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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.
21

Seedling establishment of Themeda triandra Forssk. in the montane grasslands of Natal.

Everson, Theresa Mary. January 1994 (has links)
Soil erosion and vegetation destruction have reached serious proportions in disturbed areas of the montane grasslands of the Natal Drakensberg. Little is known of the inherent ability of indigenous grasses to produce viable seed and establish seedlings for rehabilitation programmes. This study examined the effects of fire and small-scale disturbance on the seedling dynamics of the dominant grass, Themeda triandra Forssk. Annual seed production of T. triandra increased with length of burning rotation, ranging from 21 seeds m⁻² in the annual winter burn to 485 seeds m⁻² in the five-year burn. High predation of seeds (70-98%) and low viability (37% in 15 month-old seeds) contributed to the poor representation of T. triandra in the seed bank when compared to the aboveground vegetation. Seedling densities and survival were monitored by mapping quadrats at six-weekly intervals from November 1986 to September 1989. Highest establishment of T. triandra was recorded in the biennial spring burn treatment (< 184 seedlings m⁻²). Microclimatic studies of the seedling environment demonstrated that increases in photosynthetically active radiation following burning, and high soil moisture associated with accumulation of litter, favour seedling establishment. The main constraint to seedling establishment was high mortality in winter which resulted in a 1% survival of seedlings of T. triandra during the three-year study. This indicates that in the fire-climax grasslands of the study, seedlings contribute little to the population structure. The most significant factor contributing to low survivorship is intraspecific competition between seedlings. Spacing of seedlings in rehabilitation programmes is therefore a critical factor in optimizing seedling establishment. Analysis of the fate of seeds of T. triandra between their production and establishment, showed that the main constraints for seedling establishment were predation, low viability and poor germination. A population model, based on transitions between seeds, seedlings and mature tufts, predicts that a biennial spring burn is the optimal treatment for maximising both seedling establishment and vegetative growth. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1994.
22

On the climate of the Drakensberg rainfall and surface-temperature attributes, and associated geomorphic effects /

Nel, Werner. January 2007 (has links)
Thesis (D.Phil.(Geography))-University of Pretoria, 2007. / Includes summary. Includes bibliographic references (leaves 185-188).
23

Evaluating the rate of rock art deterioration in the uKhahlamba-Drakensberg Park, KwaZulu-Natal

Leuta, Tsepang Cecillia 23 February 2010 (has links)
One of the key reasons for the uKhahlamba‐Drakensberg Park’s status as a World Heritage Sites due is the abundance of rock art there. Unfortunately, through time, much of the rock art heritage in the Park is being lost through natural rock weathering processes, the decay of pigments and through the actions of people. The fragile art heritage is non‐renewable and, therefore, requires specialized management. In a case study, specific San paintings from Battle Cave study area were analysed using scanned and digital photographs with Geographic Information Systems software. Older images were compared with more recent ones and this was utilised to classify pigment colours and quantify the amount of deterioration that has taken place overtime. Various methodologies were applied to classifying the images, and it was found that manual digitising provided the best means for quantifying the amount of deterioration. A detailed analysis was undertaken of a feline painting at Battle Cave, as it had the best quality images that could be dated. Results showed that white pigment in the painting degraded more rapidly than the ochre colours. Visual analysis suggests that the damage to the figure is predominantly through pigment decay and through the granular disaggregation of the rock surface. Where pigments were applied to what were clearly weathered rock surfaces, the change was greatest over the 40‐year intervening period between images analysed. The methodology utilised in this study can be utilised to evaluate the rate of decay of rock art and is, therefore a useful tool for determining priorities with regard to the conservation of San paintings. In addition, the rate of deterioration is useful for evaluating and quantifying the contribution of rock weathering to landscape evolution. Copyright / Dissertation (MA)--University of Pretoria, 2010. / Geography, Geoinformatics and Meteorology / Unrestricted
24

A Hydrological-slope stability model for shallow landslide prediction in the Injisuthi Valley, KwaZulu-Natal Drakensberg

Bijker, Hermina Johanna 24 November 2005 (has links)
Please read the abstract in the section 00front of this document / Dissertation (MSc)--University of Pretoria, 2006. / Geography, Geoinformatics and Meteorology / Unrestricted
25

