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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.
1

A co-evolutionary landscape ecology framework for analyzing human effects on KwaZulu-Natal Province landscapes and its relevance to sustainable biodiversity conservation

Fairbanks, Dean Howard Kenneth 13 July 2006 (has links)
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 of change driven by interconnected economic and social systems, may not be a basis for sustainable biodiversity conservation. This thesis examines characteristics of avian species diversity response to abiotic environmental variables and land transformation. Environmental and land-use correlates of species gradients, species diversity patterns, and the spatial patterning of bird assemblages varied with location. The findings supported a conceptual model of multi-scaled controls on bird distribution, and the related notion that local community structure is the result of both regional environmental and local-scale landscape pattern that must be taken in to account in regional conservation planning assessments. An analytical framework including an landscape model, use of complementary-based reserve selection procedures, gradient analysis, and inclusion of the total spatial economy and development needs of the KwaZulu-Natal Province proved to be important for developing an integrated conservation plan for sustainable avian conservation. Pattern recognition results of the spatial economy and landscape pattern revealed the strong dichotomy in Western economic versus rural African landscapes, which have lead to strong differences in avian assemblage patterns. The research described in this thesis targets specific objectives of the Sustainable Biosphere Initiative by addressing requirements for landscape level analysis of humans and ecosystems in an integrated analytical framework. The development of a co-evolutionary landscape ecology framework for examining human-ecosystem interaction provides a strong basis for supporting targeted conservation planning within regions rather than supporting a generic conservation planning framework. / Thesis (DPhil (Sustainable Ecological Management))--University of Pretoria, 2007. / Zoology and Entomology / unrestricted
2

Investigation of the utilization of microsatellites for fingerprinting in three endangered southern African crane species.

Moodley, Eshia Stephany. January 2006 (has links)
Cranes are large elegant birds that occur on all continents of the world except for South America and Antarctica. Of the fifteen species of crane worldwide, three predominantly occur in southern Africa; the Wattled crane (Bugeranus carunculatus), the Blue crane (Anthropoides paradisea) and the Crowned crane (Balearica regulorum). Crane numbers throughout the world are diminishing, mostly because of the destruction of their habitat and illegal bird trading. Efforts are underway to prevent species extinction, legally and through the compilation of a studbook that contains descriptions of physical attributes, ownership, location and possible kinships of birds in captivity . This investigation, first of its kind, WdS undertaken to assess whether twelve published and unpublished microsatellite primers developed for the related Whooping crane and Red-Crowned crane could be used to fingerprint the southern African crane species using cost effective polyacrylamide gel electrophoresis. The results obtained were then used to determine the extent of genetic variation within species and distance between species. All primer sets amplified heterologous microsatellite loci in the three crane species, however, the unpublished primers produced poorly defined fingerprints even after extensive optimization. Of the twelve microsatellite loci investigated, the Blue crane and the Wattled crane revealed a high level of polymorphism. The Blue crane displayed 76% polymorphism and the Wattled crane 92%. In contrast, for the Crowned crane, that belongs to a different subfamily, Balearicinae, only 50% of the loci were polymorphic. The alleles displayed sizes similar to that of the species for which the primers were developed. Little variation in size, less than 10 bp, was noted for the different alleles of the polymorphic loci. The number of alleles, on the other hand, at each of the polymorphic loci was found to be low. The frequency of the most prevalent allele at most of the loci was generally reasonably high. These results therefore suggest that these primer sets are not suitable for individual identification and differentiation using polyacrylamide gel electrophoresis. Xll The observed heterozygosity of the three crane species was low; 12% in Blue crane; 7% in Crowned crane; and 13% in Wattled crane. Nei's identity further confirmed the high similarity between individuals; 66-100% for Blue crane; 55-100% for Crowned crane and 41-95% for Wattled crane. This low genetic variation is attributed to possible relatedness between birds supplied by aviculturists whom have a limited number of birds in captivity. A Hardy-Weinberg test for equilibrium revealed that most of the microsatellite loci displayed a deficiency of heterozygotes, while a few loci displayed an excess of heterozygotes. In general, the Hardy Weinberg test of equilibrium supported the notion that the individuals within each of the species might have been related. Differentiation between the three crane species ranged from 3-5%, with Blue and Wattled crane displaying a higher degree of genetic similarity when compared to the Crowned crane, known to be the oldest extant crane species. The limited allelic variation within the microsatellite loci tested, as well as the extensive genetic similarity between individuals suggests that a wide-ranging search for additional microsatellite loci that are more polymorphic and contain a larger number of alleles should be undertaken for the southern African crane species. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2006.
3

Avian diversity in Southern Africa : patterns, processes and conservation

Janse Van Rensburg, Berndt 30 June 2005 (has links)
Please read the abstract in the section 00front of this document / Thesis (DPhil (Zoology))--University of Pretoria, 2005. / Zoology and Entomology / unrestricted

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