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Registro Completo |
Biblioteca(s): |
Embrapa Pantanal. |
Data corrente: |
03/01/1996 |
Data da última atualização: |
04/04/2017 |
Autoria: |
HAMILTON, S. K.; SIPPEL, S. J.; MELACK, J. M. |
Título: |
Oxygen depletion and carbon dioxide and methane production in waters of the Pantanal wetland of Brazil. |
Ano de publicação: |
1995 |
Fonte/Imprenta: |
Biogeochemistry, v.30, n.2, p.115-141, 1995. |
Idioma: |
Inglês |
Conteúdo: |
This study examines dissolved O2, CO2 and CH4 in waters of the Pantanal a vast savanna floodplain. Measurements are presented for 540 samples from throughout the region, ranging from areas of sheet flooding to sluggish marsh strams to the major rivers of the region. Dissolved O2 is often strongly depleted, particularly in waters filed with emergent vascular plants, which are the most extensive aquatic environment of the region. Median O2 concentrations were 35 uM for vegetated waters, 116 uM for the Paraguay River, 95 uM for tributary rivers, and 165 uM for open lakes (atmospheric equilibrium, 230-290 uM). Air-water diffusive fluxes were calculated from dissolved gas concentrations for representative vegetated floodplain waters, based on data collected over the course of an annual cycle. These fluxes reveal about twice as much CO2 evasion as can be accounted for by invasion of O2 (overall means in nmol cm-2s-1:O2 0.18, CO2 0.34 and CH4 0,017). Methanogenesis is estimated to account for ca.20% of the total heterotropic metabolism in the water column and sediments, with the remainder likely due mostly to aerobic respiration. Anaerobic respiration is limited by the low concentrations of alternate electron acceptors. We hypothesize that O2 transported through the stems of emergent plants is consumed in aerobic respiration by plant tissues or microorganisms, producing CO2 that preferentially dissolves into the water and thus explaining most of the excess CO2 evasion. This hyphotesis is supported by measurements of gases in submersed stems of emergent plants. MenosThis study examines dissolved O2, CO2 and CH4 in waters of the Pantanal a vast savanna floodplain. Measurements are presented for 540 samples from throughout the region, ranging from areas of sheet flooding to sluggish marsh strams to the major rivers of the region. Dissolved O2 is often strongly depleted, particularly in waters filed with emergent vascular plants, which are the most extensive aquatic environment of the region. Median O2 concentrations were 35 uM for vegetated waters, 116 uM for the Paraguay River, 95 uM for tributary rivers, and 165 uM for open lakes (atmospheric equilibrium, 230-290 uM). Air-water diffusive fluxes were calculated from dissolved gas concentrations for representative vegetated floodplain waters, based on data collected over the course of an annual cycle. These fluxes reveal about twice as much CO2 evasion as can be accounted for by invasion of O2 (overall means in nmol cm-2s-1:O2 0.18, CO2 0.34 and CH4 0,017). Methanogenesis is estimated to account for ca.20% of the total heterotropic metabolism in the water column and sediments, with the remainder likely due mostly to aerobic respiration. Anaerobic respiration is limited by the low concentrations of alternate electron acceptors. We hypothesize that O2 transported through the stems of emergent plants is consumed in aerobic respiration by plant tissues or microorganisms, producing CO2 that preferentially dissolves into the water and thus explaining most of the excess CO2 evasion. This hyphote... Mostrar Tudo |
Palavras-Chave: |
Aquatic plant; Decomposition; Sediment. |
Thesagro: |
Decomposição; Planta Aquatica; Sedimento. |
Thesaurus Nal: |
floodplains; Pantanal; wetlands. |
Categoria do assunto: |
-- |
Marc: |
LEADER 02264naa a2200253 a 4500 001 1786579 005 2017-04-04 008 1995 bl --- 0-- u #d 100 1 $aHAMILTON, S. K. 245 $aOxygen depletion and carbon dioxide and methane production in waters of the Pantanal wetland of Brazil. 260 $c1995 520 $aThis study examines dissolved O2, CO2 and CH4 in waters of the Pantanal a vast savanna floodplain. Measurements are presented for 540 samples from throughout the region, ranging from areas of sheet flooding to sluggish marsh strams to the major rivers of the region. Dissolved O2 is often strongly depleted, particularly in waters filed with emergent vascular plants, which are the most extensive aquatic environment of the region. Median O2 concentrations were 35 uM for vegetated waters, 116 uM for the Paraguay River, 95 uM for tributary rivers, and 165 uM for open lakes (atmospheric equilibrium, 230-290 uM). Air-water diffusive fluxes were calculated from dissolved gas concentrations for representative vegetated floodplain waters, based on data collected over the course of an annual cycle. These fluxes reveal about twice as much CO2 evasion as can be accounted for by invasion of O2 (overall means in nmol cm-2s-1:O2 0.18, CO2 0.34 and CH4 0,017). Methanogenesis is estimated to account for ca.20% of the total heterotropic metabolism in the water column and sediments, with the remainder likely due mostly to aerobic respiration. Anaerobic respiration is limited by the low concentrations of alternate electron acceptors. We hypothesize that O2 transported through the stems of emergent plants is consumed in aerobic respiration by plant tissues or microorganisms, producing CO2 that preferentially dissolves into the water and thus explaining most of the excess CO2 evasion. This hyphotesis is supported by measurements of gases in submersed stems of emergent plants. 650 $afloodplains 650 $aPantanal 650 $awetlands 650 $aDecomposição 650 $aPlanta Aquatica 650 $aSedimento 653 $aAquatic plant 653 $aDecomposition 653 $aSediment 700 1 $aSIPPEL, S. J. 700 1 $aMELACK, J. M. 773 $tBiogeochemistry$gv.30, n.2, p.115-141, 1995.
