GNGTS 2022 - Atti del 40° Convegno Nazionale

456 GNGTS 2022 Sessione 3.2 SMALL-SCALE CHARACTERIZATION OF PLANT ROOT ARCHITECTURE AND BIOMECHANICAL DYNAMICS VIA 4D ELECTRICAL RESISTIVITY TOMOGRAPHY A. Carrera 1 , J. Boaga 1 , S. Sartori 2 , W. Bertoldi 2 1 Dipartimento di Geoscienze, Università degli Studi di Padova, Padova, Italy 2 Dipartimento di Ingegneria Civile Ambientale e Meccanica, Università degli Studi di Trento, Trento, Italy In this work we introduce an application of time-lapse 3Dmicro-electrical tomography (ERT) to track the plant-soil interaction in the radical zone. The goal of the study focused on a non- invasive analysis of the roots apparatus of two characteristic species of riparian vegetation, a poplar ( Populus nigra) and an alder ( Alnus incana) , in order to understand the different soil- vegetation interactions and the botanical influence who can exercise on the river morphology. Generally, alders have a fasciculated root system with greater biomass and concentrate in the most superficial layers compared to poplars which instead develop vertical roots in search of the water table. Indeed, the root system, besides providing nutrients to the plant and ensuring anchorage, enhancing soil cohesion, increasing the research interest in the biomechanical action for riverbanks reinforcement (Bertoldi and Gurnell, 2020; Sartori, 2021). For this reason, we tried to recreate a controlled environment where to examine the plants growth in terms of aerial and especially root biomass, taking advantages of the interesting perspectives provided by ERT (Boaga et al. , 2013; Vanella et al. , 2018; Ehosioke et al. , 2020; Mary et al. , 2020). Having to adapt quickly to environmental changes (e.g. river flooding, dry events), the riparian species show rather high growth rates, so that even in short time spans it is possible to study their development. We designed, built and installed a 3D electrical tomography system for the monitoring of the two riparian species root zone, in an experimental apparatus located at the University of Trento, Italy (Fig. 1). Fig. 1. - Instrument connections and 3D electrical tomography system configuration.