Effects of a periodically changing environment on a predator-prey ecology.

We study the Lotka-Volterra model for predator-prey competition subject to a periodically varying carrying capacity. The Lotka-Volterra model with on-site lattice occupation restrictions (i.e., finite local carrying capacity) that represent finite food resources for the prey population, exhibits a continuous active-to-absorbing phase transition. Monte Carlo simulations on a two-dimensional lattice are utilized to investigate the effect of seasonal variations of the environment on species coexistence. The results of our simulations are also compared to the mean-field analysis in order to specifically delineate the impact of stochastic fluctuations and spatial correlations. Different effective static environments are explored in the extreme limits of fast and slow periodic switching. Analysis of the mean-field equations in the fast-switching regime enables a semi-quantitative description of the (quasi-)stationary state.