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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Vegetation ecology of Drakensberg foothill moist grassland on Hlogoma Mountain, Underberg, KwaZulu-Natal

Berruti, Sharron Marion 11 1900 (has links)
Hlogoma Mountain is a small inselberg surrounded by farms and commercial forestry in the Underberg district (KwaZulu-Natal) within the Gs10 Drakensberg Foothill Moist Grassland. As little is known about the vegetation on Hlogoma, a survey was undertaken to classify, map and describe the plant communities occurring on the inselberg. A total of 100 (16 m2) randomly stratified sample plots were placed in homogeneous vegetation units within the 117 ha study area. A TWINSPAN classification, refined by Braun-Blanquet procedures, resulted in the identification of two major communities, five communities, 12 sub-communities and four variants. All communities were described and a vegetation map constructed. Ordinations identified key environmental variables that have an impact on the vegetation at the study site. A plant species checklist was created and analysed for floristic composition; rarity and threatened species; medicinal plants; endemism; phenology; flower colour and elevation range; species richness and plant community biodiversity. A total of 467 species were identified, represented by 271 genera and 87 families. Four Red Data species and a new Aspidoglossum species were discovered. Two near-endemic genera, two endemic species and 88 near-endemic species belonging to the Drakensberg Alpine Centre were found on Hlogoma. This study showed that Hlogoma Mountain is an inselberg with high plant species richness and endemism, and is a refuge of conservation importance for biodiversity. / Environmental Sciences / M. Sc.(Environmental Science)
32

Remote sensing of leaf area index in Savannah grass using inversion of radiative transfer model on Landsat 8 imagery : case study Mpumalanga, South Africa

Masemola, Cecilia Ramakgahlele 03 1900 (has links)
Savannahs regulate an agro-ecosystem crucial for the production of domestic livestock, one of the main sources of income worldwide as well as in South African rural communities. Nevertheless, globally these ecosystem functions are threatened by intense human exploitation, inappropriate land use and environmental changes. Leaf area index (LAI) defined as one half the total green leaf area per unit ground surface area, is an inventory of the plant green leaves that defines the actual size of the interface between the vegetation and the atmosphere. Thus, LAI spatial data could serve as an indicator of rangeland productivity. Consequently, the accurate and rapid estimation of LAI is a key requirement for farmers and policy makers to devise sustainable management strategies for rangeland resources. In this study, the main focus was to assess the utility and the accuracy of the PROSAILH radiative transfer model (RTM) to estimate LAI in the South African rangeland on the recently launched Landsat 8 sensor data. The Landsat 8 sensor has been a promising sensor for estimating grassland LAI as compared to its predecessors Landsat 5 to 7 sensors because of its increased radiometric resolution. For this purpose, two PROSAIL inversion methods and semi- empirical methods such as Normalized difference vegetation index (NDVI) were utilized to estimate LAI. The results showed that physically based approaches surpassed empirical approach with highest accuracy yielded by artificial neural network (ANN) inversion approach (RMSE=0.138), in contrast to the Look-Up Table (LUT) approach (RMSE=0.265). In conclusion, the results of this study proved that PROSAIL RTM approach on Landsat 8 data could be utilized to accurately estimate LAI at regional scale which could aid in rapid assessment and monitoring of the rangeland resources. / Environmental Sciences / M. Sc. (Environmental Science)
33

The place of community values within community-based conservation : the case of Driftsands Nature Reserve, Cape Town

Foot, Shelley 06 1900 (has links)
The most contemporary approach to biodiversity conservation within South Africa is that of community-based initiatives, which seek to combine biodiversity conservation with socioeconomic development. As a challenge to the Western, science laden approaches to conservation there is an increasing need for community initiatives to reflect the values of local communities. Values of local communities and the management body, CapeNature, with regards to Driftsands Nature Reserve, Cape Town, were captured and analytically coded through the qualitative methods of interviewing and participant observation in order to develop a grounded theory and model. A discussion of the expressed values suggests that community-based conservation initiatives are doing little to include community values even though there is a large degree of agreement between these and corporate values. As such, it is questioned whether community-based conservation can be practised within an organisation which, due to procedures and protocols, is top-down in its approach. / Geography / M. Sc. (Geography)
34

Development of a sustainable land and ecosystem services decision support framework for the Mphaphuli Traditional Authority, Limpopo Province, South Africa

