Don’t you know that you’re toxic? Allelopathic invasive plants expanding in the Northeast with climate change
Summary written and edited by Suvi Birch, Abby Guinan, Nicole Read, and Justin Salva
Summary
Early Detection and Rapid Response (EDRR) is crucial to controlling the spread of invasive species. This is especially true in the case of allelopathic invasive plants, which may enhance their competitiveness by using ‘novel weapons’, or root chemicals that limit growth and fitness of native plants. While previous work by Allen & Bradley (2016) showed an increase in risk to the Northeast for these and many other plant species, a closer focus on allelopathic plants is warranted given their unique impacts. Wang et al. (2022) created climatic suitability models for six allelopathic invasive plants (Ailanthus altissima, Casuarina equisetifolia, Centaurea stoebe ssp. micranthos, Dioscorea bulbifera, Lantana camara, and Schinus terebinthifolia) under current and extreme future emissions scenarios. Consistent with Allen & Bradley (2016), results indicate that the northeastern United States is especially vulnerable to invasion with climate change, with all six species studied having suitable ranges within this geographic region. Allelopathic species that are not yet widespread in the Northeast might be candidates for early detection and rapid response.
Take home points
Six allelopathic invasive plants are projected to shift northwards over time, losing ground in the southeastern United States while gaining territory in the northeastern and coastal northwestern United States.
Invasive species ranges are projected to expand more than they contract.
Range shifts are not equal among species, and different species are likely to relocate in response to different climatic factors.
Management implications
Based on models from Allen & Bradley (and posted in EDDMapS.org), risk from A. altissima is likely to remain stable in the mid-Atlantic and southern New England and expand into northern New England. Risk from C. stoebe is likely to remain stable across the Northeast. But, the remaining species modeled by Wang et al. (2022) are unlikely to reach the Northeast by 2050.
A. altissima is projected to have a larger shift in its range than all other species modeled, meaning that managers may want to put more resources into tracking the distribution of this species than others.
Keywords
A. altissima, Allelopathy, Invasive species, Species distribution models, Ecological niche models, Invasion impacts, Multi-species assessment