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Auteur Fournier, B.; Mouquet, N.; Leibold, M.A.; Gravel, D. doi  openurl
  Titre An integrative framework of coexistence mechanisms in competitive metacommunities Type Article scientifique
  Année 2017 Publication Revue Abrégée Ecography  
  Volume 40 Numéro 5 Pages 630-641  
  Mots-Clés assembly processes; biodiversity; community ecology; dispersal; metapopulation dynamics; neutral metacommunities; niche; recruitment limitation; Restoration; species-diversity  
  Résumé Species distribution in a metacommunity varies according to their traits, the distribution of environmental conditions and connectivity among localities. These ingredients contribute to coexistence across spatial scales via species sorting, patch dynamics, mass effects and neutral dynamics. These mechanisms however seldom act in isolation and the impact of landscape configuration on their relative importance remains poorly understood. We present a new model of metacommunity dynamics that simultaneously considers these four possible mechanisms over spatially explicit landscapes and propose a statistical approach to partition their contribution to species distribution. We find that landscape configuration can induce dispersal limitations that have negative consequences for local species richness. This result was more pronounced with neutral dynamics and mass effect than with species sorting or patch dynamics. We also find that the relative importance of the four mechanisms varies not only among landscape configurations, but also among species, with some species being mostly constrained by dispersal and/or drift and others by sorting. Changes in landscape properties might lead to a shift in coexistence mechanisms and, by extension, to a change in community composition. This confirms the importance of considering landscape properties for conservation and management. Our results illustrate the idea that ecological communities are the results of multiple mechanisms acting at the same time and complete our understanding of spatial processes in competitive metacommunities.  
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  Langue English Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé (up)  
  Volume de collection Numéro de collection Edition  
  ISSN 0906-7590 ISBN Médium  
  Région Expédition Conférence  
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  Numéro d'Appel MARBEC @ alain.herve @ collection 2141  
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Auteur Wasof, S.; Lenoir, J.; Hattab, T.; Jamoneau, A.; Gallet-Moron, E.; Ampoorter, E.; Saguez, R.; Bennsadek, L.; Bertrand, R.; Valdes, A.; Verheyen, K.; Decocq, G. doi  openurl
  Titre Dominance of individual plant species is more important than diversity in explaining plant biomass in the forest understorey Type Article scientifique
  Année 2018 Publication Revue Abrégée J. Veg. Sci.  
  Volume 29 Numéro 3 Pages 521-531  
  Mots-Clés biodiversity; biomass; biomass ratio hypothesis; community biomass; current knowledge; deciduous forests; ecosystem productivity; forest understorey; functional diversity; ivy; multiple traits; niche conservatism; phylogenetic diversity; phylogeny; production; richness  
  Résumé QuestionsHow does plant community diversity influence variation in plant biomass? There are two competing hypotheses: the biomass ratio' hypothesis, where biomass is influenced by the abundance and traits of the most dominant species, and the diversity' hypothesis, where the diversity of organisms influences biomass through mechanisms such as niche complementarity. However, no studies have tested which one of these two hypotheses better explains the variation in plant biomass in the forest understorey. LocationTemperate deciduous forests in northern France. MethodsFor the forest understorey, we assessed species diversity and biomass as well as soil and light conditions in 133 forest plots of 100m(2) each. Using mixed-effect models and after controlling for potential confounding factors, we tested the biomass ratio' hypothesis by relating the relative abundance of the most dominant species across our study sites and the CWM of plant traits (leaf area and plant height) to biomass. The diversity' hypothesis was tested by relating biomass to various measures of taxonomic, functional and phylogenetic diversity. ResultsBiomass of the forest understorey was mainly related to the relative abundance and the trait values of the most dominant species, supporting the biomass ratio' hypothesis. In contrast to the diversity' hypothesis, functional diversity indices had a negative impact on biomass. We found no contribution of taxonomic or phylogenetic diversity indices. ConclusionThe abundance and traits of the most dominant species matter more than taxonomic, functional or phylogenetic diversity of the forest understorey in explaining its biomass. Thus, there is a need for experiments that aim to fully understand keystone species' responses to on-going changing biotic and abiotic conditions and to predict their effects on ecosystem functioning and processes.  
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  Langue English Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé (up)  
  Volume de collection Numéro de collection Edition  
  ISSN 1100-9233 ISBN Médium  
  Région Expédition Conférence  
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  Numéro d'Appel MARBEC @ alain.herve @ collection 2397  
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Auteur Arnaud-Haond, S.; Aires, T.; Candeias, R.; Teixeira, S.J.L.; Duarte, C.M.; Valero, M.; Serrao, E.A. doi  openurl
  Titre Entangled fates of holobiont genomes during invasion: nested bacterial and host diversities in Caulerpa taxifolia Type Article scientifique
  Année 2017 Publication Revue Abrégée Mol. Ecol.  
