Studying invasive species - Lycée Bellevue (Alès) Colegiul National Mihail Eminescu (Satu Mare - Roumanie)

In order to model in a simple way the scattering of pampas grass, we imagine a square garden divided into nine identical plots. The reproduction of the plant is of course made by its seeds, so, to simplify, we will suppose that a fifth of the seeds will remain on the spot and the other four fifth will be scattered in equal parts over the adjacent plots. Make the system evolve by putting the first sowing plan in one of the nine plots and by imagining that this first sowing plan will give one unit of seeds at its first flowering.