%0 Journal Article %J Geochimica et Cosmochimica Acta %D 2022 %T Carbon dynamics driven by seawater recirculation and groundwater discharge along a forest-dune-beach continuum of a high-energy meso-macro-tidal sandy coast %A Charbonnier, Céline %A Anschutz, Pierre %A Gwenaël Abril %A Mucci, Alfonso %A Deirmendjian, Loris %A Poirier, Dominique %A Bujan, Stéphane %A Lecroart, Pascal %B Geochimica et Cosmochimica Acta %V 317 %P 18 - 38 %8 Jan-01-2022 %G eng %U https://linkinghub.elsevier.com/retrieve/pii/S0016703721006244 %! Geochimica et Cosmochimica Acta %R 10.1016/j.gca.2021.10.021 %0 Journal Article %J Arquivos de Ciências do Mar %D 2022 %T Coastal ocean acidification in Brazil: a brief overview and perspectives %A Cotovicz Jr., Luiz C %A Valente Marins, Rozane %A Gwenaël Abril %B Arquivos de Ciências do Mar %V 55 %P 345 - 368 %8 Sep-03-2023 %G eng %U http://periodicos.ufc.br/arquivosdecienciadomar/issue/view/1159 %N Especial %! ACMAR %R 10.32360/acmar.v55iEspecial10.32360/acmar.v55iEspecial.78514 %0 Journal Article %J Estuarine, Coastal and Shelf Science %D 2022 %T Contrasting organic matter composition in pristine and eutrophicated mangroves revealed by fatty acids and stable isotopes (Rio de Janeiro, Brazil) %A Chynel, Mathias %A Rockomanovic, Sofia %A Gwenaël Abril %A Barroso, Glenda %A Marotta, Humberto %A Machado, Wilson %A Sanders, Christian J. %A Najet Thiney %A Tarik Meziane %X Mangrove sediments have a high capacity of carbon storage, as the result of larger organic matter (OM) inputs from mangrove trees (litter fall and fine roots production) than OM microbial degradation and export to coastal waters. Mangrove sediments also act as traps for suspended matter and particulate OM (POM) from surrounding water masses. Fatty acids (FAs) markers, δ13C and δ15N signatures were used here to characterize the OM composition in three mangroves located in three coastal embayments of the Rio de Janeiro state (Brazil) with increasing urbanization from a pristine mangrove M1 to a moderately impacted mangrove M2 and a highly impacted mangrove M3. In these mangroves, the δ15N signature of tree leaves and sediments increases with anthropogenic influence, consistent with a large-scale eutrophication gradient along the three regions. At mangrove M1, predominant OM inputs from mangrove trees are highlighted by high proportions of long-chain fatty acids, particularly in the inland station, where high organic carbon concentrations (126 ± 108 mg g−1) indicate limited sedimentation of mineral particles and high carbon storage capacities. The sedimentary OM of M3 mangrove was more labile as confirmed by the higher proportions of algal fatty acids, enriched δ13C signature and the C/N ratio 1.6 times lower (p < 0.001) than in the pristine mangrove M1. At the M2 mangrove site, high contribution of bacterial FAs (around 20%) to sedimentary OM and high proportion of poorly biodegradable saturated fatty acids suggest that bacteria degrade algal labile OM in surface sediments but do not mineralize the most refractory fraction of OM. At the eutrophic M3 site, our findings suggest that deposition of labile POM induced an increase of fungal biomass on the sediment, apparently enhancing the microbial loop, and potentially leading to mineralization of refractory OM and carbon losses through a priming effect. %B Estuarine, Coastal