Urban trees felling and failures: preliminary results from an investigation on an urban green infrastructure – locating the most sensitive species and defining the causes

Urban arboriculture increasingly requires integration between data collection and management. Today, it is fundamental to quickly shift from detailed to large-scale evaluations. Urban arboreal heritages are truly complex, heterogeneous and scattered infrastructures. At the very beginning few administrations willed to develop a full knowledge about their green assets. Currently, the need for high-proficiency tools is urgent due to communitarian policies and trends. Moreover, risk assessment practices represent a powerful tool to sustainably manage biological and structural variability of urban trees. From 2010 on, the University of Bologna has been carrying out a long-term experimentation collaborating with the Municipality of Senigallia (AN, Italy) in order to master and efficiently manage their urban green infrastructure. Preliminary results from data processing concerning felled and failed trees are here presented. Four key parameters were extrapolated from the VTA (visual tree assessment) database established between 2016 and 2021: i) health status, ii) structural flaws, iii) likelihood of failure, iv) site disturbances. First, these factors were used to highlight the most affected species. Additionally, individual and combined causes were defined. Eventually, by means of a GIS (geographic information system) map, the results were used to define the sites where sensitive species gathered, providing useful information to prioritize future data surveys, monitoring activities and interventions.