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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.
71

Análise das mudanças na extensão do gelo marinho antártico e ártico entre 1979 e 2007 e sua relação com a variabilidade climática global. / Changes in arctic and antartic sea ice extent between 1979 and 2007 and its relationship to global climate variability.

Newton de Magalhães Neto 14 April 2011 (has links)
Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro / Recentes observações satelitais têm demonstrado um aumento na extensão total do gelo marinho Antártico e redução do gelo marinho no Ártico. Apesar destas constatações, no Oceano Sul análises regionais apontam tendências negativas nos mares de Bellingshausen-Amundsen e positivas no mar de Ross, enquanto que para o Ártico ocorrer uma redução uniforme do gelo marinho. Neste estudo, foi realizada uma análise multivariada para identificar as mudanças na extensão do gelo marinho Antártico e Ártico em resposta à variabilidade de um conjunto de forçantes/parâmetros/índices climáticos de reconhecida importância em escala global. Especificamente, as associações entre o gelo marinho e os parâmetros e forçantes climáticos foram examinadas através da correlação linear e da análise de agrupamento. Diferentes respostas em diferentes setores foram examinadas e discutidas. Os resultados indicam que a variabilidade do gelo marinho Antártico e Ártico é um fenômeno multivariado e que a extensão de gelo marinho mínima, média e máxima podem apresentar diferentes padrões espaciais e responderem a diferentes conjuntos de parâmetros e forçantes climáticos. Foi identificado um significativo impacto de forçantes/parâmetros/índices climáticos sobre o gelo marinho no Oeste Antártico. No hemisfério Norte o aumento da temperatura média global e do CO2 atmosférico são os principais responsáveis pela redução na extensão do gelo marinho. / Recent satellite observations have shown an increase in the total extent of Antarctic sea ice and a reduction of sea ice in the Arctic. Despite these findings, regional analyses in the Southern Ocean indicates negative trends in the Bellingshausen-Amundsen Sea and positive trends in the Ross Sea, while in the Arctic seems to occur a uniform reduction of sea ice. In this study, mutivariate analysis was performed to identify changes in Antarctic sea ice in response to changes in a set of climate forcings/parameters/indices. More specifically, the relationships between sea ice and climate forcings and parameters were examined by linear correlation and cluster analysis. Different responses in different sectors were examined and discussed. The findings indicate that Antarctic sea ice variability is a multivariate phenomenon and that the minimum, maximum, and mean sea ice extent depicts different spatial pattern and may respond to a different set of climate forcings/parameters/indices. A significant impact of climate forcings/parameters/indices occurs over western Antarctic. In the northern hemisphere the increase in global mean temperature and atmospheric CO2 seems to be the major responsible for the reduction in sea ice extent.
72

Processos pedogenéticos atuais e pretéritos em solos alcalino-sódicos do Pantanal Norte / Current and past pedogenic processes in alkaline-sodic soils of northern Pantanal

