Why are non-native plants successful? Consistently fast economic traits and novel origin jointly explain abundance across US ecoregions

Authors: Blumenthal, Dana; DIEZ, JEFFREY - University Of Oregon; PEARSE, IAN - Us Geological Survey; SOFAER, HELEN - Us Geological Survey; SORTE, CASCADE - University Of California Irvine; BARNETT, DAVID - National Ecological Observatory Network (NEON); BEAURY, EVELYN - Princeton University; BRADLEY, BETHANY - University Of Massachusetts, Amherst; CORBIN, JEFFREY - Union College; DUKES, JEFFREY - Carnegie Institute - Stanford; EARLY, REGAN - University Of Exeter; IBÁÑEZ, INÉS - University Of Michigan; LAUGHLIN, DANIEL - University Of Wyoming; PETRI, LAÍS - Michigan State University; VILÀ, MONTSERRAT - University Of Sevilla

Submitted to: New Phytologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/29/2025
Publication Date: 6/24/2025
Citation: Blumenthal, D.M., Diez, J., Pearse, I., Sofaer, H.R., Sorte, C.J., Barnett, D.T., Beaury, E.M., Bradley, B., Corbin, J.C., Dukes, J.S., Early, R., Ibáñez, I., Laughlin, D.C., Petri, L., Vilà, M. 2025. Why are non-native plants successful? Consistently fast economic traits and novel origin jointly explain abundance across US ecoregions. New Phytologist. https://doi.org/10.1111/nph.70307.
DOI: https://doi.org/10.1111/nph.70307

Interpretive Summary: To limit impacts of invasive plants, it is essential to understand why they become so abundant. We quantified the relative importance of novel origin (being introduced from another continent) and fast-growth traits to non-native species success using data from 69,480 vegetation surveys across the United States. Non-native species had faster leaf economic traits than native species in most plant communities (77%, 86% and 82% of plots for leaf nitrogen concentration, specific leaf area, and leaf dry matter content), and these differences often contributed to their high abundance. However, non-native species were also more abundant than functionally similar native species in some ecoregions, and in plots where co-occurring species had fast traits (e.g., due to disturbances or favorable climates). These results suggest high abundance of non-native species is due primarily to their distinct traits and may also depend on ecological novelty in some ecosystems. These results demonstrate that limiting limiting disturbance and plant resource availability will be essential for long-term management of plant invasions.

Technical Abstract: Understanding why non-native plant species become abundant is essential to limiting their impacts. It remains unclear, however, whether high non-native species abundance comes from ecological novelty, leading to advantages over native species, or from ‘fast’ resource strategies, leading to advantages in disturbed environments. We quantified the relative importance of these processes in 69,480 plots across the United States encompassing 11,280 species. Non-native species had faster leaf economic traits than native species in most plant communities (77%, 86% and 82% of plots for leaf nitrogen concentration, specific leaf area, and leaf dry matter content), and these differences often contributed to high abundance of non-native species. After statistically accounting for traits, however, species origin explained additional variation in abundance, suggesting a role for ecological novelty. Compared to functionally similar native species, non-native species were more abundant in the plains and deserts but less abundant in forested ecoregions. Non-native species were also more abundant than similar natives in plots where co-occurring species had fast traits (e.g., due to disturbances or favorable climates). These results suggest that distinct patterns of abundance in non-native species are due primarily to their distinct traits, but that ecological novelty may also increase their abundance in some ecosystems.