Preliminary field data of selected deep-rooted vegetation effects on the slope-vegetation-atmosphere interaction: results from an in-situ test

The soil-vegetation-atmosphere interaction is becoming more and more the subject of intense scientific research, motivated by the wish of using smart vegetation implants as sustainable mitigation measure for erosive phenomena and slope instability processes. 
The use of novel naturalistic interventions making use of vegetation has been already proven to be successful in the reduction of erosion along sloping grounds, or in increasing the stability of the shallow covers of slopes, whereas the success of vegetation as slope stabilization measure still needs to be scientifically proven for slopes location of deep landslides, whose current activity is climate-induced, as frequent in the south-eastern Apennines. Recently, though, peculiar natural perennial grass species, which develop deep root systems, have been found to grow in the semi-arid climate characterizing the south-eastern Apennines and to determine a strong transpirative flow. Therefore, their peculiar leaf architecture, their crop density, combined with their perennial status and transpiration capacity, make such grass species suitable for the reduction of the net infiltration rates, equal to the difference between the rainfall rate and the sum of the runoff plus the evapotranspiration rate. As such, the grass species here of reference have been selected as vegetation measure intended to determine a reduction of the piezometric levels in the slope down to large depths, in order to increase the stability of deep landslide bodies. 
At this stage, only preliminary field data representing the interaction of clayey soils with the above cited vegetation species are available. These have been logged within a full scale in-situ test site, where the deep-rooted crop spices have been seeded and farmed. The test site (approximatively 2000 m²) has been set up in the toe area of the climate-induced Pisciolo landslide, in the eastern sector of the Southern Apennines.
The impact of the vegetation on the hydro-mechanical state of the soil is examined in terms of the spatial and temporal variation of the soil water content, suction an pore water pressure from ground level down to depth, both within the vegetated test site and outside it, where only spare wild vegetation occur, in order to assess the effects of the implant of the selected vegetation. The soil water contents, suctions and pore water pressures have been also analyzed taking into account of the climatic actions, monitored by means of a meteorological station.