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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.
21

Diversity and abundance of medicinal plants among different forest-use types of the Pakistani Himalaya / Diversität und Abundanz von Medizinalpflanzen in unterschiedlich genutzten Wäldern des Pakistanischen Himalaya

Adnan, Muhammad 20 January 2012 (has links)
No description available.
22

Rural livelihoods in south-eastern Zimbabwe : the impact of HIV/AIDS on the use and management of non-timber forestry products.

Mutenje, Munyaradzi Junia. January 2010 (has links)
Non-timber forest products (NTFPs) constitute an important source of livelihood for most poor rural households and communities in Zimbabwe. NTFPs also serve as a vital livelihood safety net in times of hardship. An important feature of this dependence is that almost all NTFPs are deemed to have ‘public good’ characteristics, with no exclusive property rights. Consequently, extraction is often intense and exhaustive because of lack of alternative income sources, unreliable productivity and weak enforcement of institutional arrangements governing NTFPs use. In recent years, with HIV/AIDS rampant in Zimbabwe, there are indications of a rapid increase in the extraction of NTFPs, mostly from common property resources. Appropriate natural resources policies need to be based on comprehensive research, yet to date scant attention has been paid to understanding the role of NTFPs in mitigating the predicaments of HIV/AIDS-affected households in Zimbabwe. The main objective of this study was to determine the types of and need for natural resource management interventions to help ensure the sustainability of local responses to HIV/AIDS. The research focused on five communities of Sengwe Communal in the Chiredzi district, Zimbabwe. Multistage cluster sampling was used to select ten villages and households for the survey. Two villages from each community, representing the most and the least affected by epidemic were selected for each community using stratified random sampling. A cluster analysis was used to improve understanding of the challenges of rural livelihoods and how households diversify their livelihood strategies to cope with the various constraints. Five dominant groups based on their livelihood diversification patterns were identified : (1) smallholders/unskilled workers; (2) subsistence smallholder/non-timber forestry products harvesters; (3) crop production and non-timber forestry products extraction integrators; (4) commercial smallholders with regular off-farm employment; and (5) specialised commercial livestock producers. Multinomial logit model results showed that the level of education of the household head, the value of physical assets, cattle numbers and income, remittances, NTFPs income and economic shocks were the main determinants of these livelihood choices. Empirical evidence also revealed that households that were statistically significantly affected by HIV/AIDS economic shocks practised ‘distress-push’ diversification by extracting NTFPs. These results suggest that policy makers need to advise rural households on how to improve their risk management capacities and move from geographically untargeted investments in livelihood assets to a more integrated approach adapted to the asset base of individual households. Using panel data from 200 households in 2008 and 2009, regression models revealed that NTFPs extraction is an important ex-post coping mechanism for many HIV/AIDS-afflicted households. The results also revealed that the main determinants of livelihood strategy choices were differences in asset endowment, especially education, land and livestock and the impact of the shock. Asset constraints compelled diversification into lower-return activities such as NTFPs extraction. Findings from a comparative analysis of HIV/AIDS-afflicted and non-afflicted households showed that HIV/AIDS-afflicted households were relatively young, with relatively few physical and livestock assets. A fixed-effect Tobit model indicated a positive significant relationship between HIV staging and quantity of NTFPs extracted. The relatively young, poorly educated households with low household coping capacity in terms of livestock value relied more on the natural insurance of forests in buffering HIV/AIDS economic shocks. These results have important policy implications for development planners, conservationists and non-governmental organisations working in the region. There is a need for programmes that reduce pressure on forest resources, and improved access to education and health care, thus helping the poor to cope with the HIV/AIDS economic crisis. This study also examined the extent to which forest degradation is driven by existing common property management regimes, resource and user characteristics, ecological knowledge and marketing structure. A Principal Component Analysis indicated that the existence of agreed-upon rules governing usage (including costs of usage), enforcement of these rules, sanctions for rule violations that are proportional to the severity of rule violation, social homogeneity, and strong beliefs in ancestral spirits were the most important attributes determining effectiveness of local institutions in the management of Common Pool Resources (CPRs). Empirical results from an ordinary least regression analysis showed that resource scarcity, market integration index, and infrastructural development lead to greater forest resource degradation, while livestock income, high ecological knowledge, older households, and effective local institutional management of the commons reduce forest resource degradation. The results suggest that there is a need for adaptive local management systems that enhance ecological knowledge of users and regulates market structure to favour long-term livelihood securities of these forest-fringe communities. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2010.
23

