How do social and personal identity, sense of place, connectedness to nature and environmental understanding influence the implementation of collective, large-scale biodiversity stewardship initiatives in South Africa?
- Authors: Potts, Tracey Ann
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3663 , vital:20534
- Description: Biodiversity stewardship is a mechanism that is used to conserve high value biodiversity assets. Biodiversity stewardship programmes focus on areas that are under immediate threat from development or under medium to long term threat from degradation or transformation that will result in habitat loss. Biodiversity stewardship provides a solution to the resource crisis being faced by many state and provincial conservation agencies, NGO’s (Non-Governmental Organisations) and PBO’s (Public Benefit Organisations) in that it facilitates the declaration, and the subsequent improved conservation management, of private or communally owned land whilst still retaining the existing tenure. The rate of habitat loss can often be slowed, or even reversed, by proactively securing these areas and facilitating management decision-making with a focus on biodiversity outcomes without the capital investment required by the State to purchase the land. In return for conservation management actions, certain land-use restrictions and the associated opportunity costs, the State offers a suite of incentives and benefits that are, where possible, tailored to meet the needs of the landowner. Particular regions of South Africa lend themselves well to the development of biodiversity stewardship initiatives which are designed to secure ecological processes and ecosystems across a landscape or an ecological feature at scales of tens of thousands of hectares. When developing landscape level biodiversity stewardship initiatives, negotiations tend to be focussed on groups of landowners. This requires collaboration and the collective alignment of natural resource management decision-making and conservation actions amongst neighbours. Gaining a better understanding of how the social constructs of ecological understanding, place attachment, connectedness to nature, occupational identity and social and personal identity influence decision-making, behaviour and group structure is a critically important factor when developing a tool to predict the likelihood of landowners to collectively commit to long-term, legally binding biodiversity stewardship programmes. The overarching hypothesis was that the social constructs listed above influence group dynamics within the context of collective pro-conservation behaviour. Social dynamics associated with large-scale biodiversity stewardship initiatives become complex when multiple landowners are involved. Could social cohesion and group culture be influenced by aspects of identity and do these in turn develop into barriers or motivators to coordinated and sustained conservation efforts? Further influences on the successful implementation of landscape scale biodiversity stewardship initiatives could include ecological understanding, connectedness to nature and place attachment. Structured interviews were held with the landowners engaged in two separate large-scale biodiversity stewardship sites, the Compassberg Protected Environment and the Baviaanskloof Hartland, in the Eastern Cape Province of South Africa. The interviews were followed up with surveys containing psychometric scales related to the influence of ecological understanding, place attachment, connectedness to nature and aspects of identity on commitment to collective long-term, large-scale biodiversity stewardship initiatives. The results from a set of non-parametric (exact) Wilcoxon rank-sum tests showed that scores on the new ecological paradigm scale and the place attachment scale latent variables were significantly different at the two study sites, at the 10% level of significance. Demographic differences between the two study sites influenced group dynamics, collective decision-making and commitment. The relationship between the latent variables (the five psychometric scales measured) and the ancillary variables (the demographic data describing the respondents) cannot be considered conclusive; however they do provide relatively useful insights into the development of a scale or tool to measure conservation opportunity. The thesis concludes with a proposed conservation opportunity assessment tool that can be utilised alongside the existing, well refined, conservation priority assessment tools to assist in decision-making when planning large, landscape scale biodiversity stewardship initiatives in South Africa.