and Shelf Science %P 108061 %8 Jan-09-2022 %G eng %U https://linkinghub.elsevier.com/retrieve/pii/S0272771422003195 %! Estuarine, Coastal and Shelf Science %R 10.1016/j.ecss.2022.108061 %0 Journal Article %J Science of The Total Environment %D 2022 %T Linking eutrophication to carbon dioxide and methane emissions from exposed mangrove soils along an urban gradient %A Barroso, Glenda C. %A Gwenaël Abril %A Machado, Wilson %A Abuchacra, Rodrigo C. %A Peixoto, Roberta B. %A Bernardes, Marcelo %A Marques, Gabriela S. %A Sanders, Christian J. %A Oliveira, Gabriela B. %A Oliveira Filho, Silvio R. %A Amora-Nogueira, Leonardo %A Marotta, Humberto %B Science of The Total Environment %V 850 %P 157988 %8 Jan-12-2022 %G eng %U https://linkinghub.elsevier.com/retrieve/pii/S0048969722050872 %! Science of The Total Environment %R 10.1016/j.scitotenv.2022.157988 %0 Journal Article %J Estuaries and Coasts %D 2022 %T Seasonal, Diurnal, and Tidal Variations of Dissolved Inorganic Carbon and pCO2 in Surface Waters of a Temperate Coastal Lagoon (Arcachon, SW France) %A Polsenaere, Pierre %A Delille, Bruno %A Poirier, Dominique %A Charbonnier, Céline %A Deborde, Jonathan %A Mouret, Aurélia %A Gwenaël Abril %B Estuaries and Coasts %8 Apr-09-2023 %G eng %U https://link.springer.com/10.1007/s12237-022-01121-6 %! Estuaries and Coasts %R 10.1007/s12237-022-01121-6 %0 Journal Article %J Arquivos de Ciências do Mar %D 2022 %T SPREADING EUTROPHICATION AND CHANGING CO2 FLUXES IN THE TROPICAL COASTAL OCEAN: A FEW LESSONS FROM RIO DE JANEIRO %A Gwenaël Abril %A C. Cotovicz Jr., Luiz %A Nepomuceno, Aguinaldo %A Erbas, Thaís %A Costa, Suzan %A V. Ramos, Vinicius %A Moser, Gleyci %A Fernandes, Alexandre %A Negri, Eduardo %A A. Knoppers, Bastiaan %A Brandini, Nilva %A Machado, Wilson %A Bernardes, Marcelo %A Vantrepotte, Vincent %B Arquivos de Ciências do Mar %V 55 %P 461 - 476 %8 Sep-03-2023 %G eng %U http://periodicos.ufc.br/arquivosdecienciadomar/issue/view/1159 %N Especial %! ACMAR %R 10.32360/acmar.v55iEspecial10.32360/acmar.v55iEspecial.78518 %0 Journal Article %J Estuarine, Coastal and Shelf Science %D 2021 %T A CO2 sink in a tropical coastal lagoon impacted by cultural eutrophication and upwelling %A Erbas, Thaís %A Marques, Aguinaldo %A Gwenaël Abril %B Estuarine, Coastal and Shelf Science %V 263 %P 107633 %8 Jan-12-2021 %G eng %U https://linkinghub.elsevier.com/retrieve/pii/S0272771421004820 %! Estuarine, Coastal and Shelf Science %R 10.1016/j.ecss.2021.107633 %0 Conference Proceedings %B Radiocarbon %D 2021 %T Establishing water sample protocols for radiocarbon analysis at LAC-UFF, Brazil %A Bragança, Daniela %A Oliveira, Fabiana %A Macario, Kita %A Nunes, Vinicius %A Muniz, Marcelo %A Lamego, Fernando %A Gwenaël Abril %A Nepomuceno, Aguinaldo %A Solís, Corina %A Rodríguez-Ceja, María %X Since the establishment of the first radiocarbon accelerator mass spectrometry facility in Latin America in 2009, the Radiocarbon Laboratory team of Universidade Federal Fluminense (LAC-UFF) has worked to improve sample preparation protocols and increase the range of environmental matrices to be analyzed. We now present the preliminary results for DIC sample preparation protocols. The first validation tests include background evaluation with pMC value (0.35 ± 0.04) using bicarbonate dissolved in water. We also analyzed surface seawater resulting