title: Population cycles produced by delayed density dependence in an annual plant.
abstract: In contrast to insect and animal populations, little attention has been directed to the study of cycles in plant populations. It has been argued on theoretical grounds that plants present stable dynamics. Nevertheless, there are examples where plant populations appear to exhibit oscillatory dynamics, but the oscillatory signal is variable and comes from very short time series data. Using a combination of time series, models, and empirical results, we present evidence of population cycles for Descurania sophia in a 16-year field experiment. Endogenous and exogenous causal mechanisms were studied to identify processes underlying this temporal dynamic. Our results show a 4-year cycle produced by delayed density dependence. We suggest that high nutrient levels might be responsible for the observed dynamics of D. sophia. Our results suggest that although plant population dynamics may be stabilized by direct density dependence, delayed density dependence could destabilize dynamics.
authors.affiliation: Departamento Protección de Cultivos, Instituto de Agricultura Sostenible (Consejo Superior de Investigaciones Científicas), Apartado 4084, 14080 Córdoba, Spain. andujar@cica.es
authors.forename: J L
authors.initials: JL
authors.lastname: Gonzalez-Andujar
authors.forename: C
authors.initials: C
authors.lastname: Fernandez-Quintanilla
authors.forename: L
authors.initials: L
authors.lastname: Navarrete
mesh_terms: D019607:Brassicaceae / Q000502:physiology*; D008954:Models, Biological; D011157:Population Dynamics; D013997:Time Factors