Made available in DSpace on 2016-06-02T19:51:45Z (GMT). No. of bitstreams: 1 3170.pdf: 3930564 bytes, checksum: 6bc091724513b521d14710a292adacf5 (MD5) Previous issue date: 2010-06-28 / Financiadora de Estudos e Projetos / The purpose of this research is to analyse the participatory construction of the technological space of a solidarity economy organization of production and commercialization of Brazil nuts integrated by inhabitants of riverside communities of the Lower Madeira River, in Rondônia. The restore of household extractive economies is one of the proposals of forest peoples social movements to match life quality improvement and environmental conservation. This opposes to the hegemonic model of development of the Amazon Rainforest region, based on technocratic state intervention, which is responsible for the harsh social and environmental crises that hit the region and which has in the expel of.traditional forest people from their home lands one of the most perverse effects. New extractive economies have two features that also oppose the early rubber tapping period. Firstly it is based on democratic work relations, what suggest a connection with solidarity economy movement. On the other hand, it purposes it should incorporate new technologies which would radically improve productive forces, calling for integration with social technology movement. Exploring the existing synergies of these counter-hegemonic movements, the dissertation aims to demonstrate that engineers, technologists and other professionals involved with technological development may assume an important role to merge community strengthen and forest conservation. To do so, the methodology developed by Herrera (1981), alluding to the generation and technology for rural areas, is taken as an important reference. The scope of this method is adapted to be applicable to a solidarity economy organization including extractivists of the Lower Madeira River producing and commercializing Brazil nuts. Recognizing the social character of rational systems, the methodology demands qualified participation of the workers and results in the technological space of the organization, agreed upon the associated producers and the professionals aiming to support them. The experience of the adapted method proved to be effective, pointing out that real engagement of specialists with social transformation demands the capacity of dialoguing with groups which and usually considered irrelevant in the technological development process. / O trabalho busca analisar a construção participativa do espaço tecnológico de um empreendimento econômico solidário de produção e comercialização de castanha da Amazônia formado por moradores de comunidades ribeirinhas do Baixo Rio Madeira, em Rondônia. A revigoração da economia extrativista constitui uma das propostas dos movimentos sociais de populações tradicionais da floresta, buscando compatibilizar a melhoria na qualidade de vida com a conservação ambiental. Contrapõe-se, assim, ao modelo de desenvolvimento baseado na intervenção tecnocrática do Estado, responsável pela instauração da crise socioambiental vivenciada atualmente na região, que tem no violento processo de desterritorialização de comunidades tradicionais, um de seus componentes mais perversos. O novo extrativismo tem duas características fundamentais para sua viabilização e que o diferenciam do extrativismo praticado durante os ciclos da borracha. Primeiramente, ele se baseia em formas democráticas de organização do trabalho, o que sugere o diálogo com o movimento da economia solidária. Além disso, propõe a melhoria da qualidade das forças produtivas por meio da incorporação de novas tecnologias, o que aponta para interação com o movimento da tecnologia social. Ao explorar as sinergias existentes entre esses movimentos contra-hegemônicos, a dissertação busca mostrar que engenheiros, tecnólogos e outros especialistas envolvidos com o desenvolvimento tecnológico podem assumir um papel importante para compatibilizar o fortalecimento das comunidades da floresta e a conservação da Amazônia. Para tanto, toma-se como referência a metodologia desenvolvida por Herrera (1981), voltada para áreas rurais, que foi adaptada para a geração e avaliação de tecnologias em empreendimentos econômicos solidários e aplicada no âmbito da produção e comercialização coletivas de castanha pelos extrativistas do Baixo Madeira. Tal método reconhece o caráter social dos sistemas racionais, demandando a participação qualificada dos produtores e tem como resultado o espaço tecnológico do empreendimento, que corresponde a uma agenda pactuada com os associados para a atuação de profissionais engajados em seu apoio. Sua aplicação junto aos produtores se mostrou eficaz, contribuindo para evidenciar que o efetivo engajamento de especialistas com a transformação social demanda disposição para dialogar com grupos cujas formas de enxergar o mundo e saberes são muitas vezes vistas como irrelevantes no processo de desenvolvimento tecnológico.

