Participatory planning of a urban tree-lined: the case of study of Calcinaia (Pisa)

Calcinaia is a small town in the province of Pisa (Tuscany - Italy). The main entrances to the town consist of two avenues with Italian stone pine (Pinus pinea L.). This species is known to cause damage to the roadway due to numerous surface roots and makes it so dangerous; therefore stone pine shows asymptomatic sudden fall of branches ( due to torsion of branches, to wind or snow load, summer heat ) or of whole plants. After an accident (fall of one of the pine trees), which fortunately did not result in casualties , the city administration decided to give appointment at the University to conduct a study on the propensity to failure of Matteotti avenue pines and to evaluate the possibility of replacing all the pines with other species. After evaluation with methodology VTA and application of pulling test , the 130 pines resulted healthy but with poor anchorage of the roots due to plant age (90 years old) and rooting conditions (steep escarpment and asphalt, restored several times with radical cuts ). The study was conducted to determine all the possible constraints to envisage citizenship and was subsequently initiated a process of participatory planning. Two meetings with citizens, eager to participate and contribute to the ultimate objective, were enough to explain to them the reasons of pine cutting and to find two solutions to reduce the impact and maintenance: 1) retrain the avenue with plane trees or 2) with oaks and linden trees , alternating them on each row. The solutions were both valid and the citizens voted preferring the former. Within a few months the project has been drawn up with the new solutions and in November 2013 was carried out . The success of participatory planning was evident because citizenship is now satisfied with the result and waits anxiously to see grow new plants, with the knowledge that everyone has personally contributed to the goal.