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Registros recuperados: 15
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Nutrient mineralization rates and ratios in the eastern South Atlantic - art. no. C05030 ArchiMer
Brea, Samenta; Alvarez Salgado, X; Alvarez, M; Perez, F; Memery, L; Mercier, Herle; Messias, M.j..
The physical and biogeochemical components of nutrients and inorganic carbon distributions along WOCE line A14 are objectively separated by means of a constrained least-squares regression analysis of the mixing of eastern South Atlantic water masses. Contrary to previous approaches, essentially devoted to the intricate South Atlantic circulation, this work is focused on the effects of circulation on nutrients and carbon biogeochemistry, with special emphasis on the stoichiometry and the rate of mineralization processes. Combination of nutrient and apparent CFC-age anomalies, derived from the mixing analysis, indicate faster mineralization rates in the equatorial (12 x 10(-2) mumol P kg(-1) yr(-1)) and subequatorial (5.3 x 10(-2) mumol P kg(-1) yr(-1)) than...
Tipo: Text Palavras-chave: South Atlantic; Biogeochemical cycles; Water masses.
Ano: 2004 URL: https://archimer.ifremer.fr/doc/2004/publication-836.pdf
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Biogeochemistry of carbon in the Amazonian Floodplains over a 2000-km reach: insights from a process-based model. Repositório Alice
BUSTILLO, V.; VICTORIA, R. L.; MOURA, J. M. S. de; VICTORIA, D. de C.; COLICCHIO, E..
The influence of Amazonian floodplains on the hydrological, sedimentary, and biogeochemical river budget was investigated over a 2000-km reach. A process-based model relying on the closure of chemical fluxes and isotopic signals was implemented. On average for the whole studied reach, the overall fluxes of carbon associated with mineralization and aquatic photosynthesis were estimated to 35.7 and 15.3 Tg C yr21, respectively. Almost 57% of the carbon sequestrated by photosynthesis comes from aerial sources (flooded forest); the remaining 43% resulted from aquatic sources (va´rzea grasses and phytoplankton). The process rates substantially fluctuate over the annual cycle, depending particularly on the extension of flooded area and on the river?floodplain...
Tipo: Artigo em periódico indexado (ALICE) Palavras-chave: Amazon river; Floodplains; Biogeochemical cycles; Carbon; CO2 outgassing.
Ano: 2011 URL: http://www.alice.cnptia.embrapa.br/handle/doc/879705
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Biogeochemistry of the Amazonian floodplains insights from six end member mixing models. Repositório Alice
BUSTILLO, V.; VICTORIA, R. L.; MOURA, J. M. S. de; VICTORIA, D. de C.; TOLEDO, A. M. A.; COLLICCHIO, E..
2010
Tipo: Artigo em periódico indexado (ALICE) Palavras-chave: Amazon river; Floodplains; Biogeochemical cycles; Sediment dynamics; Diagenesis; CO2 outgassing.
Ano: 2010 URL: http://www.alice.cnptia.embrapa.br/handle/doc/879703
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Adubação Verde na Produção Orgânica de Abacaxi na Chapada Diamantina, BA. Repositório Alice
DIAS, F. P. M.; XAVIER, F. A. da S..
A prática da adubação verde promove benefícios ao solo, dentre estes, aumenta os teores de matéria orgânica, favorece a ciclagem de nutrientes e mantém a cobertura do solo. O presente trabalho objetivou avaliar a produção de biomassa vegetal e os estoques de carbono (C) e macronutrientes na matéria seca de diferentes espécies de adubos verdes utilizados em pré-plantio na cultura do abacaxi.
Tipo: Resumo em anais de congresso (ALICE) Palavras-chave: Adubação verde; Abacaxi; Green manure; Pineapples; Biogeochemical cycles; Soil organic matter.
Ano: 2013 URL: http://www.alice.cnptia.embrapa.br/handle/doc/966276
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Hydrobiogeochemical fluxes and its relation to land use changes at small catchments in the Marapanim River Basin, Pará state, Brazil. Repositório Alice
FIGUEIREDO, R. de O.; BARROSO, D. F. R.; PIRES, C. S.; COSTA, F..