Os estudos da anatomia macro e microscópica do lenho como ferramenta auxiliar na taxonômia, sobretudo na identificação de espécies florestais, vêm sendo utilizados há décadas. A análise comparativa da estrutura anatômica do lenho permite a identificação de características morfológicas exclusivas das ordens, famílias, gêneros e, em muitos casos, de espécies, aumentando a gama de caracteres utilizados na descrição e identificação botânica de espécies arbóreas pela taxonomia clássica. No presente trabalho, foram utilizadas técnicas de análise comparativa e de descrição da estrutura anatômica macro e microscópica do lenho de árvores de espécies que ocorrem naturalmente na floresta tropical Amazônica nos municípios de Santarém, Mojú, Paragominas e Tailândia, no estado do Pará. Os objetivos do trabalho foram (i) caracterizar a estrutura anatômica macro e microscópica do lenho; (ii) identificar as características de valor taxonômico através de análise comparativa da estrutura anatômica do lenho; (iii) elaborar chaves de identificação das espécies pela estrutura anatômica macro e microscópica do lenho. Foram analisadas 100 amostras do lenho do tronco de árvores de 64 espécies, coletadas em 2004, pelo projeto Dendrogene/Embrapa Amazônia Oriental. A superfície das amostras do lenho foi polida com lixas e navalhas, seguindo-se a sua descrição macroscópica; lâminas histológicas do lenho foram preparadas com navalha de micrótomo de deslize, para a descrição microscópica do lenho. Os resultados possibilitaram, pela análise comparativa da estrutura anatômica do lenho, confeccionar as chaves de identificação macroscópica de 49 espécies dos 51 gêneros. Os gêneros Hymenolobium e Virola com 4 e 2 espécies, respectivamente, não puderam ser separados. A chave de identificação microscópica permitiu identificar 64 das espécies estudadas. A análise comparativa do lenho permitiu, da mesma forma, evidenciar 25 espécies com potencial para a dendrocronologia, sendo 10 e 15, com anéis de crescimento com distintos e pouco distintos, respectivamente. A aplicação da anatomia do lenho como importante ferramenta com potencial a taxonomia de espécies florestais é discutida no presente trabalho / Studies of macro and microscopic wood anatomy as an auxiliary tool in taxonomy, particularly in the identification of forest tree species, have been used for decades. Comparative analysis of the wood anatomical structure allows the identification of unique morphological characteristics of the orders, families, genera, and in many cases, species, increasing the range of characters used in the botanical description and identification of tree species by classical taxonomy. In this work, techniques were used for comparative analysis and description of the anatomical structure of macro and microscopic wood tree species, that occur naturally in the Amazon rainforest in the Santarém, Mojú Paragominas and Tailândia cities, in Pará State. The aims of the study were (i) to characterize the macro and microscopic anatomical wood structure, (ii) identify the characteristics of taxonomic value through a comparative analysis of the wood anatomical structure, (iii) prepare the keys for species identification by macroscopic and microscopic wood anatomical structure. Were analyzed 100 wood samples from 64 tree species collected in 2004, in the project Dendrogene/Embrapa Amazonia Oriental. The surface of wood samples was polished with sandpaper and knives, according to their macro description; histological wood sections were prepared with razor sliding microtome, for microscopic wood description. The results allowed for the comparative analysis of the anatomical wood structure, to produce the macroscopic identification keys to 49 species of 51 genera. The genera Hymenolobium and Virola species with 4 and 2, respectively, could not be separated. The results from comparative wood anatomy showed evidence of 25 tree species with high potential for dendrochronological studies in order to distinct tree-ring presence (10 species) and barely distinct tree-rings (15 species). The application of wood anatomy, as an important tool with the potential of forest species taxonomy is discussed in this paper.

