Environmental vs. demographic variability in two-species predator-prey models

TL;DR

This study explores how environmental and demographic variability differently influence predator-prey dynamics in a stochastic Lotka-Volterra model, revealing that environmental noise boosts populations while demographic variability has neutral effects.

Contribution

It provides a comparative analysis of environmental and demographic variability impacts on predator-prey models using Monte Carlo simulations.

Findings

Environmental variability increases predator and prey populations.

Demographic variability results in neutral optimization effects.

Environmental noise enhances overall population densities.

Abstract

We investigate the competing effects and relative importance of intrinsic demographic and environmental variability on the evolutionary dynamics of a stochastic two-species Lotka-Volterra model by means of Monte Carlo simulations on a two-dimensional lattice. Individuals are assigned inheritable predation efficiencies; quenched randomness in the spatially varying reaction rates serves as environmental noise. We find that environmental variability enhances the population densities of both predators and prey while demographic variability leads to essentially neutral optimization.