Monitoring disturbed habitat using UAVS: the case of habitat affected by the presence of Xylella fastidiosa subsp. multiplex in Monte Argentario (Grosseto, central Italy)

The study focuses on monitoring habitats impacted by disturbances, with the goal of assessing the conservation of plant communities. The spread of Xylella fastidiosa subsp. multiplex phylotype ST87 (XfmST87) poses a significant threat to Mediterranean ecosystems, with potential impact on plant biodiversity and habitat conservation. This study examines the impact of the pathogen on vegetation in the 5330, 6220*, and 9340 habitats of Monte Argentario through a diachronic monitoring process from 2021 to 2025. The research combines ground surveys and drone-based remote sensing, using UAV technology and photogrammetry to characterize coverage and phytosociological variations in plant communities. The study area was selected for its representativeness and investigated through the analysis of the vegetation identified within permanent plots inserted in the three habitats. Particular attention has been given to the species Spartium junceum L., Cytisus laniger DC., and Rhamnus alaternus L., identified as "targets" due to their spread and susceptibility to XfmST87 infections. The analysis aims to assess the ability of the plant communities to respond to disturbance factors in terms of resistance and resilience. At this stage of the research, no evident impacts have been observed on the plant communities or on the spread of the three target species. The study provides useful information’s on the possible levels of resistance and resilience of these habitats and emphasizes the effectiveness of UAV technologies for environmental monitoring in areas which are difficult to access due to steep slopes, dense vegetation and uneven terrain.