In recent decades expanding land-use change has caused extensive deforestation of the tropical rainforestinducing large-scale transformation of the landscape patterns across the South American continent. Landscapechange is a modification process of the natural forest cover into fragments which generate various ecologicalimpacts. Habitat loss is identified to be a major threat to biodiversity, as it exposes species to the risk ofextinction. This study investigates 80 locations within tropical rainforest biomes to examine the landscape changewhich has occurred from 1993 – 2014. The intention is to identify the impacts of landscape fragmentation onhummingbird species diversity by spatial landscape analysis in GIS and regression modeling. The analysis foundthat there is no relationship between deforestation and reduction of hummingbird diversity. The results indicatethat hummingbird species are not particularly sensitive to landscape change as they have high resilience in regardto forest fragmentation. A potential threshold value of deforestation degree could be identified, up to whichhummingbird species richness increased, but locations subjected to over 40% fragmentation were estimated tohave lower hummingbird diversity. However, by using the spatial explicit biological data, the analysis indicatethat an extinction debt may exist in the landscape, and that future extinctions may be expected to occur in thefollowing decades as consequence of deforestation. Other factors may be as important determining variables forspecies richness: the spatial scale of the study, the habitat connectivity, hummingbird generalist tendencies.Conclusively, identification of the key factors of deforestation impacts on species diversity is essential for futureefficiency in conservation planning and sustainability of the tropical rainforest biodiversity.

Introduction : Bien que les données officielles fassent état d’une diminution globale du nombre de cas de paludisme en Guyane, les orpailleurs travaillant sur les sites illégaux au cœur de la forêt amazonienne semblent très touchés par cette pathologie. L’objectif principal de cette étude était de déterminer la prévalence du paludisme dans cette population. Les objectifs secondaires évaluaient la proportion des différentes espèces plasmodiales et leur distribution géographique, le niveau de résistance des parasites aux dérivés de l’artémisinine, les connaissances attitudes et pratiques vis à vis de cette pathologie, et des données de santé de cette population. Matériel et méthodes : Les inclusions ont eu lieu sur les sites de repli des orpailleurs le long du fleuve Maroni. Après recueil du consentement éclairé, un test de diagnostic rapide du paludisme était effectué, ainsi qu’un questionnaire, un examen clinique, et un prélèvement de sang pour microscopie, PCR et tests de résistance (RSA et génotypage du gène pfK13 pour les PCR positives à Plasmodium falciparum). Résultats : De janvier à juin 2015, 421 orpailleurs ont été inclus, majoritairement des hommes (70,6%) brésiliens (93,8%), de médiane d’âge de 37 ans. La prévalence du portage de plasmodies déterminée par PCR était de 22,3% (IC95% : 18,3-26,3) à 84% asymptomatiques. Les espèces identifiées étaient principalement P. falciparum (47,9%) puis P. vivax (37,2%) avec 10,6% de coinfections. Lors du dernier accès palustre, 52,4% des orpailleurs avaient eu recours à l’automédication, majoritairement avec des dérivés de l’artémisinine (93,8%) avec une mauvaise observance (37,8%). Le fait d’être en Guyane était fortement associé à l’automédication (AOR=22,1). Le test RSA montrait un taux de survie supérieur à 1% pour un échantillon mais l’analyse du gène pfK13 ne mettait pas en évidence de mutations associées à la résistance à P. falciparum Discussion: La prévalence élevée de porteurs asymptomatiques de paludisme constitue un réservoir important pourla transmission du paludisme dans la région. L’utilisation massive de dérivés de l’artémisinine associée à une mauvaise observance sont des facteurs de risque d’émergence de résistance, ce qui entraînerait des conséquences sanitaires et économiques importantes. Avec une volonté politique, des actions sont possibles pour limiter ce risque, comme la distribution de kits d’autodiagnostic et d’auto-traitement avec une formation au niveau des sites de repli. / Introduction: Although official data show a global decrease of malaria in French Guiana, this disease often affects illegal gold miners working in the deep Amazonian forest. The main objective of this study was to evaluate the malaria prevalence in this population. The secondary objectives were to evaluate and map the proportion of Plasmodium species, to assess behavior, attitudes and practices regarding malaria in this population, to measure the artemisinin resistance level in parasites and to evaluate their general health. Material and methods: Inclusions took place at the gold miners’ resting sites, spread along the Maroni river. After recording their informed consent, a malaria rapid test was performed, as well as a questionnaire, a clinical exam and a blood sample for microscopy, PCR and resistance test (RSA and PfK13 genotyping for P. falciparum positive samples). Results: From January to June 2015, 421 gold miners were included, mainly men (sex ratio 2.4), Brazilian nationals (93.8%), with a median age of 37 years. Plasmodium prevalence using PCR was 22.3% (CI95%: 18.3 - 26.3), of whom 84% were asymptomatic. During the last malaria attack, 52.4% selfmedicated with artemisinin derivatives (93.8%) and a poor treatment adherence (37.8%). Being in French Guiana when the malaria attack occurred was strongly associated with selfmedication (AOR=22.1). One sample showed a survival rate higher than 1% in RSA test but PfK13 genotyping did not reveal any mutation in P. falciparum. Discussion: This high prevalence of asymptomatic carriers constitutes a huge reservoir for malaria transmission in the region. Massive use of artemisinin derivatives associated with poor treatment adherence are factors that may contribute to the emergence of artemisinin resistance. That would have huge sanitary and economical consequences. With political will, actions are possible to limit this risk, as the distribution of kits for self diagnosis and self-treatment with training on resting sites.

