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A aplicabilidade do índice de qualidade de vida, da pegada ecológica do turismo e dos indicadores de sustentabilidade da Organização das Nações Unidas para destinos turísticos de pequeno porte: um estudo de caso no Jalapão/TO / Applicability of quality of life index, tourism ecological footprint and sustainability indicators of the united nations for small tourist destinations: a case study in Jalapão/TOSENNA, MARY L.G.S. de 11 November 2016 (has links)
Submitted by Claudinei Pracidelli (cpracide@ipen.br) on 2016-11-11T12:57:29Z
No. of bitstreams: 0 / Made available in DSpace on 2016-11-11T12:57:29Z (GMT). No. of bitstreams: 0 / Neste trabalho buscou-se conhecer as perspectivas de sustentabilidade socioambiental no contexto do desenvolvimento do turismo na cidade de Mateiros/Tocantins. Para tanto, foi avaliada a aplicabilidade em destino de pequeno porte dos indicadores de sustentabilidade: Índice de Qualidade de Vida (IQV), Indicadores de Sustentabilidade da Organização das Nações Unidas (ONU) e Pegada Ecológica do Turismo. Percebeu-se que houve um incremento no IQV da cidade de Mateiros de 32,82% após o estabelecimento do turismo, com destaque para as famílias que atuam na produção das peças de artesanato de capim dourado. A mudança, de 0,162 para 0,215, indica que apesar de ter havido uma elevação na qualidade de vida das famílias entrevistadas, o IQV permaneceu baixo, isto é, com valores entre zero e 0,499. Tal fato demonstra que a qualidade de vida das famílias não é satisfatória. Quanto à ferramenta da ONU, percebeu-se que não há sistematização de dados suficientes para que esta ferramenta possa ser utilizada pelos órgãos governamentais na captação de recursos e utilização destes para criar novas políticas públicas para a região. Tal fato demonstra uma ineficácia em destinos de pequeno porte que se assemelhem à cidade de Mateiros na forma em que foi utilizado nesse trabalho. Quanto à Pegada Ecológica do Turismo, de acordo com a metodologia proposta, são necessários 2.194,2263 hectares de terras para absorver o CO2 demandado pela atividade turística na região. A categoria com maior impacto foi terras de energia fóssil na subcategoria transporte terrestre. Conclui-se, então, que os indicadores de sustentabilidade Pegada Ecológica do Turismo e Índice de Qualidade de Vida mostraram-se ferramentas eficazes para se avaliar as perspectivas de sustentabilidade de destinos de pequeno porte. / Tese (Doutorado em Tecnologia Nuclear) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
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Dinâmica do carbono e nitrogênio ao longo de uma sequência cronológica de florestas secundárias na bacia do rio Corumbataí / Carbon and nitrogen dynamics along a chronological sequence of secondary forests in the Corumbatai river basinMarina Conte Peluci 19 July 2017 (has links)
As mudanças no uso do solo, como por exemplo a remoção de áreas florestais para a implantação da agricultura e pecuária, promovem alterações no teor de matéria orgânica do solo. Em contrapartida, a regeneração natural surge como uma possibilidade do reestabelecimento parcial de funções ecológicas importantes, com destaque para o papel das florestas secundárias na redução do fluxo de gases atmosféricos, na influência da qualidade e quantidade da água, e no sequestro de carbono da atmosfera e estocagem no solo. O objetivo deste trabalho foi avaliar o comportamento do carbono e do nitrogênio no solo ao longo da sequência cronológica de florestas secundárias, comparando-as com floresta madura e pastagens no município de Rio Claro (SP). Com o auxílio de imagens aéreas (dos anos de 1978, 1995, 2000 e 2008) foram selecionadas 15 parcelas com 900 m2 cada, as quais consistiram em uma sequência temporal de florestas secundárias regeneradas sob pastagem (apresentando 8 a 16 anos (FS12), 21 a 38 anos (FS30) e 38 a 54 anos (FS46)), além de floresta \"fonte\" (floresta estacional semidecidual) com mais de 55 anos (FF) e pastagem em uso há mais de 50 anos (PA50). O solo da área de estudo é classificado como Argissolo de textura média. As concentrações e estoques de carbono (C) e nitrogênio (N) e os valores isotópicos de C (?13C) foram analisados na serapilheira e nas camadas de 0-10, 10-20 e 20-30 cm do solo. A análise de ?13C indicou presença do sinal isotópico oriundo de vegetação C3 já nos primeiros 12 anos de regeneração, representando 60% do C presente no solo (proveniente da FF e da FS12). Na área de pastagem foi constatada a presença de carbono remanescente da floresta nativa (C3), correspondendo por 30% do carbono total. A análise de componentes principais definiu os agrupamentos de acordo com as áreas de estudo, além de correlacionar negativamente os estoques de carbono e nitrogênio e os teores de areia. As florestas secundárias apresentaram estoques de carbono e nitrogênio na serapilheira próximos