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| Registros recuperados: 174 | |
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| FREITAS, D. A. F. de; CARDOSO, E. L.; SILVA, M. L. N.; SANTOS, S. A.. |
| O Pantanal da Nhecolândia é caracterizado por uma elevada diversidade de unidades de vegetação que apresentam diferenças na fertilidade do solo. O presente estudo objetivou avaliar a disponibilidade de micronutrientes do solo sob as diferentes fitofisionomias desta região. Amostras de solo foram coletadas na profundidade de 0-10 cm, para avaliação da disponibilidade de zinco, ferro, manganês, cobre, boro e sódio, em sete fitofisionomias sujeitas a diferentes regimes de inundação: a) livres de inundação - floresta semidecídua e cerradão; b) sujeitas a inundação ocasional ? cerrado/campo cerrado e campo limpo com predominância de Elionurus muticus; c) sujeita a inundação sazonal - campo limpo com predominância de Axonopus purpusii e Andropogon spp.; bordas... |
| Tipo: Boletim de Pesquisa e Desenvolvimento (INFOTECA-E) |
Palavras-chave: PH do solo; Native vegetation.; Matéria Orgânica; Vegetação Nativa.; Organic matter; Soil pH.. |
| Ano: 2011 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/921423 |
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| Schafer, J; Blanc, Gerard; Audry, S; Cossa, Daniel; Bossy, C. |
| Dissolved and particulate Hg fluxes in the Lot-Garonne-Gironde fluvial-estuarine system were obtained from observation of daily discharge and suspended particulate matter (SPM) concentrations. In addition to the measurements of the total dissolved (< 0.45 gm) and particulate Hg (> 0.45 gm), called HgTD and HgTp respectively, the dissolved inorganic Hg species (HgRD) were determined monthly. Geochemical background values for HgTp in sediments and SPM were similar to crustal values and to typical concentrations in SPM of non-contaminated river systems, respectively. The Riou Mort watershed already known as the origin of important historical polymetallic (e.g., Cd, Zn) pollution was identified as an important Hg point source. In the downstream Lot... |
| Tipo: Text |
Palavras-chave: Lot; Garonne; SPM; River; Organic matter; Mercury. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1343.pdf |
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| Fontanier, Christophe; Garnier, Eline; Brandily, Christophe; Dennielou, Bernard; Bichon, S.; Gayet, Nicolas; Eugene, Thibaut; Rovere, Mickael; Gremare, A.; Deflandre, B.. |
| Live (Rose-Bengal stained) deep-sea foraminiferal faunas have been studied at four stations between 530–3200-m depth in the Mozambique Channel (eastern Africa) to understand how complex environmental conditions (e.g., organic matter, oxygenation) control their ecological structure (i.e., diversity, density, and microhabitats). Two upper-slope stations, located at 530- and 780-m depth off Madagascar, are bathed by well-oxygenated bottom waters. They are characterized by fine sediments enriched in highly degraded organic matter (low amino-acid bio-availability and reduced chlorophyllic freshness). Mineralization of organic compounds results in relatively moderate oxygen penetration depth (i.e., 15 and 30 mm) in sediment. Interestingly, foraminiferal species... |
| Tipo: Text |
Palavras-chave: Mozambique Channel; Foraminifera; Diversity; Microhabitat; Organic matter. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00344/45505/45057.pdf |
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| Zilius, Mindaugas; De Wit, Rutger; Bartoli, Marco. |
| Sedimentation of pelagic cyanobacteria in dystrophic freshwater and oligohaline lagoons results in large inputs of labile organic matter (OM) to the benthos. We used an experimental approach to study the short-term impact of such phenomena on the benthic microbial community metabolism and on the nitrogen (N) fluxes across the sediment-water interface. We hypothesized an increase of respiratory activity, including N loss via denitrification and its recycling to the water column. Our results show that the incorporation within sediments of the settled bloom increases benthic bacterial activities. This is coupled to large DON and NH4+ effluxes, and to a comparatively smaller increase of N-2 production, while no significant effects were detected for the benthic... |
| Tipo: Text |
Palavras-chave: Cyanobacteria; Organic matter; Sediments; Benthic metabolism; DON; Denitrification. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00354/46504/74457.pdf |
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| Fontanier, Christophe; Sakai, Saburo; Toyofuku, Takashi; Garnier, Eline; Brandily, Christophe; Eugene, Thibaut; Deflandre, Bruno. |
| Oxygen and carbon isotopes (δ18O and δ13C) have been investigated in carbonate tests of deep-sea foraminifera living in the Mozambique Channel (eastern Africa) to understand how environmental constraints (e.g., organic matter, oxygenation) control the intra- and interspecific variability of isotopic signatures. 197 living individuals, including eight different species, from various microhabitats within the sediment were sorted from sediment samples gathered at two stations on the Malagasy upper slope. Results show that the δ18O values of foraminiferal taxa were not controlled by microhabitat pattern. They presented tremendous and intriguing intraspecific variability that is not explained by the classical ontogenetic effect. The δ13C values of infaunal... |