in pMC value (101.38 ± 0.38) and a groundwater previously dated from LEMA AMS-Laboratory with pMC value (12.30 ± 0.15). %B Radiocarbon %P 1-8 %8 09/2021 %G eng %U https://www.cambridge.org/core/product/identifier/S0033822221000011/type/journal_article %! Radiocarbon %R 10.1017/RDC.2021.1 %0 Journal Article %J Biogeochemistry %D 2021 %T Eutrophication overcoming carbonate precipitation in a tropical hypersaline coastal lagoon acting as a CO2 sink (Araruama Lagoon, SE Brazil) %A Cotovicz, Luiz C. %A Knoppers, Bastiaan A. %A Régis, Carolina R. %A Tremmel, Daniel %A Costa-Santos, Suzan %A Gwenaël Abril %B Biogeochemistry %8 Jun-08-2022 %G eng %U https://link.springer.com/10.1007/s10533-021-00842-3 %! Biogeochemistry %R 10.1007/s10533-021-00842-3 %0 Journal Article %J Environmental Science and Pollution Research %D 2021 %T Greenhouse gas emissions (CO2 and CH4) and inorganic carbon behavior in an urban highly polluted tropical coastal lagoon (SE, Brazil) %A Cotovicz, Luiz C. %A Ribeiro, Renato P. %A Régis, Carolina Ramos %A Bernardes, Marcelo %A Sobrinho, Rodrigo %A Vidal, Luciana Oliveira %A Tremmel, Daniel %A Knoppers, Bastiaan A. %A Gwenaël Abril %B Environmental Science and Pollution Research %8 04/2021 %G eng %U http://link.springer.com/10.1007/s11356-021-13362-2 %! Environ Sci Pollut Res %R 10.1007/s11356-021-13362-2 %0 Journal Article %J Marine Chemistry %D 2021 %T Thermodynamic uptake of atmospheric CO2 in the oligotrophic and semiarid São Francisco estuary (NE Brazil) %A Gwenaël Abril %A Libardoni, Bruno G. %A Brandini, Nilva %A Cotovicz, Luiz C. %A Medeiros, Paulo R.P. %A Cavalcante, Geórgenes H. %A Knoppers, Bastiaan A. %B Marine Chemistry %V 233 %P 103983 %8 01/2021 %G eng %U https://linkinghub.elsevier.com/retrieve/pii/S0304420321000682 %! Marine Chemistry %R 10.1016/j.marchem.2021.103983 %0 Journal Article %J Marine Chemistry %D 2020 %T Carbon dioxide sources and sinks in the delta of the Paraíba do Sul River (Southeastern Brazil) modulated by carbonate thermodynamics, gas exchange and ecosystem metabolism during estuarine mixing %A Cotovicz, Luiz C. %A Vidal, Luciana O. %A de Rezende, Carlos Eduardo %A Bernardes, Marcelo C. %A Knoppers, Bastiaan A. %A Sobrinho, Rodrigo L. %A Cardoso, Renan P. %A Muniz, Marcelo %A dos Anjos, Roberto Meigikos %A Biehler, Antoine %A Gwenaël Abril %B Marine Chemistry %V 226 %P 103869 %8 Jan-10-2020 %G eng %U https://linkinghub.elsevier.com/retrieve/pii/S0304420320301237 %! Marine Chemistry %R 10.1016/j.marchem.2020.103869 %0 Journal Article %J Biogeosciences %D 2020 %T Denitrification and associated nitrous oxide and carbon dioxide emissions from the Amazonian wetlands %A Guilhen, Jérémy %A Al Bitar, Ahmad %A Sauvage, Sabine %A Parrens, Marie %A Martinez, Jean-Michel %A Gwenaël Abril %A Moreira-Turcq, Patricia %A Sánchez-Pérez, José-Miguel %B Biogeosciences %V 17 %P 4297 - 4311 %8 Jan-01-2020 %G eng %U https://bg.copernicus.org/articles/17/4297/2020/ %N 16 %! Biogeosciences %R 10.5194/bg-17-4297-2020 %0 Journal Article %J Natural Hazards and Earth System Sciences %D 2019 %T Comparing the efficiency of hypoxia mitigation strategies in an urban, turbid tidal river via a coupled hydro-sedimentary biogeochemical model %A Lajaunie-Salla, Katixa %A Sottolichio, Aldo %A Schmidt, Sabine %A Litrico, Xavier %A Binet, Guillaume %A Gwenaël Abril %B Natural Hazards and Earth