Há evidências de que o clima vem sendo alterado pela ação humana desde a época da Revolução Industrial devido à crescente emissão de gases estufa na atmosfera. Inúmeras curvas da variação da temperatura média anual têm sido publicadas com uma característica comum: o crescimento da temperatura durante o último século, totalizando aproximadamente 0,5ºC. Acredita-se que o aumento na concentração atmosférica dos gases responsáveis pelo efeito estufa tenha influência direta na tendência da temperatura dos últimos 100 anos. Este trabalho foi realizado com o intuito de estudar as mudanças no comportamento sazonal e anual da temperatura da superfície do mar (TSM), pressão atmosférica ao nível do mar (PNM) e transporte barotrópico (TB) devido ao aumento na concentração dos gases estufa. Foram utilizadas duas simulações do modelo acoplado NCAR CCSM sob as condições atmosféricas do período pré-industrial e pós-industrial. Os resultados revelam que, na média anual, as variáveis estudadas sofreram intensificação do período pré para o pós-industrial. A temperatura da superfície do mar mostrou aumento no período pós-industrial, principalmente durante o inverno e primavera, quando ocorre um aquecimento superior a 2,5ºC ao sul do continente sul-americano. A pressão atmosférica ao nível do mar na maior parte da região de estudo apresentou aumento no verão e outono e diminuição nas demais estações do ano, indicando uma intensificação no padrão sazonal dessa variável durante o período pós-industrial em relação ao pré-industrial. O transporte barotrópico revelou diferenças significativas entre os dois experimentos, mostrando maiores valores no período pós-industrial. A média da região apresentou um ciclo anual com diferenças de 2,5Sv ao longo do ano entre os dois períodos, com aumento para o pós-industrial. Esse aumento deve-se basicamente à intensificação do transporte barotrópico da Corrente Circumpolar Antártica durante todas as estações do ano. O Giro Subtropical também sofreu aumento de transporte, de menor intensidade, durante o período pós-industrial. Essa mudança no comportamento do transporte barotrópico sugere uma intensificação no padrão do Giro Subtropical e no transporte da Corrente Circumpolar Antártica para o período pós-industrial. As maiores mudanças entre os dois períodos simulados ocorreram nas latitudes mais altas. / The main objective of this research is to study the impacts of the increase in greenhouse gases concentration on variables behavior at the sea-air interface. For this the NCAR CCSM coupled model is used by two climate conditions: the first one to pre-industrial period and the second one, to present day levels. Annual and seasonal climatology differences are analyzed for the of the following variables: air temperature, sea surface temperature, sea level pressure, wind stress, latent and sensible heat fluxes and barotropic transport. Statistics methods such as Empirical Ortoghonal Functions (EOF), Singular Value Decomposition (SVD) and Multi-Taper Method (MTM) are used to analyze changes in interannual behavior of these variables. The main results show that these surface variable are intensified from one period to the next. The air temperature and sea surface temperature showed increase in the pos-industrial period, mainly during the winter and spring. The sea level pressure also showed an increase on the annual mean. The wind stress revealed that the trade winds are intensified in autumn and the meridional wind component increases over the South Atlantic during winter. The winds adjacent to the South American continent also increased. Latent and sensible heat fluxes also increase, but not much, over some regions and decrease over others. Barotropic transport shows significant differences between the two experiments. There was increase of barotropic transport associated with the Subtropical Gyre and on Antartic Circumpolar Current. EOF, SVD and MTM analysis showed significant differences with respect to spatial patterns, behavior of the expansion coeficients time series and their variability.

Cette thèse porte sur la mesure du protoxyde d'azote (N2O) à partir de capteurs spatiaux. Dans un premier temps, nous avons étudié les processus d'émissions et de transport de N2O depuis l'Asie jusqu'au bassin méditerranéen. Pour cette étude, nous avons utilisé des sorties du modèle de chimie-transport LMDz-Or-INCA ansi que des profils de N2O estimés à partir d'observations du capteur spatial TANSO-FTS (Thermal And Near infrared Sensor for carbon Observation Fourier Transform Spectrometer) de la plateforme GOSAT (Greenhouses gases Observing SATellite). Ensuite, nous avons mis en place un système de restitution des profils troposphériques de N2O à partir des mesures du capteur spatial infrarouge IASI (Infrared Atmospheric Sounding Interferometer) des plateformes MetOp. Ce système a ensuite été validé en utilisant les mesures in-situ des campagnes aéroportées HIPPO (High performance Instrumented airborne platform for environmental research Pole-to-Pole Observations). Enfin, nous avons étudié l'apport théorique du capteur IASI-NG (IASI-New Generation) par rapport à IASI pour la mesure du N2O troposphérique. / This thesis focuses on the measurement of nitrous oxide (N2O) from space sensors. Firstly, we studied the transport and emission processes of N2O from Asia to the Mediterranean Basin (MB). For this study, we used N2O profiles over the period 2010-2013 retrieved from TANSO-FTS (Thermal And Near infrared Sensor for carbon Observation Fourier Transform Spectrometer) observations onboard the platform GOSAT (Greenhouses gases Observing SATellite) . We also used outputs of the chemistry-transport model LMDz-Or-INCA over the same period. Secondly, we built an algorithm to retrieve N2O profiles using observations from IASI (Infrared Atmospheric Sounding Interferometer) onboard the MetOp platforms. This algorithm was validated by comparing the retrieved profiles with in-situ measurements from HIPPO (High performance Instrumented airborne platform for environmental research Pole-to-Pole Observations) airborne campaigns. Finally, we performed a theoretical intercomparison between IASI-NG (IASI-New Generation) and IASI concerning the tropospheric N2O measurements.