  Volume 26 Numéro 8 Pages 2379-2391  
  Mots-Clés Algae; australia; Caulerpa; Chlorophyta; clonal diversity; dna; endophytic communities; genetic diversity; holobiont; invasion paradox; marine invasion; Mediterranean Sea; microsatellite markers; parasites; plant invasions; polymorphism  
  Résumé Successful prevention and mitigation of biological invasions requires retracing the initial steps of introduction, as well as understanding key elements enhancing the adaptability of invasive species. We studied the genetic diversity of the green alga Caulerpa taxifolia and its associated bacterial communities in several areas around the world. The striking congruence of alpha and beta diversity of the algal genome and endophytic communities reveals a tight association, supporting the holobiont concept as best describing the unit of spreading and invasion. Both genomic compartments support the hypotheses of a unique accidental introduction in the Mediterranean and of multiple invasion events in southern Australia. In addition to helping with tracing the origin of invasion, bacterial communities exhibit metabolic functions that can potentially enhance adaptability and competitiveness of the consortium they form with their host. We thus hypothesize that low genetic diversities of both host and symbiont communities may contribute to the recent regression in the Mediterranean, in contrast with the persistence of highly diverse assemblages in southern Australia. This study supports the importance of scaling up from the host to the holobiont for a comprehensive understanding of invasions.  
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  Langue English Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé (up)  
  Volume de collection Numéro de collection Edition  
  ISSN 0962-1083 ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel MARBEC @ alain.herve @ collection 2143  
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Auteur Leprieur, F.; Colosio, S.; Descombes, P.; Parravicini, V.; Kulbicki, M.; Cowman, P.F.; Bellwood, D.R.; Mouillot, D.; Pellissier, L. doi  openurl
  Titre Historical and contemporary determinants of global phylogenetic structure in tropical reef fish faunas Type Article scientifique
  Année 2016 Publication Revue Abrégée Ecography  
  Volume 39 Numéro 9 Pages 825-835  
  Mots-Clés biodiversity hotspots; climate-change; community ecology; coral-reefs; damselfishes teleostei; evolutionary origins; genetic-structure; indo-pacific; latitudinal diversity gradient; species richness  
  Résumé Identifying the main determinants of tropical marine biodiversity is essential for devising appropriate conservation measures mitigating the ongoing degradation of coral reef habitats. Based on a gridded distribution database and phylogenetic information, we compared the phylogenetic structure of assemblages for three tropical reef fish families (Labridae: wrasses, Pomacentridae: damselfishes and Chaetodontidae: butterflyfishes) using the net relatedness (NRI) and nearest taxon (NTI) indices. We then related these indices to contemporary and historical environmental conditions of coral reefs using spatial regression analyses. Higher levels of phylogenetic clustering were found for fish assemblages in the Indo-Australian Archipelago (IAA), and more particularly when considering the NTI index. The phylogenetic structure of the Pomacentridae, and to a lower extent of the Chaeotodontidae and Labridae, was primarily associated with the location of refugia during the Quaternary period. Phylogenetic clustering in the IAA may partly result from vicariance events associated with coral reef fragmentation during the glacial periods of the Quaternary. Variation in the patterns among fish families further suggest that dispersal abilities may have interacted with past habitat availability in shaping the phylogenetic structure of tropical reef fish assemblages.  
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  Langue English Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé (up)  
  Volume de collection Numéro de collection Edition  
  ISSN 0906-7590 ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel MARBEC @ alain.herve @ collection 1633  
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Auteur Calcagno, V.; Jarne, P.; Loreau, M.; Mouquet, N.; David, P. doi  openurl
  Titre Diversity spurs diversification in ecological communities Type Article scientifique
  Année 2017 Publication Revue Abrégée Nat. Commun.  
  Volume 8 Numéro Pages 15810  
  Mots-Clés adaptive radiations; biodiversity; colonization; competition; drive speciation; evolutionary emergence; limiting similarity; stability; sympatric speciation; trade-off  
  Résumé Diversity is a fundamental, yet threatened, property of ecological systems. The idea that diversity can itself favour diversification, in an autocatalytic process, is very appealing but remains controversial. Here, we study a generalized model of ecological communities and investigate how the level of initial diversity influences the possibility of evolutionary diversification. We show that even simple models of intra- and inter-specific ecological interactions can predict a positive effect of diversity on diversification: adaptive radiations may require a threshold number of species before kicking-off. We call this phenomenon DDAR (diversity-dependent adaptive radiations) and identify mathematically two distinct pathways connecting diversity to diversification, involving character displacement and the positive diversity-productivity relationship. Our results may explain observed delays in adaptive radiations at the macroscale and diversification patterns reported in experimental microbial communities, and shed new light on the dynamics of ecological diversity, the diversity-dependence of diversification rates, and the consequences of biodiversity loss.  
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  Langue English Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé (up)  
  Volume de collection Numéro de collection Edition  
  ISSN 2041-1723 ISBN Médium  
  Région Expédition Conférence  
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  Numéro d'Appel MARBEC @ alain.herve @ collection 2148  
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