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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

A multiscale remote sensing assessment of subtropical indigenous forests along the wild coast, South Africa

Blessing, Sithole Vhusomuzi January 2015 (has links)
The subtropical forests located along South Africa’s Wild Coast region, declared as one of the biodiversity hotspots, provide benefits to the local and national economy. However, there is evidence of increased pressure exerted on the forests by growing population and reduced income from activities not related to forest products. The ability of remote sensing to quantify subtropical forest changes over time, perform species discrimination (using field spectroscopy) and integrating field spectral and multispectral data were all assessed in this study. Investigations were conducted at pixel, leaf and sub-pixel levels. Both per-pixel and sub-pixel classification methods were used for improved forest characterisation. Using SPOT 6 imagery for 2013, the study determined the best classification algorithm for mapping sub-tropical forest and other land cover types to be the maximum likelihood classifier. Maximum likelihood outperformed minimum distance, spectral angle mapper and spectral information divergence algorithms, based on overall accuracy and Kappa coefficient values. Forest change analysis was made based on spectral measurements made at top of the atmosphere (TOC) level. When applied to the 2005 and 2009 SPOT 5 images, subtropical forest changes between 2005-2009 and 2009-2013 were quantified. A temporal analysis of forest cover trends in the periods 2005-2009 and 2009-2013 identified a decreasing trend of -3648.42 and -946.98 ha respectively, which translated to 7.81 percent and 2.20 percent decrease. Although there is evidence of a trend towards decreased rates of forest loss, more conservation efforts are required to protect the Wild Coast ecosystem. Using field spectral measurements data, the hierarchical method (comprising One-way ANOVA with Bonferroni correction, Classification and Regression Trees (CART) and Jeffries Matusita method) successfully selected optimal wavelengths for species discrimination at leaf level. Only 17 out of 2150 wavelengths were identified, thereby reducing the complexities related to data dimensionality. The optimal 17 wavelength bands were noted in the visible (438, 442, 512 and 695 nm), near infrared (724, 729, 750, 758, 856, 936, 1179, 1507 and 1673 nm) and mid-infrared (2220, 2465, 2469 and 2482 nm) portions of the electromagnetic spectrum. The Jeffries-Matusita (JM) distance method confirmed the separability of the selected wavelength bands. Using these 17 wavelengths, linear discriminant analysis (LDA) classified subtropical species at leaf level more accurately than partial least squares discriminant analysis (PLSDA) and random forest (RF). In addition, the study integrated field-collected canopy spectral and multispectral data to discriminate proportions of semi-deciduous and evergreen subtropical forests at sub-pixel level. By using the 2013 land cover (using MLC) to mask non-forested portions before sub-pixel classification (using MTMF), the proportional maps were a product of two classifiers. The proportional maps show higher proportions of evergreen forests along the coast while semi-deciduous subtropical forest species were mainly on inland parts of the Wild Coast. These maps had high accuracy, thereby proving the ability of an integration of field spectral and multispectral data in mapping semi-deciduous and evergreen forest species. Overall, the study has demonstrated the importance of the MLC and LDA and served to integrate field spectral and multispectral data in subtropical forest characterisation at both leaf and top-of-atmosphere levels. The success of both the MLC and LDA further highlighted how essential parametric classifiers are in remote sensing forestry applications. Main subtropical characteristics highlighted in this study were species discrimination at leaf level, quantifying forest change at pixel level and discriminating semi-deciduous and evergreen forests at sub-pixel level.
82

Farmers’ Responses to Drivers of Forest Cover Change: The Case of Mae Chaem District, Thailand

