Bridging past and present: integrating resurvey data with landsat time series for enhanced vegetation change detection in Italian coastal dunes.

Coastal dune ecosystems, among the most threatened habitats in Italy and Europe, host highly specialized plant communities shaped by strong environmental gradients. While historical vegetation resurvey data allow for the assessment of changes between discrete time points, they provide no insight into the dynamics occurring in the intervening period. The integration of remote sensing, particularly historical Landsat time series, could represent a powerful tool to capture continuous vegetation shifts and enhance our understanding of long-term ecological trajectories. This study explores the relationship between spectral changes and coastal dune habitats, improving our understanding and developing a faster, less labor-intensive monitoring tool. Preliminary results from two time points show no significant differences in Bray-Curtis dissimilarity among habitats, but NDVI changes reveal significant productivity shifts in plots transitioning between habitat types. GLM analyses reveal a significant interaction between NDVI changes and vegetation dissimilarity across EUNIS classes with dune grasslands showing a strong negative relationship, indicating that productivity increases where communities remain stable. These findings suggest incorporating additional remote sensing variables, with future analyses planned to use the full Landsat time series to better understand long-term coastal dune vegetation changes.