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| Registros recuperados: 68 | |
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| Santos,Isaac Rodrigues; Costa,Ronaldo Cataldo; Freitas,Ubiratan; Fillmann,Gilberto. |
| The hypothesis that effluents treated through activated sludge process cause changes in nutrient biogeochemistry of receiving water bodies was investigated in Vieira creek, southern Brazil. Dissolved oxygen, suspended matter, and pH did not vary among the sampling stations. Nutrient, biochemical oxygen demand, and conductivity values were significantly higher downstream from the Wastewater Treatment Plant (WWTP) effluents. Further downstream, nitrate concentrations were higher due to ammonium nitrification, organic matter remineralization and/or the occurrence of unidentified sources. Per capita nutrient emission factors were estimated to be 0.16 kg P.yr-1 and 4.14 kg N.yr-1. Under pristine conditions, low N:P ratios were observed, which were significantly... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Activated sludge; Nutrients; Contamination; Coastal zone; Biogeochemistry; Eutrophication. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132008000100019 |
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| Barrales Brito, Edgar. |
| El mantillo y horizontes de fermentación (CF) es un reservorio dinámico de carbono (C) en suelos forestales. Las metodologías que cuantifican la emisión de CO2 por la descomposición son escasas y requieren periodos largos de medición. Se requieren métodos para poder generar información de la emisión de CO2 de éstas capas orgánicas en tiempos cortos de medición. Los objetivos fueron: generar un protocolo para la medición de la emisión de CO2 por la descomposición de mantillo y CF con un respirómetro manométrico (OxiTop ®). Medir los reservorios de C de mantillo y CF de bosques con diferentes condiciones. Medir la emisión de CO2 del mantillo y CF y las tasas de descomposición con un respirómetro. Analizar las características químicas de los mantillos y... |
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Palavras-chave: Biogeoquímica; Emisión de CO2; Respirometría; Materia orgánica; Bosques; Biogeochemistry; CO2 emissions; Respirometry; Organic matter; Forest; Edafología; Maestría. |
| Ano: 2013 |
URL: http://hdl.handle.net/10521/2096 |
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| PARRON, L. M.; BUSTAMANTE, M. M. da C.; PRADO, C. L. C.. |
| RESUMO: Em função do gradiente de umidade na topografia do terreno e de diferenças entre estações seca e chuvosa, o presente trabalho teve como objetivos quantificar a produção anual e a disponibilidade de nutrientes (N, P, K, Ca, Mg E S) na serapilheira e estimar a eficiência do uso de nutrientes em uma Mata de Galeria. O experimento foi estabelecido numa área de 100 x 100 m da Mata de Galeria do Córrego Pitoco, na Reserva Ecológica do IBGE, DF (15°56'41"S e 47°56'07"W). Como delineamento experimental, foram estabelecidas três linhas de amostragem paralelas ao córrego, distantes 45 m entre si, denominadas, respectivamente, comunidades úmida (na margem do córrego), intermediárias e seca (adjacentes a uma área de Cerrado Típico). A produção de serapilheira... |
| Tipo: Folhetos |
Palavras-chave: Biogeoquímica; Ciclagem de nutriente; Eficiência de nutriente; Savana; Productivity; Nutrient cycling; Litterfall; Nutrient efficiency; Disponibilidade de Nutriente; Floresta Tropical; Produtividade; Biogeochemistry; Savannas; Tropical forests. |
| Ano: 2004 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/569203 |
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| Verdy, A.; Mazloff, M. R.. |
| A Biogeochemical Southern Ocean State Estimate (B-SOSE) is introduced that includes carbon and oxygen fields as well as nutrient cycles. The state estimate is constrained with observations while maintaining closed budgets and obeying dynamical and thermodynamic balances. Observations from profiling floats, shipboard data, underway measurements, and satellites are used for assimilation. The years 2008-2012 are chosen due to the relative abundance of oxygen observations from Argo floats during this time. The skill of the state estimate at fitting the data is assessed. The agreement is best for fields that are constrained with the most observations, such as surface pCO(2) in Drake Passage (44% of the variance captured) and oxygen profiles (over 60% of the... |
| Tipo: Text |
Palavras-chave: Southern Ocean; State estimation; Biogeochemistry. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00662/77394/78995.pdf |
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| Le Traon, Pierre-yves; D'Ortenzio, Fabrizio; Babin, Marcel; Leymarie, Edouard; Marec, Claudie; Pouliquen, Sylvie; Thierry, Virginie; Cabanes, Cecile; Claustre, Hervé; Desbruyeres, Damien; Lacour, Leo; Lagunas, Jose-luis; Maze, Guillaume; Mercier, Herle; Penkerc'H, Christophe; Poffa, Noe; Poteau, Antoine; Prieur, Louis; Racape, Virginie; Randelhoff, Achim; Rehm, Eric; Schmechtig, Catherine Marie; Taillandier, Vincent; Wagener, Thibaut; Xing, Xiaogang. |
