Submitted by Marco Antônio de Ramos Chagas (mchagas@ufv.br) on 2016-10-17T13:34:05Z No. of bitstreams: 1 texto completo.pdf: 4089586 bytes, checksum: d870cc4b1e255a4c1ee3e8dc54183ced (MD5) / Made available in DSpace on 2016-10-17T13:34:05Z (GMT). No. of bitstreams: 1 texto completo.pdf: 4089586 bytes, checksum: d870cc4b1e255a4c1ee3e8dc54183ced (MD5) Previous issue date: 2005-03-04 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A água doce é fonte primária de recursos para a sociedade, tais como produção de alimentos e atividades industriais. As previsões com relação a escassez de água para o suprimento das necessidades básicas do homem, têm sido motivo de intensas pesquisas visando a maximização do seu aproveitamento. Assim sendo grande atenção é dada a plantas com capacidade de limpar a água, principalmente as aquáticas e o uso de filtros plantados com macrófitas aquáticas - sistema “wetland”, surge como uma alternativa eficiente e de baixo custo operacional quando comparado com os sistemas clássicos para o tratamento de água. Foi construído um sistema “wetland” de fluxo subsuperficial, para o tratamento de água residuária de suinocultura na “Área Experimental e Drenagem” do Departamento de Engenharia Agrícola da Universidade Federal de Viçosa, Estado de Minas Gerais (UFV), utilizando Alternanthera philoxeroides (Mart.) Griseb., Cynodon dactylon (Tifton 85) e Typha latifolia L. Os objetivos foram verificar as alterações morfo-anatômicas apresentadas no sistema radicular e parte aérea destas espécies quando cultivadas no sistema “wetland’; avaliar o comportamento das mesmas em ambientes eutrofizados, verificando a relação entre a quantidade de nutrientes acumulada nos tecidos e a morfo-anatomia, e fornecer subsídios para a escolha correta de espécies vegetais a serem utilizadas neste sistema. Foram analisados órgãos subterrâneos e aéreos destas espécies, coletadas em três tratamentos: Tratamento 1 onde o dejeto de suinocultura chega, tratamento 2, que corresponde ao final do tanque, local menos eutrofizado e tratamento controle, livre de dejeto. Foi confeccionado laminário permanente com inclusão em resina e parafina, coloração com azul de toluidina e azul de astra/fuccina básica para análise do material em microscopia de luz. Para a análise quantitativa dos dados foi usado o software Image Pró-Plus Version 4.5. O material foi fotografado em microscópio de luz acoplado à câmara digital. Após a coleta, amostras foram pesadas para obtenção dos dados de peso da matéria seca e posteriormente moídas para a análise de nutrientes. De modo geral, o sistema empregado pode ser considerado eficiente na despoluição de ambientes contaminados com dejeto suíno, pois foi constatado o acúmulo de diversos elementos químicos na parte aérea e no sistema subterrâneo das plantas em resposta a adição de dejeto no substrato. As três espécies toleraram bem tanto as condições de inundação como a exposição a altas cargas orgânicas; a morfologia foi mais alterada que a anatomia quanto as respostas apresentadas frente à exposição ao aumento de nutrientes foram comparadas. A. philoxeroides foi a espécie que promoveu a extração de um número maior de nutrientes e C. dactylon a que menos acumulou. Em geral o nitrogênio foi o elemento químico mais expressivo nos tecidos das plantas. / Fresh water is primary source of resources to society as the production of food and industrial activities. The forecasts in relation to water scarcity to the supply of basic human needs, has been the cause of intensive researches aiming the maximization of its utilization. So, much attention is given to plants with the capacity of cleaning the water, mainly the aquatic ones and the use of filters with aquatic macrophytes – wetland system, comes out as an efficient and cheaper alternative when compared with classic systems to water treatment. A wetland system of subsuperficial flux was built to the treatment of swine wastewater in “Experimental Area and Drainage “ of Department of Agricultural Engineering of Federal University of Viçosa (UFV), Minas Gerais State, using Alternanthera philoxeroides (Mart.) Griseb., Cynodon dactylon (Tifton 85) and Typha latifolia L. The objectives were to verify morpho-anatomical modifications presented in root system and aerial part of these species when cultivated in wetland system; evaluate their behavior in eutrophic environments, verifying the relation between the quantity of nutrients accumulated in tissues and morpho-anatomy; and provide subsidies to the correct choice of plant species that will be used in this system. Subterranean and aerial organs of these species were analyzed, collected in three treatments: Treatment 1 where the swine culture residues come, treatment 2, that corresponds to the final portion of the reservoir, less eutrophic place, and control treatment, free of those residues. Permanent slides were made with inclusion in resin and paraffin, stained with Toluidine Blue and Astra Blue, and Basic Fuchsine. Qualitative analysis was made and to the quantitative analysis of the data, the software Image Pro-Plus Version 4.5 was used. The material was photographed in light microscope joined to a digital camera. After the collection, samples were weighed to provide the data about dry matter weight and later they were ground to the nutrient analysis. In general terms, the system used can be considered efficient in the despollution of environments contaminated with pig residue, because it was verified the accumulation of several chemical elements in aerial part and subterranean system of those plants in response to the addition of residue in the substrate. The three species were well adapted to the system, and tolerated the conditions of flood and the exposition to high organic loads; and in respect to the responses showed by the exposition to the increase of nutrients, the morphology was much altered when compared with the anatomy. A. philoxeroides was the species with the extraction of a higher number of nutrients and C. dactylon was the one which accumulated the smallest number of nutrients. In general, nitrogen was the most expressive chemical element in tissues of those plants. / Dissertação importada do Alexandria

