Connectivity drives the functional diversity of plant dispersal traits in agricultural landscapes: the example of ditch metacommunities

Abstract : Context Studying communities using a trait-based approach has contributed to major advances in the understanding of community assembly mechanisms, but research has primarily focused on the effect of local biotic and abiotic processes on plant assemblages. Objectives At the landscape level, we expect that the diversity of trait values (i.e. functional diversity) in plant assemblages is not random because there might be strong environmental constraints occurring as a filter of plant species at this level. We expect that fragmentation, through connectivity loss, may reduce functional diversity by filtering plant dispersal traits within the global pool of species toward those that present the trait values that are the most adapted. We tested this hypothesis at the metacommunity level and focused on ditch plant dispersal traits. Methods We characterised the functional diversity of 27 ditch bank metacommunities for three seed traits encompassing the whole dispersal process: production, buoyancy and mass. We computed four connectivity variables based on the ditch networks surrounding each metacommunity. Null models were designed to quantify functional convergence (i.e. convergence of the trait values around a mean) or divergence for each trait (i.e. dissimilarity in plant trait values). Results At the metacommunity level, we demonstrate that (1) connectivity loss reduces the functional diversity of dispersal traits (seed production and seed buoyancy), leading to the convergence of trait values, whereas more connected landscapes promote randomness, or even divergence (seed mass) in trait values; (2) these changes are due to the modification in the number of occurrence of plant species over the nine local communities sampled, rather than in species identity. Conclusions Our results indicated that, at the metacommunity level, reduced connectivity acts as a filter on the dispersal traits of plant species, promoting the broad distribution of species with efficient dispersal abilities in such landscapes. Thus, functional diversity helps us to understand the mechanisms underlying the effects of fragmentation on biodiversity.
Type de document :
Article dans une revue
Landscape Ecology, Springer Verlag, 2017, 32 (10), pp.2029-2040. 〈10.1007/s10980-017-0564-1〉
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Contributeur : Laurent Jonchère <>
Soumis le : jeudi 9 novembre 2017 - 14:31:14
Dernière modification le : mercredi 16 mai 2018 - 11:23:53

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Distributed under a Creative Commons Paternité 4.0 International License

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Lisa Favre-Bac, Cendrine Mony, Francoise Burel, Gaetan Seimandi-Corda, Aude Ernoult. Connectivity drives the functional diversity of plant dispersal traits in agricultural landscapes: the example of ditch metacommunities. Landscape Ecology, Springer Verlag, 2017, 32 (10), pp.2029-2040. 〈10.1007/s10980-017-0564-1〉. 〈hal-01631558〉

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