Climate change and plant invasions: restoration opportunities ahead?

Bradley, Bethany A., Michael Oppenheimer, and David S. Wilcove. "Climate change and plant invasions: restoration opportunities ahead?." Global Change Biology 15.6 (2009): 1511-1521. PDF.

Summary

Invasive plant species are likely to shift ranges into newly suitable climates in the coming decades. However, as ranges shift, new opportunities for restoration may arise as species ranges contract from areas that are no longer climatically hospitable. To assess invasion risk due to range expansion, as well as restoration opportunities due to range retraction, Bradley et al. (2009) mapped current and future distributions of 5 plants invading the Western U.S. (i.e. Bromus tectorum, Centaurea biebersteinii, Centaurea solstitialis, Tamarix spp., Euphorbia esula). For each species, many areas surrounding their current occurrences are climatically favorable and are thus at risk of invasion. Using climate projections by 2100, species other than Tamarix will likely respond to climate change by shifting into new areas. At the same time, current areas in the ranges of B. tectorum, C. biebersteinii, and E. esula will no longer be climatically suitable by 2100, thus providing eradication opportunities. As such, managing for the future and being aware of the different climate cues that species of interest respond to can help identify restoration opportunities in places where invaders are predicted to retreat.

Take home points

  • Invasive species are projected to shift their ranges in response to climate change by expanding into new areas as well as retreating out of less suitable areas.

  • Species are constrained by different climate variables, but in this study, measures of precipitation universally predicted species distributions. Including multiple sources of precipitation projections can improve confidence in distribution models.

  • Understanding current and future species distributions allows for opportunistic and active management of invasive species.

Management implications

  • Climate models that look decades into the future, and cues from seasonal patterns in precipitation can help identify opportunities for species removal and active management of range shifting invaders.

  • Although invasive species ranges are predicted to shift, native species may also expand and contract their ranges based on climate. Seeding native species from the regional species pool into invaded areas may be a ‘transformative’ restoration strategy to combat range shifts of both native and invasive species.

  • This study continues to support the need for regular, long-term monitoring and management to stop budding invasions and exploit invasive species stressed by climate.

Keywords

Shifting Seasons; Range Expansion; Model; Invasive Plant; Terrestrial Habitat; Restoration, Climate-smart Restoration