System Sciences %V 19 %P 2551 - 2564 %8 Jan-01-2019 %G eng %U https://www.nat-hazards-earth-syst-sci.net/19/2551/2019/https://www.nat-hazards-earth-syst-sci.net/19/2551/2019/nhess-19-2551-2019.pdf %N 11 %! Nat. Hazards Earth Syst. Sci. %R 10.5194/nhess-19-2551-2019 %0 Journal Article %J Biogeosciences %D 2019 %T Ideas and perspectives: Carbon leaks from flooded land: do we need to replumb the inland water active pipe? %A Gwenaël Abril %A Alberto V. Borges %B Biogeosciences %V 16 %P 769–784 %8 feb %G eng %U https://doi.org/10.5194/bg-16-769-2019 %R 10.5194/bg-16-769-2019 %0 Journal Article %J Science of The Total Environment %D 2019 %T Importance of the vegetation-groundwater-stream continuum to understand transformation of biogenic carbon in aquatic systems – A case study based on a pine-maize comparison in a lowland sandy watershed (Landes de Gascogne, SW France) %A Loris Deirmendjian %A Pierre Anschutz %A Christian Morel %A Alain Mollier %A Laurent Augusto %A Denis Loustau %A Luiz Carlos Cotovicz %A Damien Buquet %A Katixa Lajaunie %A Gwenaëlle Chaillou %A Baptiste Voltz %A Céline Charbonnier %A Dominique Poirier %A Gwenaël Abril %B Science of The Total Environment %V 661 %P 613–629 %8 apr %G eng %U https://doi.org/10.1016/j.scitotenv.2019.01.152 %R 10.1016/j.scitotenv.2019.01.152 %0 Journal Article %J Continental Shelf Research %D 2019 %T In vitro simulation of oscillatory redox conditions in intertidal sediments: N, Mn, Fe, and P coupling %A Pierre Anschutz %A Bouchet, Sylvain %A Gwenaël Abril %A Bridou, Romain %A Tessier, Emmanuel %A Amouroux, David %B Continental Shelf Research %G eng %0 Journal Article %J Estuarine, Coastal and Shelf Science %D 2019 %T Sources and sinks of dissolved inorganic carbon in an urban tropical coastal bay revealed by δ13C-DIC signals %A L.C. CotoviczJr %A Knoppers, Bastiaan A %A Deirmendjian, Loris %A Gwenaël Abril %B Estuarine, Coastal and Shelf Science %G eng %0 Journal Article %J Limnology and Oceanography %D 2019 %T The transformation of macrophyte-derived organic matter to methane relates to plant water and nutrient contents %A Charlotte Grasset %A Gwenaël Abril %A Raquel Mendonça %A Fabio Roland %A Sebastian Sobek %B Limnology and Oceanography %8 mar %G eng %U https://doi.org/10.1002/lno.11148 %R 10.1002/lno.11148 %0 Journal Article %J Marine Pollution Bulletin %D 2018 %T Aragonite saturation state in a tropical coastal embayment dominated by phytoplankton blooms (Guanabara Bay - Brazil) %A Luiz C. Cotovicz %A Bastiaan A. Knoppers %A Nilva Brandini %A Dominique Poirier %A Suzan J. Costa Santos %A Gwenaël Abril %B Marine Pollution Bulletin %V 129 %P 729–739 %G eng %U https://doi.org/10.1016/j.marpolbul.2017.10.064 %R 10.1016/j.marpolbul.2017.10.064 %0 Journal Article %J Journal of Hydrology %D 2018 %T Carbon dioxide degassing at the groundwater-stream-atmosphere interface: isotopic equilibration and hydrological mass balance in a sandy watershed %A Loris Deirmendjian %A Gwenaël Abril %B Journal of Hydrology %V 558 %P 129–143 %G eng %U https://doi.org/10.1016/j.jhydrol.2018.01.003 %R 10.1016/j.jhydrol.2018.01.003 %0 Journal Article %J Journal of Hydrology %D 2018 %T Carbon dioxide degassing at the groundwater-stream-atmosphere interface: isotopic equilibration and hydrological mass balance in a sandy watershed %A Loris Deirmendjian %A Gwenaël Abril %B Journal of