A presente tese compõe-se de três capítulos. Capitulo I. Uma revisão geral é apresentada sobre os padrões de consumo de alimentos e a problemática da segurança alimentar diante do acelerado crescimento populacional, além dos desafios impostos pelas mudanças climáticas previstas para o futuro próximo. Busca-se neste capítulo uma compreensão abrangente sobre possíveis alterações na qualidade nutricional da planta oriunda de alterações climáticas que se esperam até o final do século em curso. Capitulo II. O capítulo refere-se à caracterização e determinação dos teores de substâncias fenólicas solúveis de órgãos de plantas de sorgo (Sorghum bicolor (L.) Moench) var. \'BRS 330\', cultivadas sob déficit hídrico e distintas concentrações atmosféricas de CO2. As plantas foram cultivadas em Câmaras de Topo Aberto (OTC) por 120 dias após o plantio (DAP), sob condições de CO2 ambiente (400 ppm) e elevado (800 ppm) (tratamentos A e E, respectivamente). Após 60 dias, a irrigação foi reduzida a 23% em relação às plantas controle. As coletas foram estabelecidas em duas fases de desenvolvimento do grão: estádio imaturo (90 DAP) e maduro (120 DAP). Foram feitas determinações de flavonoides e fenilpropanoides de folhas, pedúnculo, colmo, raízes escoras, raízes e grãos por CLAE, utilizando orientina, vitexina, pinocembrina e ácido clorogênico como padrões externos para dosagem de flavonoides e fenilpropanoides, respectivamente. O teor de taninos totais dos mencionados órgãos foi determinado por precipitação com albumina de soro bovino e espectrofotometria. Técnicas de CLAE-DAD-MS-MS foram utilizadas para a caracterização das substâncias fenólicas de todos os órgãos da planta. Análises Multivariadas de Agrupamento e Componentes Principais (PCA) foram utilizadas para avaliar afinidades entre 132 substâncias detectadas e 72 substâncias caracterizadas, respectivamente. As variações de abundância relativa de fenilpropanoides (24 substâncias) e flavonoides (48 substâncias), devidas aos distintos estádios de maturação e formas de tratamento, são apresentadas por meio de heat maps para cada órgão. A maior diversidade de substâncias fenólicas foi observada em folhas, e a menor, nos grãos. Derivados de ácido ferúlico, ácidos clorogênicos, flavonas e flavanonas foram caracterizados na planta toda. Flavanonas foram detectadas apenas em raízes escoras, raízes e grãos. As O-glicoflavonas foram detectadas com frequência muito maior do que C-glicosídeos. Aos 90 DAP, alterações significativas devidas a E foram observadas no conteúdo de fenilpropanoides das folhas e raízes escoras e no conteúdo dos flavonoides das folhas e grãos. Aos 120 DAP, foi detectado incrementos no conteúdo de flavonoides das raízes escoras. O teor de taninos nos grãos da var. \'BRS 330\' é relativamente elevado, e foi reduzido significativamente com o tratamento E aos 120 DAP. Capitulo III. Esse capítulo tem por objetivo a comparação da composição de substâncias fenólicas da parede celular e ligninas das mesmas plantas e órgãos enfocados no Capítulo II. Material de folhas, pedúnculo, colmo, raízes escoras, raízes e grãos nos estádios imaturo (90 DAP) e maduro (120 DAP) foram submetidos à hidrólise alcalina para remoção dos ácidos p-cumárico e ferúlico, principais ácidos fenólicos ligados à parede celular de gramíneas. O teor de ligninas e a distribuição de seus monômeros constituintes p-hidroxifenila (H), guaiacila (G) e siringila (S) foram determinados por meio de tratamento da parede celular total dos órgãos com brometo de acetila e nitrobenzeno, respectivamente. A análise dos monômeros de lignina foi por CLAE-DAD. Aos 90 DAP, alterações significativas induzidas por E foram observadas relativamente ao teor de ácido p-cumárico de folhas, pedúnculo e grãos. Paralelamente, o teor de ácido ferúlico foi alterado nas folhas e raízes escoras. Aos 120 DAP, reduções significativas nos teores de ácidos p-cumárico e ferúlico foram observadas nas folhas. O conteúdo de lignina foi alto nas raízes escoras em ambos os estádios de maturação e reduzido significativamente por E nos grãos. O conteúdo dos monômeros H, G e S do colmo foi também reduzido significativamente por E / The present Dissertation comprises three chapters. Chapter I. Taking into account the fast population growth, a broad revision is made in this chapter about patterns of food consumption and problems related to food safety. In addition, comments are made about challenges imposed by climate changes expected to occur in the near future. It is aimed to reach a broad understanding about possible changes on food quality due to the world changes foreseen to happen by the end of the current century. Chapter II. This chapter refers to the characterization and measurement of the contents of phenolic substances of organs of sorghum plants (Sorghum bicolor (L.) Moench) var. \'BRS 330\', cultivated under the influence of hydric deficit and distinct atmospheric CO2 concentration. The plants were cultivated inside Open Top Chambers (OTC) over 120 days after planting (DAP) under the effects of environmental (400 ppm) and elevated CO2 (800 ppm) (treatments A and E, respectively). After 60 days, irrigation was dropped to 23% relative the control. Material collection was scheduled to occur on two developmental phases: immature stage (90 DAP) and mature stage (120 DAP). Measurements were made of the contents of flavonoids and phenylpropanoids from leaves, peduncle, culm, prop roots, roots and grains by HPLC, using orientin, vitexin, pinocembrin and chlorogenic acid, respectively, as calibration external standards. The contents of tannins of the mentioned sorghum organs were determined by precipitation with bovine serum albumin and spectrophotometry. Techniques of CLAE-DAD-MS-MS were used for characterization of phenolic substances of all plant organs. Multivariate Cluster and Principal Components Analysis (PCA) were used to evaluate affinities among 132 detected and 72 characterized substances, respectively. Variations of relative abundance of phenylpropanoids (24 substances) and flavonoids (48 substances), due to distinct maturation stage and CO2 concentration, are presented by means of heat maps for each organ. The highest diversity of phenolic substances was observed in leaves and the lowest in grains. Derivatives of ferulic acid, chlorogenic acids, flavones and flavanones were characterized in extracts of all organs. Flavanones were detected only in prop roots, roots and grains. O-Glycoflavones largely predominated over C-glycosides. At 90 DAP a significant increase of phenylpropanoids due to E was observed in leaves and prop roots and of flavonoids in leaves and grains. At 120 DAP an increase was observed in the flavonoid content of prop roots. The content of tannins in grains of var. \'BRS 330\' is relatively high and was significantly reduced by treatment E at 120 DAP. Chapter III. This chapter aimed to compare the composition of phenolic substances of the cell wall and lignins of the same plants and organs dealt with in Chapter II. Material of leaves, peduncle, culm, prop roots, roots and grains at the immature (90 DAP) and mature (120 DAP) stages were treated by alkaline hydrolysis for removal of p-coumaric and ferulic acids, the main phenolic acids attached to grasses cell walls. The contents and lignins and the distribution of their monomer constituents p-hydroxyphenyl (H), guaiacyl (G) and siringyl (S) were determined by treatment of whole cell walls of all organs with acetyl bromide and nitrobenzene, respectively. The analysis of lignin monomers was by CLAE-DAD. At 90 DAP, significant changes induced by E were detected in connection with the content of p-coumaric acid of leaves, peduncle and grains. At the same time, the content of ferulic acid was changed in leaves and prop roots. At 120 DAP, significant decreases of the contents of p-coumaric and ferulic acids were detected in leaves. The content of lignin was high in prop roots at both maturation stages and was significantly lowered by E in grains. The contents of the monomers H, G and S of the culm was also significantly lowered by E