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Der Klimawandel bedroht Ökosysteme auf der ganzen Welt. Besonders der Anstieg in Länge, Intensität und Häufigkeit von Dürren kann bedeutenden Einfluss auf den globalen Kohlenstoffkreislauf haben. Die Frage, ob Pflanzen und Mikroorganismen anfällig gegenüber ökologischem Stress wie Dürren sind, wurde bereits in vielen Studien für verschiedene Ökosysteme und mit verschiedenen Ansätzen untersucht, aber Analysen von Dürreauswirkungen, die ober- und unterirdische Interaktionen von Pflanzen und Mikroorganismen mit einbeziehen, sind eher selten. Deshalb wird in der vorliegenden Studie die Frage erörtert, wie Trockenheit und/oder Hitze die Interaktionen von Pflanzen und Mikroorganismen in Bezug auf ihre Kohlenstoff-Verbindung beeinflussen. Dies dient zur Bestimmung der Stärke der Pflanze-Mikroorganismen-Kohlenstoff-Verbindung, wenn das Ökosystem an seine Grenzen gebracht wird. Der Fokus liegt deshalb auf durch Trockenstress und Hitze hervorgerufenen Veränderungen in der ober-unterirdischen Kohlenstoff-Dynamik in zwei vom Klimawandel bedrohten Ökosystemen. Es wurde untersucht, wie extreme Klimaereignisse, deren Häufigkeit in Zukunft weiter ansteigen soll, die Kohlenstoff-Verbindung zwischen Pflanzen und Mikroorganismen beeinflusst und wie mikrobielle Gemeinschaften unter diesen Umständen reagieren, um die Resistenz und Reaktionsmechanismen von Ökosystemen im zukünftigen Klimawandel besser vorhersagen zu können. In Kapitel 4 wurde ein Buchenwaldunterholz-Ökosystem untersucht. Buchenwaldmonolithen wurden einem extremen Klimaereignis (Trockenheit und/oder Hitze) ausgesetzt. Die Stärke der Pflanze-Mikroorganismen-Kohlenstoff-Verbindung und Veränderungen in der mikrobiellen Gemeinschaftsstruktur und -aktivität wurden mithilfe von stabilen 13C Isotopenmethoden und Ansätzen auf molekularer Basis, wie 16S rRNA- und Phospholipid-Analysen, bestimmt. In Kapitel 5 wurde ein kleines aquatisches Ökosystems untersucht. Zwei emerse aquatische Makrophyten, Phragmites australis und Typha latifolia, wurden in einem Mesokosmos-Experiment mit Sediment aus einem Soll einer einmonatigen Dürre ausgesetzt. Mithilfe einer 13CO2 Pulsmarkierung, sowie PLFA- und nicht-strukturbildenden Kohlenhydrat-Analysen wurde Kohlenstoff von den Blättern in die Wurzeln bis ins Sediment verfolgt, wo er teilweise in mikrobielle Phospholipide eingebaut wird. Diese Studie hat gezeigt, dass die zwei untersuchten Ökosysteme Trockenstress und Hitze relativ gut widerstehen können, zumindest kurzfristig, und dass das Kohlenstoff-Kontinuum, beziehungsweise die Verbindung zwischen ober- und unterirdischen Gemeinschaften, auch unter starkem Stress intakt bleibt. Zusammenfassend scheint es, dass Ökosysteme stark von einem funktionierenden Pflanze-Boden/Sediment-Mikroorganismen Kohlenstoff-Kontinuum abhängen und versuchen, es auch unter starkem Stress zu erhalten, was möglicherweise dazu beiträgt, dem Anstieg von extremen Dürreperioden aufgrund des Klimawandels besser zu widerstehen. / Climate change is threatening ecosystems around the world. Especially the increase in duration, intensity, and frequency of droughts can have a considerable impact on the global carbon cycle. The question whether plants and microbes are susceptible to environmental stress like drought has been assessed in many studies for different ecosystem types and by using numerous approaches, but research on drought effects that includes above- and belowground interactions is rather scarce. Therefore, the present study assesses the question of how drought and/or heat influence the interactions of plants and microbes, especially the carbon coupling, in order to determine the strength of plant-microbe carbon linkages when an ecosystem is pushed to its limits. The focus of this study thus lies on changes in aboveground-belowground carbon dynamics and the subsequent effects on the soil microbial community under drought and/or heat stress in two climate-threatened ecosystems. It was evaluated how extreme climate events, that are predicted to be more frequent in the near future, affect the carbon coupling between plants and microorganisms and how microbial communities respond under these circumstances, in order to be able to better predict ecosystem resistance and response mechanisms under future climate change. In chapter 4 a beech forest understory ecosystem was investigated. An extreme climate event (drought and/or heat) was imposed on beech forest monoliths and the strength of the plant-microbe carbon linkages and changes in the microbial community structure and activity were determined by using stable 13C isotope techniques and molecular-based approaches like 16S rRNA and microbial phospholipid-derived fatty acid (PLFA) analysis. In chapter 5 a small aquatic ecosystems was investigated. Two emergent aquatic macrophytes, Phragmites australis and Typha latifolia, were grown on kettle hole sediment and then exposed to a month-long summer drought in a mesocosm experiment. By conducting a 13CO2 pulse labeling as well as PLFA and non-structural carbohydrate analyses, the fate of carbon was traced from the plant leaves to the roots and into the sediment, where some of the recently assimilated carbon is incorporated into microbial PLFAs. Overall, this study showed that the two investigated ecosystems can endure environmental stress like heat and drought relatively well, at least in the short-term, and that the carbon continuum, or the linkage between above- and belowground communities, remained intact even under severe stress. In conclusion, it seems that ecosystems strongly depend on and try to maintain a functional plant-soil/sediment microorganism carbon continuum under drought, which might help to withstand the increase in extreme drought events under future climate change.