Monitoring wetland deterioration in a coastal protected area in central Italy. Implications for management

A wetland is a complex ecosystem with high biodiversity; in some situations, the productivity of a wetland is comparable to those of a rain forest or coral reef. The stability of wetlands is under threat due to human activities. The study area of the work described here was Palo Laziale (Province of Rome), a characteristic Mediterranean woodland and wetland area in central Italy. Agricultural activities and urbanisation have considerably reduced this habitat. The first evidence of stress on the area’s tree species was detected at the end of 1995, and this stress has gradually resulted in the complete collapse of the woodland habitat, with the deaths of more than 4000 individual trees. Physicochemical data, 87Sr/86Sr isotope data and saturation indices have been used to explore the trends in the characteristics of the aquifer over 15 years. We compared geo- chemical data from 2002 with new data collected in 2010 and 2016, which confirmed the brackish nature of the aquifer. The similarity of the 2010 and 2016 datasets and a comparison of those datasets with the 2002 dataset show that the system is resilient—it strongly buffers modifications without presenting any major alterations in function. The results demonstrate that the application of a hydrogeochemical approach emphasises the strong relationship between the level of wetland exposure and the nature of the wetland area at the monitoring scale applied.