| Argo, the international array of profiling floats, is a major component of the global ocean and climate observing system. In 2010, the NAOS (Novel Argo Observing System) project was selected as part of the French “Investissements d’Avenir” Equipex program. The objectives of NAOS were to consolidate the French contribution to Argo’s core mission (global temperature and salinity measurements down to 2000 m), and also to develop the future generation of French Argo profiling floats and prepare the next phase of the Argo program with an extension to the deep ocean (Deep Argo), biogeochemistry (BGC-Argo) and polar seas. This paper summarizes how NAOS has met its objectives. The project significantly boosted France’s contribution to Argo’s core mission by... |
| Tipo: Text |
Palavras-chave: Profiling floats; Deep ocean; Biogeochemistry; Mediterranean Sea; Arctic; Atlantic; Argo. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00654/76584/77729.pdf |
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| Peguero, Guille; Sardans, Jordi; Asensio, Dolores; Fernández-martínez, Marcos; Gargallo-garriga, Albert; Grau, Oriol; Llusià, Joan; Margalef, Olga; Márquez, Laura; Ogaya, Romà; Urbina, Ifigenia; Courtois, Elodie A.; Stahl, Clément; Van Langenhove, Leandro; Verryckt, Lore T.; Richter, Andreas; Janssens, Ivan A.; Peñuelas, Josep. |
| Soil fauna is a key control of the decomposition rate of leaf litter, yet its interactions with litter quality and the soil environment remain elusive. We conducted a litter decomposition experiment across different topographic levels within the landscape replicated in two rainforest sites providing natural gradients in soil fertility to test the hypothesis that low nutrient availability in litter and soil increases the strength of fauna control over litter decomposition. We crossed these data with a large dataset of 44 variables characterizing the biotic and abiotic microenvironment of each sampling point and found that microbe-driven carbon (C) and nitrogen (N) losses from leaf litter were 10.1 and 17.9% lower, respectively, in the nutrient-poorest site,... |
| Tipo: Text |
Palavras-chave: Biogeochemistry; Extracellular enzyme activity; Litter decomposition; Nutrients; Soil fauna. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00513/62424/69469.pdf |
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| Hermin, M; Daumas, R; Drogue, N. |
| The bacterial activity of the superficial sediment layer was evaluated by incorporation super(14)C-labelled amino-acids mixed an hydrolysate of chlorella cells. Estimation of super(14)C-CO sub(2) super(14)C and super(14)C-A.A. by H.P.L.C. give some informations on the utilization of free dissolved. A.A. and on the transport of labelled compounds from water to sediment. The adsorption mechanism of A.A. on the mineral particles draw to the sediment a larger part of A.A. in the first period; but 28% of this adsorbed A.A. were discharged by an acid treatment. A part of super(14)C-A.A. was incorporated in unhydrolysable organic matter. Di-COOH A.A. are more resistant to bacterial degradation than the other A.A., but arginine is completely metabolized in ten... |
| Tipo: Text |
Palavras-chave: Biogeochemistry; Bacteria; Chromatographic techniques; Metabolism; Amino acids; Sediment water exchanges. |
| Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/acte-945.pdf |
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| Morita, R; Jones, R. |
| The nitrifying bacteria were found to survive 24 weeks in the absence of ammonium without decreasing their number of cell size. Because H sub(2), CO, and CH sub(4) are present in the marine environment, these substrates were investigated as a possible source of the energy of maintenance for the nitrifying bacteria. super(14)CO and super(14)CH sub(4) were found to be oxidized by the nitrifiers. N-serve was found to inhibit the oxidation of CO. Using the nitrifiers' ability to oxide CO, a method for the determination of the nitrification rate was developed. The ability of nitrifiers to oxidize CO may play a significant role in the cycling of CO sub(2) in the marine environment. Whether CO and CH sub(4) oxidation play a role in the survival of nitrifiers in... |
| Tipo: Text |
Palavras-chave: Methane; Carbon dioxide; Survival; Bacteria; Nitrification; Nitrogen cycle; Oxidation; Carbon cycle; Biogeochemistry; Metabolism. |
| Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/acte-975.pdf |
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| Carroll, D.; Menemenlis, D.; Adkins, J. F.; Bowman, K. W.; Brix, H.; Dutkiewicz, S.; Fenty, I.; Gierach, M. M.; Hill, C.; Jahn, O.; Landschutzer, P.; Lauderdale, J. M.; Liu, J.; Manizza, M.; Naviaux, J. D.; Roedenbeck, C.; Schimel, D. S.; Van Der Stocken, T.; Zhang, H.. |