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Registro original: |
Embrapa Pantanal (CPAP) |
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Registro Completo
Biblioteca(s): |
Embrapa Meio-Norte; Embrapa Tabuleiros Costeiros. |
Data corrente: |
16/01/2009 |
Data da última atualização: |
16/04/2009 |
Tipo da produção científica: |
Comunicado Técnico/Recomendações Técnicas |
Autoria: |
CARVALHO, H. W. L. de; CARDOSO, M. J.; ROCHA, L. M. P.; PACHECO, C. A. P.; OLIVEIRA, I. R. de; TABOSA, J. N.; LIRA, M. A.; OLIVEIRA, E. A. S.; NASCIMENTO, M. M. A. do; SIMPLÍCIO, J. B.; COUTINHO, G. V.; BRITO, A. R. de M. B.; TAVARES, J. A.; TAVARES FILHO, J. J.; MELO, K. E. de O.; FEITOSA, L. F.; MENEZES, A. F.; RODRIGUES, C. S.; SILVA, B. S. de F. |
Afiliação: |
Hélio Wilson Lemos de Carvalho, Embrapa Tabuleiros Costeiros; Milton José Cardoso, Embrapa Meio-Norte; Leonardo Melo Pereira Rocha; Cleso Antônio Patto Pacheco, Embrapa Milho e Sorgo; Ivênio Rubens de Oliveira, Embrapa Tabuleiros Costeiros; José Nildo Tabosa, IPA; Marcelo Abdon Lira; Edson Alva Souza Oliveira; Marta Maria Amâncio do Nascimento; Josimar Bento Simplício; Giseldo Viegas Coutinho; Ana Rita de Morais Brandão Brito; José Alves Tavares; José Jorge Tavares Filho; Kátia Estelina de Oliviera Melo; Lívia Freire Feitosa; Alba Freitas Menezes; Cinthia Souza Rodrigues; Bruno Santana de Freitas Silva. |
Título: |
Desempenho de cultivares de milho na região nordeste do Brasil: safra 2006/2007. |
Ano de publicação: |
2008 |
Fonte/Imprenta: |
Aracaju: Embrapa Tabuleiros Costeiros, 2008. |
Série: |
(Embrapa Tabuleiros Costeiros. Comunicado Técnico, 76). |
Idioma: |
Português |
Conteúdo: |
Desenvolveu-se o presente trabalho visando conhecer a performance produtiva de diversas variedades e híbridos de milho quando avaliados em diferentes áreas do Nordeste brasileiro, para fins de recomendação. |
Palavras-Chave: |
Brasil; Cultivar; Nordeste. |
Thesagro: |
Milho; Variedade. |
Categoria do assunto: |
-- |
URL: |
https://ainfo.cnptia.embrapa.br/digital/bitstream/CPATC-2009-09/20359/1/cot_76.pdf
https://ainfo.cnptia.embrapa.br/digital/bitstream/CPAMN-2010/23517/1/cot-76.pdf
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Marc: |
LEADER 01340nam a2200397 a 4500 001 1372840 005 2009-04-16 008 2008 bl uuuu u0uu1 u #d 100 1 $aCARVALHO, H. W. L. de 245 $aDesempenho de cultivares de milho na região nordeste do Brasil$bsafra 2006/2007. 260 $aAracaju: Embrapa Tabuleiros Costeiros$c2008 490 $a(Embrapa Tabuleiros Costeiros. Comunicado Técnico, 76). 520 $aDesenvolveu-se o presente trabalho visando conhecer a performance produtiva de diversas variedades e híbridos de milho quando avaliados em diferentes áreas do Nordeste brasileiro, para fins de recomendação. 650 $aMilho 650 $aVariedade 653 $aBrasil 653 $aCultivar 653 $aNordeste 700 1 $aCARDOSO, M. J. 700 1 $aROCHA, L. M. P. 700 1 $aPACHECO, C. A. P. 700 1 $aOLIVEIRA, I. R. de 700 1 $aTABOSA, J. N. 700 1 $aLIRA, M. A. 700 1 $aOLIVEIRA, E. A. S. 700 1 $aNASCIMENTO, M. M. A. do 700 1 $aSIMPLÍCIO, J. B. 700 1 $aCOUTINHO, G. V. 700 1 $aBRITO, A. R. de M. B. 700 1 $aTAVARES, J. A. 700 1 $aTAVARES FILHO, J. J. 700 1 $aMELO, K. E. de O. 700 1 $aFEITOSA, L. F. 700 1 $aMENEZES, A. F. 700 1 $aRODRIGUES, C. S. 700 1 $aSILVA, B. S. de F.
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