High-Impact Invasive Plants Expanding into Mid-Atlantic States

With climate change, hundreds of invasive plants are projected to shift their ranges, creating hotspots of future invasions across the U.S. Knowing the identities of new invasive plants headed to a state near you creates an opportunity for proactive prevention and management. Unfortunately, monitoring for and managing all range-shifting invasive plants (download a list for your state here) is untenable due to scarce management resources.

To help prioritize range-shifting species, NE CASC Codirector Bethany Bradley and her collaborator, Justin Salva, performed impact assessments on 104 plants projected to expand into one or more mid-Atlantic states (Delaware, Kentucky, Maryland, New Jersey, Ohio, Pennsylvania, Virginia, and/or West Virginia) by 2040 with climate change. Their study was recently published in Invasive Plant Science and Management. 

The authors identify 32 high-impact species, with reported negative impacts on ecological communities. Many of these species also have socio-economic impacts. Impact assessments are an important component for assessing invasion risk, as evidence of ecological and socio-economic impacts observed elsewhere increases the likelihood that a species will have similar impacts when expanding into a novel range due to climate change. The impact assessments for all 104 species are available here and a summary table is available here. This article is a companion to previous studies by Rockwell Postel et al. 2020 and Coville et al. 2021, which conducted impact assessments for range-shifting plants in New York and New England states. Together, these three studies provide a comprehensive assessment of high-impact, range-shifting invasive plants across the Northeast. 

Take Home Points
The study identifies 32 invasive plants with the maximum ecological impact score of 4, indicating negative impacts on ecological communities or multiple native species. The list of high-impact species is presented in Table 3, along with vulnerable states.

Management Implications
1) High-impact plants should be priorities for state regulation and proactive monitoring. Many of these species remain part of the ornamental plant trade (e.g., Beaury et al. 2021).

2) Impact assessments created here and in the companion papers listed above can be used to inform state weed risk assessments.