Hydrology %V 558 %P 129–143 %G eng %U https://doi.org/10.1016/j.jhydrol.2018.01.003 %R 10.1016/j.jhydrol.2018.01.003 %0 Journal Article %J Biogeosciences %D 2018 %T Carbon dynamics and CO2 and CH4 outgassing in the Mekong delta %A Alberto V. Borges %A Gwenaël Abril %A Steven Bouillon %B Biogeosciences %V 15 %P 1093–1114 %G eng %U https://doi.org/10.5194/bg-15-1093-2018 %R 10.5194/bg-15-1093-2018 %0 Journal Article %J Environmental Science and Pollution Research %D 2018 %T Future intensification of summer hypoxia in the tidal Garonne River (SW France) simulated by a coupled hydro sedimentary-biogeochemical model %A Katixa Lajaunie-Salla %A Aldo Sottolichio %A Sabine Schmidt %A Xavier Litrico %A Guillaume Binet %A Gwenaël Abril %B Environmental Science and Pollution Research %V 25 %P 31957–31970 %8 sep %G eng %U https://doi.org/10.1007/s11356-018-3035-6 %R 10.1007/s11356-018-3035-6 %0 Journal Article %J Biogeosciences %D 2018 %T Hydro-ecological controls on dissolved carbon dynamics in groundwater and export to streams in a temperate pine forest %A Loris Deirmendjian %A Denis Loustau %A Laurent Augusto %A Sébastien Lafont %A Christophe Chipeaux %A Dominique Poirier %A Gwenaël Abril %B Biogeosciences %V 15 %P 669–691 %G eng %U https://doi.org/10.5194/bg-15-669-2018 %R 10.5194/bg-15-669-2018 %0 Journal Article %J Biogeosciences %D 2018 %T Hydro-ecological controls on dissolved carbon dynamics in groundwater and export to streams in a temperate pine forest %A Loris Deirmendjian %A Denis Loustau %A Laurent Augusto %A Sébastien Lafont %A Christophe Chipeaux %A Dominique Poirier %A Gwenaël Abril %B Biogeosciences %V 15 %P 669–691 %G eng %U https://doi.org/10.5194/bg-15-669-2018 %R 10.5194/bg-15-669-2018 %0 Journal Article %J Frontiers in Plant Science %D 2018 %T Invasive Aquatic Plants as Ecosystem Engineers in an Oligo-Mesotrophic Shallow Lake %A Cristina Ribaudo %A Juliette Tison-Rosebery %A Damien Buquet %A Gwilherm Jan %A Aurélien Jamoneau %A Gwenaël Abril %A Pierre Anschutz %A Vincent Bertrin %B Frontiers in Plant Science %V 9 %8 dec %G eng %U https://doi.org/10.3389/fpls.2018.01781 %R 10.3389/fpls.2018.01781 %0 Journal Article %J Vadose Zone Journal %D 2018 %T OZCAR: The French Network of Critical Zone Observatories %A J. Gaillardet %A I. Braud %A F. Hankard %A S. Anquetin %A O. Bour %A N. Dorfliger %A J.R. de Dreuzy %A S. Galle %A C. Galy %A S. Gogo %A L. Gourcy %A F. Habets %A F. Laggoun %A L. Longuevergne %A T. Le Borgne %A F. Naaim-Bouvet %A G. Nord %A V. Simonneaux %A D. Six %A T. Tallec %A C. Valentin %A Gwenaël Abril %A P. Allemand %A A. Arènes %A B. Arfib %A L. Arnaud %A N. Arnaud %A P. Arnaud %A S. Audry %A V. Bailly Comte %A C. Batiot %A A. Battais %A H. Bellot %A E. Bernard %A C. Bertrand %A H. Bessière %A S. Binet %A J. Bodin %A X. Bodin %A L. Boithias %A J. Bouchez %A B. Boudevillain %A I. Bouzou Moussa %A F. Branger %A J. J. Braun %A P. Brunet %A B. Caceres %A D. Calmels %A B. Cappelaere %A H. Celle-Jeanton %A F. Chabaux %A K. Chalikakis %A C. Champollion %A Y. Copard %A C. Cotel %A P. Davy %A P. Deline %A G. Delrieu %A J. Demarty %A C. Dessert %A M. Dumont %A C. Emblanch %A J. Ezzahar %A M. Estèves %A V. Favier %A M. Faucheux %A N. Filizola %A P. Flammarion %A P. Floury %A O. Fovet %A M. Fournier %A A. J. Francez %A L. Gandois %A C. Gascuel %A E. Gayer %A C. Genthon %A M. F. Gérard %A D. Gilbert %A I. Gouttevin %A M. Grippa %A G. Gruau %A A. Jardani %A L. Jeanneau %A J. L. Join %A H. Jourde %A F. Karbou %A D. Labat %A Yvan Lagadeuc %A E. Lajeunesse %A R. Lastennet %A W. Lavado %A E. Lawin %A T. Lebel %A C. Le Bouteiller %A C. Legout %A Y. Lejeune %A E. Le Meur %A N. Le Moigne %A J. Lions %A A. Lucas %A J. P. Malet %A C. Marais-Sicre %A J. C. Maréchal %A C. Marlin %A P. Martin %A J. Martins %A J. M. Martinez %A N. Massei %A A. Mauclerc %A N. Mazzilli %A J. Molénat %A P. Moreira-Turcq %A E. Mougin %A S. Morin %A J. Ndam Ngoupayou %A G. Panthou %A C. Peugeot %A G. Picard %A M. C. Pierret %A G. Porel %A A. Probst %A J. L. Probst %A A. Rabatel %A D. Raclot %A L. Ravanel %A F. Rejiba %A P. René %A O. Ribolzi %A J. Riotte %A A. Rivière %A H. Robain %A L. Ruiz %A J. M. Sanchez-Perez %A W. Santini %A S. Sauvage %A P. Schoeneich %A J. L. Seidel %A M. Sekhar %A O. Sengtaheuanghoung %A N. Silvera %A M. Steinmann %A A. Soruco %A G. Tallec %A E. Thibert %A D. Valdes Lao %A C. Vincent %A D. Viville %A P. Wagnon %A R. Zitouna %B Vadose Zone Journal %V 17 %G eng %U https://doi.org/10.2136/vzj2018.04.0067 %R 10.2136/vzj2018.04.0067 %0 Journal Article %J Biogeochemistry %D 2018 %T Predominance of phytoplankton-derived dissolved and particulate organic carbon in a highly eutrophic tropical coastal embayment (Guanabara Bay, Rio de Janeiro, Brazil) %A Luiz C. Cotovicz %A Bastiaan A. Knoppers %A Nilva Brandini %A Dominique Poirier %A Suzan J. Costa Santos %A Renato C. Cordeiro %A Gwenaël Abril %B Biogeochemistry %V 137 %P 1–14 %G eng %U https://doi.org/10.1007/s10533-017-0405-y %R 10.1007/s10533-017-0405-y %0 Journal Article %J Comptes Rendus Geoscience %D 2018 %T Variation of the isotopic composition of dissolved organic carbon during the runoff cycle in the Amazon River and the floodplains %A Patrick Albéric %A Marcela A.P. Pérez %A Patricia Moreira-Turcq %A Marc F Benedetti %A Steven Bouillon %A Gwenaël Abril %B Comptes Rendus Geoscience %V 350 %P 65–75 %G eng %U https://doi.org/10.1016/j.crte.2017.11.001 %R 10.1016/j.crte.2017.11.001 %0 Journal Article %J Limnologica - Ecology and Management of Inland Waters %D 2016 %T The fate of C4 and C3 macrophyte carbon in central Amazon floodplain waters: Insights from a batch experiment %A Jean-Michel Mortillaro %A Passarelli, C %A Gwenaël Abril %A Cédric Hubas %A Luis Felipe Artigas %A Marc F Benedetti %A Najet Thiney %A Moreira-Turcq, P %A Pérez, M A %A Vidal, L %A Tarik Meziane %K Central amazon %K Degradation %K fatty acids %K Floodplains %K Macrophytes %K Stables isotopes %X

The central Amazon floodplains are particularly productive ecosystems, where a large diversity of organic carbon sources are available for aquatic organisms. Despite the fact that C4 macrophytes generally produce larger biomasses than C3 macrophytes, food webs in the central Amazon floodplains appear dominantly based on a C3 carbon source.

In order to investigate the respective fate and degradation patterns of C4 and C3 aquatic plant-derived material in central Amazon floodplains, we developed a 23-days batch experiment. Fatty acid and carbon concentrations as well as stable isotope compositions were monitored over time in 60 L tanks. These tanks contained Amazon water, with different biomasses of C3 and C4 macrophyte, representative of in situ densities occurring in central Amazon floodplains.

