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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.
91

Resource quantification, use and sustainable management of coastal forests in the eastern Cape province.

Obiri, John Angoro Festus. 17 December 2013 (has links)
Indigenous forests of South Africa are few, small in size and highly fragmented, yet they face intense exploitation particularly in the rural areas. Management of these forests is challenging. High rural dependency on forests and the need to ensure the maintenance of the forest ecological processes that maintain biodiversity and ecosystem integrity are at odds with one another. Rural needs from forests are mainly short-term and interfere with the longer cycle of ecosystem maintenance. In Umzimvubu District of Eastern Cape Province forest management through sustainable use is hampered by a lack of information about the forests' ecology, resource availability and exploitation patterns. Thus it is difficult to set quotas or sustainable harvesting levels. This study addresses these challenges by tackling crosscutting themes of (1) forest policy and use, (2) forest resource availability and exploitation and, (3) the ecological processes of forest regeneration - all vital components for sustainable forest management. Using questionnaires it was found that all forest stakeholders (i.e. forest resource users and managers) were opposed to a ban on forest resource use but agreed to regulated harvesting. Although the new forest policy advocates the devolution of forest management from the state to communities, resource users preferred a greater role for the state in forest management than expected. Given the choice stakeholders selected state forest management over community forest management. However, the combination of roles of the state and communities in forest management, as exemplified by the new policy of participatory forest management (PFM) is probably the most applicable management practice, although it is not without its problems. Tree species are the focus of this study. Trees were largely used for fuelwood, medicinal purposes, craftwork, fencing posts and building poles and involved twenty species. Poles and posts were indiscriminately harvested from the medium (10-20cm dbh) tree size-class. Fuelwood harvesting was selective and only certain species were used. Fuelwood harvesting is unsustainable because the average amount of deadwood produced by the forest marginally balanced that removed from forest as fuelwood. Similarly medicinal tree harvesting (largely through stem debarking) was unsustainable and at least 28% of the debarked trees died. Only one species (Macaranga capensis) could withstand the current stem bark harvesting pressure. Species suitable for pole and post harvesting were determined by a graphic method, based on linear-programming approach that examined the spatial scale or grain of regeneration of a species. The grain of a species is established by comparing the density of stems from a species at the forest canopy and sub-canopy levels and sanctions harvesting only if a species was adequately represented at both levels i.e., fine-grained. Only one species (Englerophytum natalense) met these requirements in all forests and could sustain high levels of pole and post exploitation. Harpephyllum caffrum and Heywoodia lucens are among the most coarse-grained species and their use is discouraged. A relatively high percentage of the forest is under gaps (7.8%) created via natural disturbances of windthrow (50%), breaking tree branches (20%) and snags (13%). Another 17% result from selective tree cutting activities. The gap-phase dynamics paradigm appears to play a minor role in forest tree regeneration, as gap-size niche-differentiation is weak and there is no gap-filling guild of pioneer species. A lottery paradigm best explains tree regeneration in gaps in the forests of Umzimvubu District. Although selective tree harvesting creates gaps, in moderation gap creation is unlikely to change the forests' species composition since there is no gap-filling guild that is favoured by gaps and recruitment is a chance event. Resource use in the forests of Umzimvubu District is unsustainable and PFM offers a viable option for managing these forests. Sustainable use of forest cannot be achieved without an integration of the multifaceted social and ecological issues of forest management and more importantly without prioritising and understanding the ecology of forests. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 2002.
92

Conserving forests : a biophilosophical analysis of the Durban region.

Mattson, M. C. January 1993 (has links)
Coastal forests are a significant component of the remaining natural vegetation in the greater Durban area. Being closely associated with an historical and rapidly developing urban environment, these forests are invariably small, isolated and variously disturbed. The nature of disturbance as an ecological phenomenon, coupled with unknowable disturbance histories and ongoing disturbance events poses particular challenges to traditional and tradition-bound attempts to understand and manage such forests. The intention of this study was to discuss as deeply as possible the nature of such challenges, while at the same time considering the broader relevance of practising ecology in the urban environment. At a practical level the forests were sampled in an attempt to describe forest communities, to assess the effects of disturbance on them, and to gain insight into the effects of different disturbance histories and regimes on forest physiognomy and floristics with a view to proposing management guidelines. Various descriptive approaches, as well as a multivariate analysis using Detrended Correspondence Analysis were used in an attempt to interpret the data collected. The unsatisfying nature of the data led the thesis to propose a review of the paradigm in which its methods were rooted. Both the data, and the broader issues on which the thesis touched were discussed in terms of biology's rootedness in philosophical assumptions. This led the thesis to a methodological position aligning it both epistemologically and ontologically with a philosophical method of investigation called phenomenology. While other philosophical contentions were touched upon, the main conclusion of the thesis was that phenomenological thinking, while challenging to apply, was relevant to philosophically mature and methodologically appropriate attempts to conserve the forests with which the thesis was concerned. / Thesis (M.Sc.)-University of Natal, Durban, 1993.
93

Reconciling Land Restitution and Conservation: Challenges Facing the Implementation of Land Restitution in the Dukuduku Forest, KwaZulu-Natal.

