Exploring the Potential of Portable Spectroscopic Techniques for the Biochemical Characterization of Roots in Shallow Landslides

In the present work, Raman, Fourier Transform Infrared (FTIR) and elemental Laser Induced Breakdown Spectroscopy (LIBS) spectroscopic techniques were used for the assessment ofthe influence of plant root composition towards shallow landslide occurrence. For this purpose, analyses were directly carried out on root samples collected from chestnut forests of the Garfagnana basin(northern Apennines, Italy) in different areas devoid and affected by shallow landslides due to frequent heavy rain events. Results have highlighted a correlation between the biochemical constituentsof wooden roots and the sampling areas. In particular, different content of lignin/cellulose, as well asminerals nutrients, have been detected in roots collected where shallow landslides occurred, withrespect to more stable areas. The results achieved are in line with the scientific literature which hasdemonstrated the link between the chemical composition of roots with their mechanical propertiesand, in particular, tensile strength and cohesion. Finally, portable spectroscopic instrumentationswere employed without the need for either any sample preparation for Raman and LIBS spectroscopyor minimal preparation for FTIR spectroscopy. This novel and fast approach has allowed achievinginformation on the content of the major constituents of the root cell, such as cellulose and lignin, aswell as their mineral nutrients. This approach could be reasonably included among the vegetationprotection actions towards instability, as well as for the evaluation of shallow landslide susceptibility,combining geological, vegetational and biochemical parameters with sustainability.