Estimating leaf area indexes for 10 years of simultaneous or gradual renewal of an exhausted poplar tree avenue

The management of old trees suffering from precarious health state and biomechanical issues represents a very common task for many cities in Italy. It is not possible to determine when or whether trees are going to fall, but renewal can be planned to prevent expensive management and monitoring practices in the face of poor biological, ornamental and architectural results, as well as of high levels of risk. To be precise, while the ornamental and functional services exhaust, the emotional value gets fuelled and surges over time by citizens' affection. Given this, renewal plans for tree-lined avenues are not welcomed and the lack of an effective, scientific-based communication could exacerbate the problem. The search for a shared method represents an objective starting line to assess and make far-sighted decisions. The work illustrates a method for evaluating and managing old and/or dangerous trees in urban environment so that citizens are involved too. Economic and environmental aspects are analyzed by comparing the safeguard of an old tree line both to simultaneous or gradual renewal plans. Here we focus on the extent of the environmental services brought in urban areas by the diversely managed tree lines, estimating their leaf area indexes along 10-year span. Basing on results, Public Administrations can show citizens clear and objective data making management choices and strategies easier to share and agree with. Even though necessary and fundamental, the research for a comprehensive assessment of economic, social and environmental aspects related to tree lines is poorly explored.