Six centuries (15th–21st) of environmental change and land-use in Mar Piccolo, Southern Italy: palynological and historical evidence

Coastal transitional ecosystems across the Mediterranean Region are increasingly threatened by the combined impacts of climate change, land-use intensification, and legacy pollution. This study presents a high-resolution, interdisciplinary reconstruction of ecosystem changes over the last ~ 600 years (ca. 1400–2022 CE) from the Mar Piccolo basin (Taranto, Southern Italy), a representative semi-enclosed coastal system under long-term cumulative stress. Through multiproxy analyses of a dated sediment core (S05B) and modern environmental archives (surface sediments and moss samples), we integrate palynological indicators (pollen plus dinocysts and other non-pollen palynomorphs) with historical and ecological records. This unique integration of proxy and documentary/archival evidence enables an exceptional comparison of natural and anthropogenic dynamics across centuries. Results reveal a progressive and marked decline in ecosystem integrity, reflected in the sharp reduction of native thermophilous forest taxa (e.g., deciduous Quercus), an increase in anthropogenic (e.g., Olea) and ruderal (e.g., Plantago lanceolata-type) taxa, along with a rise in eutrophication-related dinocysts (e.g., Lingulodinium machaerophorum) since the early fifteenth century. The Little Ice Age intensified environmental and socio-economic stress, accelerating transformations in both terrestrial and marine domains. In recent decades, warming trends, altered hydrology, and landscape fragility have further reduced system resilience, as evidenced by persistent records of parasite eggs (e.g., Ascaris) indicating long-term wastewater contamination and potential health risks. This case study demonstrates how coupled human–environment systems in semi-enclosed Mediterranean basins respond to prolonged and interacting pressures. The multiproxy approach offers a transferable framework for detecting ecological tipping points and supporting evidence-based restoration and adaptive management strategies.