- Full Text:
- Authors: Potts, Tracey Ann
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3663 , vital:20534
- Description: Biodiversity stewardship is a mechanism that is used to conserve high value biodiversity assets. Biodiversity stewardship programmes focus on areas that are under immediate threat from development or under medium to long term threat from degradation or transformation that will result in habitat loss. Biodiversity stewardship provides a solution to the resource crisis being faced by many state and provincial conservation agencies, NGO’s (Non-Governmental Organisations) and PBO’s (Public Benefit Organisations) in that it facilitates the declaration, and the subsequent improved conservation management, of private or communally owned land whilst still retaining the existing tenure. The rate of habitat loss can often be slowed, or even reversed, by proactively securing these areas and facilitating management decision-making with a focus on biodiversity outcomes without the capital investment required by the State to purchase the land. In return for conservation management actions, certain land-use restrictions and the associated opportunity costs, the State offers a suite of incentives and benefits that are, where possible, tailored to meet the needs of the landowner. Particular regions of South Africa lend themselves well to the development of biodiversity stewardship initiatives which are designed to secure ecological processes and ecosystems across a landscape or an ecological feature at scales of tens of thousands of hectares. When developing landscape level biodiversity stewardship initiatives, negotiations tend to be focussed on groups of landowners. This requires collaboration and the collective alignment of natural resource management decision-making and conservation actions amongst neighbours. Gaining a better understanding of how the social constructs of ecological understanding, place attachment, connectedness to nature, occupational identity and social and personal identity influence decision-making, behaviour and group structure is a critically important factor when developing a tool to predict the likelihood of landowners to collectively commit to long-term, legally binding biodiversity stewardship programmes. The overarching hypothesis was that the social constructs listed above influence group dynamics within the context of collective pro-conservation behaviour. Social dynamics associated with large-scale biodiversity stewardship initiatives become complex when multiple landowners are involved. Could social cohesion and group culture be influenced by aspects of identity and do these in turn develop into barriers or motivators to coordinated and sustained conservation efforts? Further influences on the successful implementation of landscape scale biodiversity stewardship initiatives could include ecological understanding, connectedness to nature and place attachment. Structured interviews were held with the landowners engaged in two separate large-scale biodiversity stewardship sites, the Compassberg Protected Environment and the Baviaanskloof Hartland, in the Eastern Cape Province of South Africa. The interviews were followed up with surveys containing psychometric scales related to the influence of ecological understanding, place attachment, connectedness to nature and aspects of identity on commitment to collective long-term, large-scale biodiversity stewardship initiatives. The results from a set of non-parametric (exact) Wilcoxon rank-sum tests showed that scores on the new ecological paradigm scale and the place attachment scale latent variables were significantly different at the two study sites, at the 10% level of significance. Demographic differences between the two study sites influenced group dynamics, collective decision-making and commitment. The relationship between the latent variables (the five psychometric scales measured) and the ancillary variables (the demographic data describing the respondents) cannot be considered conclusive; however they do provide relatively useful insights into the development of a scale or tool to measure conservation opportunity. The thesis concludes with a proposed conservation opportunity assessment tool that can be utilised alongside the existing, well refined, conservation priority assessment tools to assist in decision-making when planning large, landscape scale biodiversity stewardship initiatives in South Africa.
- Full Text:
Thermoluminescence of secondary glow peaks in carbon-doped aluminium oxide
- Authors: Seneza, Cleophace
- Date: 2014
- Subjects: Thermoluminescence , Aluminum oxide , Thermoluminescence dosimetry
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5537 , http://hdl.handle.net/10962/d1013053
- Description: Carbon-doped aluminium oxide, α-Al₂O₃ : C, is a highly sensitive luminescence dosimeter. The high sensitivity of α-Al₂O₃ : C has been attributed to large concentrations of oxygen vacancies, F and F⁺ centres, induced in the material during its preparation. The material is prepared in a highly reducing atmosphere in the presence of carbon. In the luminescence process, electrons are trapped in F-centre defects as a result of irradiation of the material. Thermal or optical release of trapped electrons leads to emission of light, thermoluminescence (TL) or optically stimulated light (OSL) respectively. The thermoluminescence technique is used to study point defects involved in luminescence of α-Al₂O₃ : C. A glow curve of α-Al₂O₃ : C, generally, shows three peaks; the main dosimetric peak of high intensity (peak II) and two other peaks of lower intensity called secondary glow peaks (peaks I and III). The overall aim of our work was to study the TL mechanisms responsible for secondary glow peaks in α-Al₂O₃ : C. The dynamics of charge movement between centres during the TL process was studied. The phototransferred thermoluminescence (PTTL) from secondary glow peaks was also studied. The kinetic analysis of TL from secondary peaks has shown that the activation energy of peak I is 0.7 eV and that of peak III, 1.2 eV. The frequency factor, the frequency at which an electron attempts to escape a trap, was found near the range of the Debye vibration frequency. Values of the activation energy are consistent within a variety of methods used. The two peaks follow first order kinetics as confirmed by