title: Enhanced Moran effect by spatial variation in environmental autocorrelation.
abstract: Spatial correlations in environmental stochasticity can synchronize populations over wide areas, a phenomenon known as the Moran effect. The Moran effect has been confirmed in field, laboratory and theoretical investigations. Little is known, however, about the Moran effect in a common ecological case, when environmental variation is temporally autocorrelated and this autocorrelation varies spatially. Here we perform chemostat experiments to investigate the temporal response of independent phytoplankton populations to autocorrelated stochastic forcing. In contrast to naive expectation, two populations without direct coupling can be more strongly correlated than their environmental forcing (enhanced Moran effect), if the stochastic variations differ in their autocorrelation. Our experimental findings are in agreement with numerical simulations and analytical calculations. The enhanced Moran effect is robust to changes in population dynamics, noise spectra and different measures of correlation-suggesting that noise-induced synchrony may play a larger role for population dynamics than previously thought.
authors.affiliation: Institute of Biochemistry and Biology, University of Potsdam, D-14469 Potsdam, Germany.
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Massie
authors.affiliation: Institute of Biochemistry and Biology, University of Potsdam, D-14469 Potsdam, Germany.
authors.forename: Guntram
authors.initials: G
authors.lastname: Weithoff
authors.affiliation: Clearingstelle EEG, Charlottenstrasse 65, D-10117 Berlin, Germany.
authors.forename: Nina
authors.initials: N
authors.lastname: Kuckländer
authors.affiliation: Institute of Biochemistry and Biology, University of Potsdam, D-14469 Potsdam, Germany.
authors.forename: Ursula
authors.initials: U
authors.lastname: Gaedke
authors.affiliation: Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg, D-26111 Oldenburg, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Blasius
mesh_terms: D000465:Algorithms; D048408:Chlorella vulgaris / Q000502:physiology*; D003198:Computer Simulation; D017753:Ecosystem; D015233:Models, Statistical; D016011:Normal Distribution; D010839:Phytoplankton / Q000502:physiology*; D011157:Population Dynamics; D012044:Regression Analysis; D062206:Spatial Analysis; D013269:Stochastic Processes; D013997:Time Factors