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| Lebreton, Benoit; Richard, Pierre; Radenac, Gilles; Bordes, Monique; Breret, Martine; Arnaud, Christophe; Mornet, Francoise; Blanchard, Gerard F.. |
| The role of epiphytes in an intertidal Zostera noltii seagrass bed in Marennes-Oleron Bay was assessed in comparison with the other main benthic primary producers (Z. noltii, microphytobenthos) at two bathymetric levels and on a seasonal basis. Assemblage and biomass of epiphytes were studied using scanning electron microscopy (SEM). Z noltii and its detrital matter followed a typical seasonal pattern: microphytobenthos was present in large quantities throughout the year representing 21% of the total biomass while detrital matter, above-ground parts and below-ground parts accounted for 65, 9 and 5%, respectively. Only two species of epiphytic diatoms, Cocconeis scutellum and Cocconeis placentula, were observed on seagrass leaves. Epiphyte biomass was very... |
| Tipo: Text |
Palavras-chave: SEM; Cocconeis spp.; Epiphyte diatom; Microphytobenthos; Zostera noltii; Intertidal seagrass bed; Primary producer. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6589.pdf |
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| Guarini, Jean-marc; Blanchard, Gerard F.; Gros, Philippe; Harrison, S.j.. |
| The mud surface temperature (MST) of an intertidal mudflat in Marennes-Oléron Bay (France) and the biomass-specific photosynthetic capacity (PBmax) of benthic microalgae were modelled to investigate their spatio-temporal dynamics. Simulations were performed over 2 different periods during and after the microphytobenthos spring bloom (April and June, respectively) and under 2 different tidal conditions (spring and neap tides). The deterministic MST model is based on thermodynamic processes. Comparison at different periods between measured data series and simulations clearly establishes the reliability of the model, thus allowing extrapolations over time and space. The spatio-temporal dynamics of MST is primarily controlled by the immersion-emersion... |
| Tipo: Text |
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| Ano: 1997 |
URL: http://archimer.ifremer.fr/doc/00013/12398/9184.pdf |
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| Blanchard, Gerard F.; Guarini, Jean-marc; Richard, Pierre; Gros, Philippe; Mornet, Francoise. |
| A mathematical expression is proposed to describe the relationship between the photosynthetic capacity (Pmax) of natural assemblages of motile benthic diatoms and temperature. Experiments were performed in 2 different seasons to document the response of Pmax to a rapid increase in temperature (3*C h-1). In both cases, there was a progressive increase in Pmax up to an optimum temperature (Topt), beyond which Pmax declined rapidly. Topt did not change from September to December 1995, but the maximum photosynthetic capacity (PMAX, i.e. Pmax at Topt) was twice as high in September as in December. |
| Tipo: Text |
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| Ano: 1996 |
URL: http://archimer.ifremer.fr/doc/00013/12397/9183.pdf |
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| Lebreton, Benoit; Richard, Pierre; Galois, Robert; Radenac, Gilles; Pfleger, Camille; Guillou, Gael; Mornet, Francoise; Blanchard, Gerard F.. |
| A current predominant paradigm emphasizes the role of epiphytic algae for invertebrates in most seagrass food webs. However, in some intertidal Zostera noltii beds, epiphyte biomass is very low compared to microphytobenthos and seagrass biomasses. We assessed the role of microphytobenthos in a temperate intertidal Z. noltii bed by combining stable isotope and fatty acid (FA) analyses on primary producers, composite sources suspended particulate organic matter (SPOM) and sediment surface organic matter (SSOM) and the main macrofaunal consumers. Z. noltii showed high delta C-13 (-9.9 parts per thousand) and high 18:2(n-6) and 18:3(n-3) contents. Microphytobenthos was slightly more C-13-depleted (-15.4 parts per thousand) and had high levels of diatom... |
| Tipo: Text |
Palavras-chave: Food web; Intertidal seagrass bed; Microphytobenthos; Zostera noltii; Stable isotope ratio; Fatty acid profiles; European Atlantic coast. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00035/14640/12051.pdf |
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