title: Coexistence and coevolution in fluctuating environments: can the storage effect evolve?
abstract: Both theoretical and empirical work have shown that the temporal storage effect can promote coexistence. However, the storage effect depends on temporally fluctuating demographic rates, such as interannually variable germination rates. Because variable demographic rates often reduce fitness, we asked how a storage effect might evolve. Using a model of competing annual plants, we find that variable germination (and hence a storage effect) can evolve only if germination is positively correlated with high-fecundity years (predictive germination) or if one species has limited ability to evolve. Outside of these conditions, the storage effect is evolutionarily unstable: if two species were thrown together with traits that would permit a storage effect, they would coevolve constant germination rates and the storage effect would vanish. Our results suggest that for the temporal storage effect to be widespread, either germination must commonly be positively correlated with later growth or fecundity or community assembly must reflect biogeographic processes more than they do coevolution.
authors.affiliation: Department of Biology, Case Western Reserve University, Cleveland, Ohio 44106, USA. res29@case.edu
authors.forename: Robin E
authors.initials: RE
authors.lastname: Snyder
authors.forename: Peter B
authors.initials: PB
authors.lastname: Adler
mesh_terms: D005075:Biological Evolution; D003198:Computer Simulation; D003710:Demography; D017753:Ecosystem; D005298:Fertility / Q000502:physiology; D018525:Germination / Q000502:physiology; D008954:Models, Biological; D063245:Plant Development