title: Interannual variability in species composition explained as seasonally entrained chaos.
abstract: The species composition of plankton, insect and annual plant communities may vary markedly from year to year. Such interannual variability is usually thought to be driven by year-to-year variation in weather conditions. Here we examine an alternative explanation. We studied the effects of regular seasonal forcing on a multi-species predator-prey model consisting of phytoplankton and zooplankton species. The model predicts that interannual variability in species composition can easily arise without interannual variability in external conditions. Seasonal forcing increased the probability of chaos in our model communities, but squeezed these irregular species dynamics within the seasonal cycle. As a result, the population dynamics had a peculiar character. Consistent with long-term time series of natural plankton communities, seasonal variation led to a distinct seasonal succession of species, yet the species composition varied from year to year in an irregular fashion. Our results suggest that interannual variability in species composition is an intrinsic property of multi-species communities in seasonal environments.
authors.affiliation: Department of Aquatic Ecology and Water Quality Management, Wageningen University, PO Box 47, 6700 AA Wageningen, The Netherlands.
authors.forename: Vasilis
authors.initials: V
authors.lastname: Dakos
authors.forename: Elisa
authors.initials: E
authors.lastname: Benincà
authors.forename: Egbert H
authors.initials: EH
authors.lastname: van Nes
authors.forename: Catharina J M
authors.initials: CJ
authors.lastname: Philippart
authors.forename: Marten
authors.initials: M
authors.lastname: Scheffer
authors.forename: Jef
authors.initials: J
authors.lastname: Huisman
mesh_terms: D000818:Animals; D007313:Insecta; D008954:Models, Biological; D017711:Nonlinear Dynamics; D010933:Plankton; D010944:Plants; D012621:Seasons; D013997:Time Factors