Les études dans les régions isolées de la Guyane française sont rares. L'objectif principal de ce travail est d'analyser les principales données épidémiologiques résultant de des investigations sur les maladies infectieuses et épidémiques menées dans les centres de santé des régions isolées et frontalières de la Guyane. L’étude portant sur les personnes vivant avec le VIH a mit en évidence sur le plan spatial l'importance des zones fluviales frontalières qui constituent des zones actives de l’épidémie en termes de passage et de possible propagation mais aussi en termes de prévention, dépistage et traitement. Les investigations des épidémies de shigellose, de grippe et surtout de béribéri chez les orpailleurs soulignent le lien entre conditions de vie dégradées et problématiques de santé. La description des cas groupés de cryptosporidiose chez les enfants immunocompétents amérindiens reflètent les composantes multifactorielles des épidémies en zones isolées mettant en jeux des comportements humains spécifiques au sein d’écosystèmes tropicaux. La sévérité et la diversité des co-infections associés au besoin primaire de sécurité nutritionnelle rappellent les difficultés mais aussi l’urgence de l’adaptation des politiques de santé publiques aux populations éloignées. Enfin, l’étude menée sur le paludisme autochtone a tenté de discuter d’une nouvelle approche afin d’identifier et de traiter les infections asymptomatiques dans une zone de transmission endémique. La description des enjeux sanitaires et de l'état de santé des populations isolées dans les régions éloignées est cruciale pour la mise en œuvre d'une politique de santé optimisé en Guyane. / Public health data in isolated areas of French Guiana are scarce. However, a number of different communities live in tropical forest areas.The principal objective of this study is to analyse the main epidemiological data that have resulted from clinical practice and investigations conducted at health centres in isolated areas of French Guiana and its borders. The results of HIV studies have highlighted particular events that promote the spread of outbreaks. Illegal gold miners therefore represent a significant number of cases. The importance of specific geographical border areas in epidemic dynamics has also been demonstrated. Investigations on shigellosis, influenza and, most importantly, on thiamine deficiency outbreaks in gold miners underline that precarious conditions lead to poor health. Cryptosporidiosis outbreaks among immunocompetent children also reflect the multifactorial dynamics of infectious diseases, including human behaviour and the characteristics of tropical ecosystems. The severity and diversity of parasitic, viral and bacterial co-infection associated to the need for nutrition security indicates the complexity of delivering medical care to remote populations. Finally, a study on malaria has attempted to offer a novel approach to identifying and treating asymptomatic infections in an Amerindian endemic transmission area. A description of the health status of neglected populations in remote areas is crucial to implementing a health policy in French Guiana. Considering the importance of controlling communicable disease and the severity and range of specific illnesses, new strategies are needed and should be discussed with the communities involved.