Jairo Calderari de Oliveira Junior 19 December 2014 (has links)
A ocorrência de solos sódicos é comumente relacionada a regiões de clima semiárido ou condições de drenagem fechada (endorreica), e ambientes evaporativos. No Pantanal brasileiro, conhecido como a maior área inundável continental do mundo, os solos sódicos possuem significativa expressão em termos de área e funcionalidade ambiental, pela especificidade no desenvolvimento de plantas e no consumo intencional do solo por diversos animais e servindo como refúgio durante a cheia. Estes solos estão localizados nas partes mais elevadas da paisagem (paleodiques), situação diversa da maioria dos casos. Os processos pedogenéticos em solos sódicos do Pantanal Norte foram estudados na Reserva Particular do Patrimônio Natural (RPPN) SESC-Pantanal, no município de Barão de Melgaço-MT, em paleodiques de cinco setores em diferentes estádios de dissecação. Para tanto foram utilizadas descrições morfológicas em diversas escalas, datações de 14C em precipitados de carbonato e por luminescência opticamente estimulada (LOE) em sedimentos, modelagens geoquímicas e mineralógicas, análises espaciais de atributos químicos e físicos do solo, levantamento da condutividade elétrica aparente com sensor eletromagnético (EM-38) e estatísticas multivariadas. Nos solos dos setores mais conservados, foram observadas feições típicas de ambiente sedimentar lêntico, lâminas de carbonato de cálcio e ocorrência de diatomáceas, sugerindo que a formação das feições ocorreu pela concentração de águas. Esses ambientes ocorreram em condições de drenagem distintas das atuais, em que as planícies de inundação permaneciam isoladas, com limitações de drenagem lateral e vertical, promovendo a perda d\'água por evapotranspiração e consequentemente concentrando os íons em solução. A simulação da evaporação das águas dos rios São Lourenço e Cuiabá apresentaram resultados similares, indicando que ambos poderiam resultar na precipitação de calcita e saturação do Na+ no complexo de troca. Entretanto as feições observadas na morfologia do perfil como nas lâminas delgadas sugerem que os solos sódicos atualmente estão em degradação. A argiluviação é muito intensa e se destaca como principal processo de transformação desses solos, ocorrendo desde os mais conservados até em estádio mais avançado de dissecação. A ferrólise é evidente no estádio mais avançado de transformação dos solos, na transição entre E e Bt onde se estabelece uma porosidade cavitária por depleção tanto mecânica como química. Os carbonatos associados a canais, antigos poros e sem córtex definido, sugerem que as condições atuais não favorecem a sua formação. As análises mineralógicas indicam a presença de esmectita na parte mais preservada do paleodique, que nas condições atuais sofre interestratificação esmectita-caulinita. A hidrologia atual promove a erosão gradativa dos paleodiques que, anteriormente isolavam as lagoas, passando a uma drenagem mais aberta. A análise de componentes principais (ACP) identificou o processo redox como predominante na área de estudo e, em conjunto com os eventos de inundação, são os principais responsáveis pelas transformações dos solos. A via de transformação de solos nos paleodiques da RPPN SESC Pantanal foi LUVISSOLO-PLANOSSOLO. Estes últimos são muito susceptíveis ao processo de erosão promovido pela inundação e tendem a desaparecer, estreitamento a cordilheira progressivamente. A erosão acaba deixando pequenas elevações circulares denominadas de murundus, com elevados teores de Na+. / Sodic soils are commonly associated to semi-arid climates, closed drainage systems (endorheic) and evaporative environments. In Brazilian Pantanal, knowns as the largest continental flooded area in the earth, sodic soils have significant expression in terms of area and environmental functionality, the specificity on plants development and soil intentional consumption (geophagy) by several animals, also playing as a refuge along the flooding events. These soils are located in the higher ground of the landscape (paleodiques), different from common situation. Pedogenic processes on north Pantanal sodic soils were studied in the Private Natural Heritage Reserve (PRNP) SESC Pantanal, in Barão do Melgaço-MT, performed on \"paleodiques\" from five sectors at different dissection stages. Pedogenic process was studied by means of morphologic descriptions was done in various scales, 14C dating on carbonate precipitates and optically stimulated luminescence (OSL) in sediments, geochemical and mineralogical modeling, spatial analysis of chemical and physical properties of the soil, apparent soil electrical conductivity performed by sensor electromagnetic (EM-38) and multivariate statistics. Soil profile from more conserved sectors shows typical features of lentic sedimentation environment, calcium carbonate layer and diatoms occurrence, suggesting that the formation of these features occurred by water concentration. Current condition is the opposite from earlier, wherein the flood plains remained isolated, with limited lateral and vertical drainage promoting water loss by evaporation and therefore concentrating the ions in solution. Simulation of the evaporation of water from São Lourenço and Cuiabá rivers points out similar results, suggesting that water evaporation from both could result in calcite precipitation and Na+ saturation in exchange complex. However, the features observed in both, field morphology and thin sections suggested that sodic soils are currently in degradation. The argilluviation is very intense and stands out as the main transformation process of these soils, occurring from the most preserved even in the most advanced dissection stage of. The ferrolysis is evident in the most advanced stage processing at E and Bt transition, where it establishes a cavity porosity depletion by both mechanical and chemical. Carbonates associated with channels, old pores and channels, without a cortex, suggests the current conditions do not favor sodic soil formation. Mineralogical analyzes indicates smectite presence in the paleodique of the most preserved sector, while present conditions promotes a smectite-kaolinite interestratification. Current hydrology promotes the gradual erosion of paleodiques that previously isolated the lakes from each other, becoming a slight open drainage system. The principal component analysis (PCA) identified the redox process as major process in the study area and, along the flood events, are primarily responsible for soil transformations. Pathway of sodic soil transformation in the RPPN SESC Pantanal paleodiques was Typic Natrudalf-Glossic Natraqualf. The latter are very susceptible to erosion process, promoted by flooding and tend to disappear, narrowing the paleodique progressively. Erosion process results in smalls and circulars elevations, named mounds, with high levels of Na+.
73

Contribuição ao estudo do valor, das perspectivas e da efetividade do mecanismo de desenvolvimento limpo no Protocolo de Kyoto / CONTRIBUTION TO THE VALUES STUDY, PERSPECTIVES AND EFFECTIVENESS OF THE CLEAN DEVELOPMENT MECHANISM OF THE KYOTOS PROTOCOL

Moraes, Luiz Antonio Grell de 24 June 2008 (has links)
Esta dissertação trata da história e características do Protocolo de Kyoto (PK), seguido do estudo do valor, das perspectivas e da efetividade do Mecanismo de Desenvolvimento Limpo (MDL), definido pelo Artigo 12 daquele Protocolo à Convenção Quadro das Nações Unidas sobre Mudança do Clima (CQNUMC). Nesse propósito, foram desenvolvidas análises conceituais das pretensões, possibilidades, valor e mesmo das equivocações do MDL. A grande importância desse instrumento acaba demonstrada que não é o seu objetivo primeiro, de auxilio nos compromissos dos países desenvolvidos (PDs), mas sim as diversas vantagens que promove para os países em desenvolvimento (PEDs). Esse instrumento de flexibilização, que foi concebido para auxiliar o cumprimento das obrigações (redução das emissões de CO2) dos países desenvolvidos (PDs) no Protocolo, pode ir muito além, com projetos de desenvolvimento sustentável (social, econômico, étnico, cultural, técnico e ambientalmente) adequados e favorável aos PEDs. Seus projetos podem e deve travar um bom combate à pobreza, o que garante também um avanço correto na perseguição do controle das causas e efeitos das mudanças climáticas. O MDL permeia todas essas questões e constitui o instrumento já presente e de conscientização, para trazer a necessária capacidade financeira e tecnológica do Norte ao encontro do Sul para que todas essas pretensões possam ocorrer. / This paper deals with the history and characteristics of the Kyotos Protocol (KP), followed by the values study about the prospects and effectiveness of the Clean Development Mechanism (CDM), as defined by the 12th Article of the Protocol to the United Nations Framework Convention on Climate Change (UNFCCC). In this purpose, conceptual analyses were developed about the objectives, possibilities, values and even mistakes of the CDM. The great importance of this instrument had been demonstrated that it is not its first objective to help the commitments of the developed countries, but the many advantages that promotes to the developing countries. This instrument of facility, which was conceived to assist the fulfillment of the obligations (reducing CO2 emissions) of developed countries in the Protocol, can go far beyond, with sustainable development projects (social, economic, ethnic, cultural, technical and environmentally) appropriated and favorable to developing countries. Their projects can and should fight against poverty, which also ensures a correct advance in pursuit of the causes and effects control of the climatic changes. The CDM permeates all these issues and is the instrument already present and of awareness, to bring the necessary financial and technological capacity from the North to the South, allowing these claims occur.
74