Abstract; The macro region "Nordeste Paraense" in Pará state is the oldest agricultural settlement area in the Eastern Brazilian Amazon and has been the location of widespread slash-and-burn agriculture for many years. We studied the biogeochemical changes of nine small catchments (~20-140 ha drainage areas) in the Marapanim River Basin: seven agricultural catchments and two remnant forest catchments used as references for the original landscape. Smallholder agriculture (cassava, corn, cowpea, pepper and passion fruit) is the dominant type of land use in these catchments, along with several medium-sized cattle ranches. Together, these uses form a land use mosaic that also includes large areas of fallow vegetation. Primary forests are rare and frequently...
Tipo: Artigo em anais de congresso (ALICE) Palavras-chave: Agriculture; Amazonia; Fluvial hydrochemistry; Nutrients; Water quality; Uso da terra; Agricultura; Qualidade da água; Biogeochemical cycles; Water quality; Land use.
Ano: 2014 URL: http://www.alice.cnptia.embrapa.br/handle/doc/1006348
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Long-term integrated biogeochemical budget driven by circulation in the eastern subpolar North Atlantic ArchiMer
Fontela, Marcos; Mercier, Herle; Pérez, Fiz F.
The eastern subpolar North Atlantic (eSPNA) is a key region in the Atlantic Meridional Overturning Circulation (AMOC), playing an important role in biogeochemical cycles and climate regulation. Quantitative basin-scale biogeochemical budgets are still scarce despite the current need of establishing baselines of knowledge in a changing ocean. The physico-chemical data from the eight repetitions of the OVIDE section (2002-2016) are an unique opportunity to develop a novel evaluation of biogeochemical budgets in the eSPNA by combining robust and well established decadal mean mass transports with carbon variables, oxygen and inorganic nutrients in a full-depth inverse box model. The net balance between the carbon fixation and the respiration throughout the...
Tipo: Text Palavras-chave: Subpolar North Atlantic; Biogeochemical cycles; Carbon cycle; Nutrient cycles; Oxygenation; Carbon sinks; Oceanic transports.
Ano: 2019 URL: https://archimer.ifremer.fr/doc/00480/59206/61898.pdf
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Nitrogen cycling in rice-based cropping systems International Rice Research Institute
Khadka, Yajna Gajadhar.
xxviii, 250 l. : ill. Thesis (Ph.D.) -- University of the Philippines at Los Baños
Tipo: Thesis Palavras-chave: Cropping systems; Biogeochemical cycles; Rice; Nitrogen.
Ano: 1997 URL: http://hdl.handle.net/123456789/583
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Dynamique hivernale des nutriments et du carbone dans les exutoires du Marais poitevin et flux terrestres associés en Baie de l’Aiguillon ArchiMer
Le Marchand, Marie.
  Coastal environments represent key systems in biogeochemical cycle couplings between continents, oceans and the atmosphere. Despite its relatively modest surface area (7 % of global ocean), this zone accounts for 14-30 % of all oceanic primary production. The amount of nutrients (N, P, C, Si) carried by terrestrial aquatic systems directly influences the primary production, the food web structure and the overall quality of these coastal environments. The present study deals with autumn-winter carbon and nutrients dynamics over terrestrial waters of the Marais poitevin watershed flowing to the Aiguillon bay (west of France). Five heterogeneous watercourses were sampled twice a month since January 2017 to measure nutrients and carbon concentrations and...
Tipo: Text Palavras-chave: Zones côtières; Cycles biogéochimiques; Carbone; Nutriments; PCO2; Marais poitevin; Coastal areas; Biogeochemical cycles; Carbon; Nutrients; PCO2; Marais poitevin.
Ano: 2017 URL: http://archimer.ifremer.fr/doc/00393/50487/51223.pdf
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Global warming projection of the change in dissolved oxygen concentrations in low oxygen regions of the oceans Gayana
Matear,Richard.
Global warming projections using a range of climate models included in the IPCC 4th assessment report (AR4) suggest the oceans will warm, the stratification of the upper ocean will increase and the ventilation of the ocean interior will change. These physical changes will impact dissolved oxygen levels in the ocean. Using a global warming projection from the CSIRO (Australian Commonwealth Scientific and Research Administration) climate model linked to a simple ocean biogeochemical model I investigated how dissolved oxygen levels in the ocean interior change under global warming. The climate simulations project the low oxygen regions like the eastern equatorial Pacific will expand. By the end of the century it is projected that the volume of hypoxic water...