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No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) dissertacao_lariza_benedetti.pdf: 1571715 bytes, checksum: 7f3917f043a3118e0911270d3cede0cc (MD5) Previous issue date: 2015-07-16 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / As mudanças climáticas estão cada vez mais afetando a qualidade e a quantidade da produção agrícola mundial. No estado do Rio Grande do Sul, a busca por alternativas que maximizem a produtividade e contribuam para a sustentabilidade econômica do ecossistema várzea surge como uma justificativa para a utilização da cultura da soja nestas áreas, visto que é uma das principais commodities do agronegócio brasileiro. O controle químico de plantas daninhas se constitui no método de manejo mais adotado, porém, pouco se sabe como a cultura da soja responde ao uso de herbicidas em diferentes umidades do solo. Desta forma, o presente estudo teve por objetivo avaliar respostas fisiológicas e bioquímicas em plantas de soja após a aplicação de herbicidas recomendados para a cultura em três níveis de umidade do solo. O experimento foi arranjado em delineamento inteiramente casualizado em esquema fatorial (7x3) com quatro repetições. Foi utilizada a cultivar de soja BMX Potência RR, cultivadas em vasos (8L), mantendo-se três plantas por vaso as quais, no estádio V3 foram submetidas a três umidades do solo: Capacidade de campo, Solo seco (50% abaixo da capacidade de campo) e Solo saturado (50% acima da capacidade de campo), seguido da aplicação dos tratamentos herbicidas: Glyphosate, Sulfentrazone, S-metolachlor, Glyphosate+Sulfentrazone, Glyphosate+S-metolachlor, Glyphosate+Sulfentrazone+S-metolachlor, além do tratamento sem herbicida. Aos sete, 14 e 28 dias após a aplicação (DAA) foram avaliados o índice de clorofilas, flavonoides, balanço de nitrogênio e as trocas gasosas no terceiro trifólio completamente desenvolvido. Neste período coletou-se ainda, material foliar para avaliação de potencial osmótico, teor de prolina, peróxido de hidrogênio, peroxidação de lipídios e atividade das enzimas antioxidantes superóxido dismutase (SOD), catalase (CAT) e ascorbato peroxidase (APX). Para os pigmentos e índice de balanço de nitrogênio houve pequena variação entre os tratamentos, já as trocas gasosas foram mais afetadas nas plantas em solo seco, principalmente aos 14 e 28 DAA, com efeito acentuado pela presença dos herbicidas. Aos sete DAA o herbicida Glyphosate em solo seco resultou em maior ativação das enzimas antioxidantes SOD e CAT, além da maior produção de peróxido de hidrogênio estando, provavelmente, vinculado ao aumento do estresse oxidativo causado por este herbicida. Entretanto, após 28 dias da aplicação, aumenta a síntese de prolina neste tratamento, o que leva ao ajuste osmótico, e consequente menor atividade enzimática. Em solo saturado e capacidade de campo as respostas desencadeadas pelos herbicidas Glyphosate, Sulfentrazone, S-metolachlor não seguem um padrão, porém, de maneira geral, levam a um menor estresse comparado ao solo seco. Os resultados deste estudo mostram que, embora a variação na umidade do solo, altera o metabolismo da cultura da soja, a aplicação de herbicidas em condições de solo seco ou saturado acentua este efeito, podendo resultar em prejuízos para a cultura. / Climate change is increasingly affecting the quality and quantity of the world's agricultural production. In the state of Rio Grande do Sul, the search for alternatives that maximize productivity and contribute to the economic sustainability of the wetland ecosystem emerges as a justification for the use of the soybean crop in these areas, since it is one of the main commodities of Brazilian agribusiness. Chemical weed control constitutes the most widely adopted management method, however, little is known as the soybean crop responds to the use of herbicides in different soil moisture. Thus, this study aimed to evaluate physiological and biochemical responses in soy after applying herbicides recommended plants for growing in three soil moisture levels. The experiment was arranged in a randomized design in a factorial arrangement (7x3) with four replications. It was used to cultivate soy BMX Power RR, grown in pots (8L), keeping three plants per pot which, in stage V3 were subjected to three soil moisture: field capacity, Dry soil (50% below capacity field) and saturated soil (50% above the field capacity), followed by herbicide treatment: Glyphosate, Sulfentrazone, S-metolachlor, Glyphosate + Sulfentrazone, Glyphosate + S-metolachlor, Glyphosate + Sulfentrazone + S-metolachlor, beyond without herbicide treatment. At seven, 14 and 28 days after application (DAA) were evaluated chlorophyll content, flavonoids, nitrogen balance and gas exchange in the third trefoil fully developed. This time collected is still, leaf material for evaluation of osmotic potential, proline content, hydrogen peroxide, lipid peroxidation and activity of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX). For pigments and nitrogen balance index was little variation between treatments, since gas exchange were more affected in dry soil plants, especially at 14 and 28 DAA, with marked effect by the presence of herbicides. At seven DAA the herbicide Glyphosate in dry soil resulted in greater activation of antioxidant enzymes SOD and CAT, as well as increased production of hydrogen peroxide and is probably linked to increased oxidative stress caused by this herbicide. However, after 28 days from the application, increased synthesis of proline in this treatment, which leads to osmotic adjustments and consequent lower enzymatic activity. In saturated soil and field capacity responses triggered by Glyphosate herbicides, Sulfentrazone, S-metolachlor does not follow a pattern, but, in general, lead to lower stress compared to dry soil. The results of this study show that although the variation in soil moisture, changes the soybean crop metabolism, the application of herbicides in dry soil conditions or saturated accentuates this effect and may result in damage to the crop.

