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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

Aspects of the ecology of sandy beaches along Durban's urbanised coastline.

Govender, Natasha. January 2009 (has links)
Urban sandy beaches are the primary focus of numerous pressures. Among these are the disruption of sand budgets because of an increasing demand for coastal infrastructure, pollution from landward sources, and recreation and the associated stressors such as trampling and off-road vehicles. More recently, climate change and the manifestations thereof, such as sea-level rise and increased storminess have added to the suite of threats to sandy beach ecosystems. Despite being important natural and economic resources these urban systems have not received adequate research attention and, consequently, the management of sandy beaches has been based on ecologically unsustainably principles. The aims of this study were to provide baseline biodiversity information of urban beaches along the Durban coastline, South Africa, as a step toward the application of improved ecological management procedures for metropolitan beach ecosystems. Macro- and meiofaunal communities of 15 representative beaches along the Durban coastline were quantitatively surveyed using standard sandy beach sampling protocols. This study showed that Durban’s beaches, despite being highly urbanised, harbour rich and abundant faunal communities. This is contrary to previous findings that reported a paucity of life on Durban beaches. A total of 23 macrofauna taxa were identified, with the dissipative Battery Beach having highest diversity with 13 macrofaunal species. La Lucia, a reflective beach, had the highest macrofaunal abundance and was the second most diverse beach, thus departing from global trends that report a poor macrofaunal community of reflective beaches. Twenty higher-level meiofauna taxa were recorded in this study and it was found that meiofauna abundance showed a significant and positive relationship with beach width. Because of the coarse taxonomic resolution, meiofauna diversity may likely be much greater than that recorded in this study. The conventional view that sandy beaches are resilient to exploitation was questioned when it was found that meiofauna assemblages were significantly and negatively impacted by stormwater outlets on two of the sampled beaches, possibly through freshwater intrusion or erosional effects. This raises questions regarding the functioning of beach ecosystems, and the services they provide, when faced with anthropogenic stressors that impact faunal communities. This snapshot survey of aspects of the ecology of Durban’s sandy beaches has provided much needed baseline data for this coastline. These data will be used in conjunction with other available data toward the development of a fine scale systematic conservation plan for Durban to enable the prioritisation of conservation and management efforts. The use of these data will also facilitate the development of guidelines for the integrated ecological management of urban sandy beach ecosystems. / Thesis (M.Sc.)-University of KwaZulu-Natal, 2009.
2

A comparative study of the plant ecology of three estuaries : Mgeni, Mhlanga and Mdloti.

Raiman, Feisal. 21 October 2013 (has links)
The vegetation of the Mgeni Estuary, Mhlanga Estuary and Mdloti Estuary was analysed according to the Braun-Blanquet phytosociological method using quadrats of 4m2 and 25m2 in area placed subjectively and the Point-Centred Quarter method with points chosen whilst traversing. A classification of plant communities is given. These are described floristically and related to habitat variables. Indicator species of the climatic climax of coast forest occur within the study area. The absence of coast forest is ascribed to low altitude, tidal inundation and the consequent effect of salinity, basal inundation resulting in a high water-table and the influence of man. The floodplain of the Mgeni Estuary is dominated by mangrove vegetation comprising mainly Bruguiera gymnorrhiza and Avicennia marina whereas vegetation established on Athlone Island is dominated by mesophytic thicket comprising mainly Schinus terebinthifolius, Lantana camara, Chromolaena odorata and Cardiospermum grandiflorum. The floodplain of the Mhlanga Estuary is dominated by Phragmites australis. The shores of the Mdloti Estuary are dominated by Barringtonia racemosa, Phragmites australis and Echinochloa pyramidalis. Major differences in vegetation patterns of the three systems are related primarily to the differences in the open nature of the river mouths. This is controlled mainly by river flow and longshore drift. Differences in vegetation patterns within an estuary are dependent on differences in tolerances to salinity, basal inundation and shade, together with variations in altitude and edaphic factors and competition between species. Generally soils of Mgeni Estuary had higher contents of small sized fractions, bulk densities, reserve acidities, organic matter, salts and exchangeable bases and lower pH than soils at Mhlanga Estuary and Mdloti Estuary. Differences exist between mangrove and non-mangrove soils at Mgeni Estuary and differences between the non- mangrove soils at the three study sites. Major differences in soil characteristics are as a result of differences in tidal inundation, geogenetic parameters and biotic factors. Information on topography, hydrology, geology, climatic factors, biotic factors and historical background of the area is given. A check-list of vascular plants is included. The work is illustrated by 44 figures. / Thesis (M.Sc.)-University of Durban-Westville, 1986.

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