Urban trees are a source of ecosystem services and contribute to increase quality of life for many com-munities and their residents. At the same time they could also determine disservices, such as damages tostructures and risk to human safety due to critical combination of tree defects and environmental factors.Although knowledge about tree structure and host–pathogen interactions has grown, the assessment ofrisk has not been fully explored yet. In particular, the multidimensionality of tree risk assessment aswell as the concern about weighting techniques in the construction of indices to measure it need to beaddressed.The aim of this paper is to develop a composite tree risk index (R) useful for the management of amenitytrees, with a two-fold perspective. First, the multidimensionality issue is explored by considering threedimensions of the tree risk: the Hazard, that represents the likelihood of failure of the tree, the Contactfactor, i.e. the nature and the value of the target, and the Damage factor, i.e. the potential for injury ordamage. Each dimension is assessed as a function of a set of observed variables related to dendrometricattributes, health status, proximity to buildings and artifacts, tree esthetic value, derived both from fielddata and spatial analysis performed under GIS environment. Second, in the aggregation of variables intospecific-dimension indicators we verify if and to what extent various positive and normative weightingtechniques influence the construction of composite index. The R index, obtained as the product of thespecific-dimension indicators, was computed for 130 trees located within the formal garden and the parkof Villa Lante in Bagnaia, Viterbo (Central Italy), a well-known Renaissance monumental complex, wherethe needs of cultural heritage conservation and human safety have to be balanced with recreational uses.Sensitivity analyses were carried out in order to test the robustness of R with respect to the considered techniques.
|Autori:||Tomao, A.;Secondi, L.;Corona, P.;Giuliarelli, D.;Quatrini, V.;Agrimi, M.|
|Data di pubblicazione:||2015|
|Titolo:||Can composite indices explain multidimensionality of tree risk assessment? A case study in an historical monumental park|
|Rivista:||URBAN FORESTRY & URBAN GREENING|
|Appare nelle tipologie:||1.1 Articolo in rivista|