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71	Monitoring the re-growth rate of alien vegetation after fire on Agulhas Plain, South Africa Fatoki, Oluwakemi Busayo 03 1900 (has links) Thesis (MSc (Geography and Environmental Studies))--University of Stellenbosch, 2007. / The Agulhas Plain, an area rich in fynbos, was monitored within six months after the February 2006 fire. The potential of using medium resolution imagery, specifically from the Moderate Resolution Imaging Spectroradiometer (MODIS) in determining the re-growth rates of indigenous and alien vegetation types after fire was explored. Pixels representing dense areas of each vegetation type were selected. There was a significant difference in the pixels selected for each vegetation type. A time series of Normalized Difference Vegetation Index (NDVI) data was derived and fitted to functions, such as Double Logistics and Asymmetric Gaussian as implemented in the TIMESAT software. The results show that alien vegetation grows faster after a fire occurrence than in its absence. Within the specified months of monitoring, it was observed that fynbos grew faster than the alien vegetation. Also, the re-growth rates of vegetation on the coastal soils were higher than those of vegetation on the inland soils. The determination of the re-growth rate was necessary to assist resource managers determine the appropriate time for follow-up of clearing invaded sites after fire.
72	Life history, population dynamics and conservation status of Oldenburgia grandis (Asteraceae), an endemic of the Eastern Cape of South Africa Swart, Carin January 2008 (has links) Oldenburgia grandis is a rare, long-lived woody paleoendemic of the Fynbos Biome of South Africa. Confined to quartzite outcrops, it has a small geographic range and narrow habitat specificity. O. grandis responds to its fire-prone environment by resprouting. Elasticity analysis of O. grandis reveals that growth and fecundity were traded off for persistence of adult, mature and sapling stages. Morphological adaptations such as a corky fire-resistant bark and the ability to resprout after fire are traits that O. grandis have evolved to persist in a frequently disturbed environment. Population growth rate for sites undisturbed by fire for a number of years (l = 1.01) and sites at various stages of recovery after fire (l = 1.00) were very similar. The highest variation in transition probabilities for all sites was seen in the persistence of the seedling stage and growth from seedling to sapling. Observed population structure and stable stage distribution determined by the matrix model show that sites recently undisturbed by fire had high abundances of the adult and sapling stages. A peak in sapling stages was seen for the stable stage distribution where similar peak in sapling numbers were seen for population structures of sites at various stages of recoveryafter fire. Favourable environmental conditions for the persistence of O. grandis populations include no fire with transition probabilities between the observed minimum and maximum and fire frequency at a 10 year interval where seedling protection from the fire is high and adult and mature mortalities during the fire are low. Stochastic environmental events that could put populations (particularly small populations) at an increased risk of extinction include high to moderate fire intensities where seedling protection from the fire is low and adult and mature mortalities are high as a result of the fire. Compositae
73	Hartbeespoortdam Butterfly Conservancy : an ecological splurge Pettey, Ryan Patrick 28 May 2004 (has links) The thesis focuses on different habitable spaces which have been designed to promote the existence of a number of South African butterfly species. The architecture responses to the context as well as to one of the largest insect groups, the order L e p i d o p t e r a. Following a sustainable approach, more ecological knowledge is at the core of the design. Instead of human functional needs driving the design, site components respond to the indigenous spatial character, climate, topography, soils, and vegetation as well as compatibility with the existing cultural context. / Dissertation (MArch(Prof))--University of Pretoria, 2006. / Architecture / unrestricted Environmentally responsive architecture Sustainable Environment Vegetation Tent structure Cycles Natural ventilation Climatic zones Passive systems Nature Fynbos biome Savanna biome Tourist attractions Hartbeespoortdam Hartbeespoort North west South africa Damdoryn Butterfly conservancy Heat and energy conservation Autonomous design Environmental design Local skills Magaliesberg Context Biomes UCTD

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