Musetsho, Khangwelo Desmond 05 1900 (has links)
This study aimed to investigate the spatial extent of Land-Use Land-Cover (LULC) change and the implications for ecosystem services in order to develop a sustainable land-use management framework for traditional authorities in South Africa. Effectively, this study undertook an insightful examination of the impacts that arise from policy decisions and practices, which unfortunately were found to be ineffective. The methodologies and approaches used in this study included both quantitative and qualitative techniques. The critical quantitative method employed in this research was the use of survey questionnaires to collect primary data. Qualitative approaches, such as one-on-one and key informant interviews, were used to triangulate the findings. Remote sensing and geographic information system (GIS) methods were used to investigate changes in LULC from 1990 to 2018 through the use of data obtained from the South African National Land-Cover project. Stochastic models were used to predict future LULC changes from 2018 to 2050. The Co$ting Nature Policy Support System was used to identify and undertake economic valuation of services provided by ecosystems. Statistical analysis using the Statistical Package for the Social Sciences was used to identify correlations and the reliability of the data, while graphs and tables were generated to identify patterns and lessons from the research. Between 1990 and 2018, significant changes in land cover were noticed for thickets and dense bush, woodlands, waterbodies, subsistence agriculture, and built-up areas. Woodlands changed by over 1 000 hectares (ha) per year, while thickets decreased by over 900 ha per year. Drivers of these changes include deforestation, among others. Future predictions for LULC revealed that between 2018 and 2050, almost 500 ha of woodlands would be lost to built-up areas. The aggregate value of the services flowing from ecosystems was found to be R9 509 044 608.00. A significant issue was that 90% of the traditional leaders interviewed could not positively respond to whether they knew the extent of the land they presided over, which raised questions regarding the effectiveness of their management systems. Recommendations were made in this study to address the limitations identified in the land-use management practices by adapting elements of the main theoretical frameworks, namely the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services framework; the Drivers, Pressures, States, Impacts and Responses framework; the sustainability theory; and the hierarchy of plans, into a new framework designed specifically for traditional leaders, titled the “Traditional leaders land-use decision support framework”. / Environmental Sciences / D. Phil. (Environmental Management)
35

The illegal reptile trade - a criminological perspective

Herbig, Friedo Johann Willem 30 June 2003 (has links)
The illegal reptile trade quandary in the Western Cape province is strategically and chronologically addressed in this thesis with the implicit intention of revealing its gamut and underlying dynamics, developing a pragmatic, parsimonious and authentic conservation crime category with clearly delineated parameters, and formulating an integrated theoretical explanation regarding its aetiology that will adequately explicate herpetological, and hopefully also other forms of natural resource, crime and deviance. The thesis, by essentially transcending traditional, stereotypical edicts, throws new light on a severely neglected and underestimated form of natural resource exploitation, highlighting the need for reptiles, as the sentinels of the state of our environmental health to be preserved and perpetuated for, in the final analysis, the benefit of human kind. Through an essentially explorative enquiry, utilising an integrated qualitative -quantitative research approach, the concept of conservation crime, as a vanguard to an innovative and unified conservation criminology, is introduced in this thesis in the form of unambiguous adjunct of the mainstream criminological discipline. It is, furthermore, utilised as a conduit within the herpetological crime framework to enrich the criminological discipline as a whole, broaden its frontiers, promote effective and focussed intervention/mitigation initiatives, as well as stimulate interest for further investigation in this field. Fragmented, antiquated and nebulous legislation, deficient conservation and related role-player organisational capacity and inconsistent penalties, in concert with apathetic (and decidedly generic) societal attitudes and traditional pessimistic rubric regarding reptiles, emerge as fundamental proclivities impeding the effective intercession and management of the natural resources embodied in this sphere. Injudicious manipulation of the Western Cape's scarce and specialised reptile resources and the biodiversity ramifications such exploitation realises portend the intensification and diversification potential of such criminality. Conservation criminology, as developed and presented in this thesis, underscores the significant contribution this field of criminology can make in comprehending the illegal manipulation/exploitation of herpetological and other natural resources, expanding and enhancing its theoretical constructs and implementing justice through decisive, dedicated and holistic intervention programmes/strategies in order to defend the inherent right to the continued existence of all reptile species. / Crimonology / D. Litt et Phil. (Criminology)
36

The illegal reptile trade - a criminological perspective

Herbig, Friedo Johann Willem 30 June 2003 (has links)
The illegal reptile trade quandary in the Western Cape province is strategically and chronologically addressed in this thesis with the implicit intention of revealing its gamut and underlying dynamics, developing a pragmatic, parsimonious and authentic conservation crime category with clearly delineated parameters, and formulating an integrated theoretical explanation regarding its aetiology that will adequately explicate herpetological, and hopefully also other forms of natural resource, crime and deviance. The thesis, by essentially transcending traditional, stereotypical edicts, throws new light on a severely neglected and underestimated form of natural resource exploitation, highlighting the need for reptiles, as the sentinels of the state of our environmental health to be preserved and perpetuated for, in the final analysis, the benefit of human kind. Through an essentially explorative enquiry, utilising an integrated qualitative -quantitative research approach, the concept of conservation crime, as a vanguard to an innovative and unified conservation criminology, is introduced in this thesis in the form of unambiguous adjunct of the mainstream criminological discipline. It is, furthermore, utilised as a conduit within the herpetological crime framework to enrich the criminological discipline as a whole, broaden its frontiers, promote effective and focussed intervention/mitigation initiatives, as well as stimulate interest for further investigation in this field. Fragmented, antiquated and nebulous legislation, deficient conservation and related role-player organisational capacity and inconsistent penalties, in concert with apathetic (and decidedly generic) societal attitudes and traditional pessimistic rubric regarding reptiles, emerge as fundamental proclivities impeding the effective intercession and management of the natural resources embodied in this sphere. Injudicious manipulation of the Western Cape's scarce and specialised reptile resources and the biodiversity ramifications such exploitation realises portend the intensification and diversification potential of such criminality. Conservation criminology, as developed and presented in this thesis, underscores the significant contribution this field of criminology can make in comprehending the illegal manipulation/exploitation of herpetological and other natural resources, expanding and enhancing its theoretical constructs and implementing justice through decisive, dedicated and holistic intervention programmes/strategies in order to defend the inherent right to the continued existence of all reptile species. / Crimonology / D. Litt et Phil. (Criminology)

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