5 Minutes
Plants are spreading across the globe faster than at any time in human history, driven largely by human-mediated movement and altered landscapes. Recent research led by the University of Konstanz analyzed nearly 4,000 native European vascular plant species to identify which biological traits predict success both at home and abroad. The study finds that the same characteristics that allow some species to expand rapidly within Europe also explain why those species become naturalized — and sometimes invasive — on other continents.
Cytisus scoparius, native to Europe, has now established itself in many parts of the world. Credit: Mark van Kleunen
Scientific background and study design
Naturalization — the process by which an introduced species establishes self-sustaining populations outside its native range — is a global environmental change. Among vascular plants, more than 16,000 species are now considered permanently established outside their native habitats, with the lion's share of these introductions occurring since the 1950s in heavily human-modified regions.
The Konstanz-led team compared distribution trends of 3,920 species across ten European countries with global naturalization records. Europe is among the largest exporters of naturalized plants worldwide, and this continental focus allowed researchers to link within-region success to cross-border spread. Rather than testing a single hypothesis, the team examined whether species that are expanding their range in native regions are also the ones most likely to become established elsewhere.
Key findings: traits that predict spread
The study identified a clear signal: species that are increasing in abundance and range in Europe are disproportionately the same species that have become naturalized globally. By contrast, species that are declining in their native European ranges seldom succeed in foreign habitats.
Researchers found consistent trait syndromes associated with both native expansion and successful naturalization. These species tend to be:
- Tall (structurally competitive for light),
- Ecological generalists (able to tolerate a wide range of environmental conditions),
- Preferring nutrient-rich habitats (often associated with human-disturbed sites),
- Highly competitive in plant communities.
Rashmi Paudel, first author of the study, summarized the pattern: the plants that thrive at home are often the same ones that thrive abroad, driven by the same biological mechanisms. Mark van Kleunen, who led the collaboration, noted that species declining in their native ranges rarely become global winners, implying that local success predicts global potential.
Ecological implications and management
These findings have two important ecological implications. First, the traits that make a species common in its native range — high competitive ability, broad environmental tolerance, and preference for disturbed, nutrient-rich sites — may act as preadaptations that enable successful establishment after introduction. Second, human activities that preferentially move common, widespread species (through trade, horticulture, and transport) amplify the risk that these species will naturalize elsewhere.
For managers and policymakers, monitoring which species are expanding within their native regions can provide an early-warning signal. If a plant is increasing rapidly at home, it may warrant stricter controls on trade and transport to reduce the chance of introduction to new regions. Conservation strategies should therefore combine trait-based risk assessments with surveillance of native-range dynamics.
Expert Insight
Dr. Elena Morales, an invasion ecologist (fictional), comments: "This study nicely links within-range dynamics to invasion risk. It highlights that invasion biology cannot ignore native-range trajectories — the species that capitalize on human-altered environments at home are often preadapted to do the same abroad. Effective biosecurity must integrate ecological monitoring with trade regulation."
Related research and future prospects
Follow-up work could test whether the same trait syndromes apply to other continents and taxonomic groups, or whether different human land-use patterns alter which traits are favored. Advances in global species distribution modeling, trait databases, and pathway analysis of plant introductions will improve predictive tools for identifying high-risk species before they become established.
Conclusion
The Konstanz-led study shows that many of the plants that are ‘‘taking over’’ at home are also those that succeed as naturalized aliens abroad. Tall, nutrient-loving generalists dominate both native expansion and global naturalization, suggesting common biological mechanisms and strong human mediation. Tracking native-range trends and incorporating trait-based risk assessments can strengthen early detection and prevention of future plant invasions, protecting ecosystems and biodiversity worldwide.
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