Detection, identification, and mapping of maize streak virus and grey leaf spot diseases of maize using different remote sensing techniques

Dhau, Inos January 2019 (has links)
Thesis (PhD. (Geography)) --University of Limpopo, 2019 / Of late climate change and consequently, the spread of crop diseases has been identified as one of the major threat to crop production and food security in subSaharan Africa. This research, therefore, aims to evaluate the role of in situ hyperspectral and new generation multispectral data in detecting maize crop viral and fungal diseases, that is maize streak virus and grey leaf spot respectively. To accomplish this objective; a comparison of two variable selection techniques (Random Forest’s Forward Variable, (FVS) and Guided Regularized Random Forest: (GRRF) was done in selecting the optimal variables that can be used in detecting maize streak virus disease using in-situ resampled hyperspectral data. The findings indicated that the GRRF model produced high classification accuracy (91.67%) whereas the FVS had a slightly lower accuracy (87.60%) based on Hymap when compared to the AISA. The results have shown that the GRRF algorithm has the potential to select compact feature sub sets, and the accuracy performance is better than that of RF’s variable selection method. Secondly, the utility of remote sensing techniques in detecting the geminivirus infected maize was evaluated in this study based on experiments in Ofcolaco, Tzaneen in South Africa. Specifically, the potential of hyperspectral data in detecting different levels of maize infected by maize streak virus (MSV) was tested based on Guided Regularized Random Forest (GRRF). The findings illustrate the strength of hyperspectral data in detecting different levels of MSV infections. Specifically, the GRRF model was able to identify the optimal bands for detecting different levels of maize streak disease in maize. These bands were allocated at 552 nm, 603 nm, 683 nm, 881 nm, and 2338 nm. This study underscores the potential of using remotely sensed data in the accurate detection of maize crop diseases such as MSV and its severity which is critical in crop monitoring to foster food security, especially in the resource-limited subSaharan Africa. The study then investigated the possibility to upscale the previous findings to space borne sensor. RapidEye data and derived vegetation indices were tested in detecting and mapping the maize streak virus. The results revealed that the use of RapidEye spectral bands in detection and mapping of maize streak virus disease yielded good classification results with an overall accuracy of 82.75%. The inclusion of RapidEye derived vegetation indices improved the classification accuracies by 3.4%. Due to the cost involved in acquiring commercial images, like xviii RapidEye, a freely available Landsat-8 data can offer a new data source that is useful for maize diseases estimation, in environments which have limited resources. This study investigated the use of Landsat 8 and vegetation indices in estimating and predicting maize infected with maize streak virus. Landsat 8 data produced an overall accuracy of 50.32%. The inclusion of vegetation indices computed from Landsat 8 sensor improved the classification accuracies by 1.29%. Overally, the findings of this study provide the necessary insight and motivation to the remote sensing community, particularly in resource-constrained regions, to shift towards embracing various indices obtained from the readily-available and affordable multispectral Landsat-8 OLI sensor. The results of the study show that the mediumresolution multispectral Landsat 8-OLI data set can be used to detect and map maize streak virus disease. This study demonstrates the invaluable potential and strength of applying the readily-available medium-resolution, Landsat-8 OLI data set, with a large swath width (185 km) in precisely detecting and mapping maize streak virus disease. The study then examined the influence of climatic, environmental and remotely sensed variables on the spread of MSV disease on the Ofcolaco maize farms in Tzaneen, South Africa. Environmental and climatic variables were integrated together with Landsat 8 derived vegetation indices to predict the probability of MSV occurrence within the Ofcolaco maize farms in Limpopo, South Africa. Correlation analysis was used to relate vegetation indices, environmental and climatic variables to incidences of maize streak virus disease. The variables used to predict the distribution of MSV were elevation, rainfall, slope, temperature, and vegetation indices. It was found that MSV disease infestation is more likely to occur on low-lying altitudes and areas with high Normalised Difference Vegetation Index (NDVI) located at an altitude ranging of 350 and 450 m.a.s.l. The suitable areas are characterized by temperatures ranging from 24°C to 25°C. The results indicate the potential of integrating Landsat 8 derived vegetation indices, environmental and climatic variables to improve the prediction of areas that are likely to be affected by MSV disease outbreaks in maize fields in semi-arid environments. After realizing the potential of remote sensing in detecting and predicting the occurrence of maize streak virus disease, the study further examined its potential in mapping the most complex disease; Grey Leaf Spot (GLS) in maize fields using WorldView-2, Quickbird, RapidEye, and Sentinel-2 resampled from hyperspectral data. To accomplish this objective, field spectra were acquired from healthy, moderate and xix severely infected maize leaves during the 2013 and 2014 growing seasons. The spectra were then resampled to four sensor spectral resolutions – namely WorldView-2, Quickbird, RapidEye, and Sentinel-2. In each case, the Random Forest algorithm was used to classify the 2013 resampled spectra to represent the three identified disease severity categories. Classification accuracy was evaluated using an independent test dataset obtained during the 2014 growing season. Results showed that Sentinel-2 achieved the highest overall accuracy (84%) and kappa value (0.76), while the WorldView-2, produced slightly lower accuracies. The 608 nm and 705nm were selected as the most valuable bands in detecting the GLS for Worldview 2, and Sentinel-2. Overall, the results imply that opportunities exist for developing operational remote sensing systems for detection of maize disease. Adoption of such remote sensing techniques is particularly valuable for minimizing crop damage, improving yield and ensuring food security.
75