L’histoplasmose est une infection fongique invasive. Elle était décrite comme une des principales infections opportunistes et une des premières causes de décès au stade SIDA en Guyane française.Plusieurs travaux scientifiques ont été menés. Classée première infection opportuniste au stade SIDA, l’incidence de l’histoplasmose était estimé à 1,5 p100 personne-années infectées par le VIH. Le nombre de cas incidents était stable à un niveau élevé et la proportion de décès précoces <10%. Avec une surincidence des cas en fin de saison sèche et début de petite saison des pluies, le principal processus menant à une maladie symptomatique était une nouvelle infection. La comparaison des cas de tuberculose et d’histoplasmose retrouvait respectivement, un profil clinique respiratoire dans un contexte inflammatoire marqué et, un profil disséminé accompagné de cytopénies et d’anomalies hépatiques chez des patients plus immunodéprimés. L’évaluation de la détection sérique de l’antigène galactomananne était pertinente pour le diagnostic de l’histoplasmose. Une redéfinition des critères de sévérité et le développement d’arguments pour une stratégie thérapeutique empirique à visée antifongique étaient proposés.Des résultats préliminaires démontraient la présence (au Suriname et au Guyana) et une incidence importante de l’histoplasmose chez les patients infectés par le VIH du Suriname. A l’échelle de l’Amérique Latine, la mortalité liée à l’histoplasmose était estimée équivalente voire supérieure à celle de la tuberculose chez les patients infectés par le VIH. L’histoplasmose y était jugée négligée, méconnue, responsable de nombreux décès évitables. / Histoplasmosis is an invasive fungal infection, known as one of the first AIDS-defining condition and AIDS-related deaths in French Guiana.Several scientific programmes were conducted. Ranked as the main AIDS-defining condition, histoplasmosis incidence was estimated at 1.5 p100 person-years HIV-infected. The high number of incident cases was stable and the proportion of early deaths was <10%. Following a significant increase in incidence between the end of the long dry season and the beginning of the short wet season, new infection might be the main pathophysiological mechanism leading to symptomatic disease in endemic areas. Comparison of tuberculosis and histoplasmosis in HIV-infected patients found a respiratory clinical picture in a context of pronounced inflammation and, a disseminated disease along with cytopenia and liver test abnormalities in individuals with greater immunosuppression, respectively. An evaluation of galactomannan antigen detection in serum was relevant for histoplasmosis diagnosis. Reframed severity criteria and arguments for an empiric strategy using antifungal therapy were proposed.Preliminary results showed the presence (in Suriname and Guyana) and a high incidence of histoplasmosis among HIV-infected patients in Suriname. In the whole Latin American region, we estimated that AIDS-related histoplasmosis deaths were similar or greater than AIDS-related tuberculosis deaths. HIV-associated histoplasmosis is in fact neglected, largely unknown and responsible for numerous avoidable deaths in Latin America.

Das Ziel dieser Arbeit ist die systematische Untersuchung der Auswirkungen von Änderungen in der Niederschlagshäufigkeit und -menge im Amazonas sowie eine Prognose der zukünftigen Entwicklung des Regenwaldes unter den sich ändernden Bedingungen im Rahmen des Klimawandels. Die in dieser Arbeit durchgeführten Untersuchungen der Niederschlagskorrelationsmuster des südamerikanischen Monsuns basieren auf der Theorie komplexer Netzwerke und offenbaren beispielsweise den Übergang von einem geordneten zu einem ungeordneten System zu Beginn des Monsuns. Die Erweiterung der verwendeten Methoden hin zu mehrschichtigen Netzwerken wird anschließend zur Untersuchung der Ursache von Dürren im zentralen Amazonasgebiet verwendet. Ein bivariates Netzwerk aus Niederschlagsdaten und atlantischen Meeresoberflächentemperaturen zeigt, dass bestimmte Meeresregionen im tropischen Atlantik den Niederschlag