à floresta fonte (1,8 Mg C ha-1 e 0,10 Mg N ha-1). Os estoques de C e N no solo (0-30 cm) foram maiores na floresta fonte (74,1 Mg C ha-1 e 7,6 Mg N ha-1), ocorrendo brusca redução (40%) na conversão para pastagem (41,4 Mg C ha-1 e 4,7 Mg N ha-1). Além disso, as áreas de regeneração não diferiram da área de pastagem quanto aos estoques de carbono e nitrogênio no solo / Changes in soil use, such as the removal of forest areas for the implantation of agriculture and livestock, promote changes in soil organic matter content. Due to this imbalance between the inputs and outputs of plant material in the system the MOS dynamics will be changed, affecting the ecosystem as a whole. On the other hand, natural regeneration appears as a possibility for the partial reestablishment of important ecological functions, with emphasis on the role of secondary forests in the reduction of the flow of atmospheric gases, the influence of water quality and quantity, and sequestration of carbon from the atmosphere and storage in the soil. The objective of this work was to evaluate the behavior of carbon and nitrogen in the soil along the chronological sequence of secondary forests, comparing them with old growth forest and pastures in Rio Claro (SP). Fifteen plots with 900 m2 each were selected using aerial images (from 1978, 1995, 2000 and 2008), which consisted of a temporal sequence of regenerated secondary forests under pasture (8 to 16 years old (FS12) 21 to 38 years old (FS30) and 38 to 54 years old (FS46)), as well as an old growth forest (seasonal semideciduous forest) with more than 55 years (FF) and pasture in use for more than 50 years (PA50). The soil of the study area is classified as Argissolo. with medium texture. The concentrations and stocks of carbon (C) and nitrogen (N) and the isotopic values of C (?13C) were analyzed in the litter and in the layers of 0-10, 10-20 and 20-30 cm of the soil. The analysis of ?13C indicated the presence of the isotopic signal from C3 vegetation already in the first 12 years of regeneration, representing 60% of the C present in the soil (coming from FF and FS12). In the pasture area, the remaining carbon of the native forest (C3) was observed, corresponding to 30% of the total carbon. The principal components analysis defined the groupings according to the study areas, in addition to negatively correlating the carbon and nitrogen stocks and the sand contents. Secondary forests presented carbon and nitrogen stocks in the litter approximate to the old growth forest (1,8 Mg C ha-1 and 0,10 Mg N ha-1). C and N stocks in the soil (0-30 cm) were higher in the old growth forest (74,1 Mg C ha-1 and 7,6 Mg N ha-1), with an abrupt reduction (40%) in conversion to pasture (41,4 Mg C ha-1 and 4,7 Mg N ha-1). In addition, the regeneration areas did not differ from the pasture area for carbon and nitrogen stocks in the soil
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Discursos escolares sobre o ciclo do carbono / Speeches on the school cycle of carbonBarros, Cristiane Oliveira de, 1980- 19 August 2018 (has links)
Orientador: Henrique Cesar da Silva / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Geociências / Made available in DSpace on 2018-08-19T00:30:39Z (GMT). No. of bitstreams: 1
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Previous issue date: 2011 / Resumo: Entender o funcionamento de nosso planeta em sua complexibilidade, em diferentes processos e acoplamentos entre eles, tem sido um desafio para cientistas em todo mundo em diversas áreas. Estender este conhecimento, a perspectiva da sua complexidade, à escola e aos alunos é um desafio ainda maior, já que passa pela estrutura curricular, produção de materiais didáticos, avaliação e mediação docente. Isso certamente também se relaciona com questões ambientais. Discursos sobre ambiente são produzidos por diversas ciências, com seus arquivos e suas condições de produção, mas também por outras vozes e em outras instâncias e instituições. Discursos esses que significam e re-significam as relações homem/natureza, ciências humanas/ciência naturais, homem/ambiente, relações entre sociedade, ciência, tecnologia e ambiente. Dentre as questões atualmente mais discutidas em torno da temática ambiental estão aquelas relacionadas ao aquecimento global e às mudanças climáticas, envolvidas em controvérsias sobre a ação antrópica e, principalmente no que diz respeito ao aumento do CO2 atmosférico e sua possível relação com possíveis mudanças no clima da Terra. Alguns desses discursos que significam o ambiente de diferentes maneiras chegam à escola, participam da produção de discursos escolares. Outros não. Entre os sentidos e conhecimentos que fazem parte dessas questões, estão aqueles relacionados ao ciclo do carbono. Buscamos analisar possíveis efeitos de sentidos sobre esse tema cuja circulação passa pela escola, e em cuja circulação sócio-histórica mais ampla, a