Gonyora, Ruvimbo. January 2010 (has links)
In order to have a fuller understanding of the policy implementation challenges facing land restitution in conservation areas, this research identifies and analyses the perspectives in the literature on policy implementation. The study explains how the land restitution programme emerged as a policy solution to the legacy of a deep historical racial divide regarding land ownership in South. Africa. However, it explores the implication of this on the conservation of the environment. The study shows that reconciling land restitution on conservation areas is a complex process, owing, partially to two different and conflicting policies namely the, Restitution of Land Rights Act (Act 22 of 1994) and the National Forest Act (Act 84 of 1998). The researcher has explored the policy implementation challenges encountered in reconciling land restitution in the Dukuduku forest located within the Greater St Lucia Wetland Park which has official World Heritage Site status situated in northern KwaZulu-Natal. The study should show how the ongoing conflict between Department of Water Affairs and Forestry, the Department of Environmental Affairs and Tourism and the occupants of Dukuduku forest revolves around issues of land ownership pertaining Dukuduku forest, a forest which is one of the few indigenous forests left in South Africa. It concludes that policy implementation is a complex process, especially when two divergent policy objectives Restitution of Land Rights Act (Act 22 of 1994) and the National Forest Act (Act 84 of 1998) and are sought. A formulated conceptual framework for the study, public policy analysis and policy implementation models will be discussed to provide a clear perspective on policy implementation.
94

The invertebrates of indigenous forests in Limpopo province South Africa : diversity, biogeography and conservation.

Horn, Johanna Lynn. January 2004 (has links)
In this study I investigated patterns of invertebrate diversity in Limpopo Province indigenous forests, in order to highlight forests and taxa of special conservation significance. Invertebrates from seven target taxa were sampled in 11 patches of indigenous forest in Limpopo Province from February 2001 to January 2002, including six forests in the Soutpansberg and five forests in the northern Drakensberg. Selected forests comprise three distinct vegetation subtypes and the target taxa selected were millipedes, centipedes, earthworms, terrestrial molluscs, spiders, scorpions and amphipods. Invertebrates were sampled by active searching of quadrats and line transects and pitfall traps. A total of 11 969 indigenous target group individuals were sampled, comprising 14 orders, 50 families, 86 genera and 142 species (including at least nine new). There was a significant difference in the total invertebrate species richness and diversity of forest patches but results varied considerably when different target group figures were analyzed. With the exception of spiders, the factors influencing total and individual target group richness in forests could not be determined. Introduced invertebrates comprised a large proportion of the species and individuals sampled, but were not shown to affect indigenous fauna. Invertebrate species assemblages were most similar between forests sharing the same vegetation subtype and between forests in the same mountain region. However, each forest patch had unique species and some even had unique families. Limpopo Province forests support high numbers of endemic invertebrates. A total of 47 endemic invertebrate species were sampled, including six site endemics, eight local endemics, nine regional endemics and 24 national endemics. The numbers and scales of endemism varied by target group. Invertebrate species’ distributions in Limpopo Province forests generally support the biogeographic theories of Pleistocene forest refugia and the Limpopo River valley as a radiation barrier, although some important contradictions were found. Local endemism in Limpopo Province forests is likely the product of historical processes. Although some significant relationships were found between surrogate and true measures, single taxon biodiversity indicators, the higher taxon method, morphospecies and land classes could not accurately predict patterns of target invertebrate species richness in Limpopo Province forests. Results show that formal species identification should be used if accurate richness estimates are desired; the use of surrogates is not supported by this study. Conservation of Limpopo Province forests is vital for the preservation of valuable invertebrate communities. No forest sampled in this study can be considered unimportant. Effective forest conservation and management is dependent upon the protection of forests of varying patch size, careful evaluation and control of utilization and the establishment and maintenance of corridors linking isolated forest patches. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2004.
95

The impacts of herbivores and humans on the utilisation of woody resources in conserved versus non-conserved land in Maputoland, northern KwaZulu-Natal, South Africa

