COS 36-2 - Predicting future hotspots of invasive plant abundance in the United States

Monday, August 15, 2022

3:45 PM – 4:00 PM EDT

Location: 516A

Presenting Author(s)

AE

Annette Evans

Postdoctoral Research Associate
University of Massachusetts Amherst, United States

Coauthor(s)

CJ

Catherine Jarnevich

U.S. Geological Survey, United States
EB

Evelyn M. Beaury

Postdoctoral Research Associate
Princeton University, United States
NT

Nathan Teich

Colorado State University, United States
PE

Peder Engelstad

Colorado State University, United States
BH

Brandon Hays

U.S. Geological Survey, United States
JL

Jillian LaRoe

U.S. Geological Survey, United States
BB

Bethany Bradley

Professor
University of Massachusetts Amherst, United States

Background/Question/Methods

Natural resource managers consistently name range-shifting invasive species as a top priority to mitigate the ecological impacts of climate change. With hundreds of new invasive plants projected to shift by mid-century, proactive management of high-impact invasives could stop future invasions before they start. Yet, most invasive plants only become abundant enough to cause negative impacts in a fraction of their non-native range. Identifying regions where invasive plants can not only establish but also reach high abundance with climate change is critical for identifying and managing invasive plants with the greatest potential impacts in a given area. Here, we used species distribution modeling to identify the regions where invasive plants could become abundant under current and future climate conditions. We compiled invasive plant abundance records from 14 data sources across the lower 48 U.S. states. For each species, we created abundance distribution maps based on current, +2C, and +4C climate projections by ensembling the outputs from five model algorithms using the Software for Assisted Habitat Modeling (SAHM). Finally, we combined the abundance distribution maps for all species to identify hotspots of future invasion risk.

Results/Conclusions

Out of the 1878 non-native species included in our dataset, we identified 145 invasive plants that had at least 100 records of abundance above a 5% cover threshold to model current and future abundance hotspots. By comparing the extent of suitable habitat under current and future climate projections, we identified the Northeast and Pacific Northwest as regions that are likely to become hotspots of invasive plant abundance with climate change. We compiled the results of these abundance distribution maps to create lists of invasive plants that could become abundant in each of the lower 48 states. We also examined how future hotspot predictions differed by plant growth form. Future hotspots of invasive shrubs, vines, and forbs are primarily located in the Northeastern region, while future hotspots of invasive trees and graminoids are located in the southeast and southwest regions of the U.S. Modeling future risk of invasive plant abundance can help land managers develop climate-smart management protocols by prioritizing monitoring and early detection rapid response to invasive plants most likely to cause future ecological impacts.