Spatial competition and the dynamics of rarity in a temporally varying environment
arXiv:1105.1483
Abstract
Given an endogenous timescale set by invasion in a constant environment, we introduced periodic temporal variation in competitive superiority by alternating the species' propagation rates. By manipulating habitat size and introduction rate, we simulated environments where successful invasion proceeds through growth of many spatial clusters, and where invasion can occur only as a single-cluster process. In the multi-cluster invasion regime, rapid environmental variation produced spatial mixing of the species and non-equilibrium coexistence. The dynamics' dominant response effectively averaged environmental fluctuation, so that each species could avoid competitive exclusion. Increasing the environment's half-period to match the population-dynamic timescale let the (initially) more abundant resident repeatedly repel the invader. Periodic transition in propagation-rate advantage rarely interrupted the exclusion process when the more abundant species had competitive advantage. However, at infrequent and randomly occurring times, the rare species could invade and reverse the density pattern by rapidly eroding the resident's preemption of space. In the single-cluster invasion regime, environmental variation occurring faster than the population-dynamic timescale prohibited successful invasion; the first species to reach its stationary density (calculated for a constant environment) continued to repel the other during long simulations. When the endogenous and exogenous timescales matched, the species randomly reversed roles of resident and invader; the waiting times for reversal of abundances indicate stochastic resonance. For both invasion regimes, environmental fluctuation occurring much slower than the endogenous dynamics produced symmetric limit cycles, alternations of the constant-environment pattern.
arXiv commentThe original article is available at www.evolutionary-ecology.com/issues/v12/n03/ccar2546.pdf
References in corpus (18)
- Front propagation into unstable states
- Dynamic transitions and hysteresis
- Metastable lifetimes in a kinetic Ising model: Dependence on field and system size
- Kinetic Ising model in an oscillating field: Finite-size scaling at the dynamic phase transition
- Kinetic Ising model in an oscillating field: Avrami theory for the hysteretic response and finite-size scaling for the dynamic phase transition
- Absence of First-order Transition and Tri-critical Point in the Dynamic Phase Diagram of a Spatially Extended Bistable System in an Oscillating Field
- Nonequilibrium phase transition in the kinetic Ising model: Existence of tricritical point and stochastic resonance
- Stochastic Hysteresis and Resonance in a Kinetic Ising System
- Effects of Noise in Symmetric Two-Species Competition
- Kinetic model of DNA replication in eukaryotic organisms
- Conjugate field and fluctuation-dissipation relation for the dynamic phase transition in the two-dimensional kinetic Ising model
- Extinction in population dynamics
- Internal Fluctuations Effects on Fisher Waves
- Response of a catalytic reaction to periodic variation of the CO pressure: Increased CO_2 production and dynamic phase transition
- Spatial Dynamics of Invasion: The Geometry of Introduced Species
- Nontrivial stochastic resonance temperature for the kinetic Ising model
- Ecological Invasion, Roughened Fronts, and a Competitor's Extreme Advance: Integrating Stochastic Spatial-Growth Models
- Coexistence for a multitype contact process with seasons