Effects of forest fragmentation on biomass in tropical forests / Efeitos da fragmentação florestal na biomassa em florestas tropicais

Melina Oliveira Melito 16 December 2016 (has links)
In spite tropical forests are the most important terrestrial global carbon sinks due to carbon storage in aboveground biomass, it is also the primary target of deforestation. The conversion of Tropical forests into anthropogenic areas might disrupt biological flux and also lead to severe microclimatic changes at forest edges. These combined effects can trigger profound changes in plant composition through both high mortality of fragmentation-sensitive species and proliferation of disturbed-adapted species which will ultimately impacts carbon storage. Thus, our main objective in this study was understand the role of human-induced disturbances in modulate the dimension of biomass loss at tropical forests. We applied a systematic literature review searching for empirical evidences that edge effects can drive biomass loss in tropical forests (Chapter 2). Our findings highlighted the gap of knowledge about the pattern and process related to biomass loss in tropical forests. To strengthen this understanding, we formulated a conceptual model linking landscape structure and patch-level attributes to severity of edge effects affecting aboveground biomass. Our model hypothesizes that habitat amount, isolation, time since edge creation, and the synergism between edge distance, patch size, and matrix type are the main drivers of biomass loss in anthropogenic tropical forests. We thus used a large plant dataset (18 503 trees ≥ 10 cm dbh) from 146 sites distributed across four Mexican and four Brazilian rainforest regions to test our conceptual model predictions, specifically the influence of forest cover, site isolation, edge distance, patch size and type of matrix on biomass (Chapter 3). We observed that carbon-rich sites presented species that are typical of old-growth forests (shade-tolerant, large-seeded, zoocoric) contrasting to carbon-poor sites composed by disturbed-adapted species (pioneer occupying the understory). Large shade-tolerant trees (≥ 40 cm dbh) were impacted severely by the combination of forest loss and edge effects. Edge distance, patch size, and the amount of open-matrix strongly influence small shade-tolerant trees (≤ 20 cm dbh). Although our results do not fully corroborate the initial predictions of the conceptual model, they support the idea that landscape composition interact with patch structure and ultimately impacts biomass stocks in fragmented tropical forests. Finally, we further investigated if the disturbance level of the region influences plant-structure responses to forest loss (Chapter 4). Biomass, but not plant density, was affected by forest loss in regions with intermediate disturbance levels, i.e. regions showing a combination of moderate deforestation (20-40% of remaining forest cover) disturbed during the past 30-60 years, high defaunation but harboring relictual populations of large-mammals, and areas mostly composed by heterogeneous matrices. In general, our findings highlight that both landscape composition and patch structure are the main drivers of biomass loss in Neotropical forests, and that the landscape context must be considered to obtain more reliable estimations of carbon emissions due to forest degradation. Landscape planning (e.g. restoration of forest cover) should be included in conservation strategies in order to sustain carbon storage. Moreover, we advocate that conservation initiatives will be less costly and more effective if implemented in areas under intermediate disturbance levels / Apesar das florestas tropicais serem a mais importante fonte mundial de carbono da porção terrestre do globo devido ao armazenamento de carbono na biomassa acima do solo, elas são também o alvo primário do desmatamento. A conversão das florestas Tropicais em áreas antropogênicas pode interromper o