Diffusion plays an unusual role in ecological quasi-neutral competition in metapopulations

TL;DR

This paper explores how diffusion influences species competition in metapopulations, revealing that spatial movement can unexpectedly promote species coexistence through complex birth-death and competition dynamics.

Contribution

It introduces a combined stochastic and deterministic framework to analyze the role of diffusion in quasi-neutral competition within metapopulations, highlighting nonmonotonic effects.

Findings

Diffusion can promote species coexistence by affecting birth-death ratios.

Spatial constraints lead to complex, nonmonotonic competition dynamics.

Diffusion influences the stability and persistence of species in metapopulations.

Abstract

We investigate the phenomenology emerging from a 2-species dynamics under the scenario of a quasi-neutral competition within a metapopulation framework. We employ stochastic and deterministic approaches, namely spatially-constrained individual-based Monte Carlo simulations and coupled mean-field ODEs. Our results show the multifold interplay between competition, birth-death dynamics and spatial constraints induces a nonmonotonic relation between the ecological majority-minority switching and the diffusion between patches. This means that diffusion can set off birth-death ratios and enhance the preservation of a species.