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Auteur Chevrinais, M.; Jacquet, C.; Cloutier, R.
Titre Early establishment of vertebrate trophic interactions: Food web structure in Middle to Late Devonian fish assemblages with exceptional fossilization Type Article scientifique
Année 2017 Publication Revue Abrégée Bull. Geosci.
Volume 92 Numéro 4 Pages 491-510
Mots-Clés north-america; bottom-up; body-size; predator; top-down; bottom-up control; coordinated stasis; Devonian; digestive contents; ecomorphology; escuminac formation; foraging ecology; fossil fish; fossil record; pahteoecology; prey size relationships; top-down control
Résumé In past and present ecosystems, trophic interactions determine material and energy transfers among species, regulating population dynamics and community stability. Food web studies in past ecosystems are helpful to assess the persistence of ecosystem structure throughout geological times and to explore the existence of general principles of food web assembly. We determined and compared the trophic structure of two Devonian fish assemblages [(1) the Escuminac assemblage (ca. 380 Ma), Miguasha, eastern Canada and (2) the Lode assemblage (ca. 390 Ma), Straupe, Latvia] with a closer look at the Escuminac assemblage. Both localities are representative of Middle to Late Devonian aquatic vertebrate assemblages in terms of taxonomic richness (ca. 20 species), phylogenetic diversity (all major groups of lower vertebrates) and palaeoenvironment (palaeoestuaries). Fossil food web structures were assessed using different kinds of direct (i.e. digestive contents and bite marks in fossils) and indirect (e.g. ecomoiphological measurements, stratigraphic species co-occurrences) indicators. First, the relationships between predator and prey body size established for the Escuminac fishes are comparable to those of recent aquatic ecosystems, highlighting a consistency of aquatic food web structure across geological time. Second, non-metric dimensional scaling on ecomorphological variables and cluster analysis showed a common pattern of functional groups for both fish assemblages; top predators, predators, primary and secondary consumers were identified. We conclude that Devonian communities were organized in multiple trophic levels and that size-based feeding interactions were established early in vertebrate history.
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ISSN 1214-1119 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 2251
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Auteur Donati, G.F.A.; Parravicini, V.; Leprieur, F.; Hagen, O.; Gaboriau, T.; Heine, C.; Kulbicki, M.; Rolland, J.; Salamin, N.; Albouy, C.; Pellissier, L.
Titre A process-based model supports an association between dispersal and the prevalence of species traits in tropical reef fish assemblages Type Article scientifique
Année 2019 Publication Revue Abrégée Ecography
Volume Numéro Pages
Mots-Clés biodiversity; body-size; dispersal; diversification; diversity; extinction rates; genetic-structure; geographic range size; global patterns; latitudinal gradient; mechanistic models; propagule dispersal; reef fish; speciation; traits
Résumé Habitat dynamics interacting with species dispersal abilities could generate gradients in species diversity and prevalence of species traits when the latter are associated with species dispersal potential. Using a process-based model of diversification constrained by a dispersal parameter, we simulated the interplay between reef habitat dynamics during the past 140 million years and dispersal, shaping lineage diversification history and assemblage composition globally. The emerging patterns from the simulations were compared to current prevalence of species traits related to dispersal for 6315 tropical reef fish species. We found a significant spatial congruence between the prevalence of simulated low dispersal values and areas with a large proportion of species characterized by small adult body size, narrow home range mobility behaviour, pelagic larval duration shorter than 21 days and diurnal activity. Species characterized by such traits were found predominantly in the Indo-Australian Archipelago and the Caribbean Sea. Furthermore, the frequency distribution of the dispersal parameter was found to match empirical distributions for body size, PLD and home range mobility behaviour. Also, the dispersal parameter in the simulations was associated to diversification rates and resulted in trait frequency matching empirical distributions. Overall, our findings suggest that past habitat dynamics, in conjunction with dispersal processes, influenced diversification in tropical reef fishes, which may explain the present-day geography of species traits.
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ISSN 0906-7590 ISBN Médium
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Notes WOS:000487946300001 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2647
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Auteur Jacquet, C.; Moritz, C.; Morissette, L.; Legagneux, P.; Massol, F.; Archambault, P.; Gravel, D.
Titre No complexity-stability relationship in empirical ecosystems Type Article scientifique
Année 2016 Publication Revue Abrégée Nat. Commun.
