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Auteur Manna, L.R.; Villeger, S.; Rezende, C.F.; Mazzoni, R.
Titre High intraspecific variability in morphology and diet in tropical stream fish communities Type Article scientifique
Année 2019 Publication Revue Abrégée Ecol. Freshw. Fish
Volume 28 Numéro (up) 1 Pages 41-52
Mots-Clés approach reveals; assemblages; body-size; community ecology; competition; ecology; functional diversity; functional traits; habitat use; originality; plasticity; rainforest stream; savannah stream; specialisation; specialization; traits
Résumé Functional diversity of fish communities has been measured according to (a) interspecific variability, assuming that intraspecific variability is negligible, or (b) morphological differences, as good descriptors of complex functions, such as diet. These two assumptions have been scarcely tested on the individual level, especially in species-rich tropical ecosystems. Here, we adapted intraspecific specialisation (ISpe) and intraspecific originality indices (IOri) to assess complementary components of intraspecific variability. Next, we applied these indices to evaluate the intra- and interspecific variability of morphological and diet traits in two contrasting Brazilian stream-dwelling fish assemblages (rainforest and savannah). We also compared correlations between morphology and diet at the individual and species level to test whether accounting for intraspecific variability increases the predictability of diet due to morphological differences. Significant contributions of intraspecific variability to differences between fish were revealed for morphology and diet. Intraspecific variability in the diet was higher than that in morphology in both assemblages. The ISpe was positively correlated to IOri in the diet of both ecosystems. The morphological-dietary relationships were significant but weak at both individual and species levels. Our findings highlight the importance of measuring individual variability and accounting for complementary components of the intraspecific variability (ISpe and IOri). Importantly, we showed that the variability in morphology does not predict diet variability at both intra- and interspecific levels. Thus, high intraspecific variability in morphology and diet challenges the use of functional traits measured at the species level to describe the functional diversity of different fish assemblages.
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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 0906-6691 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2472
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Auteur Zhao, T.; Villeger, S.; Cucherousset, J.
Titre Accounting for intraspecific diversity when examining relationships between non-native species and functional diversity Type Article scientifique
Année 2019 Publication Revue Abrégée Oecologia
Volume 189 Numéro (up) 1 Pages 171-183
Mots-Clés fish; Intraspecific variability; size; disturbance; Non-native species; phenotypic plasticity; Functional diversity; reveals; catfish silurus-glanis; coexistence; Community assembly; energy relationships; Functional traits; success; trait variability
Résumé Quantifying changes in functional diversity, the facet of biodiversity accounting for the biological features of organisms, has been advocated as one of the most integrative ways to unravel how communities are affected by human-induced perturbations. The present study assessed how functional diversity patterns varied among communities that differed in the degree to which non-native species dominated the community in temperate lake fish communities and whether accounting for intraspecific functional variability could provide a better understanding of the variation of functional diversity across communities. Four functional diversity indices were computed for 18 temperate lake fish communities along a gradient of non-native fish dominance using morphological functional traits assessed for each life-stage within each species. First, we showed that intraspecific variability in functional traits was high and comparable to interspecific variability. Second, we found that non-native fish were functionally distinct from native fish. Finally, we demonstrated that there was a significant relationship between functional diversity and the degree to which non-native fish currently dominated the community and that this association could be better detected when accounting for intraspecific functional variability. These findings highlighted the importance of incorporating intraspecific variability to better quantify the variation of functional diversity patterns in communities facing human-induced perturbations.
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Volume de collection Numéro de collection Edition
ISSN 0029-8549 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 2479
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Auteur Legras, G.; Loiseau, N.; Gaertner, J.-C.; Poggiale, J.-C.; Gaertner-Mazouni, N.
Titre Assessing functional diversity: the influence of the number of the functional traits Type Article scientifique
Année 2020 Publication Revue Abrégée Theor. Ecol.
Volume 13 Numéro (up) 1 Pages 117-126
Mots-Clés biodiversity; Dissimilarity metric; framework; Functional diversity; Functional traits; global hotspots; Index sensitivity; indexes; mismatch; redundancy; reveals; species richness; Trend analysis; vulnerability
Résumé The impact of the variation of the number of functional traits on functional diversity assessment is still poorly known. Although the covariation between these two parameters may be desirable in some situations (e.g. if adding functional traits provides relevant new functional information), it may also result from mathematical artefacts and lead to misinterpretation of the results obtained. Here, we have tested the behaviour of a set of nine indices widely used for assessing the three main components of functional diversity (i.e. functional richness, evenness and divergence), according to the variation in the number of functional traits. We found that the number of functional traits may strongly impact the values of most of the indices considered, whatever the functional information they contain. The FRic, TOP and n-hypervolume indices that have been developed to characterize the functional richness component appeared to be highly sensitive to the variation in the number of traits considered. Regarding functional divergence, most of the indices considered (i.e. Q, FDis and FSpe) also showed a high degree of sensitivity to the number of traits considered. In contrast, we found that indices used to compute functional evenness (FEve and Ru), as well as one of the indices related to functional divergence (FDiv), are weakly influenced by the variation in the number of traits. All these results suggest that interpretation of most of the functional diversity indices considered cannot only be based on their values as they are, but requires taking into account the way in which they have been computed.