the TM-Tstop method. A linear dependence of TL from peak I on dose is observed at various doses from 0.5 to 2.5 Gy. The peak position for peak I was also independent on dose, further confirmation that peak I is of first order kinetics. Peak I suffers from thermal fading with storage with a half-life of about 120 s. The dependence of TL intensity for peak I increased as a function of heating rate from 0.2 to 6ºCs⁻¹. In contrast to the TL intensity for peak I, the intensity of TL for peak III decreases with an increase of heating rate from 0.2 to 6ºCs⁻¹. This is evidence of thermal quenching for peak III. Parameters W = 1.48 ± 0:10 eV and C = 4 x 10¹³ of thermal quenching were calculated from peak III intensities at different heating rates. Thermal cleaning of peak III and the glow curve deconvolution methods confirmed that the main peak is actually overlapped by a small peak (labeled peak IIA). The kinetic analysis of peak IIA showed that it is of first order kinetics and that its activation energy is 1:0 eV. In addition, the peak IIA is affected by thermal quenching. Another secondary peak appears at 422ºC (peak IV). However, the kinetic analysis of TL from peak IV was not studied because its intensity is not well defined. A heating rate of 0.4ºCs⁻¹ was used after a dose of 3 Gy in kinetic analysis of peaks IIA and III. The study of the PTTL showed that peaks I and II were regenerated under PTTL but peak III was not. Various effects of the PTTL for peaks I and II for different preheating temperatures in different samples were observed. The effect of annealing at 900ºC for 15 minutes between measurements following each illumination time was studied. The effect of dose on secondary peaks was also studied in this work. The kinetic analysis of the PTTL intensity for peak I showed that its activation energy is 0.7 eV, consistent with the activation energy of the normal TL for peak I. The PTTL intensity from peak I fades rapidly with storage compared with the thermal fading from peak I of the normal TL. The PTTL intensity for peak I decreases as a function of heating rate. This decrease was attributed to thermal quenching. Thermal quenching was not observed in the case of the normal TL intensity. The cause of this contrast requires further study.
- Full Text:
- Authors: Seneza, Cleophace
- Date: 2014
- Subjects: Thermoluminescence , Aluminum oxide , Thermoluminescence dosimetry
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5537 , http://hdl.handle.net/10962/d1013053
- Description: Carbon-doped aluminium oxide, α-Al₂O₃ : C, is a highly sensitive luminescence dosimeter. The high sensitivity of α-Al₂O₃ : C has been attributed to large concentrations of oxygen vacancies, F and F⁺ centres, induced in the material during its preparation. The material is prepared in a highly reducing atmosphere in the presence of carbon. In the luminescence process, electrons are trapped in F-centre defects as a result of irradiation of the material. Thermal or optical release of trapped electrons leads to emission of light, thermoluminescence (TL) or optically stimulated light (OSL) respectively. The thermoluminescence technique is used to study point defects involved in luminescence of α-Al₂O₃ : C. A glow curve of α-Al₂O₃ : C, generally, shows three peaks; the main dosimetric peak of high intensity (peak II) and two other peaks of lower intensity called secondary glow peaks (peaks I and III). The overall aim of our work was to study the TL mechanisms responsible for secondary glow peaks in α-Al₂O₃ : C. The dynamics of charge movement between centres during the TL process was studied. The phototransferred thermoluminescence (PTTL) from secondary glow peaks was also studied. The kinetic analysis of TL from secondary peaks has shown that the activation energy of peak I is 0.7 eV and that of peak III, 1.2 eV. The frequency factor, the frequency at which an electron attempts to escape a trap, was found near the range of the Debye vibration frequency. Values of the activation energy are consistent within a variety of methods used. The two peaks follow first order kinetics as confirmed by the TM-Tstop method. A linear dependence of TL from peak I on dose is observed at various doses from 0.5 to 2.5 Gy. The peak position for peak I was also independent on dose, further confirmation that peak I is of first order kinetics. Peak I suffers from thermal fading with storage with a half-life of about 120 s. The dependence of TL intensity for peak I increased as a function of heating rate from 0.2 to 6ºCs⁻¹. In contrast to the TL intensity for peak I, the intensity of TL for peak III decreases with an increase of heating rate from 0.2 to 6ºCs⁻¹. This is evidence of thermal quenching for peak III. Parameters W = 1.48 ± 0:10 eV and C = 4 x 10¹³ of thermal quenching were calculated from peak III intensities at different heating rates. Thermal cleaning of peak III and the glow curve deconvolution methods confirmed that the main peak is actually overlapped by a small peak (labeled peak IIA). The kinetic analysis of peak IIA showed that it is of first order kinetics and that its activation energy is 1:0 eV. In addition, the peak IIA is affected by thermal quenching. Another secondary peak appears at 422ºC (peak IV). However, the kinetic analysis of TL from peak IV was not studied because its intensity is not well defined. A heating rate of 0.4ºCs⁻¹ was used after a dose of 3 Gy in kinetic analysis of peaks IIA and III. The study of the PTTL showed that peaks I and II were regenerated under PTTL but peak III was not. Various effects of the PTTL for peaks I and II for different preheating temperatures in different samples were observed. The effect of annealing at 900ºC for 15 minutes between measurements following each illumination time was studied. The effect of dose on secondary peaks was also studied in this work. The kinetic analysis of the PTTL intensity for peak I showed that its activation energy is 0.7 eV, consistent with the activation energy of the normal TL for peak I. The PTTL intensity from peak I fades rapidly with storage compared with the thermal fading from peak I of the normal TL. The PTTL intensity for peak I decreases as a function of heating rate. This decrease was attributed to thermal quenching. Thermal quenching was not observed in the case of the normal TL intensity. The cause of this contrast requires further study.
