Coastal vascular plant diversity of the Danube Delta Biosphere Reserve: rare plants, vegetation mosaics and conservation priorities

The coastal area of the Danube Delta Biosphere Reserve is a narrow but highly diverse ecological corridor at the contact between the delta, the Razim-Sinoe lagoon system and the Black Sea. This paper synthesises project-derived field data on coastal-area investigations and situates them within the published floristic, phytosociological and habitat literature on the Danube Delta and Dobrogea. The investigated sector extends from Musura Island to Corbu, while the final mapping stage covered 86.92 km of coastal area. The project dataset recorded 661 vascular plant species and 47 plant associations, distributed across beaches, embryonic dunes, fixed dunes, wet interdunes, saline depressions, coastal grasslands and shrub communities. Overall, 58 taxa had a Romanian Red List status, and 43 priority taxa were selected for discussion. Examples include Alyssum borzaeanum , Argusia sibirica , Crambe maritima , Centaurea pontica , Asparagus brachyphyllus , Convolvulus persicus , Dianthus bessarabicus , Eryngium maritimum , Limonium bellidifolium , Polygonum maritimum and Stachys maritima . The main pressures are shoreline erosion, mechanical beach cleaning, uncontrolled tourist access, vehicle traffic on sand, grazing pressure, ruderalisation and local habitat fragmentation. The conservation value of the coastal area lies in the fine-scale mosaic of habitats and microhabitats that sustains specialised coastal flora. Management should therefore combine periodic mapping, rare-species monitoring, visitor guidance, grazing regulation, avoidance of damaging mechanical interventions, and complementary in situ and ex situ conservation measures.