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Auteur (up) Lett, C.; Barrier, N.; Bahlali, M.
Titre Converging approaches for modeling the dispersal of propagules in air and sea Type Article scientifique
Année 2020 Publication Revue Abrégée Ecol. Model.
Volume 415 Numéro Pages 108858
Mots-Clés Aerial dispersal; Aquatic dispersal; Atmospheric dispersal; Biophysical model; Eulerian model; Lagrangian model; larval dispersal; long-distance dispersal; Marine dispersal; Oceanic dispersal; particle trajectories; population connectivity; Propagule dispersal; reef fish; schooling behavior; seed dispersal; spatially explicit; terrestrial ecology; understanding recruitment; Wind dispersal
Résumé Terrestrial plants seeds, spores and pollen are often dispersed by wind. Likewise, most eggs and larvae of marine organisms are dispersed by oceanic currents. It was historically believed that the spatial scale at which dispersal occurs was orders of magnitude smaller for plants than for fish. However, recent empirical estimates of seed and larval dispersal suggest that these dispersal scales are more alike than previously thought. The modeling approaches used to simulate aerial and aquatic dispersal are also converging. Similar biophysical models are developed, in which outputs of Eulerian models simulating the main physical forcing mechanism (wind or currents) are used as inputs to Lagrangian models that include biological components (such as seed terminal velocity or larval vertical migration). These biophysical models are then used to simulate trajectories of the biological entities (seeds, larvae) in three dimensions. We reflect on these converging trends by first putting them into an historical perspective, and then by comparing the physical and biological processes represented in marine larva vs. terrestrial seed dispersal models, the data used for the models output corroboration, and the tools available to perform simulations. We conclude that this convergence offers the opportunity to bridge the gap between two scientific communities which are currently largely disconnected. More broadly, we also see our comparison across systems as a useful way to strengthen the links between aquatic and terrestrial ecology by sharing knowledge, methods, tools, and concepts.
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Langue English Langue du Résumé Titre Original
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Volume de collection Numéro de collection Edition
ISSN 0304-3800 ISBN Médium
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Notes WOS:000501415400006 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2706
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Auteur (up) Lett, C.; Semeria, M.; Thiebault, A.; Tremblay, Y.
Titre Effects of successive predator attacks on prey aggregations Type Article scientifique
Année 2014 Publication Revue Abrégée Theor Ecol
Volume 7 Numéro 3 Pages 239-252
Mots-Clés Animal aggregation; Animal group; Attraction-repulsion model; Flock; Plant Sciences; School; Swarm; Theoretical Ecology/Statistics; Zoology
Résumé We study the cumulative effect of successive predator attacks on the disturbance of a prey aggregation using a modelling approach. Our model intends to represent fish schools attacked by both aerial and underwater predators. This individual-based model uses long-distance attraction and short-distance repulsion between prey, which leads to prey aggregation and swarming in the absence of predators. When intermediate-distance alignment is added to the model, the prey aggregation displays a cohesive displacement, i.e., schooling, instead of swarming. Including predators, i.e. with repulsion behaviour for prey to predators in the model, leads to flash expansion of the prey aggregation after a predator attack. When several predators attack successively, the prey aggregation dynamics is a succession of expanding-grouping-swarming/schooling phases. We quantify this dynamics by recording the changes in the simulated prey aggregation radius over time. This radius is computed as the longest distance of individual prey to the aggregation centroid, and it is assumed to increase along with prey disturbance. The prey aggregation radius generally increases during flash expansion, then decreases during grouping until reaching a constant lowest level during swarming/schooling. This general dynamics is modulated by several parameters: the frequency, direction (vertical vs. horizontal) and target (centroid of the prey aggregation vs. random prey) of predator attacks; the distance at which prey detect predators; the number of prey and predators. Our results suggest that both aerial and underwater predators are more efficient at disturbing fish schools by increasing their attack frequency at such level that the fish cannot return to swarming/schooling. We find that a mix between aerial and underwater predators is more efficient at disturbing a fish school than a single type of attack, suggesting that aerial and underwater foragers may gain mutual benefits in forming foraging groups.
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ISSN 1874-1738, 1874-1746 ISBN Médium
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Numéro d'Appel LL @ pixluser @ collection 350
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Auteur (up) Liess, A.; Faithfull, C.; Reichstein, B.; Rowe, O.; Guo, J.; Pete, R.; Thomsson, G.; Uszko, W.; Francoeur, S.N.