[Trophic Cascade]: an ecological research, education and information community centre in the Amazizi Tribal Authority of the Drakenburg

Marchant, Craig Galen January 2016 (has links)
This document is submitted in partial fulfilment for the degree: Masters of Architecture [Professional] at the University of the Witwatersrand, Johannesburg, 2015 / The focus of architecture in South Africa is often centered on intense urban areas in the country. However, important though these areas are, they represent only one facet of the greater country. The rural areas around South Africa are repeatedly overlooked. Added to that, our rich heritage and increasingly unique and threatened relationship with the natural systems around us is often sidelined. Our relationship with the natural world is a complicated one. Humans, perhaps the only species on earth able to do so, have the opportunity to decide whether to live symbiotically with nature or parasitically. Unfortunately the choice is often the latter. One of the areas where our rather strained and openended relationship with the natural world is most apparent is in the impoverished rural Bonjaneni Community of the Amazizi Tribal Authority located in the Okhahlamba District of KwaZulu-Natal, South Africa. Mankind’s negative impacts on this regions natural mechanisms are being felt locally and nationally in three particular areas that form the key points of focus for the thesis: grasslands, water systems and the decline of the Cape Vulture population. Grassland is of utmost importance ecologically, economically and socially for the region, without healthy grassland community livestock cannot survive, thatch cannot be gathered and the landscape will become prone to severe erosion during the rainy season. Erosion negatively affects the Tugela River water catchment basin too. Without healthy vegetation cover the landscape and community will become prone to flooding. Silt from the erosion will impact numerous dams further downstream that supply water to KwaZulu-Natal and the economic heartland of South Africa, Gauteng. The repercussions of a threatened population of Cape Vultures are also of concern. Without the specialised scavenger animal corpses will be left to fester in the sun, developing carrion borne diseases that can negatively affect the health of pets, people and livestock. These problems result in a considerable financial burden to the community and the government, yet these are all problems that can be addressed through responsible stewardship of the land and an awareness of our position in the natural world. / EM2017
26

The effect of burning frequency on invertebrate and indigenous flowering forb diversity in a Drakensberg grassland ecosystem.

Arnott, Wendy Lynn. January 2006 (has links)
The KwaZulu-Natal Drakensberg, South Africa, is predominantly a grassland ecosystem maintained by fire. The effect of the current burning regime on invertebrate and flowering forb diversity in this ecosystem is poorly understood. The overall aim ofthis study was to contribute towards the development of an effective burning regime for the KwaZulu-Natal Drakensberg that will conserve invertebrates and indigenous forbs, two major components of biodiversity. The objectives were to examine the effect of fire and fire frequency on flowering forb and invertebrate species diversity, to determine whether fire frequency, time since last burn or locality were influencing species composition, and to identify potential biodiversity indicators that reflect overall species richness for use in monitoring of invertebrates and forbs. Sampling took place in March, September and November of 2002 at Giants Castle Game Reserve. Invertebrates were sampled using sweep netting and targeted netting along transects, yellow pan traps and soil quadrats. Invertebrate taxa sampled were ants (Formicidae), butterflies (Lepidoptera), grasshoppers (Orthoptera), leafboppers (Cicadellidae), bees (Apoidea), bee flies (Bombyliidae), hover flies (Syrphidae), robber flies (Asilidae), spiders (Araneae), earthworms (Oligochaeta) and millipedes (Diploda). These were identified to species level with the assistance of taxon experts. Flowering forbs were sampled using five replicates of five by five metre quadrats randomly placed in each site. Overall flowering forb and invertebrate species diversity was higher in grasslands that were burnt for two consecutive years in 2001 and 2002 than in grasslands that were not burnt during those two years. Frequently (annual) and intermediately (biennial) burnt grasslands had significantly higher invertebrate and flowering forb diversity than infrequently (five years without burning) burnt grasslands. This, together with the fact that grasslands burnt during the year of sampling had higher species richness than grasslands burnt two and five years previously suggests that invertebrates and forbs are generally resilient to fire and many forb species appear to be stimulated by fire. However, each burn frequency had its own suite of unique flowering forb and invertebrate species. Invertebrate communities were influenced mostly by locality and the length of time past since the last fire and flowering forb communities were influenced mostly by the length oftime past since the last fire. Fire frequency had the least influence on both invertebrate and forb communities. Ecological succession occurred after each fire in the invertebrate communities but forb communities appear to need more than five years without fire for ecological succession to occur. The findings of this study therefore suggest that using a combination of three fire frequencies would result in patches of grassland in various stages of ecological succession, and would conserve species unique to each burning frequency, and would therefore conserve maximum diversity. Flowering forb species richness and certain invertebrate taxa (ants, leafboppers, spiders and bees) have the potential to act as indicators of overall invertebrate species richness for use in monitoring programmes. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2006.
27