Made available in DSpace on 2014-12-17T15:38:53Z (GMT). No. of bitstreams: 1 HellenCLB_DISSERT.pdf: 1274583 bytes, checksum: bff1e98a159fa77fea207af042cb90dc (MD5) Previous issue date: 2011-04-18 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / In recent years, much has been discussed about global climate changes (GCCs), popularly known as global warming. The scientific evidences point out to the influence of human actions for its drastic intensification. Therefore, studies of the psychological aspects involved become relevant. This study aimed at the investigation of the views of adolescents concerning GCCs, and the possible relations between those views and their pro-ecological commitment. Such commitment is measured by willingness for engagement in pro-environmental behaviors; environmentalism attitudes, like ecocentric and anthropocentric; consideration of future consequences; and ecological worldviews. Participants were 348 adolescents who answered a questionnaire containing questions about socio-demographic data, open questions about the practice of environmental care, and about GCCs, and the scales of Ecocentric and Anthropocentric Environmentalism, the Consideration of Future Consequences and the Ecological Worldviews assessment scale. From the inter-relationships between variables, procedures carried out by means of descriptive and correlacional statistics, it was observed that 55% of teenagers said that they did not engage in actions of environmental care, which was associated with apathyanthropocentric, immediatism, and individualism. The consideration of future consequences joined the practice of environmental care, corroborating evidence from the literature. It was evident that views concerning GCCs were superficial; adolescents perceive it as a generic environmental problem, and are confused with other problems such as pollution. This study found no association between views about GCCs and the indicators of pro-ecological commitment, perhaps due to the conceptual confusion about the subject. However, the lack of environmental care actions and other indicators of non-commitment (apathy-anthropocentric, individualism and immediatism) were associated with conceptually poor or incomplete responses (with no indication of cause, consequence or responsibility for the problem), demonstrating diminished knowledge and the failure to consider these issues / Nos ?ltimos anos, muito tem se falado a respeito das mudan?as clim?ticas globais (MCGs), popularmente conhecidas como aquecimento global. As evid?ncias cient?ficas ressaltam a influ?ncia das a??es humanas para sua dr?stica intensifica??o. Diante disto, estudos de aspectos psicol?gicos relacionados ? tem?tica ganham relev?ncia. Esta pesquisa teve como objetivo investigar o posicionamento de adolescentes diante das MCGs, e as poss?veis rela??es deste com o seu compromisso pr?-ecol?gico. Tal compromisso tem como indicadores, nesta investiga??o: o cuidado ambiental auto-relatado, ambientalismos ecoc?ntrico e antropoc?ntrico, a considera??o de conseq??ncias futuras, e as vis?es ecol?gicas de mundo. Participaram do estudo 348 adolescentes, que responderam a um question?rio, contendo quest?es sobre dados s?cio-demogr?ficos, quest?es abertas sobre a pr?tica de cuidado ambiental, e sobre MCGs, e as escalas de Ambientalismo Ecoc?ntrico e Antropoc?ntrico, de Considera??o de Conseq??ncias Futuras e de avalia??o das Vis?es Ecol?gicas de Mundo. A partir das inter-rela??es entre vari?veis, feitas por meio de procedimentos estat?sticos descritivos e correlacionais, observou-se que 55% dos adolescentes afirmaram n?o praticar a??es de cuidado ambiental, o que se associou ? apatia-antropoc?ntrica, ao imediatismo, e ao individualismo. J? a considera??o de futuro se associou ?s pr?ticas de cuidado ambiental, corroborando evid?ncias da literatura. Evidenciou-se que o posicionamento diante das MCGs ? superficial; os adolescentes as percebem como um problema ambiental gen?rico, e as confundem com outros problemas, como a polui??o. Este estudo n?o encontrou associa??o entre o posicionamento diante das MCGs e indicadores de compromisso pr?-ecol?gico, talvez devido ? confus?o conceitual a respeito do tema. Todavia, a aus?ncia de pr?tica de cuidado e os demais indicadores de n?o-compromisso (apatia-antropoc?ntrica, individualismo e imediatismo) se associaram ?s respostas mais conceitualmente pobres, ou incompletas (sem indica??o de causa, conseq??ncia ou de respons?vel pelo problema), evidenciando, al?m do conhecimento emba?ado, a n?o considera??o destas quest?es

<p>Kvantifikovanjem uticaja klimatskih promena na biljnu proizvodnju stiče se mogućnost obrazovanja dugoročnih planova u poljoprivrednoj proizvodnji kako bi se održao visok i stabilan prinos ključnih gajenih kutura (p&scaron;enice, kukuruz). Najpre su urađene analize klime i agroklimatskih pokazatelja za sada&scaron;nje uslove 1971-2000. i očekivane uslove za 2030. i 2050. godinu za 11 lokaliteta Republike Srbije. Tek nakon analize klime uzima se u obzir poznata činjenica da postoji međusobna interakcija između meteorolo&scaron;kih uslova, zemlji&scaron;ta i biljke. Na ovoj interakciji zasnivaju se modeli biljne proizvodnje i upotrebljavaju se u cilju kvantifikovanja uticaja klimatskih promena na biljnu proizvodnju tj. na dinamiku vegetacije i prinos.<br />U radu su kori&scaron;ćeni osmotreni dnevni meteorolo&scaron;ki podaci sa jedanaest stanica sakupljenih u Republičkom Hidrometeorolo&scaron;kom Zavodu Srbije. Za buduće stanje klime kori&scaron;ćeni su izlazni podaci globalnih klimatskih modela (ECHAM, HadCM, NCAR) i njihovom statističkom regionalizacijom Met &amp; Roll vremenskim generatorom dobijeni su podaci o budućem stanju klime na području jedanaest izabranih lokaliteta. Podaci o zemlji&scaron;tu (mehaničke i hemijske osobine) preuzeti su od Agencije za za&scaron;titu životne sredine iz Beograda. Ulazni podaci o biljnoj vrsti i njenoj agrotehnologiji, neophodni u radu sa modelom biljne proizvodnje (kalibraciji i validaciji), obezbeđeni su sa vi&scaron;egodi&scaron;njih ogleda zasnovanih na oglednim poljima Rimskih &Scaron;ančeva Insituta za ratarstvo i povrtarstvo u Novom Sadu.<br />Kao metod kori&scaron;ćeni su modeli za određivanje agroklimatskih parametara Agriclim i model biljne proizvodnje DSSAT v. 4.2.<br />4<br />Analizom buduće klime, temperature vazduha i padavina, utvrđeno je da se može očekivati porast temperature vazduha na godi&scaron;njem nivou i tokom svih delova vegetacinog perioda, a količina padavina se očekuje da bude vi&scaron;a tokom zimskog perioda, dok u prolećnom periodu (mart &ndash; april - maj) ne&scaron;to niža do 10 mm, a tokom letnjih meseci jun-jul-avgust značajno niža.<br />Analizom rezultata DSSAT 4.2 modela biljne proizvodnje, utvrđeno je da u očekivanim klimatskim uslovima 2030. i 2050. godine pri koncentraciji CO2 od 330 ppm prinos zrna ozime p&scaron;enice ostaje nepromenjen u većini lokaliteta izuzev Kru&scaron;evcu, Somboru i Vranju gde prinos opada do 12% u 2030. i do 11% u 2050. godini. Uzrok visokih i stabilnih prinosa su povećane količine padavina i povećanje temperature vazduha u zimskom periodu, manji broj mraznih i ledenih dana. Jedan od najvažnijih faktora stabilnosti prinosa je i dovoljna količina rezerve vlage u zemlji&scaron;tu za prolećni period i količina padavina za prolećni period, koji je u literaturi određen kao kritični period potrebe p&scaron;enice za vodom. U budućim uslovima analizom rezultata broja dana potrebnih od setve do cvetanja i od setve do zrelosti, ustanovljeno je da se očekuje manji broj dana, tj. da će fenofaze kraće trajati do cvetanja i zrelosti &scaron;to je posledica očekivanih vi&scaron;ih temperatura vazduha i suma efektivnih temperatura. U uslovima 2030. i 2050. godine i očekivane koncentracije CO2 po IPCC izve&scaron;taju iz 2007. godine, uticaj povi&scaron;ene koncentracije CO2 na prinos zrna p&scaron;enice je pozitivan. Prinosi kod većine lokaliteta ostaju nepromenjeni dok je mali pad prinosa zrna bio primećen na lokalitetima Kru&scaron;evac i Sombor, gde neznatno opada do 7% u 2030. godini i 2050. godini. U Somboru se očekuje nepromenjena količina padavina za mart &ndash; april - maj period i mnogo manja količina padavina u periodu jun &ndash; jul - avgust, a u Kru&scaron;evcu ne&scaron;to manja količina padavina u periodu mart &ndash; april &ndash; maj i do 40% manja količina u periodu jun &ndash; jul - avgust u 2050. godini.