Tipo: Journal article Palavras-chave: Global warming; Oxygen changes; Anoxia; Biogeochemical cycles; Climate change.
Ano: 2006 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-65382006000300010
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Decomposition and nutrient release of leguminous plants in coffee agroforestry systems. Repositório Alice
MATOS, E. da S.; MENDONÇA, E. de S.; CARDOSO, I. M.; LIMA, P. C. de; FREESE, D..
Abstract: Leguminous plants used as green manure are an important nutrient source for coffee plantations, especially for soils with low nutrient levels. Field experiments were conducted in the Zona da Mata of Minas Gerais State, Brazil to evaluate the decomposition and nutrient release rates of four leguminous species used as green manures (Arachis pintoi, Calopogonium mucunoides, Stizolobium aterrimum and Stylosanthes guianensis) in a coffee agroforestry system under two different climate conditions. The initial N contents in plant residues varied from 25.7 to 37.0 g kg-1 and P from 2.4 to 3.0 g kg-1. The lignin/N, lignin/polyphenol and (lignin+polyphenol)/N ratios were low in all residues studied. Mass loss rates were highest in the first 15 days, when...
Tipo: Artigo em periódico indexado (ALICE) Palavras-chave: Agrofloresta; Ciclagem de nutrientes; Leguminosae; Leguminosa; Nutriente; Decomposição; Agrossilvicultura; Cafeicultura; Biogeochemical cycles; Agroforestry; Plant residues; Fabaceae.
Ano: 2011 URL: http://www.alice.cnptia.embrapa.br/handle/doc/904191
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Modelling of oxygen and nitrogen cycling as a function of macrophyte community in the Thau lagoon ArchiMer
Plus, Martin; Chapelle, Annie; Lazure, Pascal; Auby, Isabelle; Levavasseur, G; Verlaque, M; Belsher, Thomas; Deslous-paoli, Jean-marc; Zaldivar, J; Murray, C.
A three-dimensional model coupling physical and biological processes for the whole Than lagoon (Mediterranean coast of France) was developed in order to assess the relationships between macrophytes and the oxygen and nitrogen cycles. Ten species have been inserted as forcing variables in the model. Plankton dynamics, shellfish cultivation impact and mineralization of organic matter are also considered, as well as nutrient and oxygen exchanges between the sediment and the water column. Simulations with and without the macrophytes have shown that the system can be characterized as having a highly structured pattern involving lagoon nitrogen and oxygen cycles. This pattern is created by the combined influence of macrophytes, watershed and oyster farming....
Tipo: Text Palavras-chave: Thau lagoon; Biogeochemical cycles; Ecological modelling; Macrophytes.
Ano: 2003 URL: https://archimer.ifremer.fr/doc/2003/publication-459.pdf
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Liberação de nutrientes durante a decomposição de resíduos vegetais de macaúba em áreas com variações de lençol freático. Repositório Alice
QUINTANA, L. G.; CARVALHO, A. M. de; COSER, T. R.; SOUZA, A. M. de; MALAQUIAS, J. V.; FERREIRA, E. A. B..
O objetivo deste trabalho foi determinar a liberação de macronutrientes durante o processo de decomposição de resíduos vegetais de macaúba (Acrocomia aculeata (Jacq.) Lodd. ex Mart.) em duas áreas sob condições de lençol freático alto e baixo. Para determinar a decomposição e liberação de nutrientes foram coletadas folhas secas de uma população natural de macaúba. O material vegetal foi colocado em litter bags e avaliado por um período de 420 dias (de dezembro de 2010 a janeiro de 2012). A taxa de decomposição do material vegetal de macaúba foi maior até os 180 dias após a colocação dos litter bags no campo, variando entre 49 e 59%. A liberação de K foi mais rápida sob condição de lençol freático alto. A liberação de nutrientes dos resíduos vegetais de...
Tipo: Artigo em anais de congresso (ALICE) Palavras-chave: Macaúba; Acrocomia aculeata; Matéria orgânica; Solo orgânico; Lençol freático; Bioenergia; Acrocomia aculeata; Biogeochemical cycles; Soil organic matter; Water table; Bioenergy; Brazil.
