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Registros recuperados: 11 | |
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Baisre, J. A.. |
The alteration of the nitrogen (N) cycle by human activities is widespread and has often resulted in increased flows of nitrogen to the marine environment. In this paper we have attempted to know the changes of N fluxes in Cuba by quantifying the N inputs to the landscape from (1) fertilizer applications, (2) atmospheric deposition, (3) biological nitrogen fixation and (4) net import of food and feeds. N-inputs to the country progressively increased until the end of the 20th century, reaching a peak during the 80s when low cost fertilizer imported from the former Soviet Union led to heavy rates of application. This rapid growth represented more than a 5-fold increase with respect to pristine values; higher than the two-fold global increase of anthropogenic... |
Tipo: Journal Contribution |
Palavras-chave: Nitrogen; Nitrogen cycle; Atmospheric deposition; Fertilizers. |
Ano: 2006 |
URL: http://hdl.handle.net/1834/5111 |
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Boulart, C; Flament, Pierre; Gentilhomme, V; Deboudt, K; Migon, C; Lizon, F; Schapira, M; Lefebvre, Alain. |
Wet atmospheric deposition of dissolved N, P and Si species is studied in well-mixed coastal ecosystem to evaluate its potential to stimulate photosynthetic activities in nutrient-depleted conditions. Our results show that, during spring, seawater is greatly depleted in major nutrients: Dissolved Inorganic Nitrogen (DIN), Dissolved Inorganic Phosphorus (DIP) and Silicic acid (Si), in parallel with an increase of phytoplanktonic biomass. In spring (March-May) and summer (June-September), wet atmospheric deposition is the predominant source (> 60%, relative to riverine contribution) for nitrates and ammonium inputs to this N-limited coastal ecosystem. During winter (October-February), riverine inputs of DIN predominate (> 80%) and are annually the most... |
Tipo: Text |
Palavras-chave: Strait of Dover; Nutrient cycles; River plumes; Atmospheric deposition; Coastal zone; Primary production. |
Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2007.pdf |
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Godoy,Roberto; Haneke,Jörgen; Staelens,Jeroen; Oyarzún,Carlos; Paulino,Leandro; Barrientos,Mónica. |
The growth of intensive livestock farming in the central depression of southern Chile (40° S) during the last century has resulted in elevated emissions of inorganic nitrogen (N) compounds into the atmosphere, particularly of NH3. Consequently, atmospheric N has been deposited to lakes, vegetation, and soil. Much attention has been paid to wet N deposition in southern Chile, while almost nothing is known about dry N deposition in this region. Our aim is to use an exploratory approach with SAM (Standard Air Monitoring) filters to investigate the potential contribution of the dry N deposition to the total N deposition in the central depression of southern Chile. Furthermore, the relationship between micro-climatological patterns and dry deposition was... |
Tipo: Journal article |
Palavras-chave: Atmospheric deposition; Nitrogen; Nothofagus obliqua forest; Pinus radiata plantation; Surrogate surface. |
Ano: 2005 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-66432005000200006 |
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Gazeau, Frédéric; Van Wambeke, France; Maranon, Emilio; Perez-lorenzo, Maria; Alliouane, Samir; Stolpe, Christian; Blasco, Thierry; Leblond, Nathalie; Zancker, Birthe; Engel, Anja; Marie, Barbara; Dinasquet, Julie; Guieu, Cécile. |
Although atmospheric dust fluxes from arid as well as human-impacted areas represent a significant source of nutrients to surface waters of the Mediterranean Sea, studies focusing on the evolution of the metabolic balance of the plankton community following a dust deposition event are scarce and none were conducted in the context of projected future levels of temperature and pH. Moreover, most of the experiments took place in coastal areas. In the framework of the PEACETIME project, three dust-addition perturbation experiments were conducted in 300-L tanks filled with surface seawater collected in the Tyrrhenian Sea (TYR), Ionian Sea (ION) and in the Algerian basin (FAST) onboard the R/V “Pourquoi Pas?” in late spring 2017. For each experiment, six tanks... |
Tipo: Text |
Palavras-chave: Mediterranean Sea; Atmospheric deposition; Plankton community metabolism; Carbon export; Ocean acidification; Ocean warming. |
Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00688/79967/82900.pdf |
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Staelens,Jeroen; Godoy,Roberto; Oyarzún,Carlos; Thibo,Karen; Verheyen,Kris. |
Nitrogen return by leaf litterfall was compared with atmospheric nitrogen deposition for two deciduous Nothofagus stands in southern Chile, located in areas with contrasting land use. The litterfall return of nitrogen in a Nothofagus alpina (Poepp. et Endl.) Oerst. stand at San Pablo de Tregua, in the Cordillera de los Andes, was similar to the litterfall return in a Nothofagus obliqua (Mirb.) Oerst. stand at Paillaco, in the Central Depression. In contrast, the net throughfall and stemflow deposition differed significantly between the two stands. At San Pablo de Tregua, the annual bulk deposition of NH4+ and NO3- was significantly higher than the throughfall and stemflow deposition reaching the forest floor. This demonstrates an uptake of inorganic... |
Tipo: Journal article |
Palavras-chave: Ammonium; Atmospheric deposition; Canopy interactions; Nitrate; Nutrient cycling; Amonio; Ciclos de nutrientes; Depositación atmosférica; Interacciones del dosel; Nitrato. |
Ano: 2005 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-66432005000200002 |
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Cossa, Daniel; Cotte Krief, Marie-hélène; Mason, Robert P.; Bretaudeau-sanjuan, Jane. |
The purpose of this paper is to investigate the distribution and the relative importance of processes that affect mercury distribution in the water column at the shelf edge of the Celtic Sea, on the western European continental margin. The water column, down to 4500 m, was sampled during two cruises, one in winter 1994 and the other in June 1995, on eight stations. Total mercury concentrations ranged from 0.29 to 9.37 pM with the extreme values in the first 200 m. The highly variable concentrations in the surface layers are attributed to intense atmospheric-sea water exchange processes. The low concentrations encountered in the shelf water prelude any significant influence of continental waters in this area. In the mixed layer, biological uptake and... |
Tipo: Text |
Palavras-chave: Regeneration; Atmospheric deposition; Deep profile; Upwelling; Atlantic ocean; Celtic Sea; Shelf break; Continental margin; Mercury. |
Ano: 2004 |
URL: https://archimer.ifremer.fr/doc/2004/publication-660.pdf |
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Baker, A. R.; Landing, W. M.; Bucciarelli, E.; Cheize, Marie; Fietz, S.; Hayes, C. T.; Kadko, D.; Morton, P. L.; Rogan, N.; Sarthou, G.; Shelley, R. U.; Shi, Z.; Shiller, A.; Van Hulten, M. M. P.. |
The importance of the atmospheric deposition of biologically essential trace elements, especially iron, is widely recognized, as are the difficulties of accurately quantifying the rates of trace element wet and dry deposition and their fractional solubility. This paper summarizes some of the recent progress in this field, particularly that driven by the GEOTRACES, and other, international research programmes. The utility and limitations of models used to estimate atmospheric deposition flux, for example, from the surface ocean distribution of tracers such as dissolved aluminium, are discussed and a relatively new technique for quantifying atmospheric deposition using the short-lived radionuclide beryllium-7 is highlighted. It is proposed that this field... |
Tipo: Text |
Palavras-chave: Air-sea exchange; Atmospheric deposition; Trace element solubility; Biogeochemical impacts; Mineral dust; Anthropogenic aerosols. |
Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00369/48045/48131.pdf |
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Registros recuperados: 11 | |
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