ENG: Indirect and non-destructive multidisciplinary tree root distribution analysis ITA: Approccio multidisciplinare per l’analisi della distribuzione radicale delle piante con metodologie indirette e non distruttive

The aim of this thesis is to develop indirect and non-invasive methodologies for the tree root distribution analysis, with a multidisciplinary approach. Slope stability study needs the quantification of the root distribution. Current techniques carries out direct measurements on the root system by digging, uprooting and other invasive, non-replicable and onerous techniques. The methodologies, applied in this study, come from geophysics (I) and biomechanics (II). With the first approach, the geoelectric method is applied, in order to quantify the soil resistivity, in relation to water content. By this methodology a electrical resistivity tomography of a soil profile is obtained, which has been elaborated to evaluate the variation of the resistivity in relation to the presence of plant roots. With the second approach, controlled pulling tests on trees of different sizes and different species are performed, in order to build a new mathematical model for assessing the safety factor of a plant, subject to an external force such as wind. Thanks to the model, it is possible to evaluate the root system effect, in terms of stabilizing moment, depending on the soil characteristics. The results obtained show that both methodologies are able to provide important information about the root distribution of plants. In addition, the techniques and models developed with this study can provide innovative tools in other areas of research, for example for assessing plant stability and developing innovative bioengineering works.