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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.
191

Bird community ecology and composition in afrotemperate forests of the Drakensberg Mountains, South Africa.

January 2009 (has links)
Recent research has emphasized the importance of understanding the consequences of species loss, not just for biodiversity per se, but also for ecosystem resilience and functioning. Firstly, a baseline analysis of the effects of a naturally patchy landscape on avian community composition and resilience in a high altitude Afrotemperate forest landscape in South Africa is presented. Bird data from a point count survey of 706 counts at 31 forest sites was used to test whether taxonomic species diversity, functional species richness and density of birds provide insight into community resilience in this historically patchy ecosystem. Bird species richness of forest patches ranged from 17 to 38, with a total species richness of 50. Density was slightly but negatively related to both area and species richness. That density compensation is occurring in these Afrotemperate forests suggests a level of resilience in this system. Following on from this, cumulative species-area and function-area graphs were derived to quantify the loss of forest area or taxonomic bird species richness that this landscape may potentially sustain before ecosystem functioning is negatively affected. The concept that species’ patterns of distribution, abundance and coexistence are the result of local ecological processes has recently been challenged by evidence that regionalscale processes are equally instrumental in shaping local community composition. The historically and naturally fragmented Afrotemperate forests of the uKhahlamba– Drakensberg Park, South Africa, offer an interesting test case. In this study the relative effects of local and regional-scale processes on species assemblages in a naturally patchy forest system were investigated. By employing species-area and species-isolation relationships, and nested subset analyses, we showed that isolation (regional-scale process) had a greater effect on bird species richness and composition than area (local-scale process), though the species-area relationship was significant. Using generalized linear models and an information-theoretic approach to model selection, patch area, the size of the regional species pool as well as the distance to the nearest Eastern Mistbelt forest were all influential in determining local bird species richness in these montane forests. Thus, localities are regionally enriched within the constraints on species occupancy provided by the available habitat. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2009.
192

Great Lakes environmental policy : the ecosystem approach and an economic perspective

Jutlah, Russell Sean 11 1900 (has links)
This thesis is concerned with the conceptual foundations of environmental law and policy in the Great Lakes basin, the world's largest freshwater ecosystem. The Great Lakes regime is now widely recognized as one of the most advanced international environmental management regimes in existence. Over the past two decades, toxic contamination has emerged as a highly pressing ecological issue in the Great Lakes basin. In Canada and the United States, the ecosystem approach, a comprehensive and integrated approach to environmental management, has been adopted both bilaterally and domestically in the Great Lakes' complex environmental policy framework to guide the protection of ecological integrity. There has been extensive discussion of the ecosystem approach, particularly from scientific and managerial perspectives; however, the economic content of the concept has been largely neglected, despite the importance of considering all relevant perspectives in the development of law and policy. This thesis is divided into five chapters. After discussing in Chapter 1 the ecological and institutional contexts and methodological issues of the analysis, this thesis defends, in Chapter 2, the view that economic theory has relevance to issues of environmental law and policy. In addition to highlighting the main contours of welfare and environmental economic theory, a main conclusion, and an essential premise upon which the analysis proceeds, is that economics remains a useful analytical approach to environmental issues, despite some important criticisms. Subsequently, in Chapter 3, the analysis shifts to an examination of four bilateral and domestic Great Lakes instruments that form the core of Great Lakes toxic pollution policy: (i) the Great Lakes Water Quality Agreement; (ii) the Great Lakes Binational Toxics Strategy; (iii) the Canada-Ontario Agreement; and (iv) the Final Water Quality Guidance for the Great Lakes System. After outlining key principles underpinning each instrument, the thesis underscores common themes running through the collective policy framework. The ecosystem approach constitutes a unifying concept in this framework. The ecosystem approach is examined from an economic perspective in Chapter 4. After identifying key elements of the ecosystem approach, this chapter highlights important parallels between fundamental welfare and environmental economic notions. One main conclusion is that economic concepts and approaches, such as environmental valuation, externalities, and self-interest, form an integral part of the ecosystem approach. Finally, Chapter 5 identifies some directions for further research. Given that, as the thesis seeks to establish, economic theory constitutes an important, albeit not sole, perspective on the ecosystem approach, a key challenge will be to facilitate interdisciplinary analysis and cooperation leading to effective operationalization of the concept.
193

The effect of land use on the species composition of amphibians in North Eastern KwaZulu-Natal.