Beaulieu, Antoine January 2017 (has links)
Empirical forest transition (shift from deforestation to reforestation) literature has historically struggled to establish a single universally-accepted forest transition “theory” due to various knowledge gaps hindering any efforts to do so. One such gap is the fact that very few studies have focused on how and why smallholder farmers respond to commonly accepted forest transition drivers, as well as how these responses impact forest cover and agricultural trends. Also, there remain many parts of the world where forest cover evolution has been insufficiently researched, as is the case of Mae Chaem district (Chiang Mai province, Thailand). Even though there are studies which claim forest loss occurred in the district between the 1990s and mid-2000s, there are few available records of forest cover evolution since then. To address these research needs, this thesis used secondary literature and spatial data, as well as semi-structured interviews and personal observations gathered during fieldwork in Mae Chaem district. It was first determined that forest cover in the district decreased between the 1990s and mid-2010s due to agricultural expansion. However, it appears that forest cover is expected to increase from 2016 to 2021 due to more strictly-enforced conservation measures set in motion by the Mae Chaem Model (a state-sponsored sustainable development model). These findings first suggest that the district might be currently in the early stages of a forest transition, its drivers being shifting forest policies and economic factors. Second, interviewed farmers resisted forest policies to optimize their crop productions before 2016, before beginning to develop more acceptant responses in early 2016 due to pressure from pro-conservation discourses and cognitive shifts regarding the value of protecting forest at the expense of agriculture. Also, farmers adopted ambiguous responses (motivated by their economic rationality) to pressure stemming from various economic factors, both prior and since 2016. With both environmental and socioeconomic issues deriving from these responses, the outputs from this study will hopefully help supplement existing forest transition studies on local populations responses to drivers of forest change. It is also expected to provide up-to-date information on existing and anticipated impacts of recent state development efforts, such as those deriving from the establishment of the Mae Chaem Model.
83

A feasibility study for the management of recreation and other selected non-timber resources on private industrial forest lands in coastal British Columbia

Bull, Gary January 1990 (has links)
Industrial private forest landowners in British Columbia have traditionally viewed their forest lands as a raw material supply for their wood processing facilities. However, they are now experiencing social and political changes which are restricting the way their forests are managed. These changes have enormous implications for large forestry firms, such as Canadian Pacific Forest Products. A portion of their lands, the focus of this study, has been examined to assess the impact of these restrictions on traditional land use. In addition, non-timber values have been examined for their revenue generating potential. A study area was delineated near the community of Sooke, B.C. Fishing, hunting, deer farming and camping were assessed. In order to complete the analysis, the costs in terms of foregone timber values, were calculated under a number of different assumptions. The impact of changes in bare land values on decisions with respect to the non-timber values were also examined. A number of policy changes, both by the landowner and the various levels of government involved, are required to promote forestry with a renewed emphasis on recreation. Initiating these changes is the next stage in the preparation of a recreation management plan for the area under study in this thesis. / Forestry, Faculty of / Graduate
84

Knowledge, nature, and representation : clearings for conservation in the Maine Woods

Demeritt, David 11 1900 (has links)
This thesis concerns the cultural and scientific practices involved with turn-of-the-century struggles to conserve the Maine Woods. Conservation was underwritten by the powerful and productive fiction that an essential nature exists as something completely apart from the elaborately organized exhibitions by which it has been staged for our benefit. The absolute distinction between nature and culture is profoundly problematic but tremendously productive as well. Drawing on a variety of historical and theoretical sources, this thesis describes the various ways in which the essential nature of the Maine Woods was set up and represented as something demanding protection and conservation. The thesis is divided into three parts. Part I sets the stage for the historical discussions that follow by assessing debates in geography and environmental history about the social construction of knowledge and nature. Recent scholarship has been caught on the horns of a theoretical dilemma: while understanding of the present environmental crisis and its historical roots seems to demand recognition of the independent agency of nature, social theory suggests the impossibility of stepping outside the bounds of culture to represent an independent nature as it really is. Different responses to this dilemma are discussed. It is argued that environmental critique demands a more humble approach to truth, one sensitive to the meanings of its metaphors and the politics of its practices. Part II assesses the forest conservation movement. The objects of scientific forestry depended fundamentally upon the ways in which the forest was framed as an object of knowledge. Very different programs of action flowed from competing metaphorical definitions of the Maine Woods as a crop, a mine, or a kind of capital. The ascendency of technical and quantitative knowledge of the forest and its displacement of local understandings are described as are public policy disputes in Maine about the regulation of private property, the institution of publicly owned forest reserves, and the role of the state in forestry. Part in deals with the conservation of wildlife for sport. Flocking to the forest to hunt, wealthy sportsmen articulated a variety of sexual, class, and racial anxieties about the debilitating embrace of modern life. The transfomation of the Maine Woods into a vacationland for their manly recreation demanded the institution of game laws and the criminalization of traditional lifeways to save the game for sport. In these struggles, conservationists had to contend not only with local residents, who resisted this construction of the Maine Woods, but also with a variety of non-human actors, such as deer, predators, and pathogens, whose presence, though difficult to deny outright, was culturally framed and mediated in materially significant ways. / Arts, Faculty of / Geography, Department of / Graduate
85

