Modern palynological assemblages from nearby Mediterranean coastal lagoons: implications for palaeoecological interpretation

Site-specific modern pollen assemblages are essential for interpreting fossil records, yet their links to local conditions and surrounding landscapes are often poorly understood. This study presents a modern palynological dataset from subsurface sediments of the shallow Burano and Orbetello lagoons in Tuscany, Italy. This dataset is part of a broader project which includes fossil sediment cores from the same basins. Spatially distributed samples were analyzed for grain-size, pollen, non-pollen palynomorphs, and sieved charcoal, with water physico-chemical parameters measured at each site. Terrestrial pollen assemblages mainly reflect regional wind-pollinated vegetation but show strong distortions, with forests overrepresented and open areas—especially cereal crops and vineyards—underrepresented. Modern calibration of Pinus and Olea pollen registrations is particularly informative given their key role in local human-driven landscape change. Sieved charcoal (> 125 μm), a proxy for local fire, is unevenly distributed and correlated with Glomus chlamydospores, indicating additional transport via runoff. At Burano, intra-basin pollen deposition is largely controlled by morphometric and sedimentological factors which explain 58.1% of the observed variance. In contrast, at the Orbetello lagoon, these factors explain only 26.7% of the variance, reflecting more complex hydrodynamic controls on sediment and pollen redistribution. Among aquatic groups, brackish macrophytes dominate across broad salinity ranges, primarily controlled by water depth, salinity, and associated with dissolved oxygen. Microalgal groups respond to temperature and nutrient availability, with high concentrations of harmful algae ( Alexandrium spp.) indicating ecological stress. Overall, this modern spatial dataset provides a site-specific framework for interpreting fossil records and reconstructing past environmental changes. It also demonstrates the potential of combining palaeoecological research with modern data to translate scientific knowledge into practical applications for biodiversity conservation.