| Quantifying variability in the ocean carbon sink remains problematic due to sparse observations and spatiotemporal variability in surface ocean pCO(2). To address this challenge, we have updated and improved ECCO-Darwin, a global ocean biogeochemistry model that assimilates both physical and biogeochemical observations. The model consists of an adjoint-based ocean circulation estimate from the Estimating the Circulation and Climate of the Ocean (ECCO) consortium and an ecosystem model developed by the Massachusetts Institute of Technology Darwin Project. In addition to the data-constrained ECCO physics, a Green's function approach is used to optimize the biogeochemistry by adjusting initial conditions and six biogeochemical parameters. Over seasonal to... |
| Tipo: Text |
Palavras-chave: Ocean modeling; Biogeochemistry; Ocean carbon cycle; Data assimilation; Air‐ Sea CO2 flux; Ecosystem model. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00676/78824/81108.pdf |
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| German, C. R.; Thurnherr, A. M.; Knoery, Joel; Charlou, Jean-luc; Jean-baptiste, P.; Edmonds, H. N.. |
| High-temperature hydrothermal activity occurs in all ocean basins and along ridge crests of all spreading rates. While it has long been recognized that the fluxes associated with such venting are large, precise quantification of their impact on ocean biogeochemistry has proved elusive Here, we report a comprehensive study of heat, fluid and chemical fluxes from a single submarine hydrothermal field. To achieve this, we have exploited the integrating nature of the non-buoyant plume dispersing above the Rainbow hydrothermal field, a long-lived and tectonically hosted high-temperature vent site on the Mid-Atlantic Ridge. Our calculations yield heat and volume fluxes for high-temperature fluids exiting the seafloor of similar to 0.5 GW and 450 Ls(-1), together... |
| Tipo: Text |
Palavras-chave: Hydrothermal fluxes; Biogeochemistry; Rainbow vent-field. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00003/11423/8040.pdf |
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| Dulaquais, Gabriel; Boye, Marie; Middag, Rob; Owens, Stephanis; Puigcorbe, Viena; Buesseler, Ken; Masque, Pere; De Baar, Hein J. W.; Carton, Xavier. |
| Dissolved cobalt (DCo; <0.2 µm; 14 to 93 pM) and the apparent particulate cobalt (PCo; >0.2 µm; <1 to 15 pM) were determined in the upper water column (<1000 m) of the western Atlantic Ocean along the GEOTRACES-A02 section (64°N to 50°S). The lowest DCo concentrations, typical of a nutrient-type distribution were observed in surface waters of the subtropical domains. Strong linear relationships between DCo and phosphate (P) as well as meridional gradients of decreasing DCo from high latitudes were characterized and both linked to the Co biological requirement. External sources such as the Amazon and the atmospheric deposition were found to contribute significantly (>10%) to the DCo stock of the mixed layer in the equatorial and north... |
| Tipo: Text |
Palavras-chave: Cobalt; Biogeochemistry; Atlantic Ocean; Chemical Oceanography; GEOTRACES. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00241/35222/33732.pdf |
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| Irion, Solène; Christaki, Urania; Berthelot, Hugo; L’helguen, Stéphane; Jardillier, Ludwig. |
| Phytoplankton is composed of a broad-sized spectrum of phylogenetically diverse microorganisms. Assessing CO2-fixation intra- and inter-group variability is crucial in understanding how the carbon pump functions, as each group of phytoplankton may be characterized by diverse efficiencies in carbon fixation and export to the deep ocean. We measured the CO2-fixation of different groups of phytoplankton at the single-cell level around the naturally iron-fertilized Kerguelen plateau (Southern Ocean), known for intense diatoms blooms suspected to enhance CO2 sequestration. After the bloom, small cells (<20 µm) composed of phylogenetically distant taxa (prymnesiophytes, prasinophytes, and small diatoms) were growing faster (0.37 ± 0.13 and 0.22 ± 0.09... |
| Tipo: Text |
Palavras-chave: Biogeochemistry; Microbial ecology; Stable isotope analysis. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00684/79595/82286.pdf |
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| Aumont, Olivier; Belviso, Sauveur; Monfray, Patrick. |
| [1] A global model for surface dimethylsulfide (DMS) and particulate dimethylsulfoniopropionate (DMSP) (pDMS) distributions is presented. The main goals of this work were to be able to predict the regional distribution of the air-sea fluxes of DMS and to predict eventually their future evolution with climate change. Diagnostic relationships have been established from data sets obtained during the ALBATROSS and EUMELI cruises carried out in the Atlantic Ocean. These equations nonlinearly relate DMS and pDMSP concentrations to chlorophyll concentrations and to the trophic status of surface waters. This model has been embedded in the global ocean carbon cycle model Institut Pierre et Simon Laplace-Ocean Carbon Cycle Model version 2 (ISPL-OCCM2), a simple... |
| Tipo: Text |
Palavras-chave: Ocean; Biogeochemistry; Ecosystem modeling; DMS; Global. |
| Ano: 2002 |
URL: https://archimer.ifremer.fr/doc/00223/33448/31824.pdf |
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| Registros recuperados: 68 | |
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