Gaugris, Jerome Yves, January 2008 (has links)
Thesis (Ph. D.)--University of Pretoria, 2008. / Title from PDF title page (viewed on Nov. 11, 2008). Includes bibliographical references.
96

Development of a multi-scale management perspective for wadeable stream fisheries in Mississippi

Alford, John Brian, January 2008 (has links)
Thesis (Ph.D.)--Mississippi State University. Department of Wildlife and Fisheries. / Title from title screen. Includes bibliographical references.
97

Seeing the Forests for the Tourists: Forest-Based Entrepreneurial Tourism Enterprises in the Northeast

Hummel, Brittany Ann January 2008 (has links) (PDF)
No description available.
98

Nichos bioclimáticos e predição do impacto de mudanças climáticas sobre as distribuições geográficas de Ilex paraguariensis A.St.-Hil. e Mimosa scabrella Benth / Bioclimatic niches and prediction of climate change impac on geographic distribution of Ilex paraguariensis A.St.-Hil. and Mimosa scabrella Benth.

Silva, Mariéle Alves Ferrer da 08 July 2016 (has links)
Submitted by Claudia Rocha (claudia.rocha@udesc.br) on 2017-12-08T12:55:20Z No. of bitstreams: 1 PGEF16MA064.pdf: 123055 bytes, checksum: 5b8c73da9e2d7b658129f69b87b92d37 (MD5) / Made available in DSpace on 2017-12-08T12:55:20Z (GMT). No. of bitstreams: 1 PGEF16MA064.pdf: 123055 bytes, checksum: 5b8c73da9e2d7b658129f69b87b92d37 (MD5) Previous issue date: 2016-07-08 / FAPESC / The present study aimed to model the bioclimatic niche of Mimosa scabrella and Ilex paraguariensis and to predict the impact of climate change on potential distribution of these species. The geographic coordinates of species occurrence were extract from LABDENDRO/UDESC database, from published scientific papers, and from SpeciesLink database, from the reference Center on Environmental Information (CRIA). A total of 19 bioclimatic variables and altitude from the occurrence sites were obtained from the Wordclim database. The modelling of bioclimatic niches was performed through ten algorithms: Generalized Linear Models (GLM), Generalized Boosting Model (GBM), Generalized Additive Models (GAM), Classification trees (CTA), Artificial Neural network (ANN), BIOCLIM, Discriminant Analysis (FDA), Multivariate adaptive regression splines (MARS), Random Forests (RF) and maximum entropy (MAXENT). The fits qualities were verified trough TSS statistics, with the prediction of spatial distribution of species built from the consensus of fits with TSS > 0.85. For future predictions, a best (RCP4.5) and a worst (RCP8.5) climate change scenarios were considered in 2070, based on the fifth IPCC report. For the projections of these scenarios, the HADGEM2-ES atmospheric circulation model was used. All data analyses were conduct using R statistical program language, with the packages dismo, raster, USDM and biomod2. The results indicate that Ilex paraguariensis and Mimosa scabrella presented a phytogeographic distribution associated with the Atlantic Domain. In the worst case climate change scenario Ilex paraguariensis and Mimosa scabrella presented a reduction of 15 and 19.5% in its respective potential occurrence areas. The southern and southeastern high altitude areas, such as those located at the top of Serra Geral, Serra do Mar and Mantiqueira ranges, stood out as strategic areas for the conservation and sustainable management of these two species, since these areas present the highest values of probability of occurrence for both species in the present and in the future / O presente estudo teve como objetivo principal a modelagem do nicho bioclimatico de Mimosa scabrella e Ilex paraguariensis e a predição do impacto de mudanças climáticas sobre a distribuicao potencial das mesmas. As áreas de ocorrência foram definidas a partir das coordenadas geográficas das espécies, determinadas a partir de informações contidas no Banco de Dados do LABDENDRO/UDESC, de trabalhos publicados na literatura científica e de pontos de georreferenciamento de ocorrência do banco de dados SpeciesLink, do Centro de Referência em Informação Ambiental. Foram consideradas 19 variáveis bioclimáticas e altitude das áreas de ocorrência, obtidas a partir da base de dados do Wordclim. A modelagem dos nichos bioclimáticos foi realizada por meio de dez algoritmos: Modelos Lineares Generalizados (GLM), Generalized Boosting Model (GBM), Modelos Aditivos Generalizados (GAM), Árvores de Classificação (CTA), Rede Neural Artificial (ANN), BIOCLIM, Análises Discriminante Flexível (FDA), Multivariate adaptive regression splines (MARS), Florestas Aleatórias (RF) e Máxima Entropia (MAXENT). A qualidade dos ajustes foi verificado por meio da estatística TSS, de forma que a predição da ocorrência espacial das espécies foi realizada a partir do consenso dos ajustes com TSS > 0,85. Para predições futuras, foram considerados cenários de mudanças climáticas mais (RCP4.5) e menos otimista (RCP8.5) no ano de 2070, com base no quinto relatório do IPCC. Para as projeções destes cenários utilizou-se o modelo de circulação atmosférica HADGEM2-ES. Todos os dados foram analisados no ambiente de programação estatística R, junto com as bibliotecas USDM, dismo, raster e biomod2. Com os resultados obtidos foi possível observar que Ilex paraguariensis e Mimosa scabrella apresentam uma distribuição fitogeográfica associada ao Domínio Atlântico. No pior cenário de mudanças climáticas Ilex paraguariensis e Mimosa scabrella apresentaram uma redução de 15 e 19,5% em suas respectivas áreas de ocorrência potencial. Em se tratando de áreas estratégicas para a conservação e manejo sustentável das duas espécies, se destacaram as áreas de maior altitude na região Sul e Sudeste, como aquelas situadas no topo da Serra Geral, Serra do Mar e da Mantiqueira, por apresentarem os maiores valores de probabilidade de ocorrência para ambas as espécies, tanto no presente, quanto no futuro
99

