BOTANICAL CONTRIBUTIONS TO IMPROVE THE ASSESSMENT OF SOIL BIOENGINEERING WORKS

The research described in this PhD dissertation was conducted during the period 2014-2016 at the Centre of Applied Studies for the Sustainable Management and Protection of Mountain Areas (Ge.S.Di.Mont. - University of Milan) in Edolo (BS) with the objective of devising botanical methods/tools that could be useful for improving the evaluation of soil bioengineering works in mountain areas. This research has led to the formulation of two floristic-vegetational indices: the Ecological Index of Maturity (EIM) and the Index of Ecological Success (IES). These indices were applied to three study areas located in mountainous areas of Lombardy (Northern Italy) affected by landslides which were followed by soil stabilization works using soil bioengineering techniques. On the basis of the results obtained, the indices have proven practical and functional for the evaluation of soil bioengineering works for slope stabilization as they consider their effectiveness in stabilizing soil as well as their efficiency in minimizing human impact on the ecosystem and landscape. This thesis also reports research to assess the effectiveness of the chromatographic fingerprinting of the extracts of fine roots for the identification of plant species. The results obtained showed that the analysis of chromatographic fingerprints is an effective method for the identification of some of the species studied whereas it is less useful for the identification of other species. This suggested ideas for further research on this topic and application both in soil bioengineering (e.g.: the evaluation of the success of the fine roots of plants used for soil stabilization) and in other sectors dealing with the study of the rhizosphere and plant (root)-soil interaction.