escola tem um papel. Este trabalho tem como objetivo analisar diferentes textualizações do ciclo do carbono, ou seja, materiais que nos permitem produzir sentidos sobre esse assunto, tanto na forma de imagens quanto na forma verbal escrita, enquanto definições encontradas em livros didáticos. Materiais que circulam em escolas. Além desses materiais, foram analisadas questões do ENEM que tratam especificamente desse tema, como uma das formas pelas quais determinados sentidos sobre o ciclo do carbono chegam à escola. A perspectiva teórico-metodológica foi baseada na Análise de Discurso de origem francesa que nos permite observar os efeitos de sentidos produzidos pelos diferentes discursos sobre o ciclo do carbono. Bem, como em aspectos da epistemologia das geociências, de onde derivamos as categorias de análise. Acreditamos que nosso trabalho contribui para a compreender e para ressaltar o papel de conhecimentos e da perspectiva epistemológica das geociências nas escolas, trazendo à reflexão a utilização de concepções que possibilitem aos alunos desenvolver um entendimento do sistema terrestre / Abstract: Understand the workings of our planet in its complexity, in different processes and linkages between them, has been a challenge for scientists around the world in several areas. Extending this knowledge, the prospect of their complexity, the school and students is an even greater challenge, as is the curriculum structure, production of teaching materials, teacher evaluation and mediation. This certainly relates to environmental issues. Discourses on the environment are produced by various sciences, with their files and their conditions of production, but also by other voices and other bodies and institutions. Mean that these discourses and re-signify the man / nature, human sciences / natural science, human / environment relationships between society, science, technology and environment. Among the currently most discussed issues around the environmental issues are those related to global warming and climate change, involved in controversies about human action and especially with regard to increasing atmospheric CO2 and its relation to possible changes in climate Earth. Some of these speeches that mean the environment in different ways come to school, participate in the school production of speech. Others do not. Between the senses and knowledge that are part of these issues are those related to the carbon cycle. We seek to analyze possible effects of meaning on the subject on which traffic passes through the school, whose circulation and broader socio-historical, the school has a role. This work aims to analyze different textualizações of the carbon cycle, ie, materials that allow us to make sense of this, both as images and written in verb form, while definitions found in textbooks. Materials that circulate in schools. In addition to these materials were analyzed ENEM issues that specifically this issue as one of the ways in which certain meanings about the carbon cycle to school arrive. The theoretical-methodological approach was based on Discourse Analysis of French origin that allows us to observe the effects of meaning produced by the different discourses on the carbon cycle. Well, as aspects of the epistemology of geosciences, from which we derive the categories of analysis. We believe our work helps to understand and to highlight the role of knowledge and epistemological perspective of the geosciences in schools, bringing to reflect the use of concepts that enable students to develop an understanding of the Earth system / Mestrado / Ensino e Historia de Ciencias da Terra / Mestre em Ensino e Historia de Ciencias da Terra
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Dynamique des blooms phytoplanctoniques dans le gyre subpolaire de l'Atlantique Nord / Phytoplankton blooms dynamics in the North Atlantic Subpolar GyreLacour, Léo 08 December 2016 (has links)
Le gyre subpolaire de l'Atlantique Nord est le siège de la plus importante floraison (bloom) phytoplanctonique de l'océan global. Cet événement biologique majeur joue un rôle crucial sur le fonctionnement des écosystèmes océaniques et sur le cycle global du carbone. L'objectif de cette thèse est de mieux comprendre les processus bio-physiques qui contrôlent la dynamique du bloom phytoplanctonique et l'export de carbone à différentes échelles spatio-temporelles. Dans une première étude, basée sur des données satellites climatologiques, le gyre subpolaire a été biorégionalisé en fonction des différents cycles annuels de biomasse phytoplanctonique. Les conditions de mélange, couplées à l’intensité de la lumière de surface, contrôlent l’initiation du bloom printanier au sein des différentes biorégions. La nouvelle génération de flotteurs BGC-Argo a permis, dans une deuxième étude, d’explorer des processus à des échelles plus fines, en particulier pendant la période hivernale jusqu’à