Possibili interventi di contenimento dell’ailanto nella cittadella di Alessandria

Control of three-of-heaven (Ailanthus altissima) in the fortress “Cittadella” of Alessandria -.The Cittadella of Alessandria, north-west of Italy, is one of the best preserved military fortifications present in Europe. Since the abandon- ment by the Italian Army in 2007, the fortress underwent a gradual degradation. Several herbaceous and woody species colonized most of the buildings, increasing damages. A. altissima is the most troublesome among these species because of the high ability of the root system to infest building elements (roofs, walls), outworks and roads, causing severe deterio- ration. Control strategies aimed at eradicating this noxious alien invasive species from the fortress can vary according to the features of the infested areas and should take into account biological traits of the tree. For more reliable and durable results, interventions should rely on a combination of mechanical (e.g. cutting) and chemical (e.g. cut stump application, stem injection) means.