<br />Analizom rezultata prinosa zrna kukuruza za 2030. i 2050. godinu pri koncentracije CO2 od 330 ppm dobijen je veoma značajan pad prinosa i u uslovima bez navodnjavanja i u uslovima navodnjavanja normom od 180 mm za sve lokalitete. U 2030. i 2050. godini u uslovima povi&scaron;ene koncentracije CO2 uticaj očekivane koncentracije CO2 na prinos zrna kukuruza simulacijama ocenjen je kao negativan, jer je dobijeni prinos zrna kukuruza bio jo&scaron; niži nego pri koncentraciji CO2 od 330 ppm.<br />Veoma značajan pad prinosa posledica je vi&scaron;ih temperatura vazduha u JJA periodu, povećanja fiziolo&scaron;kog stresa kod biljaka usled povećanja broja letnjih i tropskih dana, značajno smanjenje količine padavina, posebno u periodu jun &ndash; jul &ndash; avgust i povećanje broja su&scaron;nih dana tokom istog perioda. Analizom dužine trajanja vegetativne sezone za oba režima uzgajanja kukuruza moglo se zapaziti da se u budućim uslovima očekuje skraćenje perioda vegetacije zbog vi&scaron;ih temperatura vazduha i sume temperatura. Analizom rezultata simulacije prinosa zrna soje za 2030. i 2050. godinu pri koncentraciji CO2 od 330 ppm, očekuje se nepromenjen prinos zrna u lokalitetima Ćuprija, Ni&scaron;, Vranje i Prizren, ili neznatno vi&scaron;i do 9 % u lokalitetima Kraljevo, Kru&scaron;evac, Novi Sad, Sombor i Zaječar. Samo u istočnom lokalitetu Dimitrovgrad i centralnom Požega se očekuje značajno vi&scaron;i prinos do 14% u 2030. godini i do 23% u 2050. godini. U 2030. i 2050. godini pri povi&scaron;enoj koncentracije CO2 po IPCC izve&scaron;taju iz 2007. godine očekuje se veoma značajno vi&scaron;i prinos u svim lokalitetima, a posebno je nagla&scaron;eno u lokalitetima Dimitrovgrad i Požega gde su dobijene najniže srednje temperature vazduha za AMJ i JJA period, najmanji broj letnjih i tropskih dana. Nakon dobijenih rezultata prinosa zrna za izabrane biljne kulture, rezultati prinosa zrna kukuruza ukazivali su na potrebu definisanja i uvođenja mera adaptacija u dosada&scaron;nju agrotehnologiju. DSSAT model biljne proizvodnje je izabran u istraživanju i kvantifikovanju mera adpatacija, jer se potrebe i fiziolo&scaron;ke reakcije biljke u simulacijama mogu pratiti na dnevnom nivou (Wang et al., 2011). Kao mere adaptacije analizirane su adaptacija roka setve i navodnjavanje. Adaptacija roka setve urađena je za kukuruz u uslovima bez navodnjavanja, da bi se ocenio isključivo uticaj primene ranijeg roka setve na prinos, a ne i navodnjavanje. Na osnovu analize<br />5<br />rezultata relativne promene prinosa za sve lokalitete, pokazalo se da se u uslovima ranijeg roka setve očekuju vi&scaron;i prinosi nego u uslovima uobičajenog datuma setve. Međutim, u svim lokalitetima i dalje se očekuje veoma značajan pad prinosa, izuzev u Dimitrovgradu, Vranju i Prizrenu, gde se očekuje značajan porast u odnosu na prinose perioda 1971-2000. godina.<br />Na osnovu analize rezultata simuliranih prinosa za ozimu p&scaron;enicu, kukuruz i soju, konstatovano je da se p&scaron;enica može proizvoditi u uslovima bez navodnjavanja, a prolećni usevi kukuruz i soja bi morali da se navodnjavaju zbog očekivanog velikog smanjenja količine padavina u letnjem periodu. Da bi se procenila adekvatna norma navodnjavanja u proizvodnji kukuruza u simulacijama u DSSAT modelu biljne proizvodnje izabrana je opcija 50 % dostupne vode biljci. Simulacije proizvodnje kukuruza u uslovima 50% dostupne vode biljci dale su pozitivne rezultate prinosa. Prinosi su bili nepromenjeni u lokalitetima Ćuprija, Kru&scaron;evac, Kraljevo, Ni&scaron;, Novi Sad, Sombor, Vranje, Zaječar u 2030. godini i 2050. godini izuzev u Kraljevu gde je prinos bio niži do 17% u 2050. godini. U lokalitetima Dimitrovgrad, Požega i Prizren prinos je bio vi&scaron;i oko 9% u 2030. godini i nepromenjen u 2050. godini. Uvećanje norme navodnjavanja je bilo veoma značajno na većini lokaliteta od 20% do 30% sa maksimumom u Požegi do 45% u 2030. i 84% u 2050. godini. Lokalitet Požega imao je zemlji&scaron;te tipa ilovasti fluvisol i izmeren visok procenat peska, iznad 50% u svom mehaničkom sastavu, &scaron;to je uslovilo i veću propusnost vode, njeno kraće zadržavanje u profilu zemlji&scaron;ta i potrebu za većom količinom vode u navodnjavanju. Simulacije prinosa soje odmah su urađene u uslovima navodnjavanja od 50% dostupne vode biljci, jer je opcija u uslovima bez navodnjavanja davala jako niske prinose, a opcija 50% dostupne vode je davala takve norme navodnjavanja koje su bile slične u na&scaron;im uslovima na Institutu za ratarstvo i povrtarstvoPri takvoj opciji navodnjavanja u svim lokalitetima norma navodnjavanja je u budućim uslovima veoma značajno rasla od 10 do 40% u 2030. godini i od 13 do 110% u 2050. godini, a rezultati relativne promene prinosa ukazivali su na veoma značajno povećanje prinosa u budućim&nbsp;uslovima.</p> / <p>DSSAT 4.0 is a crop model commonly used to quantify the climate change impact on agriculture production. The model predictions are very important for long term planning in agriculture to keep high and stable yield production. At the first, the climate was analysed for 1971-2000 period, 2030 and 2050 year. After these analyses the crop model was run. Crop model is based on interaction between climate, soil and plant. Simulations were predicted the yield and dynamic in vegetation for 2030 and 2050 climate conditions. As input parameters were used observed daily weather data from eleven weather stations for 1971-2000 period. For 2030 and 2050, the data were used from global climatology models ECHAM5, HadCM3 and NCAR-PCM for two scenarios A1B and A2. Before crop simulations, the out results from global climatology models had to be regionalised and downscaled with Met &amp; Roll weather generator. The soil input data were assumed from Agency for Environmental Safety from Belgrade. The data were consist of mechanical and chemical characteristics of soil which were chosen near the weather station. The crop input data were collected from the literature and personal communication of Institute of Field and Vegetable Crops and their long term period experiments. A current and future agroclimatic indices were calculated with Agriclim model. As a crop model, DSSAT v. 4.2. was chosen for crop simulations of major field crops: winter wheat, maize and soybean.<br />The results of climate shown that the air temperature should be higher in all vegetation phases, and precipitation should be higher during winter months, lower for 10 mm in spring and significantly lower in summer months June- July-August.<br />In 2030 and 2050 year (CO2=330 ppm) simulations shown that winter wheat yield might be the same as in 1971-2000 period in most locations except in Krusevac, Sombor and Vranje where yield might be lower for 12% in 2030 year and lower for 11% in 2050 year. It is a consequence of expected higher precipitation and higher air temperatures during winter period, less frosty and frozen days, higher precipitation during spring, which is a critical period for winter wheat production. It was analysed the dinamyc in vegetation in future<br />9<br />conditions. The results showed the shorter vegetation, less number of days from seeding to anthesis and seeding to maturity. These changes in vegetation duration were caused by expected higher air temperatures and higher effective temperatures.<br />The yield results were also analysed for expected conditions under future CO2 concentration from IPCC report 2007, and shown that winter wheat yields were not changed for most locations except in Krusevac and Sombor in 2030 and 2050 year.<br />The maize yield results for 2030 and 2050 under CO2 concentration of 330 ppm shown a significant decrease in yield in non irrigated conditiond and irrigated conditions with 180 mm water added per vegetation season. Also, the results given under expected CO2 concentration from IPCC Report 2007, shown great decrease in 2030 and 2050 and lower yield than under CO2 was set on 330 ppm. The significant decrease in yield was caused by expected higher temperatures in JJA period, higher physiologicaly stress caused by more days with extreme high temperatures (summer and tropical days) and very significant decrease in precipitation during JJA period. The results showed the shorter vegetation, less number of days from seeding to anthesis and seeding to maturity. These changes in vegetation duration were caused by expected higher air temperatures and higher effective temperatures.