im zentralen Amazonas stark beeinflussen. Die Ergebnisse dieser Arbeit zeigen, dass einer Dürre in der Regel die Entstehung eines klimatischen Dipols der Meeresoberflächentemperaturen zwischen den identifizierten Ozeanregionen vorausgeht. Aufbauend auf diesen Ergebnissen wird in dieser Arbeit erstmalig ein Frühwarnsystem für Dürren im Amazonas vorgestellt. Der Untersuchung des Einflusses von Niederschlagsvariabilität auf die Vegetation wird eine Potentiallandschaft aus Niederschlags- und Baumbedeckungsdaten im Amazonas zugrunde gelegt. Die vorliegende Studie zeigt, dass eine direkte Abhängigkeit zwischen der lokalen, langfristigen Niederschlagsvariabilität und der Resilienz des Waldes besteht. Dies bedeutet, dass stärkere jährliche Niederschlagsvariabilität zu einem Trainingseffekt der tropischen Vegetation führen kann. Bedenkt man außerdem, dass es in Zukunft im zentralen Amazonas mehr Dürren geben soll, kann es entscheidend sein, ob die Vegetation einer Region zuvor Erfahrung mit starker Niederschlagsvariabilität gemacht hat und dementsprechend angepasst ist. Um nicht nur lokale, sondern auch globale Einflüsse zu berücksichtigen, wird zum einen der Effekt einer sich verlangsamenden thermohalinen Zirkulation durch Klimaerwärmung und zum anderen der direkte Einfluss der Klimaerwärmung auf denn zentralen Amazonas Regenwald untersucht. Die Studie zeigt, dass beide Ereignisse gegensätzliche und somit sich ausgleichende Einflüsse auf die Vegetation im Amazonasgebiet haben können. Der Regenwald könnte somit stabil in Bezug auf den Klimawandel sein. Die vorliegende Dissertation Arbeit leistet auf der Basis von neu entwickelten Methoden einen wesentlichen Beitrag, um die Kenntnisse der betrachteten klimatischen und ökologischen Systeme zu vertiefen. / This thesis investigates the impact of changes in frequency and amount of precipitation in the Amazon rainforest and analyzes its development under the changing conditions due to global warming. In this context, complex network theory is utilized to investigate the South American monsoon system. The precipitation correlation structure reveals hidden features of the system, such as the transition from a disordered to an ordered monsoon system. Further developing existing network methods towards multilayer network tools allows for the investigation of the root causes for droughts in the central Amazon basin. By using a bivariate network between monthly precipitation in the central Amazon and Atlantic sea surface temperatures, distinct oceanic regions are identified to have a strong influence on central Amazonian precipitation. The formation of a climatological dipole between the northern and southern tropical Atlantic sea surface temperatures is found to precede droughts. As a result, this study is the first to give an early warning for droughts in the Amazon. To investigate the influence of rainfall variability on vegetation, a potential landscape is constructed from precipitation and Amazonian tree cover data. The resilience of the forest is found to directly depend on the local rainfall variability in the long-term past, thereby reflecting a vegetational training effect under specific environmental conditions. Considering climate change projections, this effect could be decisive for the future survival of the present rainforest vegetation state. In order to cover long-term influences of global warming, this thesis additionally investigates the effects of a slowing down of the Atlantic meridional overturning circulation and the direct influence of global warming on the southern Amazon rainforest.. It is revealed that these effects, although caused by global warming, have competitive impacts on precipitation in the Amazon basin, with a stabilizing effect of an Atlantic meridional overturning circulation slowdown on the Amazon rainforest. This dissertation provides newly developed, as well as adjusted methods to enhance our understanding of the considered climatological and vegetational systems. Together, they provide the basic tools for a further investigation of these complex systems.