Russell, Charlene. January 2010 (has links)
Global declines in amphibian species have directed research towards investigating why this is happening. One of the major causes of these declines is the fragmentation and loss of habitat. This study examined the effect of land use on the species composition of frogs within North Eastern KwaZulu-Natal, and the use of buffer zones to facilitate the protection of these species. Three land use types were investigated: sugar cane (Saccharum officinarum), gum (Eucalyptus sp.) plantations and conservation areas. The average number of frog species differed between areas: conservation 13.2 ± 6.6; plantations 3.8 ± 1.3; and sugar cane 2.8 ± 1.4. Sugar and gum plantation were found to be lacking the wetland and grassland/woodland habitats. In addition to this, the frog species that were not present on these land use types were those that are totally dependent on water as well as those that are not dependent on a water source. Two species were highlighted as possible indicator species of land use: Amietophrynus gutturalis and Hyperolius marmoratus. To mitigate the effect of these land use types, the use of buffer zones was explored in a desktop study. A range of buffer zones were applied to wetlands in a sample study area, using a range of distances including the distances of 290 m and 159 m recommended by Semlitsch and Bodie (2003), and the recommended distances for wetlands in South Africa of 10-20 m. The application of a 290 m and 159 m buffer zone on a conglomerate of wetlands connected by a 100m buffer was the most feasible as it incorporated a percentage of the total study (6.4% and 4.3%) area similar to the percentage occupied by the recommended 20m buffer zone (5.5%) around all wetlands, and still incorporated the range under protection put forward by Semlitsch and Bodie (2003). Management implications of these findings are discussed. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2010.
194

Linking ecosystem goods and services to sustainability, risks and opportunities : informing decision-making in the Msunduzi Municipality, KwaZulu-Natal, South Africa.

Jorgensen, Paul William. 21 August 2013 (has links)
Sustainable development’s wide scale adoption has resulted in the rapid emergence of the field Sustainability Science. This trans-disciplinary field of research attempts to understand the interconnectedness, relationships and complexity between the natural environment and society. To understand these relationships and integration between the natural environment, the economy and society within a sustainability context, an ecosystem goods and services (EGS) approach can be taken. EGS research is being incorporated into mainstream environmental decision-making and strategic thinking, particularly within the corporate sector, however, adoption has been slow. The Corporate Ecosystem Services Review (ESR) is a framework, developed by the World Research Institute (WRI), which aims to assess the dependence and impact that a company has on EGS through a systematic approach. This methodological framework can be adapted into a tool that assists in more informed environmental decision-making at a local government level. This adapted tool highlights EGS issues within particular open spaces and links these issues to sustainability targets and identifies risks and opportunities for local government. For this research, the ESR tool was tested on open spaces within the Msunduzi Municipality, KwaZulu-Natal, by adapting the ESR methodological framework to relate to local government decision-making and by incorporating existing tools and strategic documents, namely the Environmental Management Framework (EMF) and the Spatial Development Framework (SDF), into the EGS assessment tool. Site-specific EGS issues were identified at two open space study sites through posing different development scenarios, and results from testing the tool revealed linkages between EGS and risks and opportunities for sustainability. The tool has applicability to local level decision-making, particularly in the early stages of development planning, by providing a more holistic input into the environmental decision-making process. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2012.
195

Designing effective protected area networks - integration of the tropical cyclone disturbance regime in the Great Barrier Reef Representative Area Program a GIS application /

Debort, Sophie. January 2006 (has links)
Thesis (M.Sc.)--University of Wollongong, 2006. / Typescript. Includes bibliographical references: p. 87-93.
196

The relative performance of surrogate measures for viable populations

Solomon, Mariaan. January 2000 (has links)
Thesis (M.Sc.(Zoology))--University of Pretoria, 2000. / Abstract in English. Includes bibliographical references.
197

A Comparative Analysis of State-Level Watershed Management Frameworks in the Pacific Northwest

Erickson, Adam Michael, 1979- 09 1900 (has links)
xiii, 236 p. : ill. (some col.) / Over the past two decades, contemporary state-level watershed management burgeoned in the Pacific Northwest. This research offers a comparative analysis of contemporary state-level watershed management frameworks in the Pacific Northwest. The four case study areas consist of Idaho, Oregon, Washington, and Northern California. This study begins with a historical analysis of the greater watershed movement in natural resource management. Next, document analysis and key informant interviews are utilized to detail the watershed management framework of each state. Finally, this study explores a comparative analysis of each state framework. Results indicate that while the case study areas share many characteristics endemic to the bioregion, the watershed management framework of each state differs substantially. Key informant interviews indicate that these differences often reflect the unique sociopolitical climate of each state. Results additionally indicate the vital importance of stable state-derived funding for the establishment and resilience of watershed management organizations. / Committee in charge: Dr. Michael Hibbard, Chairperson; Dr. Richard Margerum, Member; Dr. Max Nielsen-Pincus, Member
198

A comunidade de peixes dos reservatórios dos trechos médio e baixo rio Tietê, com ênfase nas espécies Plagioscion squamosissimus e Geophagus surinamensis. / Fish community of the reservoirs located on middle and low Tietê River, with emphasis in the introduced species Plagioscion squamosissimus and Geophagus surinamensis.

