Globally, more than 13,000 plant species, equivalent to the entire native flora of Europe, have been naturalized outside their native ranges. A long-standing debate exists over the impacts of exotic species on native ecosystems and how to manage them. Some researchers argue that exotic species are simply “hitchhikers” of environmental changes rather than primary drivers of ecosystem transformation. Understanding whether the loss of native biodiversity and the increase in exotic invasions are both driven by climate change is critical to addressing this debate.

A recent study, conducted by researchers from the Wuhan Botanical Garden, Chinese Academy of Sciences, and Rice University, provides new insights into this issue. Published in Nature Plants, the research uncovers the climatic niche mechanisms that shape both the vulnerability of native ecosystems and the invasiveness of exotic species in a warming world.

The researchers analyzed global distribution records of 142 plant species in the Yangtze River Valley and found substantial differences between the climatic niches of exotic and native species. Compared to native species, exotic species tend to thrive in warmer, drier, and more isothermal climates. These climatic preferences, particularly temperature, were key predictors of invasion intensity in the Yangtze River Valley. The study also predicts that, due to global warming, the intensity of exotic species invasions will increase over the next century, especially in colder regions.

The findings suggest that the loss of native biodiversity and the rise of exotic species invasions are two covarying aspects, both driven by climate change. As a result, researchers caution against oversimplifying the relationship between exotic species and native biodiversity. The decline in native biodiversity is more strongly influenced by rising temperatures and, to a lesser extent, human activities. Intriguingly, the study reveals that moderate levels of exotic species invasions may help maintain high biodiversity within ecosystems. This suggests that exotic species invasions could be part of a broader ecological response to climate change, representing a form of natural species turnover.

The authors of the study include Pengdong Chen, Changchao Shen, Zhibin Tao, Wenchao Qin, and Wei Huang from the Wuhan Botanical Garden, and Evan Siemann from Rice University.

This research was supported by the National Natural Science Foundation of China.