The role of biodiversity in stress alleviation: an experiment using VR

Pettersson, Anna January 2021 (has links)
Research has shown that exposure to green, natural environments can help the body recover from stress. Because of this effect, stress alleviation is considered an ecosystem service provided by nature for the benefit of human health and well-being. But is this effect equal when viewing natural environments with different levels of biodiversity? For example, is a natural forest with higher visual biodiversity better at alleviating stress than a low biodiversity spruce plantation, or an urban city? This question was tested in an experiment using virtual reality (VR). Test participants (n=31) were divided into three groups, induced with stress from a stressor, and then exposed to images of either natural forest, spruce plantation, or urban city in VR. Heart rate (HR), heart rate variability (HRV), and skin conductance level (SCL) were used as physiological measurements for stress. SCL and HR showed a significant decrease in stress for the natural forest, but not in the spruce plantation or the urban city. The results for HRV were inconclusive. The results suggest that the stress alleviation is stronger when exposed to a natural forest, indicating that visual experience of biodiversity may have an important role in stress alleviation, and further stress its value as an ecosystem service.
86

Zwischen Nord und Süd, heute und morgen: Welche Beiträge leistet das internationale Waldregime zum Abbau von Ungleichheiten?

Weber, Norbert, Pretzsch, Jürgen 11 November 2008 (has links)
Das internationale Waldregime kann als Summe von Prinzipien, Normen, Prozeduren und Programmen verstanden werden, welche den Schutz und die Nutzung von Wäldern sowie die Rolle der einzelnen Akteure hierbei regeln sollen. Als Ergebnis des Erdgipfels von Rio 1992 wurden vielfältige Forderungen und Vorschläge für den Abbau von intragenerationalen (Stichwort Nord-Süd-Konflikt) und intergenerationalen Ungleichheiten erhoben. Die Erkenntnisse aus Fallstudien in mehreren asiatischen Ländern (Bangladesh, China, Indien, Nepal) deuten jedoch darauf hin, dass diese Ansätze oft nur wenig zur Lösung von Nutzungskonflikten um Waldressourcen auf der lokalen Ebene beitragen können. Gerade hier muss aber angesetzt werden, um Veränderungen im Hinblick auf die Stabilisierung des globalen Klimas herbeizuführen. / The international forest regime is characterised by principles, norms, procedures and programs, which follow the target to regulate forest conservation and use as well as to determine the role of involved actors. In the conclusions of the Rio-process many proposals with focus on the reduction of the intergenerational and intragenerational imbalances have been made. Case studies from some Asiatic countries (Bangladesh, China, India, Nepal, Vietnam) indicate, that the above mentioned global regulations hardly respond to questions of land use and forest use on a local level. Urgent actions and interventions are necessary on this local level to stabilise the global climate.
87