Submitted by Biblioteca de Pós-Graduação em Geoquímica BGQ (bgq@ndc.uff.br) on 2017-09-04T17:31:07Z No. of bitstreams: 1 TESE_Viviane Figueiredo Souza versão final.pdf: 1973892 bytes, checksum: 8b1ac31fbe25c8a6584e68f8e3b8ff71 (MD5) / Made available in DSpace on 2017-09-04T17:31:07Z (GMT). No. of bitstreams: 1 TESE_Viviane Figueiredo Souza versão final.pdf: 1973892 bytes, checksum: 8b1ac31fbe25c8a6584e68f8e3b8ff71 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Universidade Federal Fluminense. Instituto de Química. Programa de Pós-Graduação em Geoquímica, Niterói, RJ / O nitrogênio (N) é um elemento imprescindível para todos os organismos do nosso planeta, entretanto o composto nitrogenado mais abundante, o gás dinitrogênio (N2), é assimilável apenas por poucos micro-organismos. Isso torna o N limitante, refletindo na sua disponibilização via mineralização de matéria orgânica (MO) e a nitrificação, que produzem amônio (NH4+) e nitrato (NO3-), respectivamente. Em solos, esses processos são regulados por fatores como conteúdo de MO e água no solo, pH e temperatura. Em ecossistemas florestais, tropicais e boreais, esses processos são muito relevantes e ainda pouco estudados, principalmente em áreas de floresta secundária sob influência de manejo. A mudança de uso do solo causa alterações na ciclagem e disponibilidade do N, nos fatores reguladores, e na emissão de óxido nitroso (N2O), um gás de efeito estufa. Padrões de recuperação florestal são bastante distintos entre diferentes florestas tropicais, como visto para floresta de Mata Atlântica e Amazônica, com taxas de mineralização em florestas jovens (10 anos) muito elevadas na Amazônia (20,9 μg N g-1 SWD d-1) e mais baixas na Mata Atlântica (3,2 μg N g-1 SWD d-1). Já a nitrificação teve um padrão semelhante, com baixas taxas em ambas as florestas jovens (0,6 6,8 μg N g-1 SWD d-1 na Mata Atlântica e Amazônia, respectivamente), o que indica uma ciclagem de N conservativa, evitando perdas via emissão de gás e lixiviação de NO3-. Entretanto, a emissão de N2O em área de restauração na Mata Atlântica foi maior do que na pristina (22 e 2,5 μg N2O-N g-1 SWD h-1, respectivamente) devido à maior temperatura do solo que estimula os processos microbianos produtores de N2O. Em termos de floresta pristina, a taxa de nitrificação foi bastante distinta entre a floresta de Mata Atlântica e Amazônica (0,08 e 15,9 μg N2O-N g-1 SWD h-1, respectivamente). Isso evidencia os diferentes fatores reguladores de cada região tropical, como regime de chuvas, composição vegetal, tipos de solo, etc. Em florestas boreais, foi visto que o conteúdo de MO e água do solo e o pH do solo são os principais reguladores, limitando a disponibilidade de N em florestas bem drenadas dominadas por coníferas, em comparação com florestas pouco drenadas dominadas por turfa. Dessa forma, verificamos que a mineralização e, principalmente, a nitrificação, são processos muito relevantes no controle de N, e mesmo em ecossistemas diferentes, os fatores reguladores muitas vezes são os mesmos. Isso evidencia a necessidade de mais estudos acerca da dinâmica do N nesses ambientes, principalmente em florestas em restauração / Nitrogen (N) is an essential element for all organisms; however, the most abundant nitrogen compound, dinitrogen (N2), is assimilable only by a few microorganisms. This makes N limiting, which reflects in its availability via organic matter (OM) mineralization and nitrification, which produce ammonium (NH4+) and nitrate (NO3-), respectively. In soils, these processes are regulated by factors such as OM and soil water content, pH and temperature. In forest ecosystems, tropical and boreal, these processes are very relevant and still poorly understood, especially in secondary forest previously deforested. The land use change causes alterations in cycling and availability of N, regulating factors, and emission of nitrous oxide (N2O), a greenhouse gas. Forest recovery patterns are quite distinct among different rainforests, as seen for Atlantic and Amazon rainforest, with very high levels of mineralization in young forests (10 years) in Amazonia (20.9 μg N2O-N g-1 SWD h-1) and low in the Atlantic Forest (3.2 μg N2O-N g-1 SWD h-1). Nitrification had a similar pattern between them, with low rates in both young forests (0.6 and 6.8 μg N2O-N g-1 SWD h-1 in the Atlantic and Amazon forest, respectively), indicating a conservative N cycling, avoiding losses through gas emission and NO3- leaching. However, the N2O emission in restoration area in the Atlantic Forest was higher than in pristine (22 and 2.5 μg N2O-N g-1 SWD h-1, respectively) due to the higher soil temperature, which stimulates microbial production of N2O. In terms