Influence of waterfalls on patterns of association between trout and Natal cascade frog Hadromophryne natalensis tadpoles in two headwaterstreams of the Ukhahlamba Drakensberg Park World Heritage Site

Karssing, Jeffery Robert 06 1900 (has links)
Current literature suggests that little, if any, research has been conducted in South Africa to determine the impact of alien invasive trout on indigenous amphibian biodiversity. The primary aim of the research project was to establish whether waterfalls are seasonally important in protecting the indigenous Natal Cascade Frog Hadromophryne natalensis tadpole populations from predation by alien rainbow trout Oncorhynchus mykiss and brown trout Salmo trutta at two sampling areas located at Injesuthi and Monk‟s Cowl Nature Reserve within the uKhahlamba Drakensberg Park World Heritage Site (UDPWHS). The dissertation argues in favour of a biotic rationale, namely trout predation, as being the primary cause for the decline of H. natalensis tadpoles below the waterfalls and systematically negates the influence of geo-physical (abiotic) environmental factors on tadpole abundance. Habitat isolation and fragmentation is identified as a latent threat to the continued persistence of H. natalensis populations in the UDPWHS. / Environmental Sciences / M. Sc. (Environmental Science)
28

Invertebrate diversity in afrotemperate forests : spatial and seasonal changes and implications for conservation.

Uys, Charmaine Janet. January 2006 (has links)
Forests in the Drakensberg Mountains, although generally small and fragmented, represent a wealth of globally significant biodiversity. This is especially true of the invertebrate fauna, which includes a range of localized endemic species. Ground dwelling, flightless invertebrates living in forests show relative immobility and poor dispersal abilities compared to birds, butterflies and other animal taxa. The naturally fragmented state of Afrotemperate forests also geographically isolates these taxa. No quantified, systematic surveys of flightless invertebrates have been conducted in Afrotemperate forests in the Drakensberg Mountains. This means that, to date, invertebrates have not been considered in the management of these habitats. However, invertebrates are vitally important in ecosystem functioning and maintenance and must be included in management plans. This study quantified flightless invertebrate diversity in Afrotemperate forest patches in the Drakensberg by investigating spatial patterns and seasonal changes in invertebrate diversity. The broad objectives were to: 1) Determine the appropriate spatial scale at which conservation of flightless invertebrates should be implemented; 2) Determine which season, taxa and sampling methods are most suitable for biodiversity assessment and monitoring in Afrotemperate forest; and 3) Investigate methods of prioritizing Afrotemperate forests for conservation of flightless invertebrate diversity. Seventeen forest patches in six valleys in four Drakensberg reserves (Rugged Glen Nature Reserve, Royal Natal National Park, Cathedral Peak and Injisuthi) were sampled in the summer of 2004/2005. In addition, three forests at Injisuthi were sampled in March, June, September and December 2004 to enable seasonal comparisons. Sampling methods included soil samples, leaf litter samples, pitfall traps, active search quadrats and tree beats. The study focused on terrestrial molluscs (Class Gastropoda), earthworms (Class Annelida), onychophorans (Class Onychophora), centipedes (Class Chilopoda), millipedes (Class Diplopoda) and ants (Class Insecta). Target taxa were sorted to morphospecies and then identified to species by taxonomic experts. Seventy-two species and a total of 5261 individual specimens from the six target taxa were collected. Species composition of sites varied along the north-south gradient, and species turnover (beta diversity) was related to the distance between sites. Flightless invertebrate species richness and community structure fluctuated seasonally. Therefore, I recommend that sampling should take place during the wet season (summer months). Molluscs were the most suitable taxon among those surveyed to represent flightless invertebrate diversity and leaf litter samples and active search quadrats are the most suitable sampling methods for flightless invertebrates in forest. This study compared approaches to prioritizing Afrotemperate forests in terms of their invertebrate diversity using ranked species richness with complementarity indices of species presence/absence, taxonomic distinctness (orders, families and genera) and endemicity. There was no consistent spatial trend in the priority ranking of forests based on species richness. Complementarity based on species richness only required eight out of 17 forests to represent all 62 species. Although complementarity based on taxonomic distinctness and endemicity required fewer sites, not all species were represented. The minimum set of sites identified using complementarity based on species richness and augmented with information on taxa of conservation importance (local endemic and threatened species) was the most rigorous approach to prioritizing Afrotemperate forest patches in the Drakensberg for flightless invertebrate conservation. Urgent conservation interventions are required because invertebrates play a critical role in ecosystem functioning. As many forest patches and invertebrate populations as possible should be protected to conserve the full complement of invertebrate species of the region. Special management attention should be paid to the eight forests identified as priority sites in the complementarity analyses. Forest patches cannot survive in isolation, so it is important to manage the grassland, riverine vegetation, forest ecotone and forests holistically. Provisional targets were set for the conservation of flightless invertebrates, based on estimates of the requirements for persistence of invertebrates in Afrotemperate forest, made within the constraints of available information and expert opinion. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2006.
29

