Paper No. 7
Presentation Time: 9:55 AM


BOAGA, Jacopo1, CASSIANI, Giorgio1, ROSSI, Matteo1, D'ALPAOS, Andrea1, FADDA, Giuseppe2, PUTTI, Mario3 and MARANI, Marco4, (1)Department of Geosciences, Università degli Studi di Padova, via gradenigo 6, Padova, 35131, Italy, (2)Department of Mathematics, Università degli Studi di Padova, via trieste 63, Padova, 35121, Italy, (3)Department of Mathematics, Università degli Studi di Padova, Via Trieste 63, Padova, 35121, Italy, (4)Department of Civil and Environmental Engineering, Duke University, Hudson Hall, Durham, NC 90287,

The application of time-lapse non invasive 3D micro-scale electrical resistivity tomography (ERT) has been proven to be an efficient tool to monitor the soil-plant interactions and particularly the root zone activity. This information can support water balance modeling in the upper subsoil critical zone. Here we present the results of two field experiments in very different environments: the case of a single apple tree in an orchard located in the Trentino region (Northern Italy), and the case of salt-marshes plants in the Venice Lagoon. The micro-scale ERT apparatus consists of buried electrodes installed on micro boreholes, plus mini-electrodes on the ground surface. We collected repeated ERT, TDR and tensiometer data. For the apple orchard site test we adopted controlled irrigation tests in different seasons, while in the lagoon salt-marshes we monitored the root-plant activity during tidal flooding. The results demonstrate that micro-scale ERT is a very effective tool to characterize subsoil conditions and monitor root zone activities, especially in terms of root zone suction regions. Micro-scale ERT can detect the main suction zones caused by the tree root activity, as demonstrated in the case of the apple orchard, while ERT and moisture measurements in the lagoon environment show a high resistivity suction layer located at root depth even during marsh flooding. Both observations will be important pieces of information for the comprehension of relevant eco- hydrological dynamics.