Multitemporal Optical Remote Sensing to Support Forest Health Condition Assessment of Mediterranean Pine Forests in Italy

Forests provide many services to society but climate change, biotic, and abiotic forest disturbances are altering ecological systems. Among these, Mediterranean pine forests, distinctive environmental elements of the Italian coastal area for both natural and historical reasons, are particularly susceptible. As evidenced by numerous wind damages, drought stress, and more recently Toumeyella parvicornis infestation in central Italy. On the other hand, there is a lack of reliable and spatialized data on the spread of infestations and stress states. In this context, their monitoring using all available sources of information is essential. In this study, we used Sentinel-2 optical data to monitor the health status and damage that occurred to Mediterranean pine forests in Italy in recent years (2018–2022). In terms of damaged area, we identified a growing trend over the years (4.5% of Italian Mediterranean pine forests in 2018, 4.0% in 2019, 6.4% in 2020, and 14.6% in 2021), with an abrupt increase in 2022 (24.2%). While our model was calibrated using reference data available for a Mediterranean pine forest study area of about 1000 ha in central Italy and 80% accuracy was reported, more exhaustive reference data should be used for providing solid estimates. On the other hand, Sentinel-2 data proved to be a relevant source of information, pointing to a very serious situation for Mediterranean pine forests.