fluxo biológico e também levar a severas mudanças microclimáticas na borda dos fragmentos. A combinação desses efeitos pode engatilhar profundas mudanças na composição da vegetação através tanto da mortalidade de espécies sensíveis à fragmentação como também pela proliferação de espécies adaptadas distúrbios, com impactos finais nos estoques de carbono. Assim, o maior objetivo desse estudo foi compreender o papel dos distúrbios induzidos pelo homem na modulação da dimensão da perda de biomassa em florestas Tropicais. Nós aplicamos uma revisão sistemática da literatura procurando por evidências empíricas de que o efeito de borda pode levar a perda de biomassa em florestas tropicais (Capítulo 2). Nossos resultados destacam a lacuna de conhecimento entre padrões e processos relacionados à perda de biomassa em florestas Tropicais. Para fortalecer esse conhecimento, nós formulamos um modelo conceitual conectando estrutura da paisagem e atributos na escala do fragmento à severidade do efeito de borda, e assim afetando a biomassa acima do solo. Nosso modelo hipotetiza que a quantidade de hábitat, o isolamento, o tempo desde a formação da borda e o sinergismo entre tamanho do fragmento, distância da borda e tipo de matriz são os principais condutores de perda de biomassa em florestas Tropicais antropogênicas. Utilizando um grande banco de dados (18 503 árvores ≥ 10 cm dap) provenientes de 146 locais distribuídos em quatro regiões de floresta úmida no México e quatro no Brasil, nós então testamos as predições do nosso modelo conceitual. Especificamente, a influência da cobertura florestal, isolamento, distância da borda, tamanho do fragmento e tipo de matriz sobre a biomassa (Capítulo 3). Nós observamos que áreas com muito carbono apresentaram espécies típicas de florestas maduras (tolerantes ao sombreamento, zoocóricas, com sementes grandes) contrastando com áreas com pouco carbono compostas por espécies adaptadas à distúrbio (pioneiras ocupando o sub-bosque). Árvores grandes tolerantes ao sombreamento (≥ 40 cm dap) foram impactadas severamente pela combinação de perda de cobertura florestal e efeitos de borda. Distância da borda, tamanho do fragmento e a extensão da área de matriz aberta influenciaram fortemente as árvores pequenas tolerantes a sombreamento (≤ 20 cm dap). Apesar dos nossos resultados não corroborarem completamente as predições iniciais do nosso modelo conceitual, eles dão suporte à ideia de que a composição da paisagem interage com a estrutura do fragmento com impactos finais nos estoques de biomassa em florestas Neotropicais. Por fim, nós investigamos se o nível de distúrbio da região pode influenciar nas respostas da estrutura da vegetação à perda de cobertura florestal. Biomassa, mas não a densidade de indivíduos, foi afetada pela perda de cobertura florestal em regiões com nível intermediário de distúrbio, i.e. regiões apresentando uma combinação de níveis moderados de desmatamento (20-40% de cobertura florestal remanescente) em que a perturbação ocorreu ao longo dos últimos 30-60 anos, com alto grau de defaunação mas ainda abrigando populações relictuais de grandes mamíferos e, em sua maioria, compostos por uma matriz heterogênea. Em geral, nossos resultados destacaram que tanto a composição da paisagem como a estrutura do fragmento são os principais condutores de perda de biomassa em florestas Neotropicais e que o contexto da paisagem deve ser considerado para se obter estimativas mais confiáveis de emissão de carbono devido à degradação florestal. O planejamento da paisagem (e.g. restauração da cobertura florestal) deve ser incluído em estratégias de conservação em ordem de sustentar o armazenamento de carbono. Além disso, nós defendemos que iniciativas de conservação serão menos custosas e mais efetivas se implementadas em áreas sob níveis intermediários de distúrbio
24

Modeling and Analysis of Long-Term Shifts in Bioenergy Use-With Special Reference to Ethiopia : Improving Sustainable Development

