Mediterranean coastal dune restoration: monitoring the effects of soil bioengineering techniques

Coastal dunes are vulnerable ecosystems threatened by erosion phenomena caused by anthropogenic and natural dynamics. To counteract erosion processes, a possible low-impact environmental solution is represented by soil bioengineering works, in which the use of native plants is combined with the use of inert materials. A pilot intervention has been implemented to mitigate erosion processes in a coastal area within the municipality of Massafra, Patemisco (TA). Various technical solutions have been adopted, including the use of a biomesh, the construction of a wattle to protect the base of the dune, and the planting of native shrubby species and weeds from the area. Near the intervention area, a weather station has been installed, to simultaneously monitor the climate trend in the area. Following the intervention, vegetation monitoring were carried out both in field and through remote sensing. The aim of the study is to investigate the evolution of vegetation trends and the consistency of several intervention approaches through monitoring activities, which initiated shortly after the implementation of the works. The preliminary results have shown that the wattle has protected the base of the dune and has allowed sand accumulation near the structure. The biomesh, along with the other adopted technical solutions, has positively influenced the survival rate of the plants, especially of a couple of shrubby species, which have shown survival rates ranging from 53% to 80%. The herbaceous species have displayed high survival rates, regardless of the technical solution adopted (>90%). The NDVI, used to monitor the plants cover, has increased during the months of intervention. Subsequently, a slight reduction in the index was observed, due to the plants' adaptation to the new soil conditions.