments in which staff (to benefit from redress) are required to function. This half thesis examines the narrated experiences of three such staff members at Rhodes University with specific interest in their everyday experiences in an institution which has historically been tailored for (and in many cases is still run by) white, older male academics. The thesis indicates that the emotional and psychological effects and 'taxes' of being on an accelerated development programme may be worth noting and appreciating in order to think about the retention of black woman academics. The findings show that the complexity of younger black women's experiences within historically white universities such as Rhodes University requires equally complex and multifaceted strategies and programmes. These programmes should not only support these academics but also undermine existing exclusionary institutional cultures in order to facilitate true, deep transformational practice in historically white universities such as Rhodes University.
- Full Text:
Between a cushion and a risky conversation: ARTS LOUNGE reviewed
- Authors: Baasch, Rachel M
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147703 , vital:38662 , https://doi.org/10.1080/00043389.2011.11877155
- Description: On the fringe of the National Arts Festival, at a point of transition between Rhodes University campus and the commercial side of Grahamstown, the walls of a former home and former horse-stable, now a research house, reverberate with the strain of cross-disciplinary, site-specific collaboration. The ARTS LOUNGE made its first official appearance at the Grahamstown National Arts Festival (ViPPA Research Center, Rhodes University) from 30 June to 9 July 2011. The ten-day event was organised by the Visual and Performing Arts of Africa Research (ViPPA) team in collaboration with musicians, artists, writers, performers and members of the public.
- Full Text:
- Authors: Baasch, Rachel M
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147703 , vital:38662 , https://doi.org/10.1080/00043389.2011.11877155
- Description: On the fringe of the National Arts Festival, at a point of transition between Rhodes University campus and the commercial side of Grahamstown, the walls of a former home and former horse-stable, now a research house, reverberate with the strain of cross-disciplinary, site-specific collaboration. The ARTS LOUNGE made its first official appearance at the Grahamstown National Arts Festival (ViPPA Research Center, Rhodes University) from 30 June to 9 July 2011. The ten-day event was organised by the Visual and Performing Arts of Africa Research (ViPPA) team in collaboration with musicians, artists, writers, performers and members of the public.
- Full Text:
Between place and a raised foot: the pace, protest and sway of ambulatory art
- Authors: Simbao, Ruth K
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/146468 , vital:38528 , https://www.ug.edu.gh/events/arts-council-african-studies-association-acasa-17th-triennial-symposium-august-8-â-13-2017
- Description: ACASA facilitates communication among scholars, teachers, students, artists, museum specialists, collectors, and all others interested in the arts of Africa and the African Diaspora. Its goals are to promote greater understanding of African material and expressive culture in all its forms, and to encourage contact and collaboration with African and Diaspora artists and scholars.
- Full Text:
- Authors: Simbao, Ruth K
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/146468 , vital:38528 , https://www.ug.edu.gh/events/arts-council-african-studies-association-acasa-17th-triennial-symposium-august-8-â-13-2017
- Description: ACASA facilitates communication among scholars, teachers, students, artists, museum specialists, collectors, and all others interested in the arts of Africa and the African Diaspora. Its goals are to promote greater understanding of African material and expressive culture in all its forms, and to encourage contact and collaboration with African and Diaspora artists and scholars.
- Full Text:
Between reproductive rights and access to reproductive healthcare services: narratives of reproductive rights activists in South Africa
- Authors: Jacobs, Marc
- Date: 2017
- Subjects: Reproductive rights -- South Africa , Reproductive rights -- Political aspects -- South Africa , Human reproduction -- Law and legislation -- South Africa , Reproductive health -- South Africa , Abortion -- Government policy -- South Africa , South Africa. Choice of Termination of Pregnancy Act, 1996
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: http://hdl.handle.net/10962/17707 , vital:22270
- Description: The motivation behind the research paper, “Between reproductive rights and access to reproductive healthcare services: Narratives of reproductive rights activists in South Africa” stems from the notion that civil society groups have often played a critical role in addressing social justice issues concerning women’s rights. Since 1996 after implementation of the Choice on Termination of Pregnancy (CTOP) Act, South Africa has frequently been praised for its progressive abortion laws that formally recognises women’s need for reproductive autonomy and equality. However, ineffective implementation has resulted in many women facing a combination of barriers to accessing reproductive healthcare services. Thus, resulting in some women opting for unsafe, illegal abortion services and placing their health and lives in danger. The purpose of the study, therefore, is to capture the perceptions of contemporary South African based reproductive rights activists and NGOs who engage in campaigns that seek to highlight the complex relationship between reproductive rights and access to such rights. Data for the study was collected through open-ended questionnaires in which participants provided their unique opinions as activists who regularly engage with the abortion and access issues in South Africa. Results from the study suggest that ineffective implementation of the CTOP Act can be attributed to a lack of political will to prioritise women’s sexual and reproductive rights, thereby further marginalising women in society. Results also point to the need for widespread support from civil society on women’s rights matters so that the State can more effectively be held accountable for catering to the most marginalised women in South African society.