présent très peu étudiée. En hiver, des restratifications intermittentes et locales de la couche de mélange, liées à des processus de sous-mésoéchelle, initient des blooms transitoires qui influencent la dynamique du bloom printanier. Enfin, une troisième étude a montré que la variabilité haute-fréquence de la profondeur de la couche de mélange pendant la transition hiver-printemps joue aussi un rôle crucial sur l’export de carbone. / The North Atlantic Subpolar Gyre exhibits the largest phytoplancton bloom of the global ocean. This major biological event plays a crucial role for the functioning of marine ecosystems and the global carbon cycle. The aim of this thesis is to better understand the bio-physical processes driving the dynamics of the phytoplankton bloom and carbon export at various spatiotemporal scales.In a first study, based on satellite data at a climatological scale, the subpolar gyre is bioregionalized according to distinct annual phytoplankton biomass cycles. The light-mixing regime controls the phytoplankton bloom dynamics in the different bioregions.In a second study, the new generation of BGC-Argo floats allowed for processes to be explored at a finer scale, especially during the overlooked winter season. In winter, intermittent and local restratifications of the mixed layer, triggered by sub-mesoscale processes, initiate transient winter blooms impacting the spring bloom dynamics.Finally, a third study showed how the high-frequency variability of the mixed layer depth during the winter-spring transition plays a crucial role on carbon export.
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The respiratory and gut physiology of fish : responses to environmental changeRogers, Nicholas John January 2015 (has links)
Many of the habitats occupied by fish are highly dynamic, naturally demonstrating substantial abiotic fluctuations over diurnal, tidal or seasonal cycles. It is also the case that throughout their 545 million year evolutionary history, fish have existed in aquatic environments very different to those of the present day. However, the past several decades have seen unprecedented rates of environmental change, at local and global scales, arising from human activities. The two major themes of the present thesis are: 1) Respiratory responses of fish to changes in environmental oxygen and temperature in the context of exploring intra- and inter-specific trait variation and its ecological implications 2) The effects of environmental factors (oxygen, carbon dioxide, temperature and seawater chemistry) on the intestinal precipitation and excretion of calcium carbonate by marine teleosts. In the first study (chapter two) a comprehensive database of fish critical PO2 (Pcrit) data compiled from the published literature is presented. The systematic review of this literature provided the opportunity to critically examine methodologies for determining Pcrit as well as its usefulness as an indicator of hypoxia tolerance in fish. The second study (chapter three) examines whether inter- and intra-specific variation in thermal and hypoxia tolerance in two reef snapper species (Lutjanus carponotatus and Lutjanus adetii) reflects their distributions across the contrasting biophysical environments of the reef flat and reef slope surrounding Heron Island on the Great Barrier Reef. L. carponotatus was clearly the most thermally and hypoxia tolerant of the two species, demonstrating a ~3.5 °C wider thermal tolerance zone (higher CTmax, lower CTmin) and ~26% lower Pcrit than L. adetii. These results suggest that the contrasting distribution of these species between flat and slope reef zones is reflected in their physiological tolerances. However, there was no evidence of intra-species variation in tolerance between flat and slope caught L. carponotatus individuals, indicating that this species does not form physiologically distinct subpopulations between these reef zones. The third study (chapter four) experimentally quantified the effect of hypercarbia (3000 μatm) and hypoxia (50% air saturation) on gut carbonate production by the European flounder (Platichthys flesus). Both hypercarbia and hypoxia resulted in a significant increase in carbonate excretion rate (1.5-fold and 2.4-fold, respectively) and acted synergistically when combined. In the final study (chapter five), gut carbonate production was measured in the European flounder undergoing conditions simulating the ‘calcite seas’ of the Cretaceous. The results of this study support the hypothesis that ocean conditions prevalent during the Cretaceous period resulted in piscine carbonate production rates substantially higher (~14-fold) than the present day. Ultimately, this thesis directly links the environmental physiology of fish at the individual level to wider scale implications (past, present and future), ranging from local ecological patterns all the way up to global carbon cycles.
