Tree risk assessment in the urban environment of Thessaloniki: Introducing a new tool

Urban trees are living organisms subject to constant pressure. During the different stages of their life cycles they have to deal with numerous attacks. Their intensity and duration inevitably affects the health of the tree. Trees are sometimes affected by physiological changes or may be attacked directly by pests and diseases. Tree risk management involves the process of inspecting and assessing trees for their potential to injure people or damage property. The objective of the study is to develop a tool for tree risk assessment in the urban environment, as well as to present and analyze the results through appropriate statistical methods. The specific tool includes variables related to structural defects, deviations from typical shape, age, vitality, crown, root, position of the tree and slenderness index, and can be a useful "weapon" in the hands of geotechnical municipal officers regarding the risk assessment of trees that growing in the cities, but also for making the appropriate management decisions. However, further evaluations should be carried out on representative samples of urban trees, so that the tool could be re-validated and improved.