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Registros recuperados: 13
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An experiment on the relative importance of denitrification, nitrate reduction and ammonification in coastal marine sediment OMA
Goeyens, L.; De Vries, R.T.P.; Bakker, J.F.; Helder, W..
Simultaneous determinations of <sup>15</sup>N-nitrogen gas production, <sup>15</sup>N-ammonia formation by nitrate reduction and ammonia production from organic nitrogen were carried out after addition of <sup>15</sup>N-nitrate to anaerobically incubated sediment slurries from a location in the Dutch Wadden Sea. The rate of nitrogen gas production was 1.75 µmol N.cm<sup>-3</sup> wet sediment.d<sup>-1</sup>, nitrate reduction to ammonia occurred to a rate of 0.79 µmol N.cm <sup>-3</sup>.d <sup>-1</sup> and ammonification at 1.17 µmol N-cm <sup>-3</sup>.d <sup>-1</sup>. At the end of the incubation experiment (after 30 h) 63% of the originally added...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Ammonia; Biogeochemical cycle; Coastal zone; Denitrification; Nitrates; Nitrogen cycle; Sediments.
Ano: 1987 URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3169
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Biological availability of sediment-bound trace metals. ArchiMer
Luoma, S.
It has been established that direct uptake of (at least some) trace metals from sediments contributes to metal concentrations in benthic organisms. Important controls on metal uptake from sediment are the concentration of the exposure, the partitioning of the metals among components of the sediment, and the redox potential of the sediment. Important problems in ecology, physiology, geochemistry and biogeochemistry remain unresolved, however, and a concentrated interdisciplinary research effort will be necessary before a complete understanding of the fate and impact of sediment-bound metals will be possible.
Tipo: Text Palavras-chave: Bioaccumulation; Benthos; Food webs; Biogeochemical cycle; Sediments; Availability; Trace metals.
Ano: 1985 URL: http://archimer.ifremer.fr/doc/1985/acte-1302.pdf
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Comportement chimique et geochimique des elements a l'état de traces dans l'estuaire de la Seine: Synthese des discussions ArchiMer
Guegueniat, P.
In the synthesis of discussions about the chemistry of the Seine Bay, the author after a note on natural references for metal concentrations, speaks about fluorides, nutrients, PCB, and metallic elements. In conclusion some suggestions about pollutants transfer towards ecosystems link, are enumerated.
Tipo: Text Palavras-chave: PCB; Fluorides; Chemical pollution; Trace metals; Food webs; Bioaccumulation; Biogeochemical cycle; Trace elements.
Ano: 1985 URL: http://archimer.ifremer.fr/doc/1985/acte-1303.pdf
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Devenir de l'atrazine dans le bassin de Marennes-Oléron. Approche par la modélisation hydrodynamique, hydrosédimentaire et biogéochimique ArchiMer
Vanhoutte Brunier, Alice.
Atrazine is the most widely used herbicide on cultured areas. This pesticide is degraded during its transport in rivers and streams, to the coastal area. Marennes Oléron is the main french oyster farming area, receiving the fresh water from the Charente river and ail the drainage coming from the coastal cultivated marshlands. Agriculture is thus claimed to be responsible for shellfish mortality in the aquaculture area. To simulate the changing fate of atrazine in the environment, a modelling strategy has been selected. a) First, using a two-way hydrodynamic model developped by IFREMER, the atrazine dilution trail in the Marennes Oléron area was simulated.Combined with larvae bioassays of Crassostrea gigas (Japanese oyster), the results show atrazine rates...
Tipo: Text Palavras-chave: Produits phytosanitaires; Atrazine; Cycle biogéochimique; Modélisation; Dynamique sédimentaire; Vasières intertidales; Pesticides; Atrazine; Biogeochemical cycle; Models; Sediment transport; Intertidal muflats.
Ano: 2001 URL: http://archimer.ifremer.fr/doc/00412/52312/53082.pdf
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Devenir de l'atrazine dans le bassin de Marennes-Oléron (France) - Approche par la modélisation hydrodynamique, hydrosédimentaire et biogéochlmique ArchiMer
Vanhoutte Brunier, Alice.