- Full Text:
The application of a landscape diversity index using remote sensing and geographical information systems to identify degradation patterns in the Great Fish River Valley, Eastern Cape Province, South Africa
- Authors: Tanser, Frank Courteney
- Date: 1997
- Subjects: Geographic information systems , Earth sciences -- Remote sensing , Environmental degradation -- South Africa -- Eastern Cape -- Great Fish River Valley , Forest degradation -- South Africa -- Eastern Cape -- Great Rish River Valley
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4814 , http://hdl.handle.net/10962/d1005488 , Geographic information systems , Earth sciences -- Remote sensing , Environmental degradation -- South Africa -- Eastern Cape -- Great Fish River Valley , Forest degradation -- South Africa -- Eastern Cape -- Great Rish River Valley
- Description: Using a range of satellite-derived indices I describe. monitor and predict vegetation conditions that exist in the Great Fish River Valley, Eastern Cape. The heterogeneous nature of the area necessitates that the mapping of vegetation classes be accomplished using a combination of a supervised approach, an unsupervised approach and the use of a Moving Standard Deviation Index (MSDI). Nine vegetation classes are identified and mapped at an accuracy of 84%. The vegetation classes are strongly related to land-use and the communal areas demonstrate a reduction in palatable species and a shift towards dominance by a single species. Nature reserves and commercial rangeland are by contrast dominated by good condition vegetation types. The Modified Soil Adjusted Vegetation Index (MSA VI) is used to map the vegetation production in the study area. The influence of soil reflectance is reduced using this index. The MSA VI proves to be a good predictor of vegetation condition in the higher rainfall areas but not in the more semi-arid regions. The MSA VI has a significant relationship to rainfall but no absolute relationship to biomass. However, a stratification approach (on the basis of vegetation type) reveals that the MSA VI exhibits relationships to biomass in vegetation types occurring in the higher rainfall areas and consisting of a large cover of shrubs. A technique based on an index which describes landscape spatial variability is presented to assist in the interpretation of landscape condition. The research outlines a method for degradation assessment which overcomes many of the problems associated with cost and repeatability. Indices that attempt to provide a correlation with net primary productivity, e.g. NDVI, do not consider changes in the quality of net primary productivity. Landscape variability represents a measure of ecosystem change in the landscape that underlies the degradation process. The hypothesis is that healthy/undisturbed/stable landscapes tend to be less variable and homogenous than their degraded heterogenous counterparts. The Moving Standard Deviation Index (MSDI) is calculated by performing a 3 x 3 moving standard deviation window across Landsat Thematic Mapper (TM) band 3. The result is a sensitive indicator of landscape condition which is not affected by moisture availability and vegetation type. The MSDI shows a significant negative relationship to NDVI confirming its relationship to condition. The cross-classification of MSDI with NDVI allows the identification of invasive woody weeds which exhibit strong photosynthetic signals and would therefore be categorised as good condition using NDVI. Other ecosystems are investigated to determine the relationship between NDVI and MSDI. Where increase in NDVI is disturbance-induced (such as the Kalahari Desert) the relationship is positive. Where high NDVI values are indicative of good condition rangeland (such as the Fish River Valley) the relationship is negative. The MSDI therefore always exhibits a significant positive relationship to degradation irrespective of the relationship of NDVI to condition in the ecosystem.
