Supporting proactive management in the context of climate change: prioritizing range-shifting invasive plants based on impact

Non-native, invasive plants are projected to shift their ranges with climate change, creating hotspots of risk where a multitude of novel species may soon establish and spread. The Northeast U.S. is one such hotspot. However, because monitoring for novel species is costly, these range-shifting invasive plants need to be prioritized. Preventing negative impacts is a key goal of management, thus, comparing the potential impacts of range-shifting invasive species could inform this prioritization. Here, we adapted the environmental impacts classification for alien taxa protocol to evaluate potential impacts of 100 invasive plants that could establish either currently or by 2050 in the states of New York, Massachusetts, Connecticut, or Rhode Island. We searched Web of Science for each species and identified papers reporting ecological, economic, human health, or agricultural impacts. We scored ecological impacts from 1 ('minimal concern') to 4 ('major') and socio-ecological impacts as present or absent. We evaluated 865 impact studies and categorized 20 species as high-impact, 36 as medium-impact, and 26 as low-impact. We further refined high-impact invasive species based on whether major impacts affect ecosystems found in Northeast U.S. and identified five high-priority species: Anthriscus caucalis, Arundo donax, Avena barbata, Ludwigia grandiflora, and Rubus ulmifolius. Additional research is needed for 18 data-deficient species, which had no studies reporting impacts. Identifying and prioritizing range-shifting invasive plants provides a unique opportunity for early detection and rapid response that targets future problem species before they can establish and spread. This research illustrates the feasibility of using impacts assessments on range-shifting invasive species in order to inform proactive policy and management.