Livelihoods Support Programs, Conservation Attitudes, And Tropical Biodiversity: An Evaluation Of Biocomplexity In Southeastern Ghana

Ekpe, Edem Kodzo 01 January 2012 (has links)
Human activities are a major driver of biodiversity degradation and loss, especially in tropical forest areas, where forest-fringe towns and villages depend on the forests for their livelihoods. In order to reduce threats that human activities pose to biodiversity, livelihoods support programs are employed as economic incentives for biodiversity conservation. These programs support the livelihoods activities of local communities, with the aim of triggering favorable attitudes and behaviors towards conservation, and ultimately reduce biodiversity degradation. Their effectiveness as conservation tools has not been evaluated. I investigated the effects of livelihoods programs on conservation attitudes and the consequent effects on biodiversity in the Afadjato-Agumatsa and Atewa forest areas in southeastern Ghana. The study areas are coupled human and natural systems, which are excellent for research in the theoretical framework of biocomplexity in the environment. Using literature reviews and field visits, I documented the specific livelihoods support activities (LSAs) used for biodiversity conservation, their historical trend and geographical distribution in Ghana. I used ex-post costbenefit analysis to determine socio-economic estimates of the LSAs in the two forest areas. Since communities were not randomly assigned to the interventions, I employed quasi-experimental design to evaluate the effects of LSAs on environmental attitudes. I evaluated the effect of conservation attitudes on biodiversity at two levels. These levels included 1) functional biodiversity at the landscape level represented by mean Normalized Difference Vegetation Index (NDVI) of forest; and 2) compositional biodiversity at the species level represented by species diversity of fruit bats. iv The earliest record of LSAs used for biodiversity conservation in Ghana was in 1993. I identified 71 different activities belonging to eight categories. Some of these activities are beekeeping, animal husbandry, crop farming, and snail rearing. Most LSA programs have been in northern Ghana. There was an increasing tendency to make LSAs part of every conservation program in Ghana and this satisfies the current policy of collaborative conservation. The socio-economic estimates of LSAs included: 1) capital investment; 2) net socio-economic benefits; and 3) the benefit-cost ratio. The per-community values of the three estimates were not different between the two study areas. The per capita values of capital investment and net economic benefit were not significantly different between the two study areas. However, benefitcost ratio per capita was higher in Afadjato-Agumatsa than in Atewa. Estimates of economic returns from LSAs were marginal but the perceptions of success were relatively high. Environmental attitudes in LSA communities and non-LSA communities were not significantly different, and this was confirmed by an estimate of infinitesimal effects of LSAs on forest conservation attitudes. Among LSA communities, benefit-cost ratio of LSAs predicted favorable forest conservation attitudes; and change in pro-conservation attitudes were significantly higher in communities that had active LSAs than in communities which had no active LSA. Mean NDVI of the forests decreased from 1991 to 2000 and decreased further but at a slower rate to 2010. Higher forest conservation attitudes predicted higher mean NDVI in 2010. Higher change in mean NDVI from 1991 to 2000 predicted higher change in mean NDVI from 2000 to 2010. Eleven of the 13 fruit bat species in Ghana were recorded in the study areas. Longer v distances between a local community and its forest predicted higher species diversity of forestspecialist fruit bats. The results indicate that LSAs have become a major contribution to Ghana’s current collaborative forest policy. The fact that perceptions of LSA success were moderate even though the economic returns from them were marginal suggest that other factors such as provision of employment, training in new skills and community cohesion played a part in how communities viewed the success as LSAs. Evaluations of conservation attitudes suggest that just participating in LSAs did not improve attitudes; but higher benefit-cost ratio predicted favorable conservation attitudes, and conservation attitudes were higher in communities that sustained their LSAs. Therefore, it may serve biodiversity conservation to invest in LSAs that can be sustained and involve the least costs to local communities. Primary production of the forests, a proxy for a functional habitat, continued to decrease. Preventing communities from locating closer to forests could improve fruit bat diversity, which contributes to natural forest regeneration. Improving conservation attitudes should be an objective of conservation at the landscape scale. On the basis of the results, I developed a conceptual model for forest biodiversity conservation in a biocomplexity framework. This model could be useful for evaluating conservation in tropical forest areas. Lessons from this study can be applied in other incentive-based conservation programs such as payments for ecosystem services systems and carbon market schemes. I suggest that this study be repeated after a decade and that other socio-political and biogeochemical variables be integrated into future studies.
88