Revisiting patterns and processes of forest cover change in the tropics : a case study from southeast Mexico

Gueye, Kinne January 2018 (has links)
Vast progress has been made in detecting rates of tropical deforestation, yet the relationship between visible patterns of forest change, multi-scalar human processes and the underlying drivers associated with them is poorly understood. Building on satellite imagery, a household livelihood survey and semi-structured interviews, this research scrutinised changes of forest cover from the mid-1990s to 2015 in a municipality located in southeastern Mexico and investigated the proximate causes and underlying drivers of change at the household and community levels. Emerging evidence indicated that, contrary to the persistent narrative of deforestation for the region, forest cover change is highly dynamic including periods of deforestation and forest recovery. Moreover, a close examination of 24 communities showed forest cover gained terrain, while the agricultural frontier retracted. Drawing on a comparison between the household survey and previous analyses, it could be inferred that forest resurgence was produced by the decrease in the farming area and the increase in the abandonment of farming activities by some communities. Associated with the adaptation of households was the development of formal and informal institutions at the community level in response to macro-global forces linked to the implementation of forest conservation strategies, environmental degradation, market liberalization and increased urbanization. Overall, this research adds not only to our understanding of the complexity of land-use and cover change in emerging globalized economies but also exemplifies the spatial and temporal heterogeneity of tropical forest systems, which challenges partial models of deforestation and policies designed to reduce it. The research may be focused on a narrow region of the globe, nevertheless, the insights and recommendation provided may be useful to further forest conservation schemes in other tropical regions.
100

Environmental factors influencing ecotonal changes in an indigenous forest in the Keiskammahoek Forest Estate, Eastern Cape, South Africa

Kiva, Luthando January 2016 (has links)
This study investigates environmental factors influencing ecotonal changes in the Dontsa Forest Management Unit (FMU) of the Keiskammahoek Estate Forest which is located in the Amatole Mountains of the Eastern Cape in the Republic of South Africa. The patterns of forest edge movement were analysed to show trends of forest edge movement from 1975 to 1985, 1975 to 1992, 1975 to 2002, 1975 to 2014, 1985 to 1992, 1985 to 2002, 1985 to 2014, 1992 to 2002, 1992 to 2014 and 2002 to 2014 by digitizing and assessing the scale of forest edge movement using georeferenced aerial photographs. Belt transects were established in six sites that were selected on the basis of physiographic elements for determination of the driving forces of forest ecotonal changes. The results of the study show that the forest edge moved positive towards the grassland biome while in other sites there was contraction of the forest edge from 1975 to 2014. The findings of the study show that some forest patches moved with few individual pioneer species towards the grassland while indigenous species dominated in the ecotone area of the forest in other research sites. D whyteana, A latifolius, R melanophloes, A facultus, R prenoides, C aurea, C bispinosa, C inerme, and S martina are the plant species with high density in the forest ecotone while A latifolius, R prenoides, R melanophloes were highly distributed along the grassland area. The results also show that harvesting of Pinus patula and illegal harvesting of understory species are major factors that result in ecotonal changes of Dontsa FMU. The research sites adjacent to residential areas have experienced reduction of ecotone area as compared to the research sites in high altitude areas of the Amathole Mountains where there is less disturbance. The eastern facing aspect of the forest exhibited a high density of plants in the forest ecotone as compared to the west facing slope.

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