- Full Text:
- Authors: Jacobs, Marc
- Date: 2017
- Subjects: Reproductive rights -- South Africa , Reproductive rights -- Political aspects -- South Africa , Human reproduction -- Law and legislation -- South Africa , Reproductive health -- South Africa , Abortion -- Government policy -- South Africa , South Africa. Choice of Termination of Pregnancy Act, 1996
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: http://hdl.handle.net/10962/17707 , vital:22270
- Description: The motivation behind the research paper, “Between reproductive rights and access to reproductive healthcare services: Narratives of reproductive rights activists in South Africa” stems from the notion that civil society groups have often played a critical role in addressing social justice issues concerning women’s rights. Since 1996 after implementation of the Choice on Termination of Pregnancy (CTOP) Act, South Africa has frequently been praised for its progressive abortion laws that formally recognises women’s need for reproductive autonomy and equality. However, ineffective implementation has resulted in many women facing a combination of barriers to accessing reproductive healthcare services. Thus, resulting in some women opting for unsafe, illegal abortion services and placing their health and lives in danger. The purpose of the study, therefore, is to capture the perceptions of contemporary South African based reproductive rights activists and NGOs who engage in campaigns that seek to highlight the complex relationship between reproductive rights and access to such rights. Data for the study was collected through open-ended questionnaires in which participants provided their unique opinions as activists who regularly engage with the abortion and access issues in South Africa. Results from the study suggest that ineffective implementation of the CTOP Act can be attributed to a lack of political will to prioritise women’s sexual and reproductive rights, thereby further marginalising women in society. Results also point to the need for widespread support from civil society on women’s rights matters so that the State can more effectively be held accountable for catering to the most marginalised women in South African society.
- Full Text:
Beyond benefit sharing: Place attachment and the importance of access to protected areas for surrounding communities
- Cundill, Georgina, Bezerra, Joana C, de Vos, Alta, Ntingana, Nokuthula
- Authors: Cundill, Georgina , Bezerra, Joana C , de Vos, Alta , Ntingana, Nokuthula
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/416265 , vital:71334 , xlink:href="https://doi.org/10.1016/j.ecoser.2017.03.011"
- Description: The concept of place attachment can assist to integrate relational values into ecosystem service research, and assist us to rethink the notion of benefits in contemporary protected area thinking. We present a case study from South Africa, where the concept of two-dimensional place attachment was used to understand the relationship between a protected area and a land claimant community that now owns part of this protected area but does not have physical access to the land. A place attachment lens helps refocus access to protected areas as cornerstone to long term sustainability of such areas. Such access must be considered in the context of spatially and economically differentiated users, including a focus on trade-offs between such users. Our findings highlight that when communities previously displaced from protected areas respond to offers of ‘benefit sharing’ with demands for access and recognition as land owners, they are asking for a recognition of relational values, and identity, based on close interaction with nature. A place attachment and relational values perspective raises questions about the extent to which traditional conservation practice can accommodate such values, and therefore meet local people’s expectations and remain viable in the long term.
