Bradley, B. A., Beaury, E. M., Gallardo, B., Ibáñez, I., Jarnevich, C., Morelli, T. L., Sofaer, H. R., Sorte, C. J. B., & Vilà, M. (2024). Observed and Potential Range Shifts of Native and Nonnative Species with Climate Change. https://doi.org/10.1146/annurev-ecolsys-102722-013135
Summary:
Our climate is changing at a rate that is unprecedented in Earth’s evolutionary history which may drive species to adapt to new climate conditions and/or shift their geographic range to regions that meet their climatic needs. If species fail to shift or adapt, they may become extinct, causing a decrease in biodiversity. It is estimated that land species will need to shift approximately 3.25 km/year to stay in their suitable climate, however, not all land species shift at the same rate. It is expected that some native species will fail to shift fast enough to keep up with climate change, whereas nonnative species will succeed because they tend to be more adaptable. Bradley and colleagues reviewed studies of observed and potential range shifts for both native and nonnative species to determine the validity of these expectations. They compared species’ spread rates and found that, across all taxonomic groups included in the studies (fish, birds, insects, plants, etc.), nonnative species spread significantly faster (on average 35 km/year) than native species (on average 1.74 km/year). This trend could be caused by several traits of nonnative species that give them an advantage over native species, including fast population growth and high competitive ability. Moreover, since nonnative species have a high climatic tolerance, their range is not as limited by climate conditions as native species, which must shift towards their obligate climate to survive (i.e., towards higher latitudes and/or altitudes). Overall, it was concluded that nonnative species have an advantage over native species under climate change because nonnatives have a larger potential range with future climate conditions and have traits that allow them to establish and spread quickly.
Take-home Points:
- Native species will struggle to keep up with climate change – natives will need to shift approximately 3.25 km/year to keep up with climate change, however, their current spread rate is approximately 1.74 km/year.
- With future climate change, native species will likely have smaller potential ranges compared to nonnative species.
- Nonnative species possess traits that can give them an advantage over native species, including higher competitive ability, adaptability, and growth rates.
Management Implications:
- Nonnative species have the potential to become invasive species – a subset of nonnative species differentiated by their ability to cause extensive damage to the local ecosystem. Invasives can damage the function and services of an ecosystem, including a reduction in biodiversity.
- Many management strategies aim to reduce the movement of nonnative species, however, a complementary approach would be to facilitate the movement of native species within their current and/or future range to help them cope with the stress of climate change.