Moretto, Evandro Mateus 26 May 2006 (has links)
Made available in DSpace on 2016-06-02T19:28:57Z (GMT). No. of bitstreams: 1 TeseEMM.pdf: 3928574 bytes, checksum: 41bb88a5eda2258e27b0841b94f15cb6 (MD5) Previous issue date: 2006-05-26 / From sixties, the fish species introduction has been being a constant event in the reservoir system located on middle and low Tietê River - SP, which resulted the success introduction of Plagiosicon squamosissimus and Cichla cf. ocellaris in all these reservoirs. According to this context, the present work objectified characterize the fish community, with focus on the introduction analysis of Geophagus surinamensis, a not-native specie, and its probable progressive occupation in the system, like that already had occurred with Plagioscion squamosissimus. The results showed the occurrence of Geophagus surinamensis is confirmed in these reservoir system, indicating that its fast occupation in the Três Irmãos reservoir is made possible by the free connection that Pereira Barreto provides between Três Irmãos reservoir and Ilha Solteira reservoir, on the Paraná River. This way, it is evident the great possibility that the Geophagus surinamensis comes to be disperse for the whole reservoir system of middle and low Tietê River, like that already had occurred for the Plagioscion squamosissimus. Then, it is important to consider the Geophagus surinamensis in management programs for the Três Irmãos reservoir, so as to control and to reduce its density and of avoiding its effective spread for the others reservoirs of Tietê River. / A partir da década de 60, a introdução de espécies não-nativas de peixes tornou-se um evento constante no sistema de reservatórios dos trechos médio e baixo do rio Tietê - SP, resultando no pleno sucesso de introdução das espécies Plagiosicon squamosissimus e Cichla cf. ocellaris, as quais passaram a ocupar todos os reservatórios do sistema. Neste contexto, o presente trabalho objetivou caracterizar a comunidade de peixes, de modo a avaliar o processo de introdução recente da espécie não-nativa Geophagus surinamensis e sua provável ocupação progressiva no sistema, a exemplo do que já ocorrera com Plagioscion squamosissimus. A partir dos métodos empregados, confirmou-se a ocorrência da espécie não-nativa Geophagus surinamensis no sistema em estudo, indicando que sua rápida ocupação no reservatório de Três Irmãos, onde se encontra efetivamente estabelecida, é viabilizada pela livre conexão que canal de Pereira Barreto proporciona entre o reservatório de Três Irmãos com o de Ilha Solteira, no rio Paraná. Assim, fica evidente a grande possibilidade de que a espécie Geophagus surinamensis venha a se dispersar por todo o sistema de reservatórios dos trechos médio e baixo do rio Tietê, a exemplo do que já ocorrera para a espécie não nativa Plagioscion squamosissimus. É válido considerar, portanto, a espécie Geophagus surinamensis em programas de manejo para o reservatório de Três Irmãos, de modo a controlar e reduzir a sua abudância e evitar sua dispersão efetiva para todo o sistema de reservatórios do rio Tietê.
199

The diversity of aquatic insects in the Tsitsikamma region, with implications for aquatic ecosystem conservation

Bellingan, Terence Andrew January 2011 (has links)
As a result of research carried out within the last decade to assess the diversity of macroinvertebrates of the Salt River in the Western Cape Province, South Africa, surveys of macroinvertebrates of 20 sites on 11 selected rivers from the same mountain range source were undertaken. This was done to make a preliminary assessment of the conservation status of the rivers of this region. Aquatic insects from the orders Ephemeroptera, Odonata, Plecoptera, Megaloptera, Trichoptera and the dipteran family Simuliidae were collected using techniques to maximize the number of taxa found. The insects collected were identified to species level where possible. Water physicochemical parameters were recorded at all sites for each sampling trip to characterize these rivers and to establish a set of baseline data for future comparisons. These parameters included measurements made on site and analysis of the concentrations of all the major ions in water samples in the laboratory. Multivariate analyses including Principle Components Analysis and Canonical Correspondence Analysis were used to reveal patterns within the water physicochemistry and species distributional data. Results include the identification of 123 species from 70 genera and 30 families. A total of 31 species were found to be undescribed, of which 17 were not previously collected and are thus completely new to science. In addition, four of these species could not be placed into any known genus. The analysis of water physicochemistry showed a clear distinction between rivers of Table Mountain sandstone and Bokkeveld shale origin. Downstream effects of anthropogenic influences were discernable too. Distinct macroinvertebrate assemblages were found based upon stream order and water chemistry composition. pH proved to be the most important driver of invertebrate assemblage composition. The high levels of endemism of the macroinvertebrates found within the upper reaches of these rivers and their degree of ecological specialization make these systems a priority for the conservation of aquatic biodiversity on a national and global scale.
200

The relevance of ecosystems to ecotourism in the Waterberg Biosphere Reserve

Henning, Barend Johannes 24 August 2006 (has links)
Please read the abstract in the 00front part of this document / Thesis (PhD (Botany))--University of Pretoria, 2006. / Plant Science / unrestricted

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