Volume 7 Numéro Pages 12573
Mots-Clés biodiversity; body-size; connectance; diversity; ecopath; interaction strengths; models; perturbations; real food webs; systems
Résumé Understanding the mechanisms responsible for stability and persistence of ecosystems is one of the greatest challenges in ecology. Robert May showed that, contrary to intuition, complex randomly built ecosystems are less likely to be stable than simpler ones. Few attempts have been tried to test May's prediction empirically, and we still ignore what is the actual complexity-stability relationship in natural ecosystems. Here we perform a stability analysis of 116 quantitative food webs sampled worldwide. We find that classic descriptors of complexity (species richness, connectance and interaction strength) are not associated with stability in empirical food webs. Further analysis reveals that a correlation between the effects of predators on prey and those of prey on predators, combined with a high frequency of weak interactions, stabilize food web dynamics relative to the random expectation. We conclude that empirical food webs have several non-random properties contributing to the absence of a complexity-stability relationship.
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Volume de collection Numéro de collection Edition
ISSN 2041-1723 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 1638
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Auteur Jacquet, C.; Mouillot, D.; Kulbicki, M.; Gravel, D.
Titre Extensions of Island Biogeography Theory predict the scaling of functional trait composition with habitat area and isolation Type Article scientifique
Année 2017 Publication Revue Abrégée Ecol. Lett.
Volume 20 Numéro 2 Pages 135-146
Mots-Clés Allometric theory; animal abundance; body-size; body-size distributions; complex food webs; coral-reef fishes; diversity; Ecology; evolution; Food web; global patterns; island biogeography; population-density; species richness; tropical reefs
Résumé The Theory of Island Biogeography (TIB) predicts how area and isolation influence species richness equilibrium on insular habitats. However, the TIB remains silent about functional trait composition and provides no information on the scaling of functional diversity with area, an observation that is now documented in many systems. To fill this gap, we develop a probabilistic approach to predict the distribution of a trait as a function of habitat area and isolation, extending the TIB beyond the traditional species-area relationship. We compare model predictions to the body-size distribution of piscivorous and herbivorous fishes found on tropical reefs worldwide. We find that small and isolated reefs have a higher proportion of large-sized species than large and connected reefs. We also find that knowledge of species body-size and trophic position improves the predictions of fish occupancy on tropical reefs, supporting both the allometric and trophic theory of island biogeography. The integration of functional ecology to island biogeography is broadly applicable to any functional traits and provides a general probabilistic approach to study the scaling of trait distribution with habitat area and isolation.
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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 1461-023x ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 2087
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Auteur Lefort, S.; Aumont, O.; Bopp, L.; Arsouze, T.; Gehlen, M.; Maury, O.
Titre Spatial and body-size dependent response of marine pelagic communities to projected global climate change Type Article scientifique
Année 2015 Publication Revue Abrégée Global Change Biology
Volume 21 Numéro 1 Pages 154-164
Mots-Clés biogeochemical model; body-size of organisms; climate change; climate scenario; high trophic level model; pelagic communities; trophic transfer
Résumé Temperature, oxygen, and food availability directly affect marine life. Climate models project a global warming of the ocean's surface (similar to+3 degrees C), a de-oxygenation of the ocean's interior (similar to-3%) and a decrease in total marine net primary production (similar to-8%) under the business as usual' climate change scenario (RCP8.5). We estimated the effects of these changes on biological communities using a coupled biogeochemical (PISCES) – ecosystems (APECOSM) model forced by the physical outputs of the last generation of the IPSL-CM Earth System Model. The APECOSM model is a size-structured bio-energetic model that simulates the 3D dynamical distributions of three interactive pelagic communities (epipelagic, mesopelagic, and migratory) under the effects of multiple environmental factors. The PISCES-APECOSM model ran from 1850 to 2100 under historical forcing followed by RCP8.5. Our RCP8.5 simulation highlights significant changes in the spatial distribution, biomass, and maximum body-size of the simulated pelagic communities. Biomass and maximum body-size increase at high latitude over the course of the century, reflecting the capacity of marine organisms to respond to new suitable environment. At low- and midlatitude, biomass and maximum body-size strongly decrease. In those regions, large organisms cannot maintain their high metabolic needs because of limited and declining food availability. This resource reduction enhances the competition and modifies the biomass distribution among and within the three communities: the proportion of small organisms increases in the three communities and the migrant community that initially comprised a higher proportion of small organisms is favored. The greater resilience of small body-size organisms resides in their capacity to fulfill their metabolic needs under reduced energy supply and is further favored by the release of predation pressure due to the decline of large organisms. These results suggest that small body-size organisms might be more resilient to climate change than large ones.
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Volume de collection Numéro de collection Edition
ISSN 1354-1013 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1108
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