<br />The soybean yield analyses for 2030 and 2050 under CO2 concentration of 330 ppm shown no changes in yield for Cuprija, Nis, Vranje and Prizren, a little higher to 10% in Kraljevo, Krusevac, Novi Sad, Sombor, Zajecar and up to 24% higher in Dimitrovgrad and Pozega. In 2030 and 2050 under future CO2 concentrations from IPCC Report 2007, it is expected a significantly higher yield in all locations especially for Dimitrovgrad and Pozega, where the air temperatures were lowest in AMJ and JJA period. The results showed the shorter vegetation in soybean production, less number of days from seeding to anthesis and seeding to maturity. These changes in vegetation duration were caused by expected higher air temperatures and higher effective temperatures. After all simulations for winter wheat, maize and soybean, it is concluded that maize production need some adaptation measures for future conditions. As an adaptation measure it were chosen two measures: the shift in sowing date and irrigation quantity. The adaptation in sowing date was set for maize under non irrigated conditions, to analyse only the time of sowing not irrigation. The sowing date was set 15 days earlier, on the 5th of April. The yield results shown less decrease than results given at usual sowing date (20th of April), but in all locations the predicted yield decreased except in DM, VR and PR where the yield shown significant increase in a comparison with 1971-2000 yield. The change in irrigation quantity was more efficient for yield. It was done for maize production and soybean, because winter wheat irrigation was estimated as non economic. The irrigation method was set on 50% available water for plant. The maize yield was stable in Ćuprija, Kru&scaron;evac, Kraljevo, Ni&scaron;, Novi Sad, Sombor, Vranje, Zaječar in 2030 and 2050 year except in Kraljevo where the yield decreased up to 17% in 2050 year. In Dimitrovgrad, Požega and Prizren the yield was higher for 9% in 2030 year and not chaged in 2050 year. The water requirements had significantly higher values than in 1971-2000 period up to 20-30% in 2030 year with maximum in Požega up t 45% in 2030 year and 84% in 2050 year. The location Požega has soil with a high percent of sand in structure, above 50%, what caused quick water filtration and more water in irrigation. The soybean simulations were done in irrigation option of 50% available water at the begining, because the non irrigated method did not gave the satisfied yield results in crop model. The 50% irrigation method gave adequate yield and water requirements as in experiments on Institute. The water requirements had significantly higher values in 2030 year from 10-40% and from 13% to 110% in 2050 year than in 1971-2000 period.<br />Key words: climate change, CO2 fertilization, DSSAT v. 4.2. crop model, effective irrigation, maize yield, soybean yield, vegetation, winter wheat yield.</p>

O processo de urbanização da cidade de São Paulo foi caracterizado pelo rápido adensamento populacional e desordenada expansão da área urbana, que destinou às populações mais vulneráveis socioeconomicamente áreas distantes dos núcleos centrais e sem infraestrutura urbana. Esse processo é refletido até os dias atuais, uma vez que parcela significativa da população paulistana reside em ocupações subnormais expostas aos riscos ambientais, o que a torna mais vulnerável aos impactos das mudanças climáticas se comparada às camadas sociais mais privilegiadas e melhor localizadas espacialmente. Apesar das projeções e pesquisas mais recentes relacionadas aos impactos das mudanças climáticas no Brasil, eventos recentes evidenciam que as cidades brasileiras ainda não estão devidamente adaptadas para lidar com esse fenômeno. Entendendo que a capacidade adaptativa de um sistema (uma cidade, por exemplo) refere-se à sua aptidão em mudar para um estado mais sustentável e em mobilizar os recursos necessários para antecipar ou responder aos riscos e impactos das mudanças climáticas, o objetivo desta dissertação é contribuir para uma compreensão sobre a capacidade adaptativa, particularmente quanto à capacidade específica, do município de São Paulo frente às mudanças climáticas. Para tanto, foram analisados três instrumentos vigentes: o mapeamento de áreas de risco, o sistema de alerta e os planos de contingência que possuem interface com o clima - Plano Preventivo para Chuvas de Verão (PPCV), Plano de Contingência para situações de Baixas Temperaturas (PCBT) e Plano de Contingência para situações de Baixa Umidade (PCBU), ferramentas gerenciadas atualmente pela Coordenação Municipal de Defesa Civil (COMDEC). Os resultados obtidos nesta pesquisa, a partir de revisão de literatura, pesquisa documental, realização de entrevistas e grupos focais, evidenciam que as discussões sobre mudanças climáticas e as projeções futuras ainda não estão internalizadas nas ferramentas analisadas e que não há uma integração fortemente estabelecida entre o Comitê Municipal de Mudanças do Clima e Ecoeconomia e os demais setores da Prefeitura. Ademais, revelam que há um distanciamento da população nas ações de planejamento e execução dessas ferramentas e que as descontinuidades político-partidárias interferem negativamente no andamento dessas e de outras políticas públicas, além do déficit de recursos humanos, tecnológicos e financeiros estar associado, principalmente, às práticas ineficazes de gestão (má administração) e distribuição. Um diagnóstico sobre esses instrumentos e recomendações para facilitar o processo de adaptação e aprimorar a capacidade de adaptação específica da cidade de São Paulo serão reunidos e disponibilizados também na forma de um relatório técnico. / The urbanization process of the city of São Paulo was characterized by a rapid population density increase and disorderly expansion of the urban area, which allocated remote areas without urban infrastructure to the most socioeconomically vulnerable population. This process is reflected to the present days, since a significant part of the population of São Paulo resides in subnormal occupations exposed to environmental risks, which makes it more vulnerable to the impacts of climate change when compared to the more privileged and better located social strata. Despite recent projections and researches related to the impacts of climate change in Brazil, recent events show that Brazilian cities are not yet adequately adapted to deal with this phenomenon. Assuming that the adaptive capacity of a system (a city, for example) refers to its ability to move to a more sustainable state and to mobilize necessary resources to anticipate or respond to the risks and impacts of climate change, the objective of this dissertation is to contribute to an understanding of the adaptive capacity, particularly regarding the specific capacity of the city of São Paulo in the face of climate change. For that, the mapping of risk areas, the alert system and contingency plans that have interface with the climate were analyzed - Preventive Plan for Summer Rain (PPCV), Contingency Plan for Low Temperature Situations (PCBT) and Contingency Plan for Low Humidity Situations (PCBU), tools currently managed by the Municipal Civil Defense Coordination (COMDEC). The results obtained in this research, based on literature review, documentary research, interviews and focus groups, show that the discussions about climate change and projections were not yet internalized by the analyzed tools and that there is no strongly established integration between the Municipal Committee on Climate Change and Ecoeconomics and other sectors of the City Hall. In addition, they reveal that there is a distancing between the population and the planning and execution of these tools and that party-political discontinuities impact negatively in the progress of these and other public policies, besides the fact that the lack of human, technological and financial resources is mainly associated with ineffective management (maladministration) and distribution. A diagnosis of these instruments and recommendations to facilitate the adapting process and to improve the specific adaptation capacity of the city of São Paulo will be gathered and made available in the form of a technical report.