In the C4Paspalum repens treatments, organic (POC, DOC) and inorganic carbon (DIC) got rapidly enriched in 13C, whereas in the C3Salvinia auriculata treatments, POC and DOC showed little change in concentration and isotopic composition, and DIC got depleted in 13C. The contribution of P. repens to POC and DOC was estimated to reach up to 94.2 and 70.7%, respectively. In contrast, no differences were reported between the C3S. auriculata and control treatments, an observation attributed to the lower C3 biomass encountered in the field, to a slower degradation rate of C3 compared to C4 compounds, and to similar isotopic compositions for river POC and DOC, and C3 compounds.

The 13C enrichments of POC, DOC, and DIC from P. repens treatments were attributed to an enhanced bacterially-mediated hydrolysis and mineralization of C4 material. Evolutions of bacterial abundance and branched fatty acid concentrations confirmed the role of heterotrophic microbial communities in the high P. repens decomposition rate. Our experiment highlights the predominant role of C4 aquatic plants, as a large source of almost entirely biodegradable organic matter available for heterotrophic activity and CO2 outgassing to the atmosphere.

%B Limnologica - Ecology and Management of Inland Waters %V 59 %P 90-98 %G eng %R doi:10.1016/j.limno.2016.03.008 %0 Journal Article %J Biogeosciences %D 2016 %T Spatial and seasonal contrasts of sedimentary organic matter in floodplain lakes of the central Amazon basin %A Sobrinho, R L %A Bernardes, Marcelo C %A Gwenaël Abril %A Kim, J-H %A Zell, C %A Jean-Michel Mortillaro %A Tarik Meziane %A Moreira-Turcq, P %A J S Sinningh Damsté %X


In this study, we investigated the seasonal and spatial pattern of sedimentary organic matter (SOM) in five floodplain lakes of the central Amazon basin (Cabaliana, Janauaca, Canaçari, Mirituba and Curuai) which have different morphologies, hydrodynamics and vegetation coverages. Surface sediments were collected in four hydrological seasons: low water (LW), rising water (RW), high water (HW) and falling water (FW) in 2009 and 2010. We inves-tigated commonly used bulk geochemical tracers such as the C/N ratio and the stable isotopic composition of organic carbon (13Cor). These results were compared with lignin phenol parameters as an indicator of vascular plant detritus and branched glycerol dialkyl glycerol tetraethers (brGDGTs) to trace the input of soil organic matter (OM) from land to the aquatic settings. We also applied the crenarchaeol as an indi- cator of aquatic (rivers and lakes) OM. Our data showed that during the RW and FW seasons, the surface sediments were enriched in lignin and brGDGTs in comparison to other seasons. Our study also indicated that floodplain lake sediments primarily consisted of allochthonous, C3 plant-derived OM. However, a downstream increase in C4 macrophyte-derivedOM contribution was observed along the gradient of increas-ing open waters – i.e., from upstream to downstream. Accordingly, we attribute the temporal and spatial difference in SOM composition to the hydrological dynamics between the floodplain lakes and the surrounding flooded forests.
 

%B Biogeosciences %V 13 %G eng %N 467– 482 %9 original %0 Journal Article %J Freshwater Biology %D 2015 %T Trophic opportunism of central Amazon floodplain fish %A Jean-Michel Mortillaro %A Marc Pouilly %A Wach, M %A Carlos E.C. Freitas %A Gwenaël Abril %A Tarik Meziane %B Freshwater Biology %V 60 %P 1659–1670 %G eng %0 Journal Article %J Nature %D 2014 %T Amazon River carbon dioxide outgassing fuelled by wetlands %A Gwenaël Abril %A Martinez, Jean Michel %A Luis Felipe Artigas %A Moreira-Turcq, Patricia %A Marc F Benedetti %A Vidal, Luciana %A Tarik Meziane %A Kim, Jung-Hyun %A Bernardes, Marcelo C %A Savoye, Nicolas %A Deborde, Jonathan %A Lima Souza, Edivaldo %A Albéric, Patrick %A Fernandes, Marcelo %A de Souza, Landim %A Roland, Fabio %B Nature %I Nature %V 505 %P 395-398 %G eng %R 10.1038/nature12797