of pristine forest, the nitrification rate was very different between the Atlantic forest and Amazonian forest (0.08 and 15.9 μg N2O-N g-1 SWD h-1, respectively), showing the different regulatory factors of each tropical region, such as rainfall regime, vegetal composition, soil types, etc. In boreal forests, OM, soil water content and soil pH were the main regulators, limiting the availability of N in conifer-dominated well-drained forests compared to peat-dominated poorly drained forests. In this way, we verified that mineralization and, mainly, nitrification are very relevant processes in the control of N, and even in extremely different ecosystems, the regulating factors are often the same. This evidences the need for more studies about N dynamics in these environments, especially in restoration forests

Emerging in the 1970s as part of Brazil’s energy infrastructure development plans, the Belo Monte dam project has been a hot topic throughout the years. With decades of legal battles, the construction eventually started in 2011 and was inaugurated at its full capacity in 2019. But how did power dynamics and social inequalities shape the trajectory of the Belo MonteDam project? By conducting a deep thematic analysis, drawing from multidisciplinaryframeworks such as Political Ecology Theory, Post-colonialism, and perspectives fromscholarly discourse, this thesis delves into the intricate connections of how power dynamicsintersect with political, environmental, and economic dimensions and finally how these contribute to the decision-making process of major infrastructure projects such as the Belo Monte Dam. By creating a historical timeline, leading up to the inauguration and later on analyzing the major events from the multi-/interdisciplinary perspectives presented throughout, the thesis sheds light on the interplay of the power dynamics and social inequalities shaping the project’s trajectory. The thesis ultimately reveals a complex narrative marked by historical colonial legacies, political maneuvering, as well as a globalizing governance prioritizing development and economic interest over environmental and social concerns.

Made available in DSpace on 2016-04-26T20:48:49Z (GMT). No. of bitstreams: 1 Mariano Rua Lamarca Junior.pdf: 1290492 bytes, checksum: e6240c75f20575d90a5be2b3b05d364c (MD5) Previous issue date: 2007-09-27 / We analyse in the this work the causes of deforestation of the Legal Amazonia and the environment subject present in the public policies for the region, including the Public Forests Management Law (Law 11.284/06), approved with the goal of regulating public forests management in Brazil and promoting the sustainable development. We discuss the Kyoto Protocol´s Clean Development Mechanism (CDM) problem regarding forest conservation. Through a hypothetical scenario of zero deforestation and 100% of the not emitted carbon linked to forest conservation projects, we calculate that an economic revenue equivalent to the logging activities could be obtained, contributing to the maintenance of the climatic equilibrium because of the reduced Greenhouse Gases emissions, as well as keeping preserved the biodiversity and environment services values related to the standing forest. Nevertheless, appropriate regulations should be planned and implemented to achieve the desired goal, and the solution proposed in this work is in the convergence of the international laws regulating carbon markets and the native tropical forests protection laws / Analisamos neste trabalho as causas de desmatamento da Amazônia Legal e a questão ambiental presente nas políticas públicas para a região, incluindo a Lei de Gestão de Florestas Públicas (Lei 11.284/06), sancionada com o objetivo de regulamentar a gestão de florestas públicas no Brasil e promover o desenvolvimento sustentável. Discutimos o problema do Mecanismo de Desenvolvimento Limpo (MDL) do Protocolo de Kyoto na questão da conservação florestal. Através de um cenário hipotético de desmatamento zero e 100% do carbono não emitido vinculado a projetos de conservação florestal, calculamos que uma receita econômica equivalente à da exploração madeireira poderia ser obtida, contribuindo para a manutenção do equilíbrio climático pela reduzida emissão de Gases de Efeito Estufa, bem como mantendo preservados os valores da biodiversidade e dos serviços ambientais relacionados à floresta em pé (não derrubada). Entretanto, marcos regulatórios adequados devem ser planejados e implementados para atingir o objetivo desejado, e a solução proposta neste trabalho situa-se na convergência das leis internacionais de regulação dos mercados de carbono e das leis de proteção das florestas tropicais nativas