In their region of origin, China, the ailanthus was a 'tree of heaven' given the speed with which it can grow and achieve a significant height. There, its leaves are used as food for local silk worms. It was introduced commercially in 1751 in Italy and England for the production of silkworms, and although the worm disappeared, the tree of heaven has adapted perfectly to the climate of southern Europe. It is enough to take a look at any present empty or degraded plot of the city to see how its branches emerge in a pioneer and voluptuous way This is because it is a highly invasive species that is very resistant at environmental level and with great reproductive capacity. In addition, its spread directly affects the organization of the ecosystems in which it is established as it releases allelopathic substances through their roots, that reduce the presence of other species increasing dominance for itself.