- Full Text:
- Authors: Tanser, Frank Courteney
- Date: 1997
- Subjects: Geographic information systems , Earth sciences -- Remote sensing , Environmental degradation -- South Africa -- Eastern Cape -- Great Fish River Valley , Forest degradation -- South Africa -- Eastern Cape -- Great Rish River Valley
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4814 , http://hdl.handle.net/10962/d1005488 , Geographic information systems , Earth sciences -- Remote sensing , Environmental degradation -- South Africa -- Eastern Cape -- Great Fish River Valley , Forest degradation -- South Africa -- Eastern Cape -- Great Rish River Valley
- Description: Using a range of satellite-derived indices I describe. monitor and predict vegetation conditions that exist in the Great Fish River Valley, Eastern Cape. The heterogeneous nature of the area necessitates that the mapping of vegetation classes be accomplished using a combination of a supervised approach, an unsupervised approach and the use of a Moving Standard Deviation Index (MSDI). Nine vegetation classes are identified and mapped at an accuracy of 84%. The vegetation classes are strongly related to land-use and the communal areas demonstrate a reduction in palatable species and a shift towards dominance by a single species. Nature reserves and commercial rangeland are by contrast dominated by good condition vegetation types. The Modified Soil Adjusted Vegetation Index (MSA VI) is used to map the vegetation production in the study area. The influence of soil reflectance is reduced using this index. The MSA VI proves to be a good predictor of vegetation condition in the higher rainfall areas but not in the more semi-arid regions. The MSA VI has a significant relationship to rainfall but no absolute relationship to biomass. However, a stratification approach (on the basis of vegetation type) reveals that the MSA VI exhibits relationships to biomass in vegetation types occurring in the higher rainfall areas and consisting of a large cover of shrubs. A technique based on an index which describes landscape spatial variability is presented to assist in the interpretation of landscape condition. The research outlines a method for degradation assessment which overcomes many of the problems associated with cost and repeatability. Indices that attempt to provide a correlation with net primary productivity, e.g. NDVI, do not consider changes in the quality of net primary productivity. Landscape variability represents a measure of ecosystem change in the landscape that underlies the degradation process. The hypothesis is that healthy/undisturbed/stable landscapes tend to be less variable and homogenous than their degraded heterogenous counterparts. The Moving Standard Deviation Index (MSDI) is calculated by performing a 3 x 3 moving standard deviation window across Landsat Thematic Mapper (TM) band 3. The result is a sensitive indicator of landscape condition which is not affected by moisture availability and vegetation type. The MSDI shows a significant negative relationship to NDVI confirming its relationship to condition. The cross-classification of MSDI with NDVI allows the identification of invasive woody weeds which exhibit strong photosynthetic signals and would therefore be categorised as good condition using NDVI. Other ecosystems are investigated to determine the relationship between NDVI and MSDI. Where increase in NDVI is disturbance-induced (such as the Kalahari Desert) the relationship is positive. Where high NDVI values are indicative of good condition rangeland (such as the Fish River Valley) the relationship is negative. The MSDI therefore always exhibits a significant positive relationship to degradation irrespective of the relationship of NDVI to condition in the ecosystem.
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A parser generator system to handle complete syntax
- Authors: Ossher, Harold Leon
- Date: 1982
- Subjects: Grammar, Comparative and general -- Syntax Parsing (Computer grammar) Programming languages (Electronic computers) Compilers (Computer programs)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4571 , http://hdl.handle.net/10962/d1002036
- Description: To define a language completely, it is necessary to define both its syntax and semantics. If these definitions are in a suitable form, the parser and code-generator of a compiler, respectively, can be generated from them. This thesis addresses the problem of syntax definition and automatic parser generation.
- Full Text:
- Authors: Ossher, Harold Leon
- Date: 1982
- Subjects: Grammar, Comparative and general -- Syntax Parsing (Computer grammar) Programming languages (Electronic computers) Compilers (Computer programs)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4571 , http://hdl.handle.net/10962/d1002036
- Description: To define a language completely, it is necessary to define both its syntax and semantics. If these definitions are in a suitable form, the parser and code-generator of a compiler, respectively, can be generated from them. This thesis addresses the problem of syntax definition and automatic parser generation.
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