A. Vialatte 1 , R. I. Bailey 1 , C. Vasseur 1 , A. Matocq 2 , M. Gossner 3 , D. Everhart 1 , X. Vitrac 4 , A. Belhadj 4 , A.
Ernoult 1 , A. Prinzing 1
1 UMR Ecosystèmes, Biodiversité, Evolution, Université de Rennes 1, 263 AVE du Général Leclerc, CS 74205,
35042 Rennes Cedex, France.
2 Museum national d'Histoire naturelle, Département Systématique & Evolution, 45 rue Buffon, F-75231 Paris
Cedex 05, France.
3 Institute of Ecology, Friedrich-Schiller-University, Dornburger Str. 159, 07743 Jena Deutschland.
4 Polyphénols Biotech, ISVV, Université Victor Segalen Bordeaux 2, 146 rue Léo Saignat, 33076 Bordeaux
Cedex, France.
Correspondance: aude.vialatte@univ-rennes1.fr
aude.vialatte@hotmail.com
The role of dispersal for community assembly is increasingly recognized. However, different theoretical paradigms (Island biogeography, Patch dynamics, Mass effect and
Metapopulation paradigms) make very divergent predictions on how dispersal affects community richness and structure. These predictions have not been tested together in nature.
The forest canopy represents a landscape composed of patches of distinct evolutionary histories, the crowns of individual trees. We studied Heteroptera richness, abundance and trait composition in taxonomically isolated and non-isolated oak tree crowns in order to compare support for predictions of the four main metacommunity paradigms. Despite the short distances of only less than 150 meters between taxonomically isolated and non-isolated trees we found major differences between their Heteroptera faunas. We show that taxonomically isolated trees support smaller numbers and fewer species of Heteroptera, an increasing proportion of phytophages and a decreasing proportion of omnivores, and proportionally more non host-specialists. Comparison with theoretical predictions indicates that the assembly of local Heteroptera communities is strongly driven by independent metapopulation processes at the level of the individual species.