Study finds that extreme weather helps invasive species replace native species
New analysis published this week It suggests that extreme weather associated with climate change may be much harder on native species than on non-native species.
As the planet warms, extreme weather events—heatwaves, cold waves, droughts, and floods—are becoming more common and devastating. The new paper, published Monday in the journal Nature Ecology & