Global dynamics of a chemotaxis system with toxicity in invasive species

Invasive species threaten the integrity of ecosystems by altering the structure and function of natural systems. It is crucial to predict the mode of biological invasion and control intruders. In this paper, we establish a diffusion biological invasion model with toxicant-taxis and conduct research through theoretical analysis and numerical simulation methods. We investigate the local stability of the system and find that it undergoes saddle–node bifurcation and transcritical bifurcation. We further prove the boundedness and global existence of the classical solutions of the system. By constructing appropriate Lyapunov functionals, the global stability of the positive steady state is analyzed, and the decay rate of the solution is provided. In addition, to investigate the effects of toxins and competition intensity on the survival of invasive species, we demonstrate the existence conditions of steady-state solutions through numerical simulations. By comparison, it is found that invasive species can only survive in new environments if they possess at least one advantage.