Disentangling Management and Climate Drivers in an Anthropogenic Transitional Mediterranean Coastal Groundwater-Dependent Ecosystem

Mediterranean coastal groundwater-dependent ecosystems are among the most vulnerable environments to the combined effects of climate change and local anthropogenic pressures, yet long-term quantitative assessments disentangling these drivers remain limited. The 41-year hydro-ecological dynamics (1984–2025) of “Le Soglitelle”, a transitional man-made coastal GDE located in the Campania Plain (southern Italy), were reconstructed across three management regimes: illegal hunting via electric pumps augmentation of flooded areas (1984–2004), post-seizure transition (2005–2015), and fenced natural reserve sustained by artesian wells flow (2016–2025). A monthly multi-sensor time series of seven spectral indices was derived from cross-calibrated Landsat program Surface Reflectance products via Google Earth Engine. Spectral indices were then combined with climatic variables (precipitation, reference evapotranspiration, air temperature) and then integrated in a statistical framework including Mann–Kendall test, Pettitt test, and Principal Component Analysis. Significant breakpoints were identified for the water fraction (2007; mean decrease from 0.18 to 0.09) and the Normalized Difference Vegetation Index (2009; mean increase from 0.30 to 0.42), consistent with a hydrological regime shift following the interruption of anthropogenic pressures. The relationship between the water fraction and the Vegetation Soil Salinity Index was 2.7 times steeper in the last period than the first one, indicating that, for an equivalent flooded extent, osmotic stress on vegetation is substantially higher under the artesian flow alone, likely due to reduced dilution of saline inputs combined with the effect of ongoing climate change. PCA showed that PC1 reflected the transition from anthropogenic to more natural system conditions, whereas PC2 was associated with increasing ET0, became more prominent during the last period of management, suggesting a shift toward stronger climate-driven control. Long-term satellite monitoring provides a quantitative baseline for designing targeted management interventions aimed at sustaining ecosystem functioning under ongoing Mediterranean warming.