Land of plenty (of introduced plants)

Bradley, Bethany A., Annette E. Evans, Helen R. Sofaer, Montserrat Vilà, David T. Barnett, Evelyn M. Beaury, Dana M. Blumenthal et al. "A Quantitative Classification of the Geography of Non‐Native Flora in the United States." Global Ecology and Biogeography 34, no. 4 (2025): e70041.

Written by Bethany Bradley, edited by Grace Gutierrez

Summary 

Climate-smart invasive species management (Colberg et al. 2024) includes the proactive identification of potentially invasive species before they become widespread.  Past RISCC research (Allen & Bradley 2016) has led to decision support tools that identify range shifting invasive plants.  However, past risk assessments have often focused on the distributions (presence/absence) of invasive plants whereas abundance information might be a better indicator of invasiveness (Bradley et al. 2019). In this paper, Bradley et al. (2025) compile a comprehensive spatial database of invasive plant occurrence and abundance across the conterminous U.S., totalling nearly 5,000,000 observations recorded through 2022.  They identify 1,874 introduced plants reported in the conterminous U.S., of which 565 have a widespread distribution, occupy multiple habitats, and are locally abundant.  Bradley et al. (2025) also identify species that have unexpectedly high abundance relative to their range sizes or length of time that they’ve been present in the U.S. - species that are prime candidates for further risk assessment as invasive species.  This dataset has already been used by Evans et al. (2024) to model climate-driven range shifts of abundant invasive plants in the eastern U.S. and associated models are presented as ‘future abundance habitat’ in selected county-level maps in EDDMapS (e.g. kudzu). 

Take Home Points 

  • Introduced plants that have been observed at high abundance within your ecoregion are more likely to pose an invasion risk.

Management Implications

  • Many introduced species have become widespread and/or abundant within the conterminous U.S. A list of all species and their level of commonness can be found in Appendix S3

  • Practitioners can create lists of abundant introduced species within their Level III EPA ecoregion and/or associated state using Appendix S4

Related Papers

Evans et al. 2024; Bradley et al. 2019; Allen & Bradley 2016

Keywords 

Invasive plant, abundance, range expansion, risk assessment, impact

Range ExpansionNortheast RISCCInvasive plants, abundance, range expansion, Risk Assessment, Invasion impacts