- Full Text:
- Authors: Cundill, Georgina , Bezerra, Joana C , de Vos, Alta , Ntingana, Nokuthula
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/416265 , vital:71334 , xlink:href="https://doi.org/10.1016/j.ecoser.2017.03.011"
- Description: The concept of place attachment can assist to integrate relational values into ecosystem service research, and assist us to rethink the notion of benefits in contemporary protected area thinking. We present a case study from South Africa, where the concept of two-dimensional place attachment was used to understand the relationship between a protected area and a land claimant community that now owns part of this protected area but does not have physical access to the land. A place attachment lens helps refocus access to protected areas as cornerstone to long term sustainability of such areas. Such access must be considered in the context of spatially and economically differentiated users, including a focus on trade-offs between such users. Our findings highlight that when communities previously displaced from protected areas respond to offers of ‘benefit sharing’ with demands for access and recognition as land owners, they are asking for a recognition of relational values, and identity, based on close interaction with nature. A place attachment and relational values perspective raises questions about the extent to which traditional conservation practice can accommodate such values, and therefore meet local people’s expectations and remain viable in the long term.
- Full Text:
Beyond War, Violence, and Suffering: Everyday Life in the Honde Valley Borderland Communities during Zimbabwe’s Liberation War and the RENAMO Insurgency, c.1960-2016
- Authors: Nyachega, Nicholas
- Date: 2017
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/7023 , vital:21210
- Description: This thesis examines the history of the Honde Valley area, in Mutasa District, along the Zimbabwe-Mozambique border. It uses two historic developments: the Zimbabwe liberation war and RENAMO insurgency to explore daily life and mundane experiences of the borderland communities, mainly from the late 1970s to 2016. Because earlier historians of these two historic developments have been much interested in studying the aspects of violence and suffering, this study extends the focus of analysis to the mundane experiences. I argue that in borderland areas, there are other wartime aspects of life worth investigating other than violence and suffering. In doing so, the thesis deploys the notions of conviviality and the everyday to understand the daily experiences of the Honde Valley communities during the disruptions caused to everyday life by these wars. Admittedly, twentieth century wars in Zimbabwe and Mozambique transformed the area that had previously remained at the fringes of colonial power from 1890-1950, into a new and bitterly contested ‘sharp end’ of the war. Nonetheless, peoples’ experiences during these wars cannot be understood merely in relation to violence and suffering. Furthermore, I argue that although some families were forcibly moved into liberation war “Protected Villages ”, they innovatively designed new mechanisms and alternative lifestyles in response to the state’s routinised control. The thesis concludes that beyond the confines of war-induced violence and suffering, Honde Valley communities used their borderland location to evade the pressures of war and continued with life.
- Full Text:
- Authors: Nyachega, Nicholas
- Date: 2017
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/7023 , vital:21210
- Description: This thesis examines the history of the Honde Valley area, in Mutasa District, along the Zimbabwe-Mozambique border. It uses two historic developments: the Zimbabwe liberation war and RENAMO insurgency to explore daily life and mundane experiences of the borderland communities, mainly from the late 1970s to 2016. Because earlier historians of these two historic developments have been much interested in studying the aspects of violence and suffering, this study extends the focus of analysis to the mundane experiences. I argue that in borderland areas, there are other wartime aspects of life worth investigating other than violence and suffering. In doing so, the thesis deploys the notions of conviviality and the everyday to understand the daily experiences of the Honde Valley communities during the disruptions caused to everyday life by these wars. Admittedly, twentieth century wars in Zimbabwe and Mozambique transformed the area that had previously remained at the fringes of colonial power from 1890-1950, into a new and bitterly contested ‘sharp end’ of the war. Nonetheless, peoples’ experiences during these wars cannot be understood merely in relation to violence and suffering. Furthermore, I argue that although some families were forcibly moved into liberation war “Protected Villages ”, they innovatively designed new mechanisms and alternative lifestyles in response to the state’s routinised control. The thesis concludes that beyond the confines of war-induced violence and suffering, Honde Valley communities used their borderland location to evade the pressures of war and continued with life.