Forest management and conservation in Kenya: a study of the role of law in the conservation of forest resources

Chebii, John Kipkoech 12 April 2016 (has links)
Public, Constitutional and International Law / LLD
89

Forest Conservation and the Hadzabe. An integrated approach in protecting biodiversity and cultural diversity. Case study: Carbon Tanzania.

Fassbender, Sabrina January 2016 (has links)
Preventing emissions from deforestation is propagated as an effective strategy to combat climate change. At the same time forest landscapes are habitat to the last remaining traditional societies of this planet. For a long time forest conservation programs neglected the role of these indigenous communities for forest landscapes. Historical ecology pushes a change of environmental narratives towards an understanding that biocultural diversity has had and will have a significant impact on resource use and on the transformation of landscapes. A growing number of debates on global environmental justice and poverty alleviation goals call for such an integrated approach in protecting biodiversity and cultural diversity when conserving forest landscapes. Although this topic is discussed, there is a gap in scientific literature on how such an approach can actually be implemented in practise. This paper examines how the dual-objective of forest conservation and protection of cultural diversity can be achieved in practise by applying a case study of a conservation project, Carbon Tanzania. Carbon Tanzania is operating in an area in northern Tanzania inhabited by one of the few remaining hunting and gathering societies on the planet, the Hadzabe. Carbon Tanzania conservation project issues carbon credits which can be bought by companies, organisations and individuals to offset their emissions. Interviews with the different actors have been conducted in the course of the research project in order to examine how Carbon Tanzania’s ‘community-led project’ contextualizes the dual objective of protecting forests and the Hadzabe culture. The results show that the implementation of the project is facilitated through an integrated network of different actors and organisations. Critical for the operations in the area is secured land ownership and a binding land use plan in order to protect the area from external pressure and to manage the utilization of the landscape by the different communities within the area. Payments for ecosystem services generate benefits for the local forest community and support community development. This form of ‘productive’ land utilization offers a path in changing development narratives for African countries.
90

Transplante de epífitas entre Florestas Estacionais Semideciduais para enriquecimento de florestas em processo de restauração / Enrichment of forests in process of restoration through epiphytes transplantation, in Semideciduous Seasonal Forest