Atrazine is the most widely used herbicide on cultured areas. This pesticide is degraded during its transport in rivers and streams, to the coastal area. Marennes Oleron is the main french oyster farming area, receiving the fresh water from the Charente river and all the drainage coming from the coastal cultivated marshlands. Agriculture is thus claimed to be responsible for shellfish mortality in the aquaculture area. To simulate the changing fate of atrazine in the environment, a modelling strategy has been selected, a) First, using a two-way hydrodynamic model developped by IFREMER, the atrazine dilution trail in the Marennes Oleron area was simulated.Combined with larvae bioassays of Crassostrea gigas (Japanese oyster), the results show atrazine rates...
Tipo: Text Palavras-chave: Produits phytosanitaires; Atrazine; Cycle biogéochimique; Modélisation; Dynamique sédimentaire; Vasières intertidales.; Pesticides; Atrazine; Biogeochemical cycle; Models; Sediment transport; Intertidal muflats..
Ano: 2001 URL: http://archimer.ifremer.fr/doc/00306/41764/40977.pdf
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Evolution de la complexation des metaux (Ca, Mg, Cd, Pb et Cu) dans l''estuaire de la Seine ArchiMer
Fischer, J; Wartel, M.
Interaction between metallic ions and dissolved organic matter can take major part in the biogeochemical cycle of metals in the aquatic environment. The authors point out copper behavior by the study of complexing capacity of surface and bottom waters. A systematic analysis of major elements in natural waters has allowed for a proposal of geographical distribution of metals.
Tipo: Text Palavras-chave: River plumes; Dissolved organic matter; Chemical reactions; Salinity; Biogeochemical cycle; Metals; Ion association; Water properties.
Ano: 1985 URL: http://archimer.ifremer.fr/doc/1985/acte-1299.pdf
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Evolution of Forest Systems: the Role of Biogeochemical Cycles in Determining Sustainable Forestry Practices Ecology and Society
Flueck, Werner T.; National Council for Scientific and Technical Research (CONICET), Argentina; Institute of Natural Resources Analysis, Universidad Atlantida Argentina; Swiss Tropical Institute, University of Basel; wtf@deerlab.org.
The exploitation of natural resources such as forests leads to sustainable forest management (SFM). The key question is how to define and parametrize &#8220;sustainable use.&#8221; Promoting forest use that conserves spatial characteristics of forest landscapes and the structure and composition of forest stands was proposed as a way of maintaining elements of biodiversity such as species richness and genetic variation. However, to establish the parameter space for sustainable forest use, it is essential to consider the nutrient requirements of forest systems, that is, plants and animals, the need for fertilizer application, and the effects on biogeochemical cycles, a cornerstone of biological evolution and, thus, biodiversity. The use of forest...
Tipo: Peer-Reviewed Response Palavras-chave: Biogeochemical cycle; Fertilizer; Macronutrients; Micronutrients; Phosphorus; Selenium; Sustainable forest management.
Ano: 2009
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L’algue rouge "Gracilaria verrucosa" (hudson) papenfuss de la lagune de Bizerte (Tunisie septentrionale) : essai de culture en mode suspendu et composition biochimique OceanDocs
Mensi, F.; Ksouri, J.; Hammami, W.; Romdhane, M.S..
L'algue rouge, Gracilaria verrucosa, a été cultivée, durant le printemps 2009, en mode suspendu à différents emplacements et profondeurs représentant les différences biogéochimiques de la lagune de Bizerte au Nord de la Tunisie. La concentration et la distribution des nutriments (ammonium, phosphate) dans l'eau, ainsi que la salinité, la température, l’oxygène et la transparence de l’eau ont été déterminées. Les méthodes analytiques internationales standardisées ont été appliquées. Les effets du mode de culture, de l’emplacement et de la profondeur sur les rendements en poids, protéines, R-Phycoérythrine et sucres totaux de l’algue ont été étudiés. La croissance de Gracilaria a été similaire dans les différents sites mais plus lente dans les profondeurs...
Tipo: Journal Contribution Palavras-chave: Algal culture; Ammonium compounds; Biochemical composition; Biogeochemistry; Carbohydrates; Dissolved oxygen; Environmental conditions; Growth; Intensive culture; Lagoons; Off-bottom culture; Raw materials; Red algae; Biogeochemical cycle.
Ano: 2009 URL: http://hdl.handle.net/1834/4497
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Le chrome en milieu marin ArchiMer
Chiffoleau, Jean-francois.
This document constitutes a synthesis of current knowledge on the chromium biogeochemical cycle. The natural and anthropogenic sources are evaluated, the fluxes between the various geochemical compartments are assessed, with special attention to the riverine and atmospheric inputs to the marine environment. Chromium levels in these compartments are described and show in several areas a very high contamination of marine organisms. Due to the important toxicity of this element, further investigations are absolutely required to better understand its behaviour in the marine environment.
