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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.
81

Historie vegetace Chebské pánve ze sedimentárního záznamu lokality SOOS / History of vegetational development in the Cheb basin from sedimentary record of the SOOS National Nature Reserve

Suda, Tomáš January 2012 (has links)
Vegetation development in the Cheb basin ( W Czech Republic) recorded in the sediments of the SOOS ational ature Reserve This thesis focuses on palaeoecological research of quaternary sediments in the Soos National Nature Reserve (Cheb basin, NW Czech Republic). Quaternary history of this locality is poorly known, despite it is a valuable and protected area with high natural qualities. The Soos basin is also known for its unique geological record, which is expected to cover information on landscape dynamics at least during the Holocene. A lake existed in the Soos basin enabling accumulation of diatomite and peat sediments of a broad palaeoecological potential. Records were analysed with method of pollen analysis and were dated using 14C. The results of this study bring information about vegetation development in the area of Cheb basin as well as development of lake ecosystem. It also gives a new insight on lake's origin and its age. The accumulation of peat sediments started in the Preboreal period and was continuous at least until the Atlantic following with a hiatus, therefore further detection of vegetation development is impossible. The beginning of diatomite accumulation, as well as the existence of the lake goes back to the Bølling interstadial, according to radiocarbon dating. However, this...
82

Áreas de preservação permanente (APPs) e o planejamento do seu uso no contexto das bacias hidrográficas : metodologia para adequação dos parâmetros legais