Duarte, Marina Melo 06 March 2013 (has links)
O enriquecimento com diferentes formas de vida, como com epífitas, é fundamental para o desenvolvimento de florestas em restauração, em paisagens fragmentadas, onde a dispersão natural é limitada. Epífitas são plantas que crescem sobre outras (forófitos). Têm papel ecológico importante, realizando ciclagem de nutrientes e oferecendo microambientes e alimentos a outras formas de vida. Características de forófitos, clima e microclima influenciam populações locais de epífitas. Para aumentar o sucesso do enriquecimento em florestas em restauração, é importante determinar quais filtros podem atuar no processo. Fizemos o censo de áreas que receberam autorização para supressão vegetal e obtivemos que, a cada ano, cerca de 500 ha de Florestas Estacional Semidecidual e Ombrófila Densa, em diferentes estágios de regeneração, são desmatados, apenas no estado de São Paulo. Elas podem fornecer material que pode ser recuperado e empregado na restauração de outras florestas. Neste trabalho, damos enfoque às epífitas que podem ser disponibilizadas a partir desse desmatamento. Transferimos 360 indivíduos de seis espécies delas, entre Bromeliaceae (Aechmea bromeliifolia e Tillandsia pohliana), Orchidaceae (Catasetum fimbriatum e Rodriguezia decora) e Cactaceae (Lepismium cruciforme e Rhipsalis floccosa) para duas Florestas Estacionais Semideciduais em processo de restauração, uma com 13 anos e outra com 23. As médias anuais de cobertura de dossel, entre os forófitos escolhidos, variaram entre 62,2 e 85,0% na floresta de 13 anos e entre 79,3 e 92,9% na floresta de 23 anos. Taxas de sobrevivência das diferentes espécies de epífitas foram superiores em floresta mais jovem, variando de 63.33 a 100%, enquanto em floresta mais madura variaram entre 55,17 e 89,66%. Transplantes usando fibra de palmeiras, capaz de reter água, e realizados no início de estação chuvosa podem ter explicado o maior sucesso em floresta mais nova. Taxas de sobrevivência, fixação, ramificação, floração e frutificação não estiveram relacionadas à espécie de forófito, à rugosidade de casca ou à posição de transplante. Por outro lado, elas estiveram relacionadas às espécies das próprias epífitas. Apenas em algumas situações e para determinadas espécies, taxas de fixação, ramificação e reprodução sexuada estiveram relacionadas aos valores de cobertura de dossel. Animais podem ter importantes papéis como polinizadores e dispersores de epífitas, o que mostra que sua presença na floresta é fundamental para a permanência dessas plantas em longo prazo. Ao final, separamos as principais conclusões tiradas deste trabalho e fizemos um guia de procedimentos práticos a serem adotados no enriquecimento de florestas em restauração usando epífitas provenientes de florestas a serem suprimidas. / Enrichment using non-arboreal life forms, such as epiphytes, is critical to the development of forests under restoration, in fragmented landscapes, where natural dispersal is scarce. Epiphytes are plants that grow on top of other plants (phorophytes). They play very important ecological role, performing nutrient cycling and providing microenvironments and food to other life forms. Features of phorophytes, climate, and microclimate influence local diversity of epiphytes. In order to improve success of enrichment in areas under restoration, it is important to determine what filters may play a role in this process. We censused areas that received authorization for vegetation removal and found out that, every year, about 500 ha of Semideciduous Seasonal Forests and Rainforests, in different regeneration stages, are legally cut down, only in the state of Sao Paulo. They can provide material that can be recovered and used to restore other forests. In this work, we focused on the epiphytes that may become available from deforestation. We transferred 360 individuals of six species of this life form among Bromeliaceae (Aechmea bromeliifolia and Tillandsia pohliana), Orchidaceae (Catasetum fimbriatum and Rodriguezia decora) and Cactaceae (Lepismium cruciforme and Rhipsalis floccosa) to two different Semidecidual Seasonal Forests in process of restoration, one of them was 13 years old and the other, 23 years old. Annual canopy cover averages provided by diffferent phorophytes ranged from 62.2 to 85.0% in 13-year old forest and from 79.3 to 92.9% in 23-year-old forest. Survival rates of epiphytes species were higher in the younger forest, from 63.33 to 100%, compared to the ones obtained in the more mature forest, from 55.17 to 89.66%. Transplants performance using palm tree fiber, which enables higher water retention, and at the beginning of rainy season may have been responsible for higher survival rates in the young forest. Survival, rooting, sprouting, flowering and fruiting rates were not related to phorophyte species, to their bark roughness nor to the position of transplantation. On the other hand, they were always relatated to epiphyte species. Only in some cases and for determined species, rooting, sprouting, flowering and fruiting were related to canopy cover. Animals can play important roles as pollinators and dispersers of epiphytes, which shows that their presence in forests is fundamental for the long-term persistance of these plants. In the end, we gathered the main results taken from this work and organized a guide of practical procedures to be adopted in enrichment of areas using epiphytes from forests about to be suppressed.

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