|   | 
Détails
   web
Enregistrements
Auteur Mason, N.W.H.; de Bello, F.; Mouillot, D.; Pavoine, S.; Dray, S.
Titre A guide for using functional diversity indices to reveal changes in assembly processes along ecological gradients Type Article scientifique
Année 2013 Publication Revue Abrégée J Veg Sci
Volume 24 Numéro 5 Pages 794-806
Mots-Clés Co-existence; Environmental filtering; Functional divergence; Functional evenness; Functional richness; Functional trait; Limiting similarity; Niche complementarity; Null models; species richness
Résumé Question Which functional diversity indices have the power to reveal changes in community assembly processes along abiotic stress gradients? Is their power affected by stochastic processes and variations in species richness along stress gradients?

Methods We used a simple community assembly model to explore the power of functional diversity indices across a wide range of ecological contexts. FD) and convex hull volume (FRic) – with a matrix-swap null model (yielding indices SESFD and SESFRic) to remove any trivial effects of species richness. We also compared two indices that measure both functional richness and functional divergence – Rao quadratic entropy (Rao) and functional dispersion (FDis) – with a null model that randomizes abundances across species but within communities. SESRao and SESFDis).

Results When mass effects operated, only SESRao and SESFDis gave reasonable power, irrespective of how species richness varied along the stress gradient. FD, FRic, Rao and FDis had low power when species richness was constant, and variation in species richness greatly influenced their power. SESFRic and SESFD were unaffected by variation in species richness. When priority effects operated, FRic, SESFRic, Rao and FDis had good power and were unaffected by variation in species richness. Variation in species richness greatly affected FD and SESFD. SESRao and SESFDis had low power in the priority effects model but were unaffected by variation in species richness.

Conclusions Our results demonstrate that a reliable test for changes in assembly processes along stress gradients requires functional diversity indices measuring either functional richness or functional divergence. We recommend using SESFRic as a measure of functional richness and either SESRao or SESFDis (which are very closely related mathematically) as a measure of functional divergence. Used together, these indices of functional richness and functional divergence provide good power to test for increasing niche complementarity with declining stress across a broad range of ecological contexts.
Adresse
Auteur institutionnel Thèse
Editeur Lieu de Publication Éditeur
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 1654-1103 ISBN Médium
Région Expédition Conférence
Notes Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 406
Lien permanent pour cet enregistrement
 

 
Auteur Toussaint, A.; Charpin, N.; Beauchard, O.; Grenouillet, G.; Oberdorff, T.; Tedesco, P.A.; Brosse, S.; Villeger, S.
Titre Non-native species led to marked shifts in functional diversity of the world freshwater fish faunas Type Article scientifique
Année 2018 Publication Revue Abrégée Ecol. Lett.
Volume 21 Numéro 11 Pages 1649-1659
Mots-Clés assemblages; biodiversity; Biotic exchanges; communities; extinction; extirpations; functional richness; functional divergence; homogenization; hydropower; introduction; invasion; islands; macroecology; patterns; richness
Résumé Global spread of non-native species profoundly changed the world biodiversity patterns, but how it translates into functional changes remains unanswered at the world scale. We here show that while in two centuries the number of fish species per river increased on average by 15% in 1569 basins worldwide, the diversity of their functional attributes (i.e. functional richness) increased on average by 150%. The inflation of functional richness was paired with changes in the functional structure of assemblages, with shifts of species position toward the border of the functional space of assemblages (i.e. increased functional divergence). Non-native species moreover caused shifts in functional identity toward higher body sized and less elongated species for most of assemblages throughout the world. Although varying between rivers and biogeographic realms, such changes in the different facets of functional diversity might still increase in the future through increasing species invasion and may further modify ecosystem functioning.
Adresse
Auteur institutionnel Thèse
Editeur Lieu de Publication Éditeur
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
Région Expédition Conférence
Notes Approuvé pas de
Numéro d'Appel MARBEC @ alain.herve @ collection 2425
Lien permanent pour cet enregistrement