Mengistu, Azemeraw Tadesse January 2013 (has links)
Ethiopia is one of the sub-Saharan Africa countries whose energy depends on traditional use of biomass such as wood, charcoal, agricultural residues and animal dung. The traditional use of biomass mainly wood and charcoal leads the country to massive deforestation and forest degradation. Negative environmental impacts from poorly managed municipal solid waste are also serious problems in the country. Moreover, there is a wide range of fossil fuels demand in the country fully covered by importing which results to a significant expenditure from the country’s budget. This study investigates the long-term shifts in bioenergy use of the country and evaluates the expected social, environmental and economical implications. For this purpose, three scenarios are formulated within a timeframe that goes from 2013 to 2030. The baseline scenario assumes the existing energy practices of the country would undergo no significant change in the future while the moderate shift and high shift scenarios consider the long-term shifts in bioenergy use with and without considering constraints respectively. In this context, long-term shifts means: transition from traditional use of biomass to efficient and modern in the household sector, biofuels deployment in the transport sector, introduction of agricultural residues as a fuel for cement production, and electricity generation from bagasse and municipal solid waste. To model and analyze the scenarios, the long-range energy alternatives planning system (LEAP) software tool is used. Taking the results of high shift scenario by 2030, the use of improved wood stoves and fuel switch stoves could save 65 million tons of wood. The foreign currency saving from using biofuels and agricultural residues as fossil fuels substitute would reach to 674 million USD. The greenhouse gas emissions reduction is equivalent to 46 million tons of CO2e which is about 18.4% of the CO2e abatement target of the country for 2030. The corresponding revenue from carbon trading schemes would reach to 231 million USD. Electricity generation from bagasse and municipal solid waste would be 3,672 GWh that is around 3.7% of the total electricity generation target for 2030.
25

Monitoring and quantifying forest degradation: remote sensing approaches for applied conservation in the Congo Basin

Shapiro, Aurélie 27 June 2022 (has links)
Wälder spielen global eine entscheidende Rolle bei der Regulierung des Weltklimas, da sie aktiv Kohlenstoff speichern und binden. Trotz der Bemühungen durch internationale Programme nehmen die Waldschäden weiter zu. Entwaldung und Walddegradierung sind zwei unterschiedliche Prozesse, die sich auf die globalen Wälder auswirken. Entwaldung ist eine klar definierte Umwandlung oder Abholzung der Waldflächen, während Degradierung subtiler, vorübergehend und variabel sein kann und daher schwer zu detektieren ist. Walddegradierung wird im Allgemeinen als eine funktionale Verringerung der Fähigkeit von Wäldern Ökosystemleistungen zu erbringen identifiziert. Sie wird nicht als Veränderung der Landbedeckung oder Entwaldung klassifiziert. Daraus folgt keine deutliche Verringerung der Waldfläche, sondern eher eine Abnahme der Qualität und des Zustands. Diese Veränderung kann, wie die Entwaldung dennoch mit einer signifikanten Verringerung der oberirdischen Biomasse und damit miterheblichen Treibhausgasemissionen verbunden sein. Die Schätzungen der Kohlenstoffemissionen aus Waldstörungen liegen zwischen 12 und 20 % aller weltweit emittierten Emissionen. Durch