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Auteur Villeger, S.; Grenouillet, G.; Brosse, S. url  doi
openurl 
  Titre Functional homogenization exceeds taxonomic homogenization among European fish assemblages Type Article scientifique
  Année 2014 Publication Revue Abrégée Global Ecology and Biogeography  
  Volume 23 Numéro 12 Pages 1450-1460  
  Mots-Clés beta-diversity; exotic species; functional diversity; Non-native species; taxonomic dissimilarity; translocation  
  Résumé (up) Aim Human activities and the consequent extirpations of native species and introductions of non-native species have been modifying the composition of species assemblages throughout the world. These anthropogenic impacts have modified the richness of assemblages as well as the biological dissimilarity among them. However, while changes in taxonomic dissimilarity (i.e. accounting for species composition) have been assessed intensively during the last decade there are still few assessments of changes in functional dissimilarity (i.e. accounting for the diversity of biological traits). Here, we assess the temporal changes in both taxonomic and functional dissimilarities for freshwater fish assemblages across Europe. Location Western Palaearctic, 137 river basins. Methods The Jaccard index was used to quantify the changes in both taxonomic and functional dissimilarity. We then partitioned dissimilarity to extract its turnover component and measured the changes in the contribution of turnover to dissimilarity. Results Functional homogenization exceeded taxonomic homogenization six-fold. More importantly, we found only a moderate positive correlation between these changes. For instance, 40% of assemblages that experienced taxonomic differentiation were actually functionally homogenized. Taxonomic and functional homogenizations were stronger when the historical level of taxonomic dissimilarity among assemblages was high and when a high number of non-native species were introduced in the assemblages. Moreover, translocated species (i.e. non-native species originating from Europe) played a stronger role than exotic species (i.e. those coming from outside Europe) in this homogenization process, while extirpation did not play a significant role. Main conclusions Change in taxonomic diversity cannot be used to predict changes in functional diversity. In addition, as functional diversity has been proven to be a better indicator of ecosystem functioning and stability than taxonomic diversity, further studies are required to test the potential effects of functional homogenization at the local scale.  
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  ISSN 1466-8238 ISBN Médium  
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  Numéro d'Appel MARBEC @ alain.herve @ collection 1178  
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Auteur Navarro, J.; Cardador, L.; Fernández, Á.M.; Bellido, J.M.; Coll, M. url  doi
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  Titre Differences in the relative roles of environment, prey availability and human activity in the spatial distribution of two marine mesopredators living in highly exploited ecosystems Type Article scientifique
  Année 2016 Publication Revue Abrégée J. Biogeogr.  
  Volume 43 Numéro 3 Pages 440-450  
  Mots-Clés deviance partitioning; elasmobranchs; environmental variables; human stressors; indicator species; marine biodiversity; Marine conservation; Mediterranean Sea; Raja asterias; Scyliorhinus canicula  
  Résumé (up) Aim Identifying the main factors affecting the spatial distribution of marine predators is essential in order to evaluate their distribution patterns, predict the potential impact of human activities on their populations and design accurate management actions. This information is also valuable from a more general management perspective, as marine predators are often considered indicators of habitat quality. In this context, we aimed to determine the degree to which environmental features, prey availability and human activities interact and influence spatial distribution of two marine mesopredator elasmobranchs, the small-spotted catshark (Scyliorhinus canicula) and the Mediterranean starry ray (Raja asterias), living in a highly human-exploited environment. Location Mediterranean Sea. Methods With information obtained from an extended experimental survey, we investigated the relative importance of environmental variables, prey availability and human activities on the spatial distribution of the abundance, biomass and occurrence rate of these marine mesopredators using deviance partitioning analyses. Results Our results revealed that environmental variables were the most important factors explaining the spatial distribution of Mediterranean starry ray, whereas small-spotted catshark distribution was also influenced by prey availability and human factors. From a management point of view, these findings suggest that Mediterranean starry ray could be a good candidate as an indicator species of demersal environmental quality. On the other hand, the distribution of the small-spotted catshark, which responds in an interactive and complex way to environment, prey availability and particular human activities, may be misleading as an environmental indicator. Main conclusions The spatial distribution of elasmobranchs in highly human-impacted marine areas can reflect the interactive and combined effects of multiple factors. To avoid misunderstandings, attention should be paid to statistical procedures allowing the separation of pure and joint contribution of the factors driving the observed spatial patterns.  
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  Volume de collection Numéro de collection Edition  
  ISSN 1365-2699 ISBN Médium  
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  Numéro d'Appel MARBEC @ alain.herve @ collection 1538  
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Auteur Albouy, C.; Delattre, V.L.; Mérigot, B.; Meynard, C.N.; Leprieur, F. url  doi
openurl 
  Titre Multifaceted biodiversity hotspots of marine mammals for conservation priorities Type Article scientifique
  Année 2017 Publication Revue Abrégée Diversity Distrib  
  Volume 23 Numéro 6 Pages 615-626  
  Mots-Clés conservation; Functional diversity; marine mammals; phylogenetic diversity  
  Résumé (up) Aim Identifying the multifaceted biodiversity hotspots for marine mammals and their spatial overlap with human threats at the global scale. Location World-wide. Methods We compiled a functional trait database for 121 species of marine mammals characterized by 14 functional traits grouped into five categories. We estimated marine mammal species richness (SR) as well as functional (FD) and phylogenetic diversity (PD) per grid cell (1° × 1°) using the FRic index (a measure of trait diversity as the volume of functional space occupied by the species present in an assemblage) and the PD index (the amount of evolutionary history represented by a set of species), respectively. Finally, we assessed the spatial congruence of these three facets of biodiversity hotspots (defined as 2.5% and 5% of the highest values of SR, FD and PD) with human threats at the global scale. Results We showed that the FRic index was weakly correlated with both SR and the PD index. Specifically, SR and FRic displayed a triangular relationship, that is, increasing variability in FRic along the species richness gradient. We also observed a striking lack of spatial congruence (<0.1%) between current human threats and the distribution of the multiple facets of biodiversity hotspots. Main Conclusions We highlighted that functional diversity calculated using the FRic index is weakly associated with the species richness of marine mammals world-wide. This is one of the most endangered vertebrate groups playing a key ecological role in marine ecosystems. This finding calls for caution when using only species richness as a benchmark for defining marine mammal biodiversity hotspots. The very low level of spatial congruence between hotspots of current threats and those of the multiple facets of marine mammal biodiversity suggests that current biodiversity patterns for this group have already been greatly affected by their history of exploitation.  
