Alien plant species in the Arctic could gain a foothold as temperatures rise and human activity expands, according to a new horizon scan by researchers at the NTNU University Museum and the University of Liverpool. Using global occurrence databases and climate modelling, the team identified 2,554 non-native vascular plants with climatic conditions that already overlap with parts of the Arctic, with northern Norway and the Svalbard archipelago among the areas flagged as especially exposed.
A data-driven map of potential arrivals
The researchers carried out what they call a horizon scan: a systematic, forward-looking assessment that tries to anticipate which species could become future problems, before they are widely established. They reviewed around 14,000 known alien plant species and matched them with Arctic climate conditions, drawing on more than 51 million occurrence records from GBIF (the Global Biodiversity Information Facility) and other datasets.
The result is a set of maps highlighting where many species could tolerate today’s climate if they arrive. The study does not claim that thousands of plants will inevitably colonise the Arctic, but it does suggest that the pool of species that could survive is far larger than many management plans were designed for.
Why warming and human activity open routes into the Arctic
A warmer Arctic widens the range of plants that can complete their life cycles in short summers. At the same time, more traffic means more opportunities for seeds and soil to travel—on boots and clothing, in cargo, through construction materials, or via tourism and research activity.
In the High North, the problem is not only temperature. Disturbance and nutrient inputs can create pockets of unusually fertile ground—exactly the kind of micro-habitat that helps newcomers outcompete slow-growing Arctic plants. This is why ports, settlements, and former industrial sites can act as stepping stones for biological invasions.
Where alien plant species in the Arctic could establish first
The hotspot map produced in the study shows elevated risk across several Arctic edges, including northern Norway, parts of Alaska, south-west Greenland, northern Iceland, and north-west Russia. These are areas where the climate already overlaps with the niche of many non-native plants, and where human presence provides multiple introduction pathways.
For Norway, the warning is particularly direct: the country combines a long Arctic-facing coastline with growing activity linked to infrastructure, shipping, and travel. The researchers stress that even if a species can tolerate the climate, it still needs a route in—and those routes are multiplying.
Svalbard’s nutrient hotspots and the first new finds
Svalbard is often perceived as too remote and harsh for most newcomers. Yet the horizon scan suggests that 86 alien plant species could find a suitable climatic niche even in this high-Arctic setting.
Field observations help explain why. In places such as Barentsburg and Longyearbyen, nutrient-rich slopes near old farm buildings or former dumping sites can support surprisingly lush growth. Researchers have reported new arrivals turning up repeatedly in these micro-environments. Recent examples include sticky ragwort (Senecio viscosus), considered high-risk on mainland Norway and recorded on Svalbard for the first time in 2024, and common meadow rue (Thalictrum flavum), also identified on the archipelago in 2024.
What early warning tools mean for Nordic and EU policy
Invasive alien species are widely recognised as a major driver of biodiversity loss, and global agreements increasingly focus on prevention. The Kunming–Montreal Global Biodiversity Framework includes a target to reduce the rate of introduction and establishment of invasive alien species by at least half by 2030, with particular attention to vulnerable sites such as islands.
In Norway, risk assessments are coordinated through expert processes linked to the Norwegian Biodiversity Information Centre (Artsdatabanken). The value of a horizon scan is practical: it helps authorities prioritise which species deserve formal assessment, monitoring, and—when feasible—rapid removal.
Across Europe, prevention and pathway management are also central to EU rules on invasive alien species. Even though Svalbard is outside the EU, the Arctic pressures described by the researchers are transboundary: seeds and organisms move with people, goods, and infrastructure across the Nordic region and beyond.
A narrow window for prevention
The study’s main message is about timing. Once an alien plant becomes widespread in Arctic ecosystems, eradication becomes costly and often unrealistic. Preventing introductions—through biosecurity routines, cleaning protocols for equipment and clothing, and monitoring around high-traffic areas—can be far more effective.
As the Arctic continues to warm and activity increases, the authors argue that the question is no longer whether new species will arrive, but how quickly authorities can detect them and prevent the small, nutrient-rich footholds from turning into lasting ecological change.
