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The ecology of hard substrate communities around Sardinia Bay in the warm-temperate Agulhas BioregionEvans, Adrian G, Nel, Ronel January 2016 (has links)
Hard substrates in the marine environment are an important ecosystem of great scientific and economic value. Hard substrates provide suitable habitat for a diverse assemblage of benthic organisms. This thesis investigated the ecology of benthic hard substrate communities along a section of wave-exposed coastline, including the Sardinia Bay Marine Protected Area (MPA), in the warm-temperate Agulhas bioregion of South Africa. The effect of physical variables on benthic communities, including both the intertidal and shallow subtidal, was quantitatively assessed across (Chapter 3) and along (Chapter 4) the shore to provide a model of zonation for this bioregion and a baseline of community patters and biodiversity, as this information was lacking especially for the Sardinia Bay MPA. The zones described in Chapter 3 were in agreement with previous trends described for this bioregion with the addition of different biotopes in the upper Balanoid and deeper subtidal zones as well as the addition of an intermediate/transition zone in the subtidal between the algal dominated shallow subtidal and deeper subtidal, which has an increased abundance of sessile invertebrates. Disturbance is an important process in structuring benthic communities, and its role in structuring shallow benthic communities was investigated using a disturbance simulation experiment across a wave-exposure gradient (Chapter 5). Communities were found to change along the exposure gradient and monitoring the undisturbed communities showed that large waves caused disturbances across all the exposures. The recovery process was similar across all exposures mainly through lateral vegetative growth and regrowth from basal parts with communities in disturbed quadrats recovering to resemble the surrounding undisturbed community. Recruitment did not have a significant effect in the recovery process and community composition was therefore a result of the effects of the physical environment along the exposure gradient. Lastly this thesis investigated the indirect effects of protection in the small Sardinia Bay MPA (Chapter 6). Despite the small size of the MPA this study found differences in diversity and abundance between communities inside and outside the MPA. These differences in benthic biota infer indirect effects of protection that are probably due to the increase in abundance of exploited fish inside the MPA. Lower abundances of red algae, macroinvertebrates and diversity inside the MPA in the shallow depth category was attributed to the higher abundance of the generalist fish species that concentrate in the shallows. Significantly lower abundances of Chordata in the shallow and medium depth categories inside the MPA was attributed to predation by the benthic carnivorous species as ascidians are included in the diet of these species. This chapter also compared the effectiveness of destructive (scraped quadrats) and non-destructive (visually assessed quadrats) sampling methods. Scraped quadrats were found to be more effective in detecting changes across the MPA compared to visually assessed quadrats. Destructive methods sample the entire assemblage, to a higher taxonomic level, and measure abundance using biomass. It was concluded that biomass is a better metric when comparing communities across protection or other treatments as it provides better biological information of the community.
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A plant ecological study and management plan for Mogale's Gate Biodiversity Centre, GautengTuckett, Alistair Sean 12 1900 (has links)
The Mogale’s Gate Biodiversity Centre is a 3 060 ha reserve located within the Gauteng
province. The area comprises grassland with woodland patches in valleys and lower-lying
areas. To develop a scientifically based management plan a detailed vegetation study was
undertaken to identify and describe the different ecosystems present. From a TWINSPAN
classification twelve plant communities, which can be grouped into nine major communities,
were identified. A classification and description of the plant communities, as well as, a
management plan are presented. The area comprises 80% grassland and 20% woodland
with 109 different plant families. The centre has a grazing capacity of 5.7 ha/LSU with a
moderate to good veld condition. From the results of this study it is clear that the area makes
a significant contribution towards carbon storage with a total of 0.520 tC/ha/yr stored in all
the plant communities. / Environmental Sciences / M.Sc. (Environmental Management)
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Biodiversity conservation and land rights in South Africa : whither the farm dwellers?Crane, Wendy 12 1900 (has links)
Thesis (MPhil (Public Management and Planning))--University of Stellenbosch, 2006. / ENGLISH ABSTRACT: South Africa is unique in that its globally significant biodiversity, which is under major threat,
coexists with an apartheid history of dispossession that produced a starkly unequal land
ownership pattern and widespread rural poverty. It is in this context that the post-apartheid
government must fulfil constitutional and international obligations to safeguard environmental
assets as well as undertake land reform benefiting the previously dispossessed. Consequently,
there is a continuous challenge of reconciling complex and often conflicting relationships
between poverty, inequitable access to resources, and the protection of biodiversity. Current
efforts to conserve the Cape Floral Kingdom emphasise partnerships between private
landowners and existing nature reserves to promote sustainable utilisation of biodiversity. This
paper explores the potential impact of this approach on farm dwellers, and how changing land
use may affect their land tenure rights and livelihoods. Primary research was undertaken in the
Baviaanskloof, where this model is in an early stage of implementation. The paper identifies
systemic and structural tensions in current attempts to reconcile biodiversity conservation and
farm dwellers’ interests, and documents issues of process and principle that could become
important in the future. In doing so, it highlights the influence of on-farm power relations and
highly complex institutional arrangements in determining the real extent of participation by
affected farm dwellers and the efficacy of social safeguard policies. Findings also caution
against an over-reliance on ecotourism as the major occupation and argues instead for support
to multiple livelihood strategies.
