Dynamics of a generalized Beverton-Holt competition model subject to Allee effects

TL;DR

This paper analyzes a generalized Beverton-Holt competition model with Allee effects, revealing how the interplay influences species persistence, extinction, and coexistence, with a focus on the differences between contest and scramble competition dynamics.

Contribution

The study introduces a generalized competition model incorporating Allee effects and provides a detailed dynamical analysis, highlighting differences between contest and scramble competition.

Findings

Coexistence occurs only with four interior equilibria.

Contest species are more prone to extinction at low densities.

Scramble competition models can have more complex interior dynamics.

Abstract

We propose and study {a generalized Beverton-Holt competition model} subject to Allee effects to obtain insights on how the interplay of Allee effects and contest competition affects the persistence and the extinction of two competing species. By using {the theory of monotone dynamics} and the properties of critical curves for non-invertible maps, our analysis shows that our model has simple equilibrium dynamics for most conditions. The coexistence of two competing species occurs only if the system has four interior equilibria.} We provide an {approximation to} the basins of the boundary attractors (i.e., the extinction of one or both species) where our results suggests that {contest species are more prone to extinction than scramble ones are at low densities}. In addition, {in comparison to the} dynamics of two species scramble competition models subject to Allee effects, our study suggests that (i) Both contest and scramble competition models can have only three boundary attractors without the coexistence equilibria, or four attractors among which only one is the {persistent attractor}, {whereas} scramble competition {models} may have the extinction of both species as its only attractor under certain conditions, i.e., \emph{the essential extinction} of two species due to strong Allee effects; (ii) {Scramble competition models like Ricker type models can} have much more complicated dynamical structure of interior attractors than contest ones like Beverton-Holt type models have; and (iii) Scramble competition models {like Ricker type competition models} may be more likely to promote the coexistence of two species at low and high densities under certain conditions.