Ant Association and Speciation in Lycaenidae (Lepidoptera): Consequences of Novel Adaptations and Pleistocene Climate Changes

Eastwood, Rodney Gordon, N/A January 2006 (has links)
The butterfly family Lycaenidae (including the Riodinidae) contains an estimated 30% of all butterfly species and exhibits a diverse array of life history strategies. The early stages of most lycaenids associate with ants to varying degrees, ranging from casual facultative coexistence through to obligate association where the long-term survival of the butterfly is dependent on the presence of its attendant ants. Attendant ants guard the butterflies against predators and parasites during their vulnerable period of larval growth and pupation. The caterpillars, in return, reward the ants by providing attractive secretions from specialized glands in their cuticle. The prevalence of caterpillar-ant associations in the species rich Lycaenidae is in contrast with other Lepidoptera, where ant association appears only as isolated cases in otherwise non ant-associated lineages. This has led to the proposal that ant association may have influenced lycaenid diversification or even enhanced the rates of speciation in the group. In contrast, facultative ant-associated butterflies exhibit high levels of host plant integrity, so it is reasonable to assume that host plants may have played a significant role in their diversification. Since the influence of ants (or plants) on diversification is independent of geographic speciation modes such as vicariance or peripheral isolates, there is an underlying inference of sympatric speciation. Certain prerequisites thought to be important for sympatric speciation, such as mating on the host plant (or in the presence of the appropriate ant) as well as ant dependent oviposition preferences are characteristic of many obligate myrmecophiles. Not surprisingly, it has been suggested that evidence for sympatric speciation is more likely to be found in the Insecta since this additional mode of diversification could account for the large numbers of insect species. This thesis tested the diversification processes in obligate and facultative ant associated lycaenids using comparative methodologies in hierarchical molecular phylogenetic analyses. First, several hypotheses relating to the influence of ants on diversification in obligately ant associated lycaenid butterflies were tested in a phylogeographic analysis of the Australian endemic Jalmenus evagoras. The phylogeographic analysis revealed that regional isolation of butterfly subpopulations coincident with locally adapted ant taxa could generate a phylogenetic pattern in which related lycaenids would be seen to associate with related or ecologically similar ants. Likewise, ecological shifts in habitat preferences by lycaenids could lead to co-diversification with habitat specialist ants, even though in both cases, the ants may play only an incidental role in the diversification process. A comparative methodology was then applied in a molecular phylogenetic analysis of the genus Jalmenus to test for a signal of diversification consistent with shifts in ant partners, and to infer the processes by which ants could influence speciation. Several other specific hypotheses relating to monophyly and taxonomy were also examined. Comparative analysis of the Jalmenus phylogeny found that attendant ant shifts coincided with high levels of sympatry among sister species. This pattern could be explained by sympatric speciation; however, data suggested it was more likely that ant shifts occurred during butterfly population expansions as a result of vegetation and climate changes in the Pleistocene. Fragmentation of populations associating with novel ants could promote rapid ecological and behavioural changes and this could result in reproductive isolation of conspecifics when in secondary contact. Diversification would then continue in sympatry. In contrast, secondary contact of populations associating with the same ant species would result in homogenisation of the two lycaenid lineages or the extinction of one. A phylogeographic analysis of the facultative myrmecophiles, Theclinesthes albocincta/T. hesperia, was then undertaken to infer the evolutionary processes (such as the effects of host plant shifts) that could result in extant demographics. Species-specific questions of taxonomy, relative population ages and dispersal routes in arid Australia were also addressed. Results from the analysis suggested the two taxa were conspecific and had diversified in the late Pleistocene as a consequence of isolation in refugia in and around the arid areas of mainland Australia. However, as was the case in the J. evagoras population analysis in which attendant ant shifts were not detected, host plant shifts were not detected in the population analysis of T. albocincta/hesperia. Host plant or attendant ant shifts manifest more frequently at the species level, thus it was necessary to test the influence of host plant shifts at this higher level. The comparative methodology was then applied to a molecular phylogenetic analysis of the facultative ant-associated section Theclinesthes (comprising Theclinesthes, Sahulana and Neolucia) to test for modes of diversification consistent with host plant shifts. The relative importance of other influences on diversification was also assessed. Akin to the Jalmenus analysis, the prediction that sister species ranges should broadly overlap when a shift in host plants had taken place was upheld in the comparative analysis. Species in the genera Jalmenus and Theclinesthes were found to have diversified in the Pleistocene so were subject to the same climatic oscillations that influenced patterns of vegetation expansion and contraction across much of Australia. Thus, the similarity and predictability of relationships in the comparative analyses based on biological data suggested that host plant shifts have influenced diversification in facultative myrmecophiles by inhibiting gene flow in secondary contact in similar fashion to that of attendant ant shifts identified in the Jalmenus phylogeny. Interpretation of data in these analyses suggested that allopatric diversification was the most common mode of speciation. Isolation was inferred to be the result of fragmentation following long distance dispersal across wide expanses of marginal habitat, or vicariance following the closing of biogeographical barriers. However, attendant-ant and host-plant shifts clearly played an important role in the diversification process, and in the maintenance of species integrity among lycaenid butterflies. Furthermore, exceptions to the predicted patterns of range overlap and ecological shifts provided clues to additional modes of diversification including shifts in habitat preferences and an unusual temporal shift following changes in specific host plant phenology resulting in allochronic diversification. Inferring modes of diversification using comparative methods based on range overlap and biological traits in a phylogenetic context is not new; however, the interpretation presented in this thesis is in contrast with contemporary methods. It is clear that the patterns of species range overlap and the ecological preferences of sister taxa are intimately related among lycaenid species that diversified during the Pleistocene. As a result, different influences on diversification can be highlighted in phylogenies when applying existing comparative methodologies but without necessarily drawing the same conclusions about modes of diversification. A more inclusive explanation for patterns of range overlap among sister taxa is detailed, a consequence of which is a method for estimating rates of extinction in a phylogeny where comprehensive distributional, biological and taxonomic data are available. These patterns and predictions may be applicable to a range of taxa, especially those that have diversified in the Pleistocene. Plans for future studies are outlined.
76

