PT  - JOURNAL ARTICLE
AU  - Emanuel A. Fronhofer
AU  - Delphine Legrand
AU  - Florian Altermatt
AU  - Armelle Ansart
AU  - Simon Blanchet
AU  - Dries Bonte
AU  - Alexis Chaine
AU  - Maxime Dahirel
AU  - Frederik De Laender
AU  - Jonathan De Raedt
AU  - Lucie di Gesu
AU  - Staffan Jacob
AU  - Oliver Kaltz
AU  - Estelle Laurent
AU  - Chelsea J. Little
AU  - Luc Madec
AU  - Florent Manzi
AU  - Stefano Masier
AU  - Felix Pellerin
AU  - Frank Pennekamp
AU  - Nicolas Schtickzelle
AU  - Lieven Therry
AU  - Alexandre Vong
AU  - Laurane Winandy
AU  - Julien Cote
TI  - Bottom-up and top-down control of dispersal across major organismal groups: a coordinated distributed experiment
AID  - 10.1101/213256
DP  - 2017 Jan 01
TA  - bioRxiv
PG  - 213256
4099  - http://biorxiv.org/content/early/2017/11/02/213256.short
4100  - http://biorxiv.org/content/early/2017/11/02/213256.full
AB  - Organisms rarely experience a homogeneous environment. Rather, ecological and evolutionary dynamics unfold in spatially structured and fragmented landscapes, with dispersal as the central process linking these dynamics across spatial scales. Because dispersal is a multi-causal and highly plastic life-history trait, finding general drivers that are of importance across species is challenging but highly relevant for ecological forecasting.We here tested whether two fundamental ecological forces and main determinants of local population dynamics, top-down and bottom-up control, generally explain dispersal in spatially structured communities. In a coordinated distributed experiment spanning a wide range of actively dispersing organisms, from protozoa to vertebrates, we show that bottom-up control, that is resource limitation, consistently increased dispersal. While top-down control, that is predation risk, was an equally important dispersal driver as bottom-up control, its effect depended on prey and predator space use and whether dispersal occurred on land, in water or in the air: species that routinely use more space than their predators showed increased dispersal in response to predation, specifically in aquatic environments. After establishing these general causes of dispersal, we used a metacommunity model to show that bottom-up and top-down control of dispersal has important consequences for local population fluctuations as well as cascading effects on regional metacommunity dynamics. Context-dependent dispersal reduced local population fluctuations and desynchronized dynamics between communities, two effects that increase population and community stability.Our study provides unprecedented insights into the generality of the positive resource dependency of dispersal as well as a robust experimental test of current theory predicting that predator-induced dispersal is modulated by prey and predator space use. Our experimental and theoretical work highlights the critical importance of the multi-causal nature of dispersal as well as its cascading effects on regional community dynamics, which are specifically relevant to ecological forecasting.