Gass, Sidnei Luís Bohn January 2010 (has links)
Der geschichtliche Prozess der Bodenbesetzung und – nutzung auf der Grundlage von Entwaldung und ungeordneter Bodenbewirtschaftung verursachte Konflikte zwischen der Zielsetzung der Umweltsanierung und der sozialwirtschaftlichen Reproduktion der auf Flächen mit hohen Umwelteinschränkungen siedelnden Landwirte. Diese Dichotomie zeigt sich derzeit in der Anwendung des Umweltrechts, insbesondere im neuen brasilianischen Waldschutzgesetz, das 1965 durch das Bundesgesetz Nr. 4.771 erlassen wurde, wenn es sich um Naturschutzgebiete (APPs) handelt, also um Landstriche entlang der Gewässer, die entsprechend geschützt und deren natürliche Vegetationsbedingungen erhalten werden müssen. Ausgehend von Elementen der Flussgeomorphologie gründet sich die von der vorliegenden Untersuchung verfolgte Diskussion auf die Hinterfragung der geometrischen Maβnahmen der Naturschutzbestimmungen durch die Vorlage einer Methodik zur Bestimmung dieser Flächen. Um zum Ergebnis zu gelangen, wird eine geschichtliche Rückbesinnung auf den Bodenbesetzungsprozess in Nordwest Rio Grande do Sul, zu der die Proben der Untersuchung gehören, sowie eine theoretische Interpretation des weltweiten Naturschutzes vorgenommen und werden die Naturschutzgebiete für Brasilien auf drei Untersuchungsebenen diskutiert: der gegebene gesetzliche Rahmen, die Verwendung dieser Flächen und der Zustand, in dem diese sich im Nordwesten von Rio Grande do Sul befinden. Die soziale Funktion des landwirtschaftlichen Betriebs wird als wichtiger Punkt dieser Diskussion betrachtet, denn von ihr ausgehend geschieht der ganze Prozess der Verantwortungsüberweisung für den Schutz oder Nichtschutz von Naturschutzgebieten. In diesem Sinne untersuchen wir auch, wie IBAMA, FEPAM und Staatsanwaltschaft sich positionieren und angesichts der gesetzten Thematik handeln. Für die vorgeschlagene Methodik bestimmten wir drei Bereiche des Flusses Santo Cristo zu Pilotflächen, für die wir die Längsdeiche und Auen als Parameter für die Bestimmungen der Naturschutzgebiete definierten. Ebenso beurteilten wir die Bodenstruktur der Region, um eine der Art der lokalen Betriebshöfe unmittelbar verbundene Deutung zu ermöglichen. Von diesen Vorzeichen ausgehend wurde eine kritische Lesart des Verhaltens dieser Flächen möglich, indem ihre derzeitige Verwendung derjenigen der gesetzlichen Anforderungen entgegengestellt wurde. Aus der vorliegenden Untersuchung ergeben sich als wesentliche Schlüsse: Eine vertiefte Untersuchung über die Naturschutzgebiete ist dringend und erforderlich, um einen neuen Gesetzesvorschlag zu erarbeiten, der effektive Fachparameter zur Bestimmung der Naturschutzgebiete festlegt und der gleichzeitig die Entwicklung von Untersuchungen anstrebt, die darauf zielen, alternative nachhaltige Nutzungsalternativen für diese Flächen vorzulegen; Beurteilung der Schutz- und Erhaltungskonzeptionen in der Absicht, dass letztere eine breite Palette von Vorteilen für die kleinen landwirtschaftlichen Betriebshöfe in dem Maβe mit sich bringen, wie die Bodenschutzmaβnahmen zum Ausgleich der Natur beitragen und in der Erzeugung dieser Betriebshöfe einen reellen Gewinn erbringen. Schlieβlich legen wir eine Reihe von Studien vor, die in der Absicht einer Vertiefung der von uns erforschten thematischen Diskussion verfolgt werden können. / O processo histórico de uso e ocupação da terra, baseado no desflorestamento e no manejo desordenado do solo, tem gerado conflitos entre os objetivos de recuperação ambiental e de reprodução socioeconômica dos agricultores assentados sobre áreas de elevadas restrições ambientais. Esta dicotomia reflete-se na atualidade através da aplicação mais efetiva da legislação ambiental, principalmente, do Código Florestal brasileiro, instituído pela Lei Federal n. 4.771 de 1965, que trata das Áreas de Preservação Permanente, APPs, que são as faixas marginais aos corpos hídricos que devem ser devidamente preservadas e mantidas com vegetação nativa. A discussão apresentada pelo presente estudo está pautada no questionamento das medidas geométricas contidas na definição das APPs nesse instrumento legal, buscando apresentar uma metodologia para a definição destas áreas a partir de elementos da geomorfologia fluvial, além daqueles relacionados com a cobertura vegetal de entorno. Para chegar aos resultados desse estudo se apresenta uma retomada histórica do processo de ocupação da Região Noroeste do Rio Grande do Sul, na qual se inserem as áreas amostrais, faz-se uma leitura teórica sobre conservação da natureza em nível mundial e discute-se as APPs em três níveis de análise para o Brasil: a) o arcabouço jurídico que está posto; b) o uso destas áreas e c) o estado da arte em que elas se apresentam no noroeste do Rio Grande do Sul. A discussão da função social da propriedade rural é vista como ponto importante desta discussão, por ser a partir dela que se dá todo o processo de responsabilização pela preservação ou não das APPs. Neste sentido, buscamos também compreender como o Ibama, a Fepam e o Ministério Público Estadual se posicionam e desenvolvem as suas atividades frente à temática colocada. Definimos como áreas piloto para a aplicação da metodologia proposta, três setores do Rio Santo Cristo, para os quais definimos os diques marginais e as planícies de inundação como parâmetros para a definição das APPs. Da mesma forma, avaliamos a estrutura fundiária da região para possibilitar uma leitura diretamente relacionada com o tipo de propriedade existente no local. A partir destas definições foi possível estabelecer uma leitura crítica das características dessas propriedades, comparando o seu uso atual com as exigências legais. Ficam como principais conclusões do presente estudo: a) que é urgente e necessário um estudo mais aprofundado sobre a questão das APPs para que seja possível apresentar uma proposta de alteração da legislação que busque parâmetros técnicos efetivos para a definição das APPs; b) que se busque igualmente o desenvolvimento de estudos que objetivem apresentar alternativas de uso sustentado para estas áreas; c) que se avaliem os conceitos de preservação e conservação com o intuito de compreender que o último traz uma grande gama de benefícios para as pequenas propriedades rurais, na medida em que as práticas conservacionistas auxiliam no equilíbrio da natureza e trazem um ganho real na produção destas propriedades. Por fim, apresentamos um conjunto de estudos que podem ser realizados com o intuito de aprofundar as discussões da temática por nós pesquisada. / The historic land grab and land usage process based on deforestation and disorderly land management caused conflicts between environmental cleanup and socioeconomic reproduction of the farmers settled on areas that underlie strict environment restrictions. This dichotomy at present gets evident in the application of the environmental legislation, particularly the new Brazilian Forest Code entitled by the federal Law No. 4.771 of 1965, when it involves permanent nature reserve (APPs), that is, marginal stripes along water corps that must be preserved with the associated original vegetation. The discussion herewith stated is based on the closer examination of the geometrical measures of the definition of the permanent nature reserves trying to present a method for the definition of theses areas out of the elements of the fluvial geomorphology. To reach the result, we make recourse to the historical land grab process in the northwestern region of Rio Grande do Sul, to which belong the areas herein studied. We make a theoretical interpretation of nature conservation at international level and discuss nature reserves at three study levels for Brazil: the given legal framework; the usage of these areas; and their conditions in northwest Rio Grande do Sul. The discussion of the social function of the farms is seen as an important aspect of this discussion because thereof happens the responsibleness for the conservation or not conservation of the preservation areas. We also study the positioning of Ibama, Fepam and prosecution in this question. We determinate three segments of the Santo Cristo river as pilot areas for the application of the proposed methodology, wherefore we defined natural levee and floodplains as patterns for the definition of nature preservation areas. We did also evaluate region’s estate to allow an understanding directly related to the kind of local property. These definitions allowed us establishing a critical understanding based on the behaviour of these areas comparing their current usage to the legal demands. The most important conclusions of this study are: 1) a deeper study of nature preservation areas urges and is necessary to allow the presentation of a new legal proposal that looks for effective technical patterns for the definition of nature reservation areas; 2) that one also tries to develop studies that try to show alternatives of sustainable usage of these areas; 3) that preservation and conservation concepts get evaluated with the intend to understand that this brings a wide scope of benefits to the small farms thus far as the conservation practices help to stabilize nature and to carry a real gain in the production of these farms. Finally we present a scope of studies that can be done with the aim of deepening the discussions of the question here studied.
83