Refugiados no contexto das mudanças ambientais

Costa, Claudia Silvana da 21 March 2011 (has links)
Made available in DSpace on 2016-06-02T20:38:25Z (GMT). No. of bitstreams: 1 3618.pdf: 3675621 bytes, checksum: c80eab61aef75285d92e67dd1f57e718 (MD5) Previous issue date: 2011-03-21 / This thesis aims to focus on the construction of a subject called environmental refugee, new social group s formation that came from an adverse context, caused by the damaging effects of climate changes at its land which became inhabitable and inhospitable. Like that, unlike other refugees who leaved their countries for political, ethnic-religious, economical or social reasons, environmental refugees unwittingly has to leave their countries once in their lands has no way of survival because of the deleterious effects caused by climate change that are in the process, making certain territorial bases in social production and identity of peoples. Accordingly to the United Nations (UN) data, the number of environmental refugees on the planet will increase significantly over the next few years, mostly will come from Africa and from its other small Islands, which are those with greater vulnerability to the impacts of climate changes because of their geographical location, becoming like that, the potential environmental refugees. This way, trying to contribute to build a larger problematic for this matter inside a context that shows how necessary is to designate a definition that fits ruight this kind of refugees and to build a new legal framework guaranteeing to this group human being conditions, taking by example the case of São Tomé e Príncipe, small African s Island considered as States, with the clipping sample of Ilha de São Tomé, which is already under the risks of climate effects on its territory and with potential environmental refugees, providing like that, a reflection about the challenges of the environmental refugees, placing them on the spot of the legal Constitution. / Esta tese tem como objetivo focalizar a construção de um sujeito denominado refugiado ambiental, novo grupo social em formação, constituído a partir de um contexto adverso, ocasionado pelos efeitos deletérios das mudanças climáticas no território de origem que o tornaram inabitável e inviável para sobrevivência. Assim, diferentemente dos demais refugiados que deixam seus países por motivos de perseguição política, étnicoreligiosas, econômicas ou sociais, os refugiados ambientais involuntariamente deixam seu espaço de pertencimento por estarem desterritorializados em razão dos efeitos deletérios provocados pelas mudanças climáticas que estão em processo, inviabilizando determinadas bases territoriais na produção social e identitária dos povos internos. De acordo com os dados da Organização das Nações Unidas (ONU), haverá nos próximos anos um aumento significativo do número de refugiados ambientais no planeta, provindos, principalmente, da África e dos pequenos Estados insulares, que, em decorrência da localização geográfica, serão os que apresentam maior vulnerabilidade aos impactos das mudanças climáticas, sendo, assim, potenciais refugiados ambientais. Deste modo, visando contribuir com a construção de uma problemática maior desse sujeito num contexto em que se mostre necessária a readequação do conceito de refugiado e da constituição de um novo arcabouço jurídico legal que garanta a este grupo condições de um ser humano, tomaremos como exemplo o caso de São Tomé e Príncipe, pequeno Estado insular africano, com o recorte amostral da Ilha de São Tomé, que já se encontra diante dos riscos dos efeitos do clima em seu território e com potenciais refugiados ambientais, proporcionando, com isso, a reflexão para os novos desafios postos à questão dos refugiados ambientais como sujeitos em constituição.
77

Diálogos entre stakeholders em redes de organizações de agronegócios na busca da mitigação dos efeitos da mudança climática: o caso do Instituto do Agronegócio responsável - ARES

