Comparative evaluation of inspection techniques for decay detection in urban trees

Green areas in cities are acquiring an increasingly important role in urban architecture. However, the central problem associated with urban trees is the need to know and evaluate the health of plants in order to ensure the safety and security of citizens. One important process consists of the technical assessment of health conditions of standing trees, in order to prevent falling due to strength failure or internal damage caused by internal decay. In recent years, investigations with non-destructive techniques on urban trees have shown great success in detecting internal decay, which, depending on the severity of the case, makes the stability of the entire plant or parts of it precarious. This study reports the results of applying an inspection protocol that combines, single-path stress wave timer and resistance micro-drilling, to detect internal defects on sizable Melia trees (Melia azedarach L.) located in the city ​​of Reggio Calabria, Southern Italy. From the trees subsequently felled, a disc was obtained in each test position, which is visually examined. It was found through the data obtained that the non-destructive analyzes carried out with single-path stress waves and resistance measuring drill, correctly identified a defect in the wood even if with different specificity depending on the method used.