The Arctic represents a huge area with poor infrastructure contributing to limited possibilities to establish monitoring and research programs. From the investigations that have been performed we know that the arctic environment is affected by anthropogenic emissions from lower latitudes, but knowledge about underlying transport processes, the arctic pollution extent and the rates of changes are limited. This is of particular concern since we are facing climate changes that will not only influence the pole-ward transport of pollutants, but also change conditions for the already accumulated pollutants in the arctic environment. In this thesis lake sediments and soil samples are used to study sub-arctic and arctic time trends and loads of PCBs, PBDE, pesticides, mercury and lead. The study sites are the area around Kangerlussuaq, located in western Greenland, and the Swedish mountains. The temporal trends for PCBs (69 congeners), PBDE (#47) and two pesticides (chlordane and hexachlorobenzene) are studied in seven surface lake sediment cores from Greenland. The concentrations of these persistent organic pollutants are one to two orders of magnitude lower compared to lake sediments from lower latitudes, but with temporal trends following emission and usage trends at lower altitudes, i.e., decreasing trends for PCBs, increasing for PBDE and no specific trends for the pesticides. A delayed deposition of the low-chlorinated PCBs compared to the high-chlorinated PCBs may support the hypothesis of ‘cold condensation’ and ‘global fractionation’ i.e., volatile compounds are fractionated during the pole-ward transport. For lead the concentration in three Greenland lake sediments is about 10 times lower than in sediments from industrial regions, but the past 200 years’ temporal trends follow emission trends in industrial regions. The mercury concentration and enrichment following the Industrial Revolution in the mid 19th century are in three lake sediments from Greenland and in twelve lake sediments from the Swedish mountains comparable with those in sediments from industrial regions; a result of the long atmospheric residence-time for mercury, making it a global pollution. Recently decreased mercury emissions in North America and Europe give declining concentrations in the sediment surfaces, especially in lakes located in the Swedish mountains. In Greenland deeper sediment cores, spanning the last 8000 years, there are substantial fluctuations in mercury concentration and stable lead isotopes (206Pb/207Pb). These fluctuations are the result of variations in deposition to the lake of aeolian material, driven by past variations in arctic climate. In surface soil the mercury concentrations and inventories from the Swedish mountains are 1.5-2 times higher than in soils from Greenland, but for both regions the concentrations are below the critical concentration set up by UN-ECE to protect the terrestrial ecosystem. No indications for mercury enrichment in colder areas, as suggested by the hypothesis of ‘cold condensation’, or in coastal areas, as suggested by the hypothesis of ‘mercury depletion events’, were observed. The highly minerogenic surface soils in sub-arctic and arctic regions have reduced capacity to store mercury, compared to boreal soils.

Made available in DSpace on 2016-06-02T20:39:15Z (GMT). No. of bitstreams: 1 4621.pdf: 10468707 bytes, checksum: c38c3ca9cf60dac2e6bad351d4f51f79 (MD5) Previous issue date: 2012-06-11 / Financiadora de Estudos e Projetos / The study describes and analyzes sociologically, from a qualitative approach, the social representations of the people of the island of Formosa Bijagó about possible threats related to climate change, its consequences in terms of the form of territorial occupation and way of life characteristic of that group. For this, we adopted the following methodological procedures: a) A review of the state of the art about the concepts of vulnerability related to climate change, the increasing vulnerability, risk and social representations, b) documentary research and fieldwork. For Bijagó the natural and the social are inextricably linked, to the extent that a crisis in the social system would have negative effects on natural sistem. Thus, the adverse changes that are occurring in nature around them, would be signs of displeasure from their ancestors about the differences and crises with the community, which are in power to control and manipulate the events of nature. / A pesquisa descreve e analisa sociologicamente, a partir de uma abordagem qualitativa, as representações sociais do povo Bijagó da ilha de Formosa acerca das possíveis ameaças relacionadas às mudanças do clima, seus desdobramentos em relação ao lugar, isto é, em termos da forma de ocupação territorial e correspondente modo de vida característico do referido grupo. Para isso, foram adotados os seguintes procedimentos metodológicos: a) uma revisão do estado da arte acerca dos conceitos de vulnerabilidade relacionados às mudanças climáticas, à vulnerabilização, ao risco e às representações sociais; b) uma pesquisa documental e o trabalho de campo. Para os Bijagó o meio natural e o meio social são indissociáveis, na medida em que uma crise no sistema social teria reflexos negativos no sistem natural. Conclui identificando que, nas representações dos Bijagó, as mudanças adversas que vêm ocorrendo no meio natural, seriam sinais de desagrado de seus ancestrais com relação as divergências e crises dentro da comunidade, sendo estes os detentores do poder de controlar e manipular os eventos da natureza.