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Microbial Functional Diversity and the Associated Biogeochemical Interactions Across Miami-Dade County, Florida SoilsKushwaha, Priyanka 02 November 2016 (has links)
Decomposition of soil organic matter by microbial processes results in carbon sequestration within soils and/or carbon loss via atmospheric emission of carbon dioxide and methane. Natural as well as anthropogenic factors have been documented to impact soil microbial diversity and the associated biogeochemical functions. The soil microbial communities co-inhabiting Miami-Dade County soils, Florida are under threat because of the ongoing restoration efforts in the adjoining Florida Everglades Parks, predicted climatic changes such as sea-level rise and high rainfall, as well as urbanization. Therefore, an improved understanding of the current microbial functional communities is essential to better assess the impact of soil communities when anthropogenic or climatic disturbances occur. The objectives of the current study were to characterize the biodiversity and distribution of: a) cellulose degrading microbial community, and b) methanogenic guilds responsible for producing the gas methane, across four different Miami-Dade County, Florida soil types using the high throughput technique of GeoChip 5.0 functional microarray. In addition, the influence of vegetation cover, organic content, soil moisture content, pH, and soil texture in shaping the soil functional microbial community was also investigated. The function of cellulose degradation was distributed across wide range of taxonomic lineages with the majority belonging to the bacterial groups of Actinobacteria, Firmicutes, Alphaproteobacteria, and Gammaproteobacteria, whereas Ascomycota and Basidiomycota were the only detected fungal phyla. The cellulolytic bacterial community correlated more with the vegetation cover while fungal groups showed influence of moisture and organic content as well as percent silt. Six out of the seven methanogenic orders, with the greatest numbers found in the Methanomicrobiales, Methanosarcinales, and Methanomassiliicoccales, were identified across all four soil types of Miami-Dade. The abundance of the mcrA gene sequences was significantly greater with respect to soil moisture content. Additionally, the recently classified order Methanomassiliicoccales was identified across all four soils, including soils with lower moisture content not thought to provide ideal redox conditions to support methanogens. The greater number of correlation network interactions amongst the methanogenic guilds in the Florida Everglades wetlands versus the urbanized Miami-Dade County soils depicted the impact of the historical drainage of the Florida Everglades on the methanogenic community. Overall, the current study characterized the biodiversity of cellulolytic and methanogenic organisms across dry and saturated soils of Miami-Dade County and demonstrated that microbial guilds were functionally redundant and were influenced to some extent by the soil abiotic factors. Also, results from network analyses provide a platform to assess the future impacts of disturbances on the microbial community.
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Cycles du carbone et de l’azote et émissions de gaz à effet de serre (CH4, CO2 et N2O) du lac de barrage de Petit Saut et du fleuve Sinnamary en aval du barrage (Guyane Française) / Carbon and nitrogen cycles and greenhouse gases emissions (CH4, CO2, N2O) of the Petit Saut reservoir and the Sinnary river downstream of the dam (French Guiana)Cailleaud, Emilie 01 December 2015 (has links)
