CROSSING THE DESERT: A MODEL FOR ALIEN SPECIES INVASION CONTAINMENT OR TO LESSEN HABITAT DISRUPTION EFFECTS

In this paper we present a model for a possible containment way of alien species invasions. It relies on the application of one or more stripes on the ground for which the survival conditions are harsher. After reviewing a number of possible threats for biodiversity that are the main motivation of this study, as well as a few instances of landscape disruption, we present a reaction–diffusion model and report the simulations results in various conditions. The inferences indicate that the diffusion process can be delayed, through the use of multiple obstacles, thereby allowing the possibility of taking alternative measures in order to contain the invasion, at least for some time. We discuss the diffusion delay in terms of the level of hostility, the length and the number of consecutive repetitions of the harsh environments. Comparisons on the parameter space show that the harshness and structural characteristics of the stripes are intertwined in a non-trivial way. Alternatively, the model can be used to ascertain the situations in which a population living in a territory can still thrive when its habitat is broken by artifacts, whether human-built or resulting from natural causes. Examples of this sort are presented in the final discussion.