Gervais et al. 2020

Searching for Research: Lack of species-specific information on effects of climate change on invasives

Gervais, J. A., Kovach, R., Sepulveda, A., Al-Chokhachy, R., Joseph Giersch, J., & Muhlfeld, C. C. (2020). Climate-induced expansions of invasive species in the Pacific Northwest, North America: A synthesis of observations and projections. Biological Invasions, 22(7), 2163–2183.

Keywords:

Tools & practice, Range shifts & invasion hotspots, Range Expansion, Invasive Species, Climate Change, Terrestrial, Aquatic, Pacific Northwest

Summary:

There are many invasive species which threaten terrestrial and aquatic environments. Ideally, we would have specific scientific information about how individual species are responding to climate change and projections of how their distribution and impact might shift with climate change. However, species-specific information is often lacking. Gervais et al. (2020) sought to assess the availability of literature on observed and predicted impacts of climate change on invasive species. The authors created a list of 398 aquatic and terrestrial invasive species (Table S1) that are now present or a major threat to ecosystems in the Pacific Northwest (PNW; defined in this instance as Washington, Oregon, Idaho, western Montana, and British Columbia) then searched the peer-reviewed literature through March 2018 for evidence and predictions of the impacts of climate change on these species in and beyond the PNW. They found that very few (15) studies have been conducted on the observed effects of climate change on invasive species of concern for the PNW, and those studies focused on only five of the 398 priority species. Additionally, they found species-specific predictions based on future climate projections in the PNW for only 30 of the 398 priority species. Based on the existing research, some invasive species are predicted to expand as climate change progresses, with aquatic systems showing a stronger trend toward expansion than terrestrial systems. However, general predictions lack the nuance of studies on observed changes, which were found to be in short supply. This analysis is likely representative of our larger body of knowledge of observed and projected interactions between invasive species and climate change. Thus, managers must continue to make inferences from more general observed and projected interactions to inform species-specific management action.

Take Home Points:

• The impacts of climate change on invasive species are still understudied, particularly in the Pacific Northwest.

• Among studies on the invasive species most threatening the Pacific Northwest, species-specific observations of the effects of climate change are rare across taxa and habitat type.

• General projections of potential effects of climate change on invasive species in the PNW are more common than observed effects, especially for terrestrial plants.

• Climate change, especially increasing water temperatures and shifting hydrology, is predicted to facilitate the spread and increase the abundance of invasive fish species of concern in the PNW, although as of March 2018, those predictions were largely based on data from outside of the PNW.

Management Implications:

• Priority invasive species identified in this paper (Table S1) may be of concern to managers in the Northwest despite being under-researched.

• Climate change may increase the spread and abundance of invasive species of concern in the PNW, but more species- and PNW-specific information is needed on these impacts.

• Implement horizon scanning and communication with regions to the south to learn how management practices need to adapt to climate change and which range-shifting species to watch for.

• Consider creating and sharing a cross-jurisdictional invasive species list documenting invasive species in your area to address the lack of information available to other managers and promote communication and responsiveness.

More like this:

• NW RISCC webinar by the original article’s lead author

• Adjusting the lens of invasion biology to focus on the impacts of climate-driven range shifts (NE RISCC Research Summary of Wallingford et al., 2020)

• What’s our policy? Include climate change! (NE RISCC Research Summary of Bradley et al., 2023) 

This research summary was adapted from NE RISCC by Berlin Nelson.