Tipo: Text Palavras-chave: Economic analysis; Air water exchanges; Toxicity; Biogeochemical cycle; Marine environment; Pollution; Chromium.
Ano: 1994 URL: http://archimer.ifremer.fr/doc/1994/rapport-1430.pdf
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Mineral and organic soluble forms of zinc, iron and copper: Distribution in the Seine Estuary. ArchiMer
Gandon, R; Guegueniat, P; Fischer, J; Wartel, M.
One characteristic of the Seine Estuary system is the process of sediment resuspension by the specific hydrodynamics of this environment. It's the main factor of trace metals transport. Autotrophic activities also have an effect on the estuary, by pH variation. The behavior of soluble and organic copper, iron, have been studied in relation to salinity in and out of the estuary. The results are compared with those of other estuaries.
Tipo: Text Palavras-chave: Hydrodynamics; Physicochemical properties; Water properties; Dissolved organic matter; Biogeochemical cycle; Resuspension; Metals; Suspended particulate matter.
Ano: 1985 URL: http://archimer.ifremer.fr/doc/1985/acte-1300.pdf
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Nutrients in the aerial biomass and litter in Caatinga areas in floresta, Pernambuco State, Brazil PFB - Pesquisa Florestal Brasileira
Alves, Allyson Rocha; Ferreira, Rinaldo Luiz Caraciolo; da Silva, José Antônio Aleixo; Dubeux Júnior, José Carlos Batista; Salami, Gabriela.
This study aimed to quantify nutrient content in shoot biomass components and litter in two areas of savanna vegetation with different ecological characteristics, one in regeneration and the other as a preserved area, in Floresta, Pernambuco State, Brazil. It was carried out an initial inventory launching 40 plots of 400 m2 in each area, with inclusion level of circumference at 1.3 m above ground level ≥ 6.0 cm. The five species with highest importance value were used for biomass analysis. Chemical analysis were carried out in samples of 100 g taken from the different component of each of those species. To estimate the stock of litter assortments were made in dry and rainy seasons, using a hollow square mold with 0.5 m randomly released in plots. It was...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Biogeochemical cycle; Regeneration; Dry forest Recursos Florestais; Engenharia Florestal Ciclo biogeoquímico; Regeneração; Floresta seca.
Ano: 2017 URL: http://pfb.cnpf.embrapa.br/pfb/index.php/pfb/article/view/1060
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Phytoplankton versus macrophyte contribution to primary production and biogeochemical cycles of a coastal mesotidal system. A modelling approach ArchiMer
Plus, Martin; Auby, Isabelle; Maurer, Daniele; Trut, Gilles; Del Amo, Y.; Dumas, Franck; Thouvenin, Benedicte.
This study presents an assessment of the contributions of various primary producers to the global annual production and N/P cycles of a coastal system, namely the Arcachon Bay, by means of a numerical model. This 3D model fully couples hydrodynamic with ecological processes and simulates nitrogen, silicon and phosphorus cycles as well as phytoplankton, macroalgae and seagrasses. Total annual production rates for the different components were calculated for different years (2005, 2007 and 2009) during a time period of drastic reduction in seagrass beds since 2005. The total demand of nitrogen and phosphorus was also calculated and discussed with regards to the riverine inputs. Moreover, this study presents the first estimation of particulate organic carbon...
Tipo: Text Palavras-chave: Primary production; Macrophyte; Phytoplankton; Biogeochemical cycle; Physical-ecological coupled model; Arcachon bay.
Ano: 2015 URL: http://archimer.ifremer.fr/doc/00278/38963/37503.pdf
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Pouvoir complexant des eaux de l'estuaire de la Seine ArchiMer
Fischer, J; Wartel, M; Guegueniat, P; Gandon, R.
Copper has been studied, by the authors, owing to its ability to complex with various organic ligands of natural waters. Metals extraction and liberation can be explained, in part, by this complexing capacity.
Tipo: Text Palavras-chave: Estuaries; Suspended particulate matter; Dissolved organic matter; Copper; River discharge; Ion association; Metals; Biogeochemical cycle; Water properties.
Ano: 1985 URL: http://archimer.ifremer.fr/doc/1985/acte-1298.pdf
Registros recuperados: 13
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