Ano: 2014 URL: http://www.alice.cnptia.embrapa.br/handle/doc/1001912
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Produção de serapilheira de árvores e arbustos de sistemas agrossilvipastoris da caatinga em Sobral, CE. Repositório Alice
SILVA, L. A.; PRIMO, A. A.; SILVA, K. da F.; MENESES, F. M. N.; MELO, M. D.; SOUZA, H. A. de.
O conhecimento da deposição de serapilheira e da ciclagem de nutrientes de espécies nativas da Caatinga é de grande importância, principalmente, para a verificação do aporte de nutrientes em sistemas agrossilvipastoris em região semiárida. Com isso objetivou-se avaliar a produção total de serapilheira de árvores e arbustos de um Sistema Agrossilvipastoril em área de Caatinga. O ensaio foi desenvolvido no Sistema Agrossilvipastoril da Embrapa Caprinos e Ovinos, em Sobral ? CE. As espécies avaliadas foram: catingueira (Poincianela pyramidalis), jucá (Libidibia ferrea), jurema-preta (Mimosa tenuiflora), marmeleiro (Croton sonderianus), mofumbo (Combretum leprosum), pau-branco (Auxemma oncocalyx), pereiro (Aspidosperma pirifolium) e sabiá (Mimosa...
Tipo: Resumo em anais de congresso (ALICE) Palavras-chave: Bioma caatinga; Ciclagem de nutrientes; Biogeochemical cycles; Sistema Agrossilvipastoril; Serapilheira; Espécie nativa; Indigenous organisms.
Ano: 2015 URL: http://www.alice.cnptia.embrapa.br/handle/doc/1051597
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A Review of the Stable Isotope Bio-geochemistry of the Global Silicon Cycle and Its Associated Trace Elements ArchiMer
Sutton, Jill N.; Andre, Luc; Cardinal, Damien; Conley, Daniel J.; De Souza, Gregory F.; Dean, Jonathan; Dodd, Justin; Ehlert, Claudia; Ellwood, Michael J.; Frings, Patrick J.; Grasse, Patricia; Hendry, Katharine; Leng, Melanie J.; Michalopoulos, Panagiotis; Panizzo, Virginia N.; Swann, George E. A..
Silicon (Si) is the second most abundant element in the Earth's crust and is an important nutrient in the ocean. The global Si cycle plays a critical role in regulating primary productivity and carbon cycling on the continents and in the oceans. Development of the analytical tools used to study the sources, sinks, and fluxes of the global Si cycle (e.g., elemental and stable isotope ratio data for Ge, Si, Zn, etc.) have recently led to major advances in our understanding of the mechanisms and processes that constrain the cycling of Si in the modern environment and in the past. Here, we provide background on the geochemical tools that are available for studying the Si cycle and highlight our current understanding of the marine, freshwater and terrestrial...
Tipo: Text Palavras-chave: C - N - O - Si isotopes; Biogenic silica; Element/Si ratios; Biogeochemical cycles; Silicon.
Ano: 2018 URL: https://archimer.ifremer.fr/doc/00431/54217/55547.pdf
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Benthic macroinvertebrates and degradation of phytomass as indicators of ecosystem functions in flooded rice cropping. Repositório Alice
WINCKLER-SOSINSKI, L.T.; GUTHS, A. K.; GAYER, P. R..
The objective of this work was to evaluate the ecosystem functions of a natural wetland and of artificially flooded rice areas, managed under organic and conventional systems, by phytomass degradation and by the colonization of this material by benthic macroinvertebrates. The experiment was carried out in a natural wetland area, and in two flooded rice areas managed under organic and conventional systems. Twenty-five decomposition bags filled with 10 g of dry vegetation were installed in each site. At 14, 28, 42, 56, and 70 days after the beginning of the experiment, five bags from each site were collected. Macroinvertebrates were identified and classified by functional trophic group. The number of species of benthic macroinvertebrates increased: natural...
Tipo: Artigo em periódico indexado (ALICE) Palavras-chave: Degradação da biomassa; Serviço ecossistêmico; Ciclagem de nutriente; Solo de várzea; Oryza sativa; Planossolo; Oryza sativa; Aqualfs; Ecosystem services; Biogeochemical cycles; Paddy soils.
Ano: 2017 URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1078201
Registros recuperados: 15
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