eine fehlende einheitliche Definition oder Methode zur Quantifizierung der Degradation, der Vielzahl an Einflussfaktoren und der Unsicherheit bei der Schätzung der Biomasse variieren die Werte stark. Die von der Walddegradierung betroffene Fläche könnte in der Tat viel größer sein als die der Entwaldung, die ohnehin jedes Jahr auf eine Fläche von etwa der Größe Islands geschätzt wird. Die REDD+-Mechanismen zur Finanzierung von Emissionsreduktionen zur Minderung des Klimawandels erfordern robuste, transparente und skalierbare Methoden zur Quantifizierung der Walddegradierung, zusammen mit der Erfassung der damit verbundenen Treibern. Da die Degradierung oft der Entwaldung vorausgeht, kann ein schnelles Monitoring mit einer Beurteilung der Waldschäden und ihren Treibern ein wichtiges Frühwarnsystem sein. Nur so können Maßnahmen frühzeitig ergriffen werden, die die Wälder schützen und sowohl der Natur und der Biodiversität als auch dem Lebensunterhalt, der Gesundheit und dem Wohlbefinden von Millionen von Menschen auf der ganzen Welt zugute kommen. In dieser Arbeit werden Methoden für konsistente, reproduzierbare, skalierbare und satellitengestützte Indikatoren zur Identifizierung und Quantifizierung verschiedener Arten von Walddegradation um zukünftige Risiko- und Politikszenarien zu unterstützen. / Global forests play a crucial role in regulating global climate by actively storing and sequestering carbon. Despite efforts to mitigate climate through international efforts, human-caused forest disturbance and forest-related greenhouse gas emissions continue to rise. Deforestation and forest degradation are two different processes affecting global forests. Deforestation is a clearly defined conversion or removal of forest cover, while degradation can be more subtle, temporary, variable, and therefore difficult to detect. Forest degradation is generally identified as a functional reduction in the capacity of forests to provide ecosystem services, that does not qualify as a change in land cover or forest clearing. That means no clear reduction of the forest area, but rather a decrease in quality and condition. This change, like deforestation can still be associated with significant reductions in above-ground biomass and therefore considerable greenhouse gas emissions. Estimates of carbon emissions from forest degradation and disturbance range anywhere from 12-20% of all emissions emitted globally with values varying widely because of a lack of uniform definition or method for quantifying degradation, the broad number of influencing factors, and uncertainty in biomass estimates. The area affected by forest degradation could in fact be much larger than that of deforestation, which is already estimated to be an area about the size of Iceland every year. The REDD+ mechanisms of financing emissions reductions to mitigate climate change require robust, transparent and scalable methods for quantifying degradation, along with a quantification of associated direct drivers. Furthermore, as degradation often precedes deforestation, timely monitoring and assessment of forest degradation and changes in drivers can provide crucial early warning to engage interventions to keep forests intact, benefitting nature and biodiversity as well as the livelihoods, health and well-being of millions of people around the world. This research proposes methods for consistent, repeatable and scalable satellite-derived indicators for identifying and quantifying different types of forest degradation and its causes to inform future risk and policy scenarios.
26