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Langue English Langue du Résumé Titre Original
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Volume de collection Numéro de collection Edition
ISSN 1874-1738 ISBN Médium
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Notes WOS:000515172600009 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2750
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Auteur McLean, M.; Auber, A.; Graham, N.A.J.; Houk, P.; Villeger, S.; Violle, C.; Thuiller, W.; Wilson, S.K.; Mouillot, D.
Titre Trait structure and redundancy determine sensitivity to disturbance in marine fish communities Type Article scientifique
Année 2019 Publication Revue Abrégée Glob. Change Biol.
Volume 25 Numéro (up) 10 Pages 3424-3437
Mots-Clés biodiversity; climate change; climate-change; coral reefs; coral-reef fish; diversity stability; ecological traits; ecosystem functioning; ecosystem productivity; egg buoyancy; English Channel; functional diversity; functional redundancy; north-sea; regime shifts; response diversity; vulnerability
Résumé Trait diversity is believed to influence ecosystem dynamics through links between organismal traits and ecosystem processes. Theory predicts that key traits and high trait redundancy-large species richness and abundance supporting the same traits-can buffer communities against environmental disturbances. While experiments and data from simple ecological systems lend support, large-scale evidence from diverse, natural systems under major disturbance is lacking. Here, using long-term data from both temperate (English Channel) and tropical (Seychelles Islands) fishes, we show that sensitivity to disturbance depends on communities' initial trait structure and initial trait redundancy. In both ecosystems, we found that increasing dominance by climatically vulnerable traits (e.g., small, fast-growing pelagics/corallivores) rendered fish communities more sensitive to environmental change, while communities with higher trait redundancy were more resistant. To our knowledge, this is the first study demonstrating the influence of trait structure and redundancy on community sensitivity over large temporal and spatial scales in natural systems. Our results exemplify a consistent link between biological structure and community sensitivity that may be transferable across ecosystems and taxa and could help anticipate future disturbance impacts on biodiversity and ecosystem functioning.
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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 1354-1013 ISBN Médium
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Notes WOS:000486150200018 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2652
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Auteur Barnagaud, J.-Y.; Kissling, W.D.; Tsirogiannis, C.; Fisikopoulos, V.; Villeger, S.; Sekercioglu, C.H.; Svenning, J.-C.
Titre Biogeographical, environmental and anthropogenic determinants of global patterns in bird taxonomic and trait turnover Type Article scientifique
Année 2017 Publication Revue Abrégée Glob. Ecol. Biogeogr.
Volume 26 Numéro (up) 10 Pages 1190-1200
Mots-Clés Anthropocene; Beta diversity; Beta-diversity; biogeographical legacies; biotic homogenization; climate changes; community; components; dispersal; functional diversity; functional diversity; life-history traits; mammal assemblages; net primary production; regional assemblages; specialization; species richness
Résumé AimTo assess contemporary and historical determinants of taxonomic and ecological trait turnover in birds worldwide. We tested whether taxonomic and trait turnover (1) are structured by regional bioclimatic conditions, (2) increase in relationship with topographic heterogeneity and environmental turnover and change according to current and historical environmental conditions, and (3) decrease with human impact. Major TaxaBirds. LocationGlobal. MethodsWe used computationally efficient algorithms to map the taxonomic and trait turnover of 8,040 terrestrial bird assemblages worldwide, based on a grid with 110km x 110 km resolution overlaid on the extent-of-occurrence maps of 7,964 bird species, and nine ecological traits reflecting six key aspects of bird ecology (diet, habitat use, thermal preference, migration, dispersal and body size). We used quantile regression and model selection to quantify the influence of biomes, environment (temperature, precipitation, altitudinal range, net primary productivity, Quaternary temperature and precipitation change) and human impact (human influence index) on bird turnover. ResultsBird taxonomic and trait turnover were highest in the north African deserts and boreal biomes. In the tropics, taxonomic turnover tended to be higher, but trait turnover was lower than in other biomes. Taxonomic and trait turnover exhibited markedly different or even opposing relationships with climatic and topographic gradients, but at their upper quantiles both types of turnover decreased with increasing human influence. Main conclusionsThe influence of regional, environmental and anthropogenic factors differ between bird taxonomic and trait turnover, consistent with an imprint of niche conservatism, environmental filtering and topographic barriers on bird regional assemblages. Human influence on these patterns is pervasive and demonstrates global biotic homogenization at a macroecological scale.
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ISSN 1466-822x ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 2212
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