I studied the spatial distribution of South African avian species richness from the viewpoint that humans are a substantial modifying force on earth, and have also modified the historical spatial distribution of species richness. The main aim of the thesis is to investigate the way in which humans have modified avian species richness patterns in South Africa at the quarter-degree square (QDS) resolution, which is a phenomenon that has been either overlooked, or not completely clarified, in many previous studies of the same region and data at the same resolution. In particular, I investigated hypotheses that were proposed to explain the maintenance of a positive relationship between native species richness and human population density in the face of negative human impacts. Further, I investigated which of the possible anthropogenic and natural environmental factors determine spatial distribution in exotic bird species. Highlighted from these studies are that substantial positive and negative human influences on bird species richness distribution patterns are observable at the QDS resolution, that there are differences between common native birds and rare native birds with regard to their relationships with anthropogenic environmental conditions and exotic bird species, and that the particular combination of environmental covariates that is important for the spatial distributions of exotic species is taxon- and scale-dependent. Even though these results have contributed much towards our understanding on how human modifications have affected species richness patterns, this thesis leaves some unanswered questions. Finer resolution studies and temporal studies are needed to examine many of these questions. Further, an interdisciplinary approach incorporating politics and economics into ecological studies is needed to enhance our understanding of the factors that modify the distribution of humans and their associated threats and benefits to species richness. / Dissertation (MSc)--University of Pretoria, 2010. / Zoology and Entomology / unrestricted
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:up/oai:repository.up.ac.za:2263/29583 |
| Date | 19 November 2008 |
| Creators | Hugo, Sanet |
| Contributors | Janse Van Rensburg, Berndt, upetd@up.ac.za |
| Source Sets | South African National ETD Portal |
| Detected Language | English |
| Type | Dissertation |
| Rights | © 2008 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. |
Page generated in 0.0018 seconds