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Comparative impacts of fragmentation on birds in two bioregions in a biodiversity hotspot, the Cape Floristic RegionKieck, Marius Burger 03 1900 (has links)
Thesis (MScConsEcol (Conservation Ecology and Entomology))--University of Stellenbosch, 2009. / Habitat loss and fragmentation are two of the most pressing threats to biodiversity. Avifaunal
diversity and integrity is under immense pressure from these two processes. We have made
major advances in our understanding of avifaunal responses to habitat fragmentation, but mostly
focus on either fragment scale and/or landscape scale influences of fragmentation on birds. A
more comprehensive approach to assessing the impacts of fragmentation was used in this study.
The avifaunas of two different geographical regions and bioregions were surveyed and a multiscale
analysis of avifaunal responses to fragmentation was attempted. The study sites include the
West Coast and East Coast Renosterveld Bioregions in the Cape Floristic Region, South Africa.
Assemblage shifts, feeding guild compositional changes, species abundance variation and species
persistence were examined at the three spatial scales. Time- and distance-restricted point counts
were used to document birds that were directly dependent on the habitat fragments. Forty
fragments were selected in each bioregion and a once-off snapshot of the avifaunal richness and
diversity was obtained.
Results indicate that the avifauna of the two bioregions responded differently to habitat
fragmentation. In the East Coast Renosterveld Bioregion, the assemblages, guild composition
and species abundances were most accurately predicted by landscape configuration. An
assemblage shift occurred at 20 ha fragment area, compared to the 50 ha fragment area threshold
of the West Coast Renosterveld Bioregion’s avifauna composition. In the West Coast
Renosterveld Bioregion, fragment area was the better predictor of assemblage, guild composition
and species abundances. However in both bioregions, the persistence of common species was
equally sensitive to area and landscape scale effects.
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Soil, vegetation and large herbivore relations in Mkuzi Game Reserve, NatalGoodman, Peter Styan 13 February 2012 (has links)
Ph.D., Faculty of Science (Botany), University of the Witwatersrand, 1990
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Land-cover change in the Berg River catchment : implications for biodiversity conservationStuckenberg, Tristan 12 1900 (has links)
ENGLISH ABSTRACT: Biodiversity refers to the variety of life on earth at all scales of observation. Its persistence underlies ecological and evolutionary processes and is pivotal for the sustenance and future development of human societies through the provision of ecosystem services. Especially since the industrial revolution, anthropogenic land-cover change has placed ever-increasing strain on natural systems through the destruction and degradation of habitat. The Cape Floristic Region (CFR) is a global biodiversity hot spot which contains some of the highest levels of floristic diversity and endemism on the planet. Since European settlement large swathes of this region have been transformed to facilitate socio-economic development, placing tremendous pressure on indigenous biodiversity.
Due to the intimate relationship that exists between land cover and biodiversity it is possible to draw inferences on the current state of the biodiversity of an area, assess the pressures that will likely face it in the future and plan accordingly based on an analysis of land-cover change. As a means of assessing the state of biodiversity in the CFR, this thesis has developed a series of three land-cover maps for the Berg River catchment in the Western Cape province for 1986/1987, 1999/2000 and 2007 using Landsat TM and ETM+ data. Areas of natural vegetation were delineated on the land-cover maps using an object-orientated nearest neighbour supervised classification. Remnants of natural vegetation were classified according to potential vegetation boundaries described by Mucina and Rutherford’s map of the vegetation of South Africa, Lesotho and Swaziland.
Contrary to initial expectations, the area occupied by natural vegetation had increased by 14%. However, considerable variation was recorded between vegetation types with certain types exhibiting marked increases in extent while others had been encroached by expanding cultivated and urban areas. An assessment of the accuracy of the 2007 land-cover map showed that significant swathes of natural vegetation were infested with alien invasive species or dominated by particularly resilient species which are not as severely affected by anthropogenic activities as other species. It is concluded that the methodology employed in this study provides a scoping mechanism by which more intensive research may be directed toward areas exhibiting significant land-cover change. / AFRIKAANSE OPSOMMING: Biodiversiteit verwys na die verskeidenheid lewe op aarde op alle waarnemingsvlakke. Die volhouding daarvan onderlê ekologiese en ewolusionêre prosesse en die verskaffing van ekosisteemdienste is deurslaggewend vir die onderhoud en toekomstige ontwikkeling van menslike samelewings deur. Veral sedert die industriële rewolusie het veranderinge in antropologiese gronddekking toenemende druk op natuurlike sisteme geplaas, grootliks deur die vernietiging en ontaarding van habitatte. Die Kaapse Floristiese Streek (KFS) met van die hoogste vlakke van floristiese diversiteit en endemisiteit op aarde, is ‘n brandpunt van wêreldwye biodiversiteit. Sedert die vestiging van Europese setlaars is uitgebreide dele van hierdie streek omskep om sosio-ekonomiese ontwikkeling te bevorder, wat geweldige druk op inheemse biodiversiteit geplaas het.