- Full Text:
Biogeographical comparison of the emergent macrophyte, Sagittaria platyphylla in its native and introduced ranges
- Kwong, Raelene M, Sagliocco, Jean Louis, Harms, Nathan E, Butler, Kym L, Green, Peter T, Martin, Grant D
- Authors: Kwong, Raelene M , Sagliocco, Jean Louis , Harms, Nathan E , Butler, Kym L , Green, Peter T , Martin, Grant D
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/76980 , vital:30652 , https://doi.org/10.1016/j.aquabot.2017.05.001
- Description: Understanding why some plant species become invasive is important to predict and prevent future weed threats and identify appropriate management strategies. Many hypotheses have been proposed to explain why plants become invasive, yet few studies have quantitatively compared plant and population parameters between native and introduced range populations to gain an objective perspective on the causes of plant invasion. The present study uses a biogeographical field survey to compare morphological and reproductive traits and abundance between the native range (USA) and two introduced ranges (Australia and South Africa) of Sagittaria platyphylla (Engelm.) J.G. Sm (Alismataceae), a highly invasive freshwater macrophyte. Introduced and native populations differed in sexual reproductive output with the number of achenes per fruiting head and individual achene weight found to be 40% and 50% greater in introduced populations respectively. However, no other morphological traits were found to be consistently different between the native and both introduced ranges, especially after taking into account differences in environmental conditions between the three ranges. Although populations in introduced regions were larger and occupied greater percentage cover, no differences in plant density were evident. Our results suggest that, apart from sexual reproduction, many of the trait patterns observed in S. platyphylla are influenced by environmental and habitat conditions within the native and invaded ranges. We conclude that the enemy release hypothesis best explains the results observed for sexual reproduction. In particular, we hypothesise that a release from natural enemies, specifically a pre-dispersal seed predator, may induce reproductive plasticity in S. platyphylla.
- Full Text:
- Authors: Kwong, Raelene M , Sagliocco, Jean Louis , Harms, Nathan E , Butler, Kym L , Green, Peter T , Martin, Grant D
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/76980 , vital:30652 , https://doi.org/10.1016/j.aquabot.2017.05.001
- Description: Understanding why some plant species become invasive is important to predict and prevent future weed threats and identify appropriate management strategies. Many hypotheses have been proposed to explain why plants become invasive, yet few studies have quantitatively compared plant and population parameters between native and introduced range populations to gain an objective perspective on the causes of plant invasion. The present study uses a biogeographical field survey to compare morphological and reproductive traits and abundance between the native range (USA) and two introduced ranges (Australia and South Africa) of Sagittaria platyphylla (Engelm.) J.G. Sm (Alismataceae), a highly invasive freshwater macrophyte. Introduced and native populations differed in sexual reproductive output with the number of achenes per fruiting head and individual achene weight found to be 40% and 50% greater in introduced populations respectively. However, no other morphological traits were found to be consistently different between the native and both introduced ranges, especially after taking into account differences in environmental conditions between the three ranges. Although populations in introduced regions were larger and occupied greater percentage cover, no differences in plant density were evident. Our results suggest that, apart from sexual reproduction, many of the trait patterns observed in S. platyphylla are influenced by environmental and habitat conditions within the native and invaded ranges. We conclude that the enemy release hypothesis best explains the results observed for sexual reproduction. In particular, we hypothesise that a release from natural enemies, specifically a pre-dispersal seed predator, may induce reproductive plasticity in S. platyphylla.
- Full Text:
Biogeographical comparison of the emergent macrophyte, Sagittaria platyphylla in its native and introduced ranges
- Kwong, Raelene M, Sagliocco, Jean L, Harms, Nathan E, Butler, Kym L, Green, Peter T, Martin, Grant D
- Authors: Kwong, Raelene M , Sagliocco, Jean L , Harms, Nathan E , Butler, Kym L , Green, Peter T , Martin, Grant D
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/419287 , vital:71631 , xlink:href="https://doi.org/10.1016/j.aquabot.2017.05.001"
- Description: Understanding why some plant species become invasive is important to predict and prevent future weed threats and identify appropriate management strategies. Many hypotheses have been proposed to explain why plants become invasive, yet few studies have quantitatively compared plant and population parameters between native and introduced range populations to gain an objective perspective on the causes of plant invasion. The present study uses a biogeographical field survey to compare morphological and reproductive traits and abundance between the native range (USA) and two introduced ranges (Australia and South Africa) of Sagittaria platyphylla (Engelm.) J.G. Sm (Alismataceae), a highly invasive freshwater macrophyte. Introduced and native populations differed in sexual reproductive output with the number of achenes per fruiting head and individual achene weight found to be 40% and 50% greater in introduced populations respectively. However, no other morphological traits were found to be consistently different between the native and both introduced ranges, especially after taking into account differences in environmental conditions between the three ranges. Although populations in introduced regions were larger and occupied greater percentage cover, no differences in plant density were evident. Our results suggest that, apart from sexual reproduction, many of the trait patterns observed in S. platyphylla are influenced by environmental and habitat conditions within the native and invaded ranges. We conclude that the enemy release hypothesis best explains the results observed for sexual reproduction. In particular, we hypothesise that a release from natural enemies, specifically a pre-dispersal seed predator, may induce reproductive plasticity in S. platyphylla.