Data de aprova??o retirada da vers?o impressa do trabalho. / ?rea de concentra??o: Produ??o Vegetal. / Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2018-08-14T22:18:43Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) camila_rodrigues_costa.pdf: 5661319 bytes, checksum: b9deab885dfc53d90534a8a979f8d00d (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2018-10-05T19:35:26Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) camila_rodrigues_costa.pdf: 5661319 bytes, checksum: b9deab885dfc53d90534a8a979f8d00d (MD5) / Made available in DSpace on 2018-10-05T19:35:26Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) camila_rodrigues_costa.pdf: 5661319 bytes, checksum: b9deab885dfc53d90534a8a979f8d00d (MD5) Previous issue date: 2018 / Funda??o de Amparo ? Pesquisa do estado de Minas Gerais (FAPEMIG) / As turfeiras s?o ambientes de transi??o entre os ecossistemas terrestres e aqu?ticos, formados pela acumula??o sequencial de mat?ria org?nica. Extremamente sens?veis as mudan?as nos padr?es de precipita??o e temperatura, as turfeiras s?o consideradas verdadeiros arquivos da evolu??o do ambiente ao seu redor. Nas depress?es das ?reas dissecadas da Serra do Espinha?o Meridional, Minas Gerais, ocorrem ambientes propicios para forma??o de turfeiras. Dentre elas encontra-se a turfeira do Rio Preto (18?14'5,25"S e 43?19'7,24" WGS, 1.593 m.s.m) inserida no Parque Estadual do Rio Preto. A turfeira do Rio Preto ? colonizada por diferentes fisionomias do Bioma Cerrado principalmente o Campo ?mido e Campo Rupestre, sendo encontrados ainda redutos de Floresta Estacional Semidecidual (Cap?es de Mata). O objetivo deste trabalho foi reconstituir as mudan?as paleoambientais ocorridas desde o final do Pleistoceno Tardio. Para isto foi utilizada uma abordagem multi-proxy, consistindo em estratigrafia do perfil do solo da turfeira, an?lises palinol?gicas, de is?topos est?veis (13C e 15N), de composi??o geoqu?mica e data??es radiocarb?nicas. A idade mais antiga, obtida da base do testemunho, foi de 23.037 anos cal. AP, indicando que a forma??o da turfeira se deu a partir do Pleistoceno Tardio. A partir da an?lise conjunta dos proxys foi poss?vel inferir cinco principais fases de mudan?as paleoambientais: RP-I, entre ~ 23.037 e 13.500 anos cal. AP, clima bastante ?mido e frio, possibilitando a presen?a de indicadores de Floresta Montana e o empobrecimento do sinal isot?pico. Este foi um per?odo de bastante instabilidade na bacia hidrogr?fica da turfeira, inferida pelo alto teor de Si, indicador de sinal de material mineral local; RP-II, entre ~13.500 e 11.700 anos cal. AP, ligeiro aumento da temperatura e queda na umidade levando a redu??o de indicadores de clima frio e a expans?o da vegeta??o campestre. No entanto as condi??es ainda eram mais ?midas e frias que as atuais, e a ind?cios de diminui??o do sinal de material mineral local; RP-III, entre ~11.700 e 8.500 anos cal. AP, tend?ncia de aumento da temperatura e diminui??o da umidade em conjunto com a mudan?a da vegeta??o de plantas C3 para C4, causando a forte retra??o das Floresta Estacional Semidecidual e Floresta Montana, em conjunto aumento do fluxo de sinal de material mineral local; RP-IV, entre ~8.500 e 7.000 anos cal. AP, condi??es de clima ainda mais seco e quente, causando o desaparecimento dos indicadores de clima frio, retra??o do Campo ?mido e expans?o do Campo Rupestre. Per?odo de bastante estabilidade da bacia hidrogr?fica da turfeira, sugerido pelo baixo conte?do de material mineral; RP-V, de 7.000 anos cal. AP at? o presente, clima era novamente mais ?mido e temperaturas mais amenas, semelhante ?s condi??es atuais, aumento na acumula??o de turfa, possibilitando o reaparecimento dos indicadores de Floresta Montana e Floresta Estacional Semidecidual junto com a retra??o do Campo, e diminui??o da entrada de material mineral. Flutua??es no clima influenciaram fortemente as mudan?as na paleovegeta??o e na estrutura sedimentar do registro da turfeira do Rio Preto. Devido ? import?ncia das turfeiras, n?o s? como arquivo de mudan?as paleoambientais, mas tamb?m pelos seus servi?os ambientais (armazenamento de ?gua e de carbono), estes ambientes precisam ser melhores protegidos. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Produ??o Vegetal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2018. / The peatlands are transitional environments between terrestrial and aquatic ecosystems, formed by the sequential accumulation of organic matter. Extremely sensitive to changes in precipitation and temperature patterns, peatlands are real archives of the evolution of the environment around them. In Serra do Espinha?o Meridional, Minas Gerais State, Brazil, in depressions of the dissected areas occurs an environment conducive to formation of peatlands. Among them the peatland of Rio Preto (18?14'5,25"S e 43?19'7,24" WGS, 1.593 m.s.m), located in the Rio Preto State Park. The area is colonized by different vegetation physiognomy of the Cerrado Biome, mainly Rupestre Fields and Wet Fields, beyond of redoubts of Semidecidual Stationary Forests, called Capon Forests. The area is colonized by different vegetation physiognomy of the Cerrado Biome, mainly Rupestre Fields and Wet Fields, beyond of redoubts of Semidecidual Stationary Forests, called Capon Forests. The objective of this work was to reconstruct the paleoenvironmental changes that have occurred since the Late Pleistocene. The work was constituted by the application of a multi-proxy approach, such as peatland soil stratigraphy, palynological analyzes, stable isotopes (13C and 15N), geochemical composition analyzes and 14C dating. The oldest age obtained at the base of the peatland profile was 23.037 cal. years BP, indicating that the formation of the peatland occurred during the Late Pleistocene. In this study it was possible to infer five main stages of paleoenvironmental changes: RP-I ~23.000-13.500 cal. years BP, very cold climate and very humid, presence of Montana Forest indicators and impoverishment of the isotopic signal, period of instability in hydrographic basin of the peatland; RP-II ~13.500-11.700 cal. years BP, small increase in temperature and decreased humidity, reduction of the indicators of cold climate and the expansion of the field vegetation, however the climatic conditions were more humid and cooler than the current, decrease of the entrance of local mineral material; RP-III ~11.700-8.500 cal. years BP, trend of increased temperature and decreased humidity, change in vegetation from C3 to C4 plants, reduction of the Semideciduous Seasonal Forest and Mountain Forests, increased flow of local mineral material; RP-IV ~8.500-7.000 cal. years BP, drier and hotter weather, causing the disappearance of the indicators of cold weather, retraction of the Wet Field and expansion of Rupestre Field. Period of very stability in the watershed of the peatland; RP-V 7.000 cal. years BP until present, increased humidity and decrease in temperature, as current conditions, increased accumulation of peat, reappearance of the indicators of Montana Forest and Seasonal Semideciduous Forest and retraction of the Field, decrease of regional and local dust. Fluctuations in the climate influenced changes in paleovegetation and the sedimentary structure of the peatland Rio Preto. Given the value of peatlands as archives of paleoenvironmental changes and their environmental functions, these environments need to be better protected.