Robinia pseudoacacia L. in the forested agricultaral landscape pf the Pisan hills (Tuscany)

This study is part of a larger research project on transformations in the forested agricultural landscape of the Pisan Hills in the course of the last 50 years. Over time, both soil utilization for agricultural purposes and spontaneous ground cover have undergone substantial change and fluctuation in terms of the area occupied (Bertacchi and Onnis 1995). One major aspect concerns Robinia pseudoacacia L, an exotic species of North American origin naturalized in Tuscany. Although its presence in Tuscany was reported as early as the beginning of the 1800s (Savi 1801), it has spread extensively over vast stretches of formerly agricultural but now abandoned land, often giving rise to monophytic populations. In many cases the Robinia pseudoacacia populations have fully replaced the original phytocenoses.