Influence of waterfalls on patterns of association between trout and Natal cascade frog Hadromophryne natalensis tadpoles in two headwaterstreams of the Ukhahlamba Drakensberg Park World Heritage Site

Karssing, Jeffery Robert 06 1900 (has links)
Current literature suggests that little, if any, research has been conducted in South Africa to determine the impact of alien invasive trout on indigenous amphibian biodiversity. The primary aim of the research project was to establish whether waterfalls are seasonally important in protecting the indigenous Natal Cascade Frog Hadromophryne natalensis tadpole populations from predation by alien rainbow trout Oncorhynchus mykiss and brown trout Salmo trutta at two sampling areas located at Injesuthi and Monk‟s Cowl Nature Reserve within the uKhahlamba Drakensberg Park World Heritage Site (UDPWHS). The dissertation argues in favour of a biotic rationale, namely trout predation, as being the primary cause for the decline of H. natalensis tadpoles below the waterfalls and systematically negates the influence of geo-physical (abiotic) environmental factors on tadpole abundance. Habitat isolation and fragmentation is identified as a latent threat to the continued persistence of H. natalensis populations in the UDPWHS. / Environmental Sciences / M. Sc. (Environmental Science)
30

Wilderness planning using the limits of acceptable change system : a case study of the overnight caves in the Mlambonja wilderness area of the uKhahlamba-Drakensberg Park.

Long, Brian. January 2004 (has links)
Human-induced impacts associated with recreational use in wilderness areas have the potential to imperil the wilderness resource and the quality of visitor experiences. One approach to address this problem is the Limits of Acceptable Change System, which helps Protected-area managers determine acceptable levels of resource impacts and social conditions in wilderness areas. This study's objective was to determine the possible applicability of the Limits of Acceptable Change System to the overnight caves in the wilderness areas of the uKhahlamba-Drakensberg Park. Component A of the study discusses the ten steps of the Limits of Acceptable Change system and the management approaches for the wilderness areas and overnight caves in the uKhahlamba-Drakensberg Park. A product of Component A is a procedure manual for inventorying indicators of resource conditions in the overnight caves. During a brief period of field research this procedure manual was applied to four overnight caves in the Mlambonja Wilderness area. Component B of the study summarizes much of the information found in Component A and examines the results from the field research. Recommendations are made to improve the effectiveness of measuring the resource indicators for the overnight caves in the procedure manual. This study's conclusions indicate that the Limits of Acceptable Change System can be applied to the overnight caves and would provide a valid management framework to address visitor impacts / Thesis (M.Env.Dev.)-University of KwaZulu-Natal, Pietermaritzburg, 2004.

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