Les eaux continentales sont des sources de méthane (CH4), de dioxyde de carbone (CO2)et de protoxyde d’azote (N2O). Dans le but de préciser leur importance dans le bilan global des émissions de gaz à effet de serre (GES), de nombreuses études ont été réalisées afin de quantifier les différents flux de carbone et d’azote les parcourant. Ces flux sont perturbés par la mise en place de barrages sur le lit des fleuves. Peu d’études présentent des bilans de carbone et d’azote complets (apports, exports, flux vers l’atmosphère et enfouissement) pour les lacs de barrages, et elles concernent uniquement des écosystèmes boréaux et tempérés. Suite à la création d’un barrage, de la matière organique (MO) est mise en eau (sols et forêts), elle se dégrade rapidement les premières années suivant la mise en eau puis plus lentement par la suite. L’état de dégradation de la MO et la principale source de GES dans un lac de barrage près de 20 ans après la mise en eau sont souvent méconnus. L’étude réalisée 18 ans après la mise en eau du lac de Petit Saut (Guyane Française) est la première étude où les principaux éléments des cycles du carbone et de l’azote d’un lac de barrage hydroélectrique, et de son fleuve en aval, situé en climat équatorial et dont la création a entraîné la mise en eau de forêt primaire, sont étudiés près de 20 ans après la mise en eau. Cette étude se base sur (i) la mesure mensuelle de la qualité des eaux et des concentrations en carbone et azote en amont, dans, et en aval du lac de barrage, (ii) la mesure et/ou le calcul des différents flux de GES vers l’atmosphère, (iii) des données de la signature isotopique et de l’état de dégradation de la MO en amont, dans, et en aval du lac, (iv) des prélèvements de sédiments et de troncs d’arbres ennoyés en 1994 et (v) des incubations d’eau du fleuve, de sédiments et de troncs d’arbres du lac. L’ensemble des données collectées au cours des 12 mois de campagnes réalisées en 2012 - 2013 nous a permis de déterminer que (i) les sols inondés sont toujours des sources significatives de GES contrairement aux troncs d’arbres ennoyés, (ii) dans le lac 84 % des émissions de CH4 et 51 % des émissions de CO2 ont lieu dans la zone littorale (< 10 m de profondeur), (iii) 54 % du CO2 produit dans le fleuve en aval provient de la dégradation de la MO apportée par le lac. Cette étude nous a aussi permis de réaliser des bilans de carbone et d’azote à Petit Saut et un bilan des émissions de chacun des GES émis (CH4, CO2, N2O) près de 20 ans après la mise en eau. / Inland waters are sources of methane (CH4), carbon dioxide (CO2) and nitrous oxide (N2O). In order to define their importance in the global balance of greenhouse gases (GHG) emissions, numerous studies have been conducted to quantify the different fluxes of the carbon and nitrogen browsing them. These fluxes are modified by the creation of dams on river beds. Few studies present full carbon and nitrogen balances (inputs, outputs, fluxes to the atmosphere and sequestration) for reservoirs, and they concern only boreal and temperate ecosystems. The creation of a dam floods organic matter (OM) (soils and forests), which is rapidly degraded the first years following the impoundment and thereafter more slowly. The state of degradation of the OM and the main source of GHG in a reservoir nearly 20 years after impoundment are often unknown. The study conducted 18 years after the impoundment of the Petit Saut Reservoir (French Guiana) is the first study where the main elements of carbon and nitrogen cycles of an hydroelectric reservoir, and its river downstream, located in equatorial climate and which creation resulted in the flooding of primary forest, are studied nearly 20 years after impoundment. This study is based on (i) a monthly measurement of water quality and carbon and nitrogen concentrations upstream, in, and downstream of the reservoir, (ii) measurements and/or calculations of the different fluxes of GHG through the atmosphere, (iii) data of the isotopic signature and of the state of degradation of OM upstream, in, and downstream of the reservoir, (iv) sediments and 1994’s flooded tree trunks sampling and (v) incubations of downstream river water, sediments and tree trunks from the reservoir. All the data collected during the 12 months of campaigns carried out in 2012 - 2013 allowed us to determine that (i) flooded soils are still significant sources of GHG unlike flooded tree trunks, (ii) in the reservoir 84 % of CH4 emissions and 51 % of CO2 emissions occur in the littoral zone (< 10 m depth), (iii) 54 % of the CO2 produced in the river downstream of the dam come from the degradation of the OM provided by the reservoir. This study also allowed us to achieve carbon and nitrogen balances in Petit Saut and emission balance of each GHG emitted (CH4, CO2, N2O) nearly 20 years after impoundment.
