English

A modified chemostat exhibiting competitive exclusion "reversal"

Dynamical Systems 2024-06-24 v2

Abstract

The classical chemostat is an intensely investigated model in ecology and bio/chemical engineering, where n-species, say x1,x2...xnx_{1}, x_{2}...x_{n} compete for a single growth limiting nutrient. Classical theory predicts that depending on model parameters, one species competitively excludes all others. Furthermore, this ''order'' of strongest to weakest is preserved, x1>>x2>>...xnx_{1} >> x_{2} >> ...x_{n}, for say D1<D2<...DnD_{1} < D_{2} <...D_{n}, where DiD_{i} is the net removal of species xix_{i}. Meaning x1x_{1} is the strongest or most dominant species and xnx_{n} is the weakest or least dominant. We propose a modified version of the classical chemostat, exhibiting certain counterintuitive dynamics. Herein we show that if only a certain proportion of the weakest species xnx_{n}'s population is removed at a ''very'' fast density dependent rate, it will in fact be able to competitively exclude all other species, for certain initial conditions. Numerical simulations are carried out to visualize these dynamics in the three species case.

Cite

@article{arxiv.2312.03947,
  title  = {A modified chemostat exhibiting competitive exclusion "reversal"},
  author = {Thomas Griffin and James Lathrop and Rana Parshad},
  journal= {arXiv preprint arXiv:2312.03947},
  year   = {2024}
}

Comments

14 pages, 4 figures

R2 v1 2026-06-28T13:43:28.861Z