- Full Text:
- Authors: Kwong, Raelene M , Sagliocco, Jean L , Harms, Nathan E , Butler, Kym L , Green, Peter T , Martin, Grant D
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/419287 , vital:71631 , xlink:href="https://doi.org/10.1016/j.aquabot.2017.05.001"
- Description: Understanding why some plant species become invasive is important to predict and prevent future weed threats and identify appropriate management strategies. Many hypotheses have been proposed to explain why plants become invasive, yet few studies have quantitatively compared plant and population parameters between native and introduced range populations to gain an objective perspective on the causes of plant invasion. The present study uses a biogeographical field survey to compare morphological and reproductive traits and abundance between the native range (USA) and two introduced ranges (Australia and South Africa) of Sagittaria platyphylla (Engelm.) J.G. Sm (Alismataceae), a highly invasive freshwater macrophyte. Introduced and native populations differed in sexual reproductive output with the number of achenes per fruiting head and individual achene weight found to be 40% and 50% greater in introduced populations respectively. However, no other morphological traits were found to be consistently different between the native and both introduced ranges, especially after taking into account differences in environmental conditions between the three ranges. Although populations in introduced regions were larger and occupied greater percentage cover, no differences in plant density were evident. Our results suggest that, apart from sexual reproduction, many of the trait patterns observed in S. platyphylla are influenced by environmental and habitat conditions within the native and invaded ranges. We conclude that the enemy release hypothesis best explains the results observed for sexual reproduction. In particular, we hypothesise that a release from natural enemies, specifically a pre-dispersal seed predator, may induce reproductive plasticity in S. platyphylla.
- 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:
Biological and geophysical feedbacks with fire in the Earth System
- Archibald, S, Lehmann, C E, Belcher, C, Bond, W J, Bradstock, R A, Daniau, A L, Dexter, K, Forrestel, E J, Greve, M, He, T, Higgins, Simon I, Ripley, Bradford S
- Authors: Archibald, S , Lehmann, C E , Belcher, C , Bond, W J , Bradstock, R A , Daniau, A L , Dexter, K , Forrestel, E J , Greve, M , He, T , Higgins, Simon I , Ripley, Bradford S
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/61413 , vital:28024 , http://iopscience.iop.org/article/10.1088/1748-9326/aa9ead/meta
- Description: Roughly 3% of the Earth’s land surface burns annually, representing a critical exchange of energy and matter between the land and atmosphere via combustion. Fires range from slow smouldering peat fires, to low-intensity surface fires, to intense crown fires, depending on vegetation structure, fuel moisture, prevailing climate, and weather conditions. While the links between biogeochemistry, climate and fire are widely studied within Earth system science, these relationships are also mediated by fuels – namely plants and their litter – which are the product of evolutionary and ecological processes. Fire is a powerful selective force and, over their evolutionary history, plants across diverse clades have evolved numerous traits that either tolerate or promote fire. Here we outline a conceptual framework of how plant traits determine the flammability of ecosystems and interact with climate and weather to influence fire regimes. We explore how these evolutionary and ecological processes scale to impact biogeochemistry and Earth system processes. Finally, we outline several research challenges that, when resolved, will improve our understanding of the role of plant evolution in mediating the fire feedbacks driving Earth system processes. Understanding current patterns of fire and vegetation, as well as patterns of fire over geological time, requires research that incorporates evolutionary biology, ecology, biogeography, and the biogeosciences.