Azevedo, Denise Barros de January 2010 (has links)
O atual momento de incertezas induzidas pelas mudanças climáticas no agronegócio brasileiro tem-se mostrado oportuno para pesquisar as ações em torno das cadeias produtivas como um todo. Analisar como o agronegócio brasileiro está se preparando para se posicionar e agir diante das novas realidades climáticas é crucial tanto para a academia como para o futuro das atividades produtivas. As incertezas geradas por esse novo contexto associadas à ausência de diálogos e de diretrizes assim como a resistência a mudanças e a falta de confiança entre os stakeholders do agronegócio tornam-se problemas para o agronegócio,. Assim, a formação de redes entre stakeholders do agronegócios é fundamental para promover o conhecimento coletivo e propor convenções específicas para o momento atual e para o futuro. Nesse contexto, o conflito entre produção de bioenergia e alimentos é uma discussão central no agronegócio mundial e nacional. As questões levantadas nesta pesquisa são: como os diálogos entre stakeholders do agronegócio podem contribuir com os relacionamentos entre as organizações em rede? Qual o papel no agronegócio na discussão das mudanças climáticas no contexto do dilema da bioenergia? O objetivo da presente pesquisa é o de propor um framework para analisar a natureza dos diálogos entre stakeholders e os modelos criados para atuar nos conflitos da bioenergia e das oportunidades em redes voltadas para bioenergia com relação às mudanças climáticas no agronegócio brasileiro. Para isso, foram usadas as abordagens teóricas de Stakeholders, Redes, Negociação, Conflitos e Teoria das Convenções. Esta pesquisa classifica-se como de natureza exploratória e qualitativa, e o método adotado para a realização desta pesquisa é o de estudo de casos. Foram analisadas as organizações relacionadas com bioenergia participantes do Instituto ARES. O ARES é uma instituição inédita ligado ao agronegócio Brasileiro com intuito de promover o diálogo entre as cadeias produtivas.Os resultados da pesquisa mostram que o dilema de produção de bioenergia e alimento são aceitos seriamente pelos stakeholders, uma vez que estão dispostos a agirem em conjunto, criando bases para construção da confiança entre as diferentes cadeias produtivas; isto é, cadeias produtivas diferentes preocupando-se com outras cadeias. Esta visão permite a formação de redes, mesmo com os conflitos que existem entre elas, com negociações embasadas em confiança, coletividade, comunicação, interesses diversos com soluções únicas (estratégicas) em forma de convenções. A contribuição da pesquisa está relacionada as novas formas de análises teóricas entre os stakeholders do agronegócios. / The current moment of uncertainties induced by climate changes in the Brazilian agribusiness has been convenient for researching the actions related to the productive chains as a whole. Analyzing the way chosen by the Brazilian agribusiness to face the new climate realities is crucial both for the academy and the future of productive activities. The uncertainties generated by the new context associated to the absence of dialogues and guidelines as well as the resistance to changes and the lack of confidence among the agribusiness stakeholders have become a problem for the agribusiness. Then, it is fundamental the network formation among the agribusiness stakeholders to promote the collective knowledge and propose specific conventions for the current moment and the future. In this context, the conflict between bioenergy production and food is the central discussion of the national and international agribusiness. The issues raised in this survey are: How can the dialogues among the agribusiness stakeholders contribute to the relationships among the organizations of the network? What is the role of agribusiness in the discussion of climate changes within the bioenergy dilemma? The goal of this survey is to propose a framework to analyze the nature of dialogues among stakeholders and the models created to act in the conflicts of bioenergy and the opportunities in networks linked to bioenergy in relation to the climate changes in the Brazilian agribusiness. The theoretical approaches of Stakeholdes, Networks, Negotiation, Conflicts and Convention Theories were used to answer these questions. This survey is classified as exploratory and qualitative in nature and the method adopted is the case study. It was analyzed the organizations related to bioenergy participating in the Institute ARES. ARES is a new institution linked to the Brazilian agribusiness, aiming at promoting the dialogue among the production chains. The results of the survey show that the dilemma of bioenergy and food production are seriously considered by the stakeholders, since they want to act together, creating bases for the construction of confidence among the different productive chains; that is, different productive chains worried about other chains. This view allows the network formations, even with the conflicts existing among them, using negotiations based in trust, collectivity, communication and different interests related to exclusive solutions (strategies) used as conventions.The contribution of this survey is related to the new ways of theoretical analyzes among the stakeholders of agribusiness.
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Pegada de carbono do melão produzido em sistema convencional ou conservacionista / Melon carbon Footprint produced in conventional or conservation system