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A modeling study of the marine biogeochemistry, plankton dynamics, and carbon cycle on the continental shelf off the West Antarctic PeninsulaSchultz, Cristina. January 2019 (has links)
Thesis: Ph. D., Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), 2019 / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 189-202). / Over the past several decades, the West Antarctic Peninsula (WAP) has undergone physical and ecological changes at a rapid pace, with warming surface ocean and a sharp decrease in the duration of the sea ice season. The impact of these changes in the ocean chemistry and ecosystem are not fully understood and have been investigated by the Palmer-LTER since 1991. Given the data acquisition constraints imposed by weather conditions in this region, an ocean circulation, sea ice and biogeochemistry model was implemented to help fill the gaps in the dataset. The results with the present best case from the suite of sensitivity experiments indicate that the model is able to represent the seasonal and interannual variations observed in the circulation, water mass distribution and sea ice observed in the WAP, and has identified gaps in the observations that could guide improvement of the simulation of the regional biogeochemistry. Comparison of model results with data from the Palmer-LTER project suggests that the large spatial and temporal variability observed in the phytoplankton bloom in the WAP is influenced by variability in the glacial sources of dissolved iron. Seasonal progression of the phytoplankton bloom is well represented in the model, and values of vertically integrated net primary production (NPP) are largely consistent with observations. Although a bias towards lower surface dissolved inorganic carbon (DIC) and alkalinity was identified in the model results, interannual variability was similar to the observed in the Palmer-LTER cruise data. / by Cristina Schultz. / Ph. D. / Ph.D. Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution)
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Carbon Fluxes and Pools in a Montane Rainforest in Sulawesi, IndonesiaHeimsch, Florian 25 March 2021 (has links)
No description available.
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The Susceptibility of the Circumpolar North to Zombie Wildfire : An Exploratory Case Study of SwedenHurst, Stephanie Louise January 2021 (has links)
Climate change is warming the North and exposing its immense carbon stores not only to wildfire disturbances, but overwintering, or zombie, fire. These remnants of summer fires can spend months smouldering under the surface, hidden under the protection of layers of snow, burning through immense amounts of carbon, which is then released into the atmosphere, further exacerbating climate change. In order to prevent these potential megafires, areas that are prone to their occurrence need to be identified so that detection and management protocols can be put into place. Using a GIS approach, this paper attempts to identify any areas in the northern circumpolar country of Sweden that are currently susceptible to zombie fire and any that might be susceptible in 2050 using a RCP8.5 scenario projection. Based on spatial and climatic variables, the results found 88 km2 of land that is currently susceptible, 20.19 km2 of which is most prone due to mild winter and spring conditions. In the 2050 projection, most regions were found to have a decrease in susceptibility due to warmer winters reducing snow coverage. However, three counties in the north were found to have an increased susceptibility due to the earlier arrival of spring. Climate projections still contain uncertainties and how the annual precipitation of Sweden will be affected by climate change varies greatly between models, which naturally effects the likelihood of future wildfires, and ensuing zombie fires. There is a need for more research surrounding zombie fires, particularly with regards to snow depth and coverage and how this affects the mechanisms of smouldering combustion and smouldering to flaming transition. This paper is an example of how regions can be assessed for hazardous events if they have some spatial and temporal predictability. / Klimatförändringarna värmer upp Norden och utsätter dess enorma kolsänkor inte bara för skogsbrandstörningar utan också för övervintrande (eller zombie-) bränder. Dessa gamla sommarbränder kan spendera månader under ytan, gömda under skydd av snötäcke, brännande enorma mängder kol, som sedan släpps ut i atmosfären, vilket ytterligare förvärrar klimatförändringarna. För att förhindra dessa potentiella megaeldar (eng. megafires) måste områden med benägenhet för dess inträffande identifieras så att detektions- och hanteringsprotokoll kan införas. Med hjälp av ett GIS-tillvägagångssätt försöker denna uppsats att identifiera alla områden i Sverige som för närvarande är i riskzonen för zombiebränder och alla områden som kan vara i riskzonen 2050 med hjälp av en RCP8.5-scenarioprojektion. Baserat på rumsliga och klimatvariabler fann resultaten att 88 km2 mark för närvarandet är i riskzonen, varav 20,19 km2 är mest benägen på grund av milda vinter- och vårväder. I 2050-projiceringen visade sig de flesta regioner ha en minskad risk på grund av varmare vintrar som minskade snötäckningen. Men tre län i norr hade en ökad risk på grund av vårens tidigare ankomst. Klimatprognoser innehåller fortfarande osäkerheter och hur den årliga nederbörden i Sverige kommer att påverkas av klimatförändringen varierar kraftigt mellan olika modeller, vilket naturligtvis påverkar sannolikheten för framtida skogsbränder och således zombiebränder. Det finns ett behov av mer forskning kring zombiebränder, särskilt med avseende på snödjup och täckning och hur detta påverkar mekanismerna för pyrande förbränning och pyrande-till-flammande-övergång. Denna uppsats är ett exempel på hur regioner kan utvärderas för faror om de har viss rumslig och tidsmässig förutsägbarhet.
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