Analysis of Land Use/Land Cover Change Impacts Upon Ecosystem Services in Montane Tropical Forest of Rwanda: Forest Carbon Assessment and REDD+ Preparedness

Mlotha, McArd Joseph 31 May 2018 (has links)
No description available.
27

Linking agents, patterns and outcomes of forest disturbances to understand pathways of degradation in the Argentine Dry Chaco

De Marzo, Teresa Rita 17 November 2023 (has links)
Tropische Trockenwälder sind von großer Bedeutung für das Klima, die biologische Vielfalt und den Lebensunterhalt von Millionen von Menschen. Die Walddegradation bedroht die tropischen Trockenwälder, aber es fehlt an Wissen über ihre Muster, ihr Ausmaß und ihre Ursachen. Ziel dieser Arbeit war es, das derzeitige Verständnis der Walddegradation im argentinischen Dry Chaco mit Hilfe der Fernerkundung zu verbessern. Mithilfe des Landsat-Archivs habe ich die Störungsgeschichte des verbleibenden Waldes charakterisiert, die räumlichen und zeitlichen Muster der Störungsfaktoren bewertet und die langfristigen Auswirkungen der verschiedenen Faktoren auf die Waldstruktur untersucht. Die Ergebnisse zeigen, dass über 30 Jahre hinweg große Gebiete des argentinischen Dry Chaco (etwa 8 %) von Störungen betroffen waren. Meine Ergebnisse zeigen einen anthropogenen Zusammenhang mit den meisten Störungsarten, deuten aber auch auf einen komplexen indirekten Einfluss von Niederschlagsmustern hin, wobei Waldstörungen in Dürrejahren besonders verbreitet sind. Die Analyse der zeitlichen Muster der verschiedenen Einwirkungen zeigt Trends in der Landnutzung im Laufe der Zeit, wobei neue Landnutzungsformen wie silvopastorale Systeme entstehen und alte Praktiken wie die Abholzung jedes Jahr einen relativ stabilen Anteil der Flächen betreffen. Die Ergebnisse zu den langfristigen Auswirkungen von Störungen zeigen, dass sich die Waldstruktur bei den am weitesten verbreiteten Störungen über drei Jahrzehnte kaum oder gar nicht erholt, was auf eine großflächige Walddegradation schließen lässt. Diese Arbeit zeigt das Potenzial von Satellitenzeitreihen für eine robuste Charakterisierung der Walddynamik im Zusammenhang mit der Degradation auch in tropischen Trockenwäldern. Die aus dieser Arbeit resultierenden Karten, Ansätze und Erkenntnisse tragen zu einem besseren Verständnis der Walddegradation im Dry Chaco bei und können zu einem wirksameren Schutz der tropischen Trockenwälder beitragen. / Tropical dry forests are of great importance for climate regulation, harbour biodiversity and sustain the livelihood of millions of people. Deforestation and degradation threaten tropical dry forests but whereas our understanding of tropical deforestation has increased tremendously over the last decades, knowledge of the patterns, extent and drivers of forest degradation is lacking. This thesis aimed to advance the current understanding of forest degradation in the Dry Chaco by means of remote sensing. Using the Landsat archive, I characterized the disturbance history of the remaining Argentine Dry Chaco forest, assessed spatial and temporal patterns of disturbance agents, and investigated the long-term effect of different agents on forest structure. Results show that over 30 years large areas of the Argentine Dry Chaco (about 8%) were affected by disturbances. My findings reveal an anthropogenic link to most types of disturbances, while also suggesting complex indirect influence of precipitation patterns, with forest disturbances being particularly widespread during drought years. The analyses of temporal patterns of different agents reveals trends in land-use practices over time, with new land uses emerging, such as silvopastoral systems, and old practices such as logging, affecting a fairly stable share of areas every year. Findings on the long-term impact of disturbances indicate that for the most widespread disturbances, forest structure shows little or no recovery over three decades, which suggests forest degradation affecting large areas. This thesis demonstrates the potential of satellite time series for robust characterization of forest dynamics related to degradation also in tropical dry forests, despite the complex conditions these systems represent. The maps, approaches and knowledge resulting from this thesis contribute to a better understanding of forest degradation in the Dry Chaco and can inform more effective conservation of tropical dry forests.
28