Barros, Viviane da Silva 09 October 2015 (has links)
Made available in DSpace on 2016-08-12T19:18:36Z (GMT). No. of bitstreams: 1 VivianeSB_TESE.pdf: 3169033 bytes, checksum: 502e3e06c40421e419b1e2cd13178f58 (MD5) Previous issue date: 2015-10-09 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This study evaluates the environmental impact of melon production systems on climate change, integrating the research lines of the Brazilian Agricultural Research Corporation (Embrapa). It is the result of partnership held among Embrapa - Tropical Agroindustry, the Federal Rural University of Semi-Arid (UFERSA), and the University of Massachusetts (UMass). The research is based on an evaluation of the product life cycle (melon), focusing on climate change impact category. The study was conducted in two stages, one held in Brazil, in 2011, and the second, in the US, between 2014 and 2015. In Brazil, data were collected in the experimental area located in Agricola Famosa farm, located in the municipality of Tibau, RN, with order to determine the efficiency of farming systems practiced today (conventional) and conservation, based on the use of green manure. In the conventional system, the melon (Goldex) was cultivated after the merger of spontaneous vegetation and conservation system, after overturning or incorporation of plant biomass from the green manure with maize intercropped with braquiária and Guandu beans. The product system refers to melon production in Brazil covered production in conventional and conservation systems considering the following processes: production of green fertilizers seeds and melon, biomass production of green manure production melon seedlings production melon field, packaging and transport of melons to Europe, as well as production and transportation of supplies for the experimental area. The stage of the research conducted in the United States sought to determine the conventional cultivation system efficiency currently practiced in the experimental farm of UMass. Thus, this product system included the production of seeds and melon seedlings production in melon field, packaging and transport of melon, production and transport of inputs for the experimental area of UMass. In Brazil, the best result of carbon footprint was the conservationist corn intercropping system with braquiária with incorporation that generates an average carbon footprint of 647.82 CO2-eq / t melon, while the footprint of Brazilian conventional system is 756, 90 kg CO2-eq / t. Detailing the process, we observe that the change of land use and melon transportation Port of Pecém, CE, to the port of Rotterdam, in the Netherlands, are the processes that most contribute to the carbon footprint of melon produced in Brazil. The change of land use, due to the increasing number productive melon areas in Northeast Brazil, including Jaguaribe-Açu polo, we consider the emissions for the transformation of land with scrub vegetation to melon producing area. In the US, the footprint is 356 kg CO2-eq/t, and the packaging process is the largest contributor to this result. It is important to note that the land use change impact was not considered in the US, because this change has occurred more than 20 years ago on the farm UMass. We conclude that in terms of environmental efficiency, the best result in Brazil occurs in the conservation system, showing that green manure increases soil organic matter, thus reducing the carbon footprint. In order to reduce the footprint of Brazilian melons, making it as competitive as the US, it is necessary to held to melon production in agricultural areas with natural vegetation removed for more than 20 years before. The results of this research subsidize actions to improve the competitiveness of Brazilian melons front of potential non-tariff barriers related to reducing emissions of greenhouse gases by agriculture and adoption of low carbon practices / Esse estudo avalia o impacto ambiental de sistemas de produção de melão sobre as mudanças climáticas, integrando as linhas de pesquisa da Empresa Brasileira de Pesquisa Agropecuária (Embrapa). É resultado de parceria realizada entre a Embrapa - Agroindústria Tropical, a Universidade Federal Rural do Semi-Árido (UFERSA), e a University of Massachusetts (UMass). A pesquisa é baseada na avaliação do ciclo de vida do produto (melão), com foco na categoria de impacto Mudança Climática. O trabalho foi realizado em duas etapas, uma realizada no Brasil, em 2011, e a segunda, nos EUA, entre 2014 e 2015. No Brasil, dados foram coletados na área experimental localizada na fazenda Agrícola Famosa, situada no município de Tibau-RN, com o objetivo de determinar a eficiência de sistemas de cultivo atualmente praticados (convencional) e conservacionistas, fundamentados no uso de adubação verde. No sistema convencional, o melão (Goldex) foi cultivado após a incorporação da vegetação espontânea, e no sistema conservacionista, após o tombamento ou incorporação da biomassa vegetal proveniente dos adubos verdes milho consorciado com braquiária e feijão guandu. O sistema de produto referente à produção de melão no Brasil abrangeu a produção em sistemas convencional e conservacionistas, considerando os seguintes processos: produção de sementes de adubos verdes e de melão, produção da biomassa de adubo verde, produção de mudas de melão, produção em campo de melão, embalagem e transporte do melão à Europa, bem como produção e transporte dos insumos para a área experimental. A etapa da pesquisa realizada nos Estados Unidos buscou determinar a eficiência do sistema de cultivo convencional atualmente praticado na fazenda experimental da UMass. Assim, esse sistema de produto abrangeu a produção de sementes e mudas de melão, produção em campo de melão, embalagem e transporte do melão, produção e transporte dos insumos para a área experimental da UMass. No Brasil, o melhor resultado de pegada de carbono foi do sistema conservacionista milho consorciado com braquiária com incorporação que gera uma pegada de carbono média de 647,82CO2-eq/t de melão, ao passo que a pegada do sistema convencional brasileiro é de 756,90 kg CO2-eq/t. No detalhamento dos processos, observa-se que a mudança do uso da terra e o transporte do melão do Porto do Pecém, CE, para o porto de Roterdam, na Holanda, são os processos que mais contribuem para a pegada de carbono do melão produzido no Brasil. Na mudança do uso da terra, devido ao crescente aumento de áreas produtoras de melão no Nordeste Brasileiro, incluindo o polo Jaguaribe-Açu, consideram-se as emissões referentes à transformação da terra com vegetação de caatinga para área produtora de melão. Nos EUA, a pegada é de 356 kg CO2-eq/t, sendo o processo de embalagem o que mais contribui com esse resultado. É importante salientar que o impacto da mudança do uso da terra não foi considerado nos EUA, em virtude de essa mudança ter ocorrido há mais de 20 anos na fazenda UMass. Conclui-se que, em termos de eficiência ambiental, o melhor resultado no Brasil ocorre no sistema conservacionista, demonstrando que a adubação verde incrementa a matéria orgânica no solo, reduzindo, consequentemente, a pegada de carbono. Para reduzir a pegada do melão brasileiro, tornando-o tão competitivo quanto o americano, deve-se realizar a produção de melão em áreas agrícolas com vegetação natural removida há mais de 20 anos. Os resultados desse trabalho subsidiam ações visando à melhoria da competitividade do melão brasileiro frente às potenciais barreiras não tarifárias relacionadas à redução das emissões de gases de efeito estufa pela agricultura e adoção de práticas de baixo carbono
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[en] WHAT IS GLOBAL IN THE CLIMATE THREAT?: CARTOGRAPHIC ANALYSIS OF THE CLIMATE-SECURITY NEXUS / [pt] O QUE HÁ DE GLOBAL NA AMEAÇA CLIMÁTICA?: ANÁLISE CARTOGRÁFICA DO NEXO SEGURANÇA E CLIMA

BRUNO EDUARDO PORTELA BORGES DE MAGALHAES 11 August 2010 (has links)
[pt] A dissertação reconstrói o plano social formado em torno do debate público sobre os impactos de segurança das mudanças climáticas. Emprega para tanto o método de mapeamento de controvérsias desenvolvido por Pierre Bourdieu, que consiste no posicionamento dos agentes envolvidos no debate em um plano cartesiano, simbolizando as distâncias sociais entre os mesmos. Neste plano se cruzam um eixo horizontal, no qual os agentes são posicionados em função da caracterização que oferecem da ameaça climática (ênfase em segurança humana x ênfase em segurança geopolítica e militar), e um eixo vertical, no qual as coordenadas dos agentes são definidas a partir do tipo de medidas que advogam para o enfrentamento dos impactos de segurança do fenômeno (adaptação preventiva x adaptação reativa). Cruzando as tomadas de posição dos agentes nestes dois eixos, a pesquisa se propõe a avaliar a compatibilidade entre os resultados encontrados e os argumentos de Ulrich Beck, Didier Bigo, Jef Huysmans, Claudia Aradau e Rens Van Munster acerca dos impactos políticos do novo tipo de risco incomensurável que o fenômeno representa. Discute-se, em específico, a tese que associa a securitização das mudanças climáticas à transição de um modelo comunitarista de organização do sistema internacional rumo a um modelo centrado em um senso de pertencimento global. A dissertação tem como ambição, portanto, analisar os efeitos que as diferentes concepções de segurança climática vêm exercendo sobre a compreensão espaço-temporal moderna. Como conclusão, captura uma inclinação do debate em favor de uma concepção do global entendida como troca entre unidades particulares e uma predileção dos agentes por práticas de gerenciamento de risco. / [en] The dissertation maps the social space created around the public discussion concerning the security impacts of climate change. Pierre Bourdieu’s method of controversy mapping was applied, which consisted in positioning the agents involved in the debate on a Cartesian plane, symbolizing the social distances between them. The social map is formed by the intersection of two axes: first, the horizontal axis, in which actors are positioned according to how they frame the climate threat (emphasis on human security x emphasis on geopolitical and military security). Second, a vertical axis, in which agents are located according to the type of measures they advocate to deal with the security impacts of the phenomenon (preventive adaptation x reactive adaptation). By crossing agents’ positions in these two axes, the research tried to evaluate the consistency between its results and the arguments of Ulrich Beck, Didier Bigo, Jef Huysmans, Claudia Aradau and Rens van Munster concerning the political impacts of the new kind of unmanageable risk climate change represents. The dissertation evaluates, in particular, the hypothesis linking the securitization of climate change with the transcendence move from a communitarian international system towards a model based on a global sense of belonging. The research aimed, therefore, to analyze the effects that the different conceptions of climate security are having upon the modern understanding of space and time. As a conclusion, the dissertation identified an inclination among the analyzed agents towards a conception of the global understood as an exchange between well delineated particulars and a propensity towards practices of risk management.
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Diálogos entre stakeholders em redes de organizações de agronegócios na busca da mitigação dos efeitos da mudança climática: o caso do Instituto do Agronegócio responsável - ARES

