Spreading Speeds for A Diffusive Three-Species System with Strong Competition

This paper investigates the propagation properties of a competition-diffusion system involving three species. The system describes the colonization of a large open space by three competing species, in which there is no interaction between two of the species, and the competition among all species is strong. We establish the spreading speeds of each species using traveling wave speeds derived from the Fisher-KPP equation and two- and three-species competition-diffusion models. Our results reveal that species spread includes at least four distinct propagation modes, illustrating varied spreading behaviors that emerge under differing levels of interspecies competition and non-interaction.