Protected area management and environmental decision-making : the case of Dlinza Forest Nature Reserve, KwaZulu-Natal.

Malaza, Khethiwe. January 2004 (has links)
Colonial conservation emerged as colonial conservationists perceived the threat of deforestation, climatic change and famine. The sense that there were limits to nature's capacity to meet human demands, led to colonial conservationism which portrayed nature as separated from human life. Protected areas (PA's), both forest and game reserves, were created that excluded local people in terms of both access and management. In South Africa the National Forests Act 84 of 1998 has created new conditions in which there is a greater opportunity for communities to benefit from indigenous forests, which apart from their other uses are a valuable resource from the point of view of ecotourism. This study thus seeks to assess moves from exclusivist to community based forms of environmental decision-making (EDM) at Dlinza Forest Nature Reserve. This study provides an example of an ecotourism project started during the democratic period in South Africa and at the height of the global move to community conservation. First however it traces the management history of the forest in order to assess change in the management style over time. The study investigates rural people's attitudes towards the forest and it was found that although the forest was preserved for many years, the rural people still feel much attached to it as a result of the beliefs they have about it. The study contrasts different visions of the forest in terms of competing use and non-use values, and demonstrates that each group exercised its will and attempted to display "ownership" of the forest through a number of activities undertaken at the forest. An analysis of the public participation followed in terms of the ecotourism project was undertaken to determine the extent to which the rural community was involved. Theoretical models of environmental decision-making were applied in order to identify the mode of decisionmaking used historically and in the present. The results of the study show that poor rural people are still marginalized in EDM despite the new philosophies of PA management and the democratising shifts taking place in the country. Resistance to the policies and regulations of the reserve has been observed and this may lead to severe degradation of the resources that the reserve is meant to protect. The study thus recommends strengthening locally based EDM via partnerships as partnerships do not only provide relief for the consequences of conflict, they also strive for a win-win situation. The study concluded that greater involvement of the rural community requires a change in the mindset of conservation authorities, in particular with regard to the issue of representivity in EDM. / Thesis (M.Sc.)-University of Natal, Durban, 2004.
84

Land suitability evaluation for rainfed agriculture using GIS : the case study of Weenen Nature Reserve, KwaZulu-Natal, South Africa.