Te wyte aan die intieme verhouding wat tussen gronddekking en biodiversiteit bestaan, is dit moontlik om deur middel van ‘n ontleding van gronddekkingsveranderinge afleidings te maak rakende die huidige stand van biodiversiteit in ‘n streek. Sodoende kan bepaal word watter druk ʼn streek moontlik in die toekoms sal moet weerstaan. Vooruitbeplanning kan dienooreenkomstig gedoen word. Ten einde die stand van biodiversiteit in die KFS te beraam, het hierdie tesis ‘n reeks van drie gronddekkingskaarte (1986/1987, 1999/2000 en 2007) vir die Bergrivier-opvangsgebied in die Wes-Kaapprovinsie met behulp van Landsat TM en ETM+ data ontwikkel. Areas met natuurlike plantegroei is met behulp van ‘n voorwerp-georiënteerde naaste-buurman klassifikasie afgebaken. Oorblyfsels van natuurlike plantegroei is volgens potensiële plantegroeigrense, soos beskryf deur Mucina en Rutherford se kaart van die plantegroei van Suid-Afrika, Lesotho en Swaziland, geklassifiseer.
In teenstelling met aanvanklike verwagtinge, het die area wat deur natuurlike plantegroei bedek word met 14% toegeneem. Tog is aansienlike variasie tussen plantegroeitipes opgemerk, met sekere soorte wat opvallende omvangstoename toon, terwyl ander plantegroeitipes deur landbou en stedelike groei vervang is. ‘n Beraming van die akkuraatheid van die 2007-gronddekkingkaart toon dat noemenswaardige stroke natuurlike plantegroei deur uitheemse indringerspesies besmet word of deur uiters weerstandige spesies, wat nie so ernstig as ander spesies deur antropologiese aktiwiteite beïnvloed word nie, gedomineer word. Die gevolgtrekking is dat die metodologie wat in hierdie studie gebruik is ‘n meganisme verskaf waardeur meer intensiewe navorsing op areas wat aansienlike verandering in gronddekking ten toon stel, gerig kan word.
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The epibiotic relationship between mussels and barnaclesBell, Caroline Margaret January 2014 (has links)
Epibiosis is an ecological relationship that has been described as one of the closest possible associations in marine ecosystems. In the space limited rocky intertidal, mussel beds provide important secondary space for barnacles. The epibiotic relationship between mussels and barnacles on the south-east coast of South Africa was considered at different scales, from large-scale, natural patterns of epibiosis on the rocky shore, to fine-scale settlement choices of barnacles and the effects on the condition and growth rates of individual mussels. Mussel and barnacle assemblages were generally stable over a 12-month period. The tracking of individual mussels with and without barnacle epibionts resulted in a significant increase in mortality rate of mussels with epibionts over 12 months (two-way ANOVA, p = 0.028). Barnacles on rocks, as well as on mussels, were also tracked with no significant effect of substratum on mortality of barnacles (two-way ANOVA, p = 0.119). Prevalence and intensity of barnacle infestations was also examined in relation to coastline topography on two co-occurring mussel species, the indigenous Perna perna and invasive Mytilus galloprovincialis. The results were complex, but bay status had significant effects on prevalence and intensity for both mussel species, depending on the time and zone. The effect of bay in relation to time was particularly relevant for M. galloprovincialis (four-way nested ANOVA, Season X Site(Bay): p = 0.0002), where summer prevalence was higher than that of winter in bays, regardless of zone, while in open coast sites, the effect of season was only significant in the mid zone. Patterns of intensity generally showed higher values in summer. Substratum preference by barnacles was investigated by recording settlement, survival and mortality of Chthamalus dentatus barnacles on various treatments. There was a strong preference for the rock-like plastic substratum by primary settlers (pair-wise tests of PERMANOVA: Dead < Rock mimic (p = 0.0001); Replica < Rock mimic (p = 0.019) and Live < Rock mimic (p = 0.0001)). This indicates that barnacles settle on mussel shells only as a secondary choice and that micro-topography is an important variable in barnacle settlement. The effect of barnacle epibiosis on condition index and growth of P. perna and M. galloprovincialis was also examined as a direct indication of the health of mussels subjected to the biological stress of epibiosis. Although not significant (PERMANOVA: P. perna: p(perm) = 0.890; M. galloprovincialis: p(perm) = 0.395), growth for both mussel species was slower for barnacle-infested individuals in summer, which is the main growing season for mussels in the region. Results from condition index calculations, however, showed no negative impacts of epibiotic barnacles (three-way ANCOVA: P. perna: p = 0.372; M. galloprovincialis: p = 0.762). Barnacle epibionts create a new interface between the mussel and its environment and this interaction can affect other members of the community. The possibility of the barnacle epibiont causing increased drag also needs further investigation. Biological processes operating within a wide range of physical stressors drive the interactions on the rocky shore, such as epibiosis. Overall, the results of this study suggest that the epibiotic relationship between mussels and barnacles on the south-east coast of South Africa does not significantly affect the mussel species present and that barnacles only use mussel shells as a secondary choice of substratum.