Mudanças climáticas e o protocolo de Quioto: desafios jurídicos e ambientais

Silva, Flávia Martins da 16 May 2012 (has links)
Submitted by Rosina Valeria Lanzellotti Mattiussi Teixeira (rosina.teixeira@unisantos.br) on 2015-05-29T14:16:36Z No. of bitstreams: 1 FLAVIA MARTINS DA SILVA.pdf: 497417 bytes, checksum: 0a7e626a4d3f5de72fb63eb68446fdeb (MD5) / Made available in DSpace on 2015-05-29T14:16:36Z (GMT). No. of bitstreams: 1 FLAVIA MARTINS DA SILVA.pdf: 497417 bytes, checksum: 0a7e626a4d3f5de72fb63eb68446fdeb (MD5) Previous issue date: 2012-05-16 / The problem of climate change is one of the major challenges faced by mankind. The situation of the greenhouse effect and the ozone layer hole is the foremost threat to human life. One of the key causes for this situation was the exploration and fossil fuels usage and the high rates of deforestation in the world, mainly in Brazil. The Kyoto Protocol, created during the Conference of the Parties nº III held in the city of Kyoto, Japan in 1997 with the purpose of supplementing the United Nations Framework Convention on Climate Change and establish a quantitative emission reduction limit of greenhouse gas (GHG) for countries under such Convention. At the present time the Kyoto Protocol is the only international climate agreement. The Protocol created flexibility mechanisms to achieve the ultimate goal of the Framework Convention, which is highlighted by the Clean Development Mechanism, which generated the carbon credits market. The mechanism for Reducing Emissions from Deforestation and Forest Degradation with increasing forest carbon stocks in developing countries (REDD) is currently a voluntary mechanism suggested by some countries that take part in the Convention, and recommended to assist developing countries to combat deforestation and degradation especially in tropical forests. The present paper aims to provide an overview of the trajectory of the Kyoto protocol in international environmental law, as well as demonstrate the importance and urgency of the matter of the problem of climatic changes. / O problema das mudanças climáticas é um dos maiores desafios enfrentados pelo ser humano. A situação do efeito estufa e do buraco na camada de ozônio é uma grande ameaça para a vida humana. Uma das maiores causas para esse panorama foi a exploração e uso de combustíveis fósseis e as taxas elevadas de desmatamento no mundo, principalmente no Brasil. O Protocolo de Quioto, criado durante a Conferência das Partes n° 3, realizada na cidade de Quioto, Japão, em 1997, com a finalidade de complementar a Convenção Quadro das Nações Unidas sobre o Clima e estabelecer de maneira quantitativa limites de redução de emissão de gases de efeito estufa (GEE) para os países comprometidos pela Convenção. Atualmente o Protocolo de Quioto é o único Protocolo internacional climático. O Protocolo criou mecanismos de flexibilização para alcançar o objetivo final da Convenção Quadro, dos quais destacamos o Mecanismo de Desenvolvimento Limpo, que gerou o mercado de créditos de carbono. O mecanismo de Redução de Emissão do Desmatamento e Degradação Florestal com aumento de estoques de carbono florestal em países em desenvolvimento (REDD+) é atualmente um mecanismo voluntário sugerido por alguns países partes da Convenção, e recomendado para auxiliar os países em desenvolvimento a combaterem o desmatamento e degradação em especial nas florestas tropicais. O presente trabalho pretende fornecer um panorama sobre a trajetória do Protocolo de Quioto e do problema das mudanças climáticas, bem como mostrar a importância e urgência do tratamento do tema em questão.
29

Changes in tropical rainforests landscapes as a consequence of selective logging and indigenous shifting cultivation in Forest Reserve Imataca (central zone) Bolívar State, Venezuela. / Cambios en paisajes de bosque húmedo tropical como consecuencia de la explotación selectiva y la agricultura indigena migratoria en la Reserva Forestal Imataca (zona central) Estado Bolívar, Venezuela.

Rodriguez Aponte, Glenda Ysolina 09 June 2005 (has links)
La degradación del bosque tropical causada por la agricultura indigena tradicional y la explotación forestal comercial fue evaluada, en el sector central de la Reserva Forestal Imataca en la Guayana venezolana.El enfoque conceptual de paisajes permitió combinar dos niveles de análisis, local y paisajes, con el objeto de detectar las relaciones espaciales que forman patrones, gradientes y estructuras, útiles para el seguimiento y control de los usos del bosque tropical y su estado de conservación. La evaluación integró varios métodos orientados a describir y analizar la composición, estructura y distribución de las comunidades arbóreas, tomando en cuenta su condición: no perturbado o perturbado.Se levantó información social relativa a los usos de la tierra considerados, a través de visitas y mediciones en las áreas de producción de las comunidades Kariñas, al igual que en concesiones forestales tomadas como muestra. Un inventario forestal en parcelas muestra, permitió colectar datos sobre algunos parámetros estructurales del bosque, los cuales sirvieron de base para calcular índices tales como diversidad alfa y beta, complejidad estructural y otros. La detección y cartografía de los bosques no perturbados y perturbados segun el uso considerado, se hizo sobre imagenes de satélite Landsat, a las cuales se aplicó técnicas de percepción remota tales como analisis textural, indices de vegetación y cobertura fraccional.Se estimaron áreas de superposición entre territorios tradicionales Kariña y concesiones forestales comerciales, las cuales probablemente serán objeto de nuevos conflictos que pueden ser graves, considerando el proceso de demarcación de territorios indígenas tradicionales en curso, y la explotación minera próxima a comenzar.El interés de estudiar la compleja situación de la Reserva Forestal Imataca se debe a la necesidad de promover un modelo sustentable de manejo y conservación de bosques para la Guayana venezolana.

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