Titre Terrestrial runoff may reduce microbenthic net community productivity by increasing turbidity: a Mediterranean coastal lagoon mesocosm experiment Type Article scientifique
Année 2015 Publication Revue Abrégée Hydrobiologia
Volume 753 Numéro 1 Pages 205-218
Mots-Clés Bacteria; Dissolved organic carbon (DOC); Ecology; Enclosure experiment; Freshwater & Marine Ecology; Microbenthos; Nutrient subsidy; Terrestrial subsidy; Zoology
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ISSN 0018-8158, 1573-5117 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 1338
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Auteur (up) Lopez, N.; Navarro, J.; Barria, C.; Albo-Puigserver, M.; Coll, M.; Palomera, I.
Titre Feeding ecology of two demersal opportunistic predators coexisting in the northwestern Mediterranean Sea Type Article scientifique
Année 2016 Publication Revue Abrégée Estuar. Coast. Shelf Sci.
Volume 175 Numéro Pages 15-23
Mots-Clés abundance; anglerfish lophius-budegassa; Black anglerfish; communities; diet; fish; habits; linnaeus; Lophius budegassa; Lophius piscatorius; osteichthyes; piscatorius; Spatial distributions; Stable isotopes; Stomach contents; Trophic ecology; White anglerfish
Résumé The study of the feeding ecology of marine organisms is crucial to understanding their ecological roles and advancing our knowledge of marine ecosystem functioning. The aim of this study was to analyse the trophic ecology of two demersal predator species, black anglerfish (Lophius budegassa) and white anglerfish (L. piscatorius), in the northwestern Mediterranean Sea. Both species are important in the study area due to their high abundance and economic value, but information about their feeding behaviour is scarce. Here, we described the diet composition and ecological role of these two species, investigating whether trophic segregation exists between them and amongst fish of different sizes. In addition, by using experimental survey data we described the spatial distribution of both species to help us interpret trophic behaviour patterns. We gathered samples of two different sizes (small individuals of a total length <30 cm and large individuals >= 30 cm) of both species and combined stomach content analyses (SCA) and stable isotope analyses (SIA) of nitrogen and carbon with isotopic mixing models. Our results revealed that both anglerfish species are opportunistic predators, showing a diet composed mainly of fishes and, to a lesser extent, of crustaceans, with a small proportion of cephalopods, gastropods, bivalves and echinoderms. We found trophic segregation between the two species and the two sizes, indicating that they feed on different prey, in line with differences in their spatial distribution within the study area. This partial partition of food resources could also be explained by the differences in rhythms of activity that were reported in previous studies. In addition, although both species occupied a high position within the food web, our results showed that white anglerfish individuals and the large-sized fish of both species held higher trophic positions. This study demonstrates the usefulness of complementary approaches for trophic studies and confirms that both anglerfish species play an important role as predators in the northwestern Mediterranean Sea food web. (C) 2016 Elsevier Ltd. All rights reserved.
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Langue English Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 0272-7714 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 1647
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Auteur (up) Maire, Eva; Grenouillet, G.; Brosse, S.; Villeger, S.
Titre How many dimensions are needed to accurately assess functional diversity? A pragmatic approach for assessing the quality of functional spaces Type Article scientifique
Année 2015 Publication Revue Abrégée Global Ecology and Biogeography
Volume 24 Numéro 6 Pages 728-740
Mots-Clés Diversity indices; functional dendrogram; functional dissimilarity; functional ecology; functional traits; multidimensional space
Résumé Aim Functional diversity is a key facet of biodiversity that is increasingly being measured to quantify its changes following disturbance and to understand its effects on ecosystem functioning. Assessing the functional diversity of assemblages based on species traits requires the building of a functional space (dendrogram or multidimensional space) where indices will be computed. However, there is still no consensus on the best method for measuring the quality of functional spaces. Innovation Here we propose a framework for evaluating the quality of a functional space (i.e. the extent to which it is a faithful representation of the initial functional trait values). Using simulated datasets, we analysed the influence of the number and type of functional traits used and of the number of species studied on the identity and quality of the best functional space. We also tested whether the quality of the functional space affects functional diversity patterns in local assemblages, using simulated datasets and a real study case. Main conclusions The quality of functional space strongly varied between situations. Spaces having at least four dimensions had the highest quality, while functional dendrograms and two-dimensional functional spaces always had a low quality. Importantly, we showed that using a poor-quality functional space could led to a biased assessment of functional diversity and false ecological conclusions. Therefore, we advise a pragmatic approach consisting of computing all the possible functional spaces and selecting the most parsimonious one.
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ISSN 1466-8238 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 1341
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