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  Langue en Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition  
  ISSN 1472-4642 ISBN Médium  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2125  
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Auteur Su, G.; Villeger, S.; Brosse, S. doi  openurl
  Titre Morphological diversity of freshwater fishes differs between realms, but morphologically extreme species are widespread Type Article scientifique
  Année 2019 Publication Revue Abrégée Glob. Ecol. Biogeogr.  
  Volume 28 Numéro 2 Pages 211-221  
  Mots-Clés diet; ecology; patterns; vulnerability; richness; freshwater fish; functional diversity; extinction risk; traits; biogeographical realms; functional redundancy; functional vulnerability; mismatch; morphological traits; morphologically extreme species; rivers  
  Résumé (up) Aim The aim was to analyse the morphological diversity of the world freshwater fish fauna. We tested to which extent the distributions of morphological traits are supported by extreme morphologies and how those extreme morphologies are distributed among realms and affect the functional vulnerability. We also analysed the contribution of between- and within-order morphological variability to the morphological differences between realms. Major taxa studied Freshwater fish. Location Global. Time period 1960s-2010s. Methods We used a global database of freshwater fishes from the six realms. Ten morphological traits were measured on 9,150 species, that is, 75% of the ca. 13,000 freshwater fish species. A principal components analysis was conducted to combine the 10 traits into a multidimensional space. We used Kolmogorov-Smirnov tests to compare the difference in morphological diversity between the six realms and between and within the major fish orders. We then identified the morphologically extreme species and quantified their contributions to the morphological range to assess the functional vulnerability and redundancy of fish faunas in the six biogeographical realms for freshwater ecosystems. Results We report a strong morphological variability among freshwater fishes of the world, with significant morphological differences among realm fish faunas, caused by an interplay between taxonomic composition of the realm faunas and morphological differences within orders among the realms. Morphologically extreme species accounted for a large percentage of the filling of the global morphological space and are distributed throughout the world. Main conclusions Fish morphological diversity is largely supported by a few species with extreme trait combinations, indicating that functional vulnerability exists throughout the world. Our results suggest that more attention should be paid to these morphologically extreme species and that they should be protected to ensure the sustainability of functions they support.  
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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 1466-822x ISBN Médium  
  Région Expédition Conférence  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2528  
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Auteur Leclerc, C.; Villeger, S.; Marino, C.; Bellard, C. doi  openurl
  Titre Global changes threaten functional and taxonomic diversity of insular species worldwide Type Article scientifique
  Année 2020 Publication Revue Abrégée Divers. Distrib.  
  Volume 26 Numéro 4 Pages 402-414  
  Mots-Clés biodiversity; birds; conservation; dimensions; extinction risk; functional specialization; functional originality; functional richness; islands; mammals; redundancy; species traits; trait; vulnerability  
  Résumé (up) Aim The assessment of biodiversity patterns under global changes is currently biased towards taxonomic diversity, thus overlooking the ecological and functional aspects of species. Here, we characterized both taxonomic and functional diversity of insular biodiversity threatened by multiple threats. Location Worldwide islands (n = 4,348). Methods We analysed the relative importance of eleven major threats, including biological invasions or climate change, on 2,756 insular endemic mammals and birds. Species were functionally described using five ecological traits related to diet, habitat and body mass. We computed complementary taxonomic and functional diversity indices (richness, specialization, originality and vulnerability) of species pools affected by each threatening process to investigate relationships between diversity dimensions and threats. We also determined whether species-specific traits are associated with specific threats. Results On average, 8% of insular endemic species at risk of extinction are impacted by threats, while 20% of their functional richness is affected. However, a marked disparity in functional richness values associated with each threat can be highlighted. In particular, cultivation and wildlife exploitation are the greatest threats to insular endemic species. Moreover, each threat may contribute to the loss of at least 10% of functional diversity, because it affects threatened species that support unique and extreme functions. Finally, we found complex patterns of species-specific traits associated with particular threats that is not explain by the threatening processes (directly affecting survival or modifying habitat). For instance, cultivation threatens very large mammals, while urbanization threatens very small mammals. Main conclusions These findings reinforce the importance of exploring the vulnerability of biodiversity facets in the face of multiple threats. Anthropogenic pressures may result in a loss of unique functions within insular ecosystems, which provides important insights into the understanding of threatening processes at a global scale.  
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  Langue English Langue du Résumé Titre Original  
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  Volume de collection Numéro de collection Edition  
  ISSN 1366-9516 ISBN Médium  
  Région Expédition Conférence  
  Notes WOS:000511022100001 Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2738  
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