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A plant ecological study and management plan for Mogale's Gate Biodiversity Centre, GautengTuckett, Alistair Sean 12 1900 (has links)
The Mogale’s Gate Biodiversity Centre is a 3 060 ha reserve located within the Gauteng
province. The area comprises grassland with woodland patches in valleys and lower-lying
areas. To develop a scientifically based management plan a detailed vegetation study was
undertaken to identify and describe the different ecosystems present. From a TWINSPAN
classification twelve plant communities, which can be grouped into nine major communities,
were identified. A classification and description of the plant communities, as well as, a
management plan are presented. The area comprises 80% grassland and 20% woodland
with 109 different plant families. The centre has a grazing capacity of 5.7 ha/LSU with a
moderate to good veld condition. From the results of this study it is clear that the area makes
a significant contribution towards carbon storage with a total of 0.520 tC/ha/yr stored in all
the plant communities. / Environmental Sciences / M.Sc. (Environmental Management)
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The effectiveness of biosphere reserve as a tool for sustainable natural resource management in Vhembe District Municipality, Limpopo Province, South AfricaMphidi, Mosima Florina 22 October 2019 (has links)
MENVSC / Department of Geography and Geo-Information Sciences / The purpose of this study was to contribute towards a better understanding of the
effectiveness of Biosphere Reserve as a tool in managing natural resources in the Vhembe
District Municipality (VDM), Limpopo Province of South Africa. There are limited
documented materials for a better understanding of the effectiveness of Biosphere
Reserve (BR) as a tool in managing natural resources in the Vhembe District Municipality
(VDM). As a result, this study was undertaken to bridge this gap and to discover new
insights to assist in understanding the effectiveness of BR as a tool in managing natural
resources.
This study adopted a pragmatic research approach, which is a mixture of the qualitative
and quantitative research approaches, wherein data were collected using primary and
secondary sources. Both primary and secondary data were used, in order to obtain
information concerning the effectiveness of biosphere reserve in the study area. Primary
data were obtained using a combination of methods, including participatory rural appraisal
(PRA) tools and techniques, and informal and formal surveys. The secondary data was
collected from desk-based examination of relevant documentation relating to conservation
of the Biosphere Reserves areas. The documents included previous reports from Greenest
Municipality Competition (GMC) results for all local municipalities from 2012 to 2017,
Management Effective Tracking Tool (METT-SA) from 2016 to 2018, and previous research
data on conservation.
The results obtained revealed that Biosphere Reserve (BR) is an effective tool for the
conservation of natural resources within Vhembe District, South Africa. This is because
natural resources are taken into consideration when there are developments and projects
being undertaken. Furthermore, the communities in Vhembe District Municipality benefit
from the programmes and projects aimed at conserving natural resources within the VBR.
The study also revealed that there are environmental challenges within the Vhembe
Biosphere Reserve due to mining activities, climate change, developments in natural
resources and deforestation, which require the enforcement of by-laws and programmes
and projects aimed at conserving natural resources. / NRF
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The place of community values within community-based conservation : the case of Driftsands Nature Reserve, Cape TownFoot, Shelley 24 October 2013 (has links)
The most contemporary approach to biodiversity conservation within South Africa is that of
community-based initiatives, which seek to combine biodiversity conservation with socioeconomic
development. As a challenge to the Western, science laden approaches to
conservation there is an increasing need for community initiatives to reflect the values of
local communities.
Values of local communities and the management body, CapeNature, with regards to
Driftsands Nature Reserve, Cape Town, were captured and analytically coded through the
qualitative methods of interviewing and participant observation in order to develop a
grounded theory and model.
A discussion of the expressed values suggests that community-based conservation
initiatives are doing little to include community values even though there is a large degree of
agreement between these and corporate values. As such, it is questioned whether
community-based conservation can be practised within an organisation which, due to
procedures and protocols, is top-down in its approach. / Geography / M. Sc. (Geography)
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