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Abstract: Conventional approaches to water management have traditionally treated social systems and ecosystems as distinct, and to a large degree have failed to achieve outcomes that are simultanously efficient, equitable, and sustainable. Perhaps nowhere has the need to reform the way water is managed and even conceived been more apparent than in South Africa in the last decade, where a tremendous opportunity for change has been created in the form of the National Water Act of 1998. In this...
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Abstract: Ungulate browsing and its ecological effects at plant, population, community, and ecosystem levels were addressed in a eutrophic southern African savanna. This was to test predictions of prevailing hypotheses, which are based on research in boreal and temperate forests. Changes in plant morpho-functional traits and population structure of a staple palatable species, Acacia nigrescens Miller were addressed over a two-year survey among vegetation stands with very different histories ...
Abstract: The pouched mouse, Saccostomus campestris Peters, 1846 from southern Africa shows a high degree of karyotypic variation where up to 16 variants (2n = 30–50) have been reported. This has led to a systematic uncertainty that the present study attempts to assess using: 1) cytochrome b (cyt b; 1077 bp) and 16S rRNA (528 bp) partial sequences; 2) G-banding cytogenetic data; and 3)geometric morphometric data of various views of the cranium and mandible. The results from these multidisc...
Abstract: Simulium chutteri is considered a major pest in South Africa and it has been estimated that it can potentially cause stock losses amounting to more than R88 million per annum. Although a larval control programme has been launched to control the pest, major outbreaks still occur, since major fitness traits such as longevity are ignored in the planning of control actions. To improve the control programme, the aim of this study was to study the longevity of S. chutteri females under v...
Abstract: Insects are considered to be responsible for 80-85% of all pollination, with honeybees being well known for their pollination services for many crops. The effect of managed honeybee pollination on sunflower seed yield and quality (germination percentage and oil content) was investigated at the University of Pretoria experimental farm and in commercial sunflower fields at Settlers. This was done through pollinator exclusion and pollinator surveys on sunflower field plots located at ...
Abstract: Southern Africa contains 58% of the world’s savannah elephant population, yet 72% of their range occurs outside of protected areas. It is, therefore, important to develop management guidelines that satisfy the needs of both elephants and people while maintaining environmental heterogeneity and ecosystem processes. Managing elephants as a metapopulation may provide the solution. The goal of this thesis was then to use a habitat-based approach to identify landscape characteristics ...
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Abstract: Killer whales are the oceans’ apex predator and are known to have important effects on ecosystems. At Subantarctic Marion Island, southern Indian Ocean, they have only been studied opportunistically, resulting in limited knowledge of their ecosystem impact here. This dissertation describes the prey and seasonal abundance, estimates the population size and assesses the predatory impact of killer whales on seals and penguins at Marion Island, using dedicated and opportunistic shore...
Abstract: This study provides the first quantitative analysis of the littoral and supralittoral arthropod assemblages of sub-Antarctic Marion Island. Seventeen mite species (126 203 individuals) from 11 families were found on the shore at Macaroni Bay. Three families dominated the assemblages in both abundance and diversity: the Hyadesiidae, Ameronothridae and Halacaridae. Six insect species from three orders were found on the shore. Species richness increased from one in the littoral, to fo...
Abstract: The conservation of biotic diversity is a growing challenge within southern Africa at the beginning of the 21st century. Growing populations and trends toward a questionable Western development model place demands on the use of land for food, fiber, and fuel production. The traditional establishment and use of formal conservation areas is being challenged against the needs of humans and the past unbalances created by colonial rule. Conservation areas, as isolated islands in a sea o...
Abstract: The inter- and intraspecific taxonomy of the genus Lepus is highly controversial. Since these animals play an important ecological role as prey species, their conservation is of high priority. A prerequisite for adequate management strategies is the precise knowledge of taxonomic borders and geographic distributions of the taxa in question. Especially in African hares the clear delimitations of the species and subspecies are still unresolved. In an attempt to obtain a clearer under...
Abstract: Please read the abstract in the section, 00front, of this document