Celtic Invasive Plants database

Alien Invasive Species (AIS) are among the principal threats to humanity due to their substantial ecological, social, and economic impacts. International efforts to harmonize national AIS checklists and databases is often hindered by fragmented data across multiple platforms. The Celtic Fringe, a biogeographically coherent unit within the European Atlantic Floristic Region, includes part of the Iberian Peninsula, France and the British Isles, and is notable for its extensively documented flora. Here, we present the first unified AIS checklist and georeferenced occurrence database for the entire Celtic Fringe, with occurrences mapped to a 10 × 10 km UTM grid resolution. Occurrence data were aggregated from public datasets, while the harmonized AIS checklist of 271 taxa was developed through the integration of national and international sources. The resulting database comprises 164,974 occurrences, each enriched with taxonomic, floristic, and administrative metadata to facilitate use across multiple geographic and governance levels. This harmonized and standardised resource is designed to support AIS management at local, national, and transnational scales, while facilitating conservation planning and research on invasion dynamics.