Horizon scanning of potential new alien vascular plant species and their climatic niche space across the Arctic

The terrestrial Arctic faces increasing vulnerability to alien plant invasions due to climate change and intensifying human activities. Using a data-driven horizon scanning approach that leverages the Global Naturalized Alien Flora (GloNAF) database, species occurrence data from the Global Biodiversity Information Facility (GBIF), and climate data from WorldClim, we identified 2,554 potential new alien vascular plant species with climatic niches overlapping Arctic floristic provinces. Six major potential hotspots for introductions were detected, with western Alaska, southwestern and southeastern Greenland, northern Iceland, Fennoscandia, and Kanin–Pechora showing the highest numbers of potential alien species. Potential source regions for these species extended globally across diverse climate zones, with substantial contributions from proximate temperate regions in Europe and North America. Taxonomic analysis revealed that most Arctic floristic provinces exhibited compositions similar to global patterns, with only Franz Joseph Land showing significant deviation after multiple comparison corrections, although island provinces generally demonstrated greater compositional distinctiveness than mainland provinces. Zero-inflated beta regression analysis confirmed our hypothesis that species with higher absolute latitude distributions demonstrate greater potential for climatic overlap with Arctic floristic provinces. Our findings emphasize the need to develop effective biosecurity measures in high-risk regions and to proactively manage emerging invasion risks across the rapidly changing terrestrial Arctic ecosystems. This will provide a foundation for supporting community-based monitoring networks essential for early detection and rapid response initiatives.