| Tipo: Text |
Palavras-chave: Oxygen and carbon isotopes; Deep-sea foraminifera; Organic matter; Oxygenation; Microhabitat. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00357/46831/46979.pdf |
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| Jacq, E; Moal, Jeanne; Samain, Jean-francois; Corre, S; Daniel, J; Nicolas, Jean-louis; Cochard, Jean-claude; Fera, P. |
| Larval rearings were performed with seawater either freshly pumped or after storage in a pond. Concerning bacterial populations these waters were characterized by a high diversity, little sized bacteria whose few of them (1%) were cultivable on Zobell medium. In the tanks, the bacterial ecosystem was modified by the presence of antibiotics, larvae and algae: the diversity was lowered, the cellular volume was increased by a factor 2 to 5, 100% bacteria were cultivable and chloramphenicol resistant, and their metabolism changed. Taxonomic screening showed no differences among the two waters neither at the beginning nor at the end of the rearings. However, depending on the water (stored or not) differences were identified for bacterial physiology and... |
| Tipo: Text |
Palavras-chave: Marine aquaculture; Pond culture; Scallop culture; Ecology; Antibiotics; Organic matter; Grazing; Carbohydrates; Mathematical models; Modelling; Growth; Bacterial diseases; Biological production; Culture tanks; Larvae; Rearing. |
| Ano: 1992 |
URL: http://archimer.ifremer.fr/doc/1992/acte-914.pdf |
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| Jacq, Kévin; Perrette, Yves; Fanget, Bernard; Sabatier, Pierre; Coquin, Didier; Martinez-lamas, Ruth; Debret, Maxime; Arnaud, Fabien. |
| In the case of environmental samples, the use of a chemometrics-based prediction model is highly challenging because of the difficulty in experimentally creating a well-ranged reference sample set. In this study, we present a methodology using short wave infrared hyperspectral imaging to create a partial least squares regression model on a cored sediment sample. It was applied to a sediment core of the well-known Lake Bourget (Western Alps, France) to develop and validate a model for downcore high resolution LOI550 measurements used as a proxy of the organic matter. In lake and marine sediment, the organic matter content is widely used, for example, to reconstruct carbon flux variations through time. Organic matter analysis through routine analysis methods... |
| Tipo: Text |
Palavras-chave: Hyperspectral imaging; Chemometrics; Near-infrared spectroscopy; High resolution analysis; Organic matter. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00478/59018/61636.pdf |
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| Chamroux, S.; Boucher, G.. |
| Chemical and Biological evolution of sediments in closed circuit : I. Nitrogen and bacteria. A series of well controlled sea water closed circuit sand filters allowed the study of chemical and biological regulation processes in the sediment. Bacteria, Nitrogen chemistry and meiofauna were mainly investigated. The evolution of the different forms of nitrogen is rather similar, whatever the organic matter flow in the sediment. As long as the amount of organic input works as limiting factor, bacteria densities are proportional to its flow. No correlation was found between bacteria and chemical parameters in the sand or in the water. The temperature does not seem to play a determinant part neither in the evolution of bacteria nor in the mineralization of... |
| Tipo: Text |
Palavras-chave: Circuit clos; Sédiment; Bactéries; Matière organique; Azote; Closed circuit; Sediment; Bacteria; Organic matter; Nitrogen. |
| Ano: 1979 |
URL: http://archimer.ifremer.fr/doc/00305/41652/40861.pdf |
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| Boucher, G.. |
| Chemical and Biological evolution of sediments in closed circuit : II. Effect of soluble organic matter input on meiofauna in polytrophic systems. The effect on meiofauna of the input of soluble organic matter in closed circuit sand filters was followed during two years for an oligotrophic, a mesotrophic and an eutrophic tank, and during one year for an atrophic tank. In the case of no input, the density, biomass and species richness of nematodes decreases even if equitability remains constant. Oligotrophy maintains the stability and diversity. Mesotrophy changes the community composition by species succession. Eutrophy allows biomass increase, due to one dominant species. |
| Tipo: Text |
Palavras-chave: Circuit clos; Matière organique; Meiofaune; Closed circuit; Organic matter; Meiofauna. |
| Ano: 1979 |
URL: http://archimer.ifremer.fr/doc/00305/41653/40862.pdf |
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| Registros recuperados: 174 | |
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