Ghebremeskel, Legesse Abraham. January 2003 (has links)
Weenen Nature Reserve (WNR) has a long history of unwise land use that resulted in severe overgrazing and soil degradation. Since 1948 several soil conservation and reclamation programs have been undertaken to halt the degradation process and regain the agricultural potential of the area. This study evaluates the current agricultural potential of the reserve under rainfed cultivation primarily based on climatic, soil, topographic and crop requirement data collected from different sources. Spatial information on each of the land resources parameters was digitally encoded in a GIS database to create thematic layers of the land resources. Crop requirement information on seven different crops that were selected as representative crops under rainfed agriculture in the area namely, maize, Sorg):mm, cotton, dry bean, soya bean, potato and cabbage was compared with the land resources parameters. The thematic layers of the land resources were then overlyed using a GIS to select areas that satisfy the crop requirements. The results showed that WNR has two major limitations in relation to its use for rainfed agriculture, namely its shallow and rocky soils and its arid climate. Consequently, the resulting land suitability maps indicate that WNR has very low suitability for all of the crops considered. Dry beans are relatively well adapted to the area followed by sorghum. Maize and soya beans are preferred over cotton. Potatoes'and cabbages are least adapted to the area because of the high temperatures during thCl/growing season. It was concluded that generally the reserve is not suitable for rainfed agriculture. However, there is a small area of land in the northern part of the reserve that can be cultivated. The rugged area in the central part of the reserve can be used for grazing with careful managemeIit. The eastern and southern parts can only be used as habitats for wildlife owing to their steep topography and inaccessibility, whereas the highly degraded areas in the western parts of the reserve should be kept under soil conservation and reclamation. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2003.
85

Re-vegetation dynamics of land cleared of Acacia mearnsii (black wattle)

Glaum, Melanie Jane. January 2005 (has links)
The overall aim of the study was to investigate re-vegetation of disturbed sites, using nursery grown plugs (from seedling trays) of Themeda triandra, Heteropogon contortus and Hyparrhenia dregeana in order to reach practical management guidelines for re-vegetation using indigenous grass plugs. A number of field trials were set up at Kamberg Nature Reserve (29°24'S, 29°40'E) on a site that was clear felled of A. mearnsii in October 1997. The trials were established in January 1998 and January 1999. A total of approximately 52 ,000 nursery raised plugs of T. triandra, H. contortus and H. dregeana were planted into an area of approximately 7,000 m2 . In the planting density trial , plugs of H. dregeana only and a combination of T. triandra/H. contortus were planted at 15 cm and 30 cm spacings. The T. triandra/H. contortus combination at 30 spacing showed the greatest survival and lateral plant growth (tiller number and basal area) and this combination is thus recommended. In the over-sowing trials, the H. dregeana and T. triandra/H. contortus combination at both 15 cm and 30 cm spacing were over-sown with E. curvula. The survival and lateral growth of the T. triandra/ H. contortus combination at 30 cm was again greater than the other treatments. Over-sowing with E. curvula suppressed the survival and lateral growth of the planted plugs across all treatments compared to not over-sowing. The over-sown conditions showed a significant decrease in the diversity of the plots, both in the number of species present and the Shannon diversity index. An area that had been cleared of A. mearnsii and sown to E. curvula 25 years previously was shown to have a lower number of species than the neighbouring veld. Nursery raised plugs of T. triandra were planted into the mature E. curvula in an attempt to improve the biodiversity of these areas. To re-introduce T. triandra into these E. curvula swards the plugs must be planted into the centre of a gap rather than around the base of an E. curvula plant. For improved survival of the plugs the E. curvula tufts must be clipped, while for best lateral growth the E. curvula tufts must be sprayed with a glyphosate herbicide three months prior to planting and clipping. However, the added expense of spraying and clipping is not warranted as the clipped treatments also showed good growth. Transplant shock is common when planting nursery raised plugs out into the field, as there is a relatively small root volume in the plug compared to the above ground leaf biomass. Alleviation of moisture stress at planting using a starch based polymer with high water holding capacity (Terrasorb®) and a white, needle punched geo-fabric (Agrilen®) to provide a seven day period of artificial shade after planting did not show significant improvements over the control with regards to survival or plant growth. Thus these methods of moisture amelioration are not recommended in revegetation through planting of plugs at this study site. A trial was established to investigate the biomass production of six different treatments to determine their potential to support a fire. The total biomass for the plots which were over-sown by E. tef and planted to only H. dregeana were on average sufficient for a fire, but there was a discontinuous fuel load across these plots, especially in the replications that had very low survival rates and thus these plots could not be burnt. The control and herbicide sprayed plots also showed sufficient fuel load for a fire, but this fuel load was made up of A. mearnsii saplings and bramble with very little grass cover and thus a fire would not have burnt through these plots either. The T. triandra/H. contortus combination did not produce sufficient fuel load, due to poor survival. Thus only the plots over-sown with E. curvula were able to burn in this trial and as a burning trial per se the trial was abandoned. Seed bearing hay (thatch) was collected in early summer (December 1997) and late summer (April 1998). Both times of year of harvesting proved to be successful in terms of grass cover, although the early harvested thatch had a greater number of species per plot. The Shannon diversity indexes of the two treatments were not significantly different. The multi-response permutation procedure technique confirmed that there was a compositional difference between the treatments. By the end of the trial Harpochloa falx and T. triandra and H. dregeana were indicators for the early and the late harvested thatch respectively. Comparing the thatching trial and the planting density trial indicated that the T. triandra/H. contortus combination at 30 cm spacing would be recommended to maximize biodiversity. The summer months have been shown to be the best time to plant the plugs, although the actual success will be dependant on the conditions within a particular year. The plugs should not be kept in the nursery for longer than three months and larger plugs (96 seedlings per tray) should be used. Nursery raised plugs of T. triandra and H. contortus were planted in an equal mix in an area that was cleared of A. mearnsii in 1996. By June 1998 661 H. contortus seedlings and 14 T. triandra seedlings had germinated naturally. The November 1998 population consisted of 418 H. contortus seedlings and 18 T. triandra seedlings. By May 2000 the June 1998 population showed a survival of 78.4% and the November 1998 population showed a survival of 91 .1 %. In the various trials, the ability of the nursery raised plugs used for re-vegetation to suppress the regrowth of A. mearnsii was investigated by determining the number of A. mearnsii seedlings per metre squared. The plant spacing and species of plugs used did not have a significant effect on the number of A. mearnsii seedlings per metre squared. Over-sowing with E. curvula did, however, significantly suppress the wattle re-growth. In the thatching trial the early harvested plots showed lower numbers of A. mearnsii per metre squared than the late harvest plots, as they were covered with a thick layer of thatch soon after the A. mearnsii was cleared which suppressed the A. mearnsii re-growth. Although E. curvula is able to produce a high biomass and suppress the A. meansii seedlings, it has a detrimental effect on the biodiversity of the area. Therefore, in conservation areas, where biodiversity is of great importance the planted plugs (at 30 cm spacing) or seed bearing hay must be used in preference to sowing E. curvula , although it must be remembered that greater follow up control is likely to be needed with planted plugs or seed bearing hay. The area must be planted or thatched as soon as possible after clear felling to provide competition for the A. mearnsii seedlings. / Thesis (M.Sc.Agric.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.
86