Azevedo, Denise Barros de January 2010 (has links)
O atual momento de incertezas induzidas pelas mudanças climáticas no agronegócio brasileiro tem-se mostrado oportuno para pesquisar as ações em torno das cadeias produtivas como um todo. Analisar como o agronegócio brasileiro está se preparando para se posicionar e agir diante das novas realidades climáticas é crucial tanto para a academia como para o futuro das atividades produtivas. As incertezas geradas por esse novo contexto associadas à ausência de diálogos e de diretrizes assim como a resistência a mudanças e a falta de confiança entre os stakeholders do agronegócio tornam-se problemas para o agronegócio,. Assim, a formação de redes entre stakeholders do agronegócios é fundamental para promover o conhecimento coletivo e propor convenções específicas para o momento atual e para o futuro. Nesse contexto, o conflito entre produção de bioenergia e alimentos é uma discussão central no agronegócio mundial e nacional. As questões levantadas nesta pesquisa são: como os diálogos entre stakeholders do agronegócio podem contribuir com os relacionamentos entre as organizações em rede? Qual o papel no agronegócio na discussão das mudanças climáticas no contexto do dilema da bioenergia? O objetivo da presente pesquisa é o de propor um framework para analisar a natureza dos diálogos entre stakeholders e os modelos criados para atuar nos conflitos da bioenergia e das oportunidades em redes voltadas para bioenergia com relação às mudanças climáticas no agronegócio brasileiro. Para isso, foram usadas as abordagens teóricas de Stakeholders, Redes, Negociação, Conflitos e Teoria das Convenções. Esta pesquisa classifica-se como de natureza exploratória e qualitativa, e o método adotado para a realização desta pesquisa é o de estudo de casos. Foram analisadas as organizações relacionadas com bioenergia participantes do Instituto ARES. O ARES é uma instituição inédita ligado ao agronegócio Brasileiro com intuito de promover o diálogo entre as cadeias produtivas.Os resultados da pesquisa mostram que o dilema de produção de bioenergia e alimento são aceitos seriamente pelos stakeholders, uma vez que estão dispostos a agirem em conjunto, criando bases para construção da confiança entre as diferentes cadeias produtivas; isto é, cadeias produtivas diferentes preocupando-se com outras cadeias. Esta visão permite a formação de redes, mesmo com os conflitos que existem entre elas, com negociações embasadas em confiança, coletividade, comunicação, interesses diversos com soluções únicas (estratégicas) em forma de convenções. A contribuição da pesquisa está relacionada as novas formas de análises teóricas entre os stakeholders do agronegócios. / The current moment of uncertainties induced by climate changes in the Brazilian agribusiness has been convenient for researching the actions related to the productive chains as a whole. Analyzing the way chosen by the Brazilian agribusiness to face the new climate realities is crucial both for the academy and the future of productive activities. The uncertainties generated by the new context associated to the absence of dialogues and guidelines as well as the resistance to changes and the lack of confidence among the agribusiness stakeholders have become a problem for the agribusiness. Then, it is fundamental the network formation among the agribusiness stakeholders to promote the collective knowledge and propose specific conventions for the current moment and the future. In this context, the conflict between bioenergy production and food is the central discussion of the national and international agribusiness. The issues raised in this survey are: How can the dialogues among the agribusiness stakeholders contribute to the relationships among the organizations of the network? What is the role of agribusiness in the discussion of climate changes within the bioenergy dilemma? The goal of this survey is to propose a framework to analyze the nature of dialogues among stakeholders and the models created to act in the conflicts of bioenergy and the opportunities in networks linked to bioenergy in relation to the climate changes in the Brazilian agribusiness. The theoretical approaches of Stakeholdes, Networks, Negotiation, Conflicts and Convention Theories were used to answer these questions. This survey is classified as exploratory and qualitative in nature and the method adopted is the case study. It was analyzed the organizations related to bioenergy participating in the Institute ARES. ARES is a new institution linked to the Brazilian agribusiness, aiming at promoting the dialogue among the production chains. The results of the survey show that the dilemma of bioenergy and food production are seriously considered by the stakeholders, since they want to act together, creating bases for the construction of confidence among the different productive chains; that is, different productive chains worried about other chains. This view allows the network formations, even with the conflicts existing among them, using negotiations based in trust, collectivity, communication and different interests related to exclusive solutions (strategies) used as conventions.The contribution of this survey is related to the new ways of theoretical analyzes among the stakeholders of agribusiness.

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