- Full Text:
- Authors: Archibald, S , Lehmann, C E , Belcher, C , Bond, W J , Bradstock, R A , Daniau, A L , Dexter, K , Forrestel, E J , Greve, M , He, T , Higgins, Simon I , Ripley, Bradford S
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/61413 , vital:28024 , http://iopscience.iop.org/article/10.1088/1748-9326/aa9ead/meta
- Description: Roughly 3% of the Earth’s land surface burns annually, representing a critical exchange of energy and matter between the land and atmosphere via combustion. Fires range from slow smouldering peat fires, to low-intensity surface fires, to intense crown fires, depending on vegetation structure, fuel moisture, prevailing climate, and weather conditions. While the links between biogeochemistry, climate and fire are widely studied within Earth system science, these relationships are also mediated by fuels – namely plants and their litter – which are the product of evolutionary and ecological processes. Fire is a powerful selective force and, over their evolutionary history, plants across diverse clades have evolved numerous traits that either tolerate or promote fire. Here we outline a conceptual framework of how plant traits determine the flammability of ecosystems and interact with climate and weather to influence fire regimes. We explore how these evolutionary and ecological processes scale to impact biogeochemistry and Earth system processes. Finally, we outline several research challenges that, when resolved, will improve our understanding of the role of plant evolution in mediating the fire feedbacks driving Earth system processes. Understanding current patterns of fire and vegetation, as well as patterns of fire over geological time, requires research that incorporates evolutionary biology, ecology, biogeography, and the biogeosciences.
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Biology and rearing of Ectomyeolis ceratoniae Zeller (Lepidoptera: Pyralidae) carob moth, a pest of multiple crops in South Africa
- Thackeray, Sean R, Moore, Sean D, Strathie, Lorraine W, Kirkman, Wayne, Hill, Martin P
- Authors: Thackeray, Sean R , Moore, Sean D , Strathie, Lorraine W , Kirkman, Wayne , Hill, Martin P
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59799 , vital:27652 , https://doi.org/10.4001/003.025.0474
- Description: Ectomyeolis ceratoniae Zeller (Lepidoptera: Pyralidae), carob moth, is a pest of several crops in South Africa. A laboratory culture was established from field-collected larvae infesting mummified pecan nuts. Biological parameters of larvae reared on an artificial diet were measured. The insect goes through five larval instars, and the head capsule sizes of the five instars were determined to be <0.34 mm, 0.35-0.64 mm, 0.65-0.94 mm, 0.95-1.14 mm and >0.15 mm for the five instars, respectively. The insect was reared individually and communally in glass vials, the latter to develop a mass-rearing technique. Developmental time from neonate to pupa was significantly slower when larvae were individually reared (38.18 ±1.2 days) compared to when they were communally reared (24.6 ± 0.65 days). A microsporidian infection (Nosema sp.) was recorded in the culture, causing significantly (fy6 = 14.99, P = 0.0082) higher mortality of communally reared larvae (76.25 % ± 11.87) than individually reared larvae (24.9 % ± 9.6).
- Full Text:
- Authors: Thackeray, Sean R , Moore, Sean D , Strathie, Lorraine W , Kirkman, Wayne , Hill, Martin P
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59799 , vital:27652 , https://doi.org/10.4001/003.025.0474
- Description: Ectomyeolis ceratoniae Zeller (Lepidoptera: Pyralidae), carob moth, is a pest of several crops in South Africa. A laboratory culture was established from field-collected larvae infesting mummified pecan nuts. Biological parameters of larvae reared on an artificial diet were measured. The insect goes through five larval instars, and the head capsule sizes of the five instars were determined to be <0.34 mm, 0.35-0.64 mm, 0.65-0.94 mm, 0.95-1.14 mm and >0.15 mm for the five instars, respectively. The insect was reared individually and communally in glass vials, the latter to develop a mass-rearing technique. Developmental time from neonate to pupa was significantly slower when larvae were individually reared (38.18 ±1.2 days) compared to when they were communally reared (24.6 ± 0.65 days). A microsporidian infection (Nosema sp.) was recorded in the culture, causing significantly (fy6 = 14.99, P = 0.0082) higher mortality of communally reared larvae (76.25 % ± 11.87) than individually reared larvae (24.9 % ± 9.6).
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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.
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