Land restitution and conservation : social capital in the Mkambati community.

Zeka, Sandile. January 2013 (has links)
This study highlights the role social capital plays in promoting relationships within and between organizations so that they are able to act with common cause. For years relationships between parks and local communities have hinged upon access to, and use of natural resources that are more abundant within parks. Contestation over these resources has overtime led to covert, and in most cases open conflict between these two stakeholders in conservation. Intrinsic in relationship building is social capital. Using the case of the community of Mkambati this study presents both historical and, as developed in recent organizational studies, mental models as critical variables through which social capital evolves and sustains itself within organizations. The argument advanced in this study is that social capital plays an important factor in helping previously displaced communities to regain their land. Relationships play a pivotal role in bonding people, communities, and organizations. Secondly, this study provides a historical perspective of the role played by the community of Mkambati in challenging dispossession of their land. Since the expropriation of their land, the community of Mkambati has relied on bonding social capital in their resolve to regain this land. As this study demonstrates, trust, reciprocity, solidarity and empowerment are some of the properties of social capital that have bonded the community of Mkambati in the struggle for the restitution of their land. The success of the community of Mkambati in regaining their land is also attributed to this community’s resilience to withstand challenges it faced through its protracted battle to have its land back. This resilience, as this study demonstrates emanates from this community’s reliance on social capital. Also, and equally important, the robustness of the community of Mkambati to resist change is founded on relational capital drawn from the shared mental model of injustice – the wish to have their land back. This relational capital was continuously reinforced by the actions this community resorted to achieve this goal. Land restitution and the emergence of a democratic government made redundant the strongly shared mental model that bound people together for many years. With the return of the land to the people of Mkambati, many new opportunities arose around access to, and use of resources. These opportunities are framed as mental models so that whereas in the past the people held a shared mental model, now they differ among themselves according to their preference for access to, and use of resources. It is suggested that, if not managed, opportunistic behaviour could lead to the privatization of resources and an erosion of the present common property regime and a weakening of a community social capital. On this understanding it is prudent for the community of Mkambati to instil a new shared mental model that will enable this community to use relational connectedness and relational capital to enhance collaborative behaviour necessary for the community’s realization of opportunities associated with the return of common property through land restitution. This study highlights the importance of understanding the role of mental models in sustaining social capital and directing collective action. This study suggests that particularly in the context of common property, explicit attention should be given to understanding the diversity of mental models held by stakeholders, and to a process that constructs and sustains a strategic shared mental model. This is because mental models are perceived to provide a foundation for social learning which is necessary to sustain social capital that promotes collective action within the community. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2013.
87

Influence of drought or elephant on the dynamics of key woodland species in a semiarid African savanna.

MacGregor, Shaun Donovan. January 2000 (has links)
Extensive drought - and elephant-related dieback of Colophospermum mopane and Acacia tortitis, respectively, offered an opportunity for increasing understanding of the causes of drought-related patch dieback, the factors influencing elephant utilization of woody plants, and the response of woody plants to both aforementioned determinants of savanna structure and function. The dendrochronological analysis of both species was undertaken to estimate potential rates of replacement, following extensive mortality. Areas of discrete dieback were compared with adjacent paired areas of 'healthy' vegetation, which revealed, on average, 87% and 13% loss of basal area by mortality, respectively. 'Live' and 'dead' plots did not differ in soil type, topography or mean slope, but differed in vegetation structure, soil surface condition, and soil chemistry. Although there was evidence of self-thinning, neither inter - nor intra-specific competition explained dieback. 'Dead', by comparison with 'live' plots, had changed from functioning as sinks of sediment and water to sources, were less likely to retain water because of a poor soil surface condition, and were predisposed to drought effects because of a greater proportion of fines, and Na concentration. Dieback resulted from insufficient soil water for survival during a drought owing to the development of a dysfunctional landscape during 50 years of livestock ranching. Spatial heterogeneity within a landscape was suggested to enhance woodland resilience to severe droughts by ensuring the survival of plants in run-on sinks or 'drought refuge' sites. Stem sections were removed from 40 multi-stemmed C. mopane trees and prepared for examination under a dissecting microscope. It was impossible to age C. mopane, owing to a hollow and/or dark heartwood. Nevertheless, the distribution of stem diameters suggested a single recruitment event. Fire scars attributed to the last recorded fire in 1948 could explain the trees' multi-stemmed growth form and indicate that most trees of VLNR were > 50 years of age. Growth rings were identified in 29 A. tortilis trees of unknown age, but were not correlated with annual rainfall records. Growth rates varied between trees; mean ring width ranged from 1.4 to 3.5 mm (overall mean 2.4 ± 0.1 mm). A technique was proposed for predicting growth rate from annual rainfall, using selected data, and several factors potentially influencing ring width in semiarid environs were identified. Permanent ground-based transects were located within riparian (n = 16) and Acacia (n = 5) woodlands to monitor elephant utilization. Elephant had not changed the population structure of the woodlands by 2000, but had reduced stem density from 215.6 stems ha -1 (1996) to 84.4 stems ha -I (2000). Acacia tortitis trees in the woodlands had branches removed, were debarked, uprooted and broken. Acacia tortitis trees in the riverine had lower levels of utilization, whilst Acacia nilotica trees were mostly debarked. The method of elephant feeding varies within and between woody species, provided it is within the mechanical constraints of a certain size or species. Elephant behaviour is concluded to depend on spatiotemporal variation of forage abundance/quality, abundance of a preferred species, and species response (coppice or mortality). Elephant can cause a change of vegetation state, and increase spatial homogeneity of a plant population. The remnant population of woodland trees should provide the potential for recolonization, in which case the system would reflect the stable limit cycle. However, if browsing inhibits seedling recruitment, the system could reflect either a multiple stable state system or an artificial equilibrium imposed on a stable limit cycle. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2000.
88

Metagenomic discovery and characterisation of restriction endonuclease from Kogelberg Biosphere Reserve

Mtimka, Sibongile 05 1900 (has links)
Restriction endonucleases are a group of enzymes that cleave DNA at or around specific sequences, which are typically palindromic. A fosmid library was constructed from a metagenome isolated from soil from the Kogelberg Nature Reserve, Western Cape and was functionally screened for restriction endonucleases. Next-generation (NGS) Illumina sequencing technology was used to identify putative endonucleases. The sequence data generated was assembled and analysed using CLC Bio Genomics Workbench and bioinformatics tools (NCBI BLAST, REBASE and MG-RAST). Using these tools, genes encoding restriction-modification systems and endonuclease homologues were discovered. Three genes were identified and were recombinantly produced in Rosetta™ (DE3) pLysS and purified with IMAC using Ni-TED resin and subsequently characterised. These three genes were selected based on the identity percentage when compared to sequences on the NCBI database. Production of Endo8 was scaled up using 2 l fermenter and the purification done using ÄKTA Avant 150 FPLC using a HiScale 50 column packed with Ni-TED resin and the total amount of protein achieved was 58.82 mg.g-1. The productivity achieved at 17 hours (8 h harvest) was 2-fold greater than at 12 hours. Endonuclease activity of endo8 and endo52 was tested, both exhibited strong non-specific activity at 37 °C with an incubation period of 30 min. This work demonstrates that environmental soil samples are a valuable source for discovery of novel enzymes and also the utility of functional metagenomics to discover and purify these enzymes. These endonucleases may contribute to the next generation of reagent enzymes for molecular biology research. / Chemistry / M. Sc. (Life Sciences)
89

Bergsgorillorna i Rwandas Volcanoes National Park : Turism under extrema förhållanden - en studie om ekoturism & hållbar utveckling

Immanuel, Jenling, Mugisha, Hafsa January 2018 (has links)
This study examines the impact mountain gorillas has on the sustainable and developmental life of the Volcanoes National Park (VNP) in Rwanda. The study is equally based on the on psychosocial perspectives as it concerns the behavior of the population. It emphases on how ecotourism works and how it affects the mountain gorillas on the nature reserve. The study also investigates the impact of ecotourism with regards to the locals, society and the country using research that has been previously carried out.   The study's findings show that the revenue-sharing system from mountain gorilla tourism activities has changed local communities view on ecotourism both positively and negatively through opportunities and weaknesses in sustainable development. In addition, the study shows the government's ongoing commitment to improving and maintaining the eco-tourism sector by diversifying its activities. It shows that the government of Rwanda has included conferences, ceremonies, and tours in its ecotourism efforts that further provides variation for visitors so that tourism develops throughout the country. / Denna studie undersöker bergsgorillornas påverkan utifrån ett hållbarhets- och utvecklingsperspektiv i Volcanoes National Park (VNP) i Rwanda. Studien utgår från ett psykosociolaperspektiv, hur ekoturismen fungerar och påverkar bergsgorillorna i VNP. Studien undersöker även med hjälp av tidigare forskning; vilka konsekvenser som tillkommer med ekoturism med avseende på lokalbefolkning, samhället och landet. Studiens resultat visar att intäktsdelningsystemet från bergsgorillaturismen har förändrat lokala samhällen både positivt och negativt genom möjligheter och svagheter i hållbarutveckling. Studien visar regeringens ständiga åtaganden att förbättra och upprätthålla ekoturismsektorn genom att diversifiera verksamheten. Rwanda har inkluderat konferenser, ceremonier och turer i sin ekoturism som ytterligare ger variation för besökarna så att turismen utvecklas i hela landet.
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An investigation of the potential role for environmental education in the conservation of the Swartkops estuary and Swartkops Nature Reserve

Kitson, Brian Anthony Austen January 1994 (has links)
This study explores the potential role of an environmental education approach towards the conservation of the Swartkops Estuary and Swartkops Nature Reserve. More specifically it examines the opinions, feelings and perceptions of a sample of twenty seven people, who have a vested interest, in the possible conservation of the area. These stakeholders were comprised of people representing all the various groups and communities that use either or both the estuary and reserve. Opinions were examined by means of a qualitative data analysis from semi-structured interviews. The conservation opinions of respondents were obtained on both general topics and more detailed areas. Due to the small sample and exploratory nature of the project, these results should be viewed as tentative. Proposals are made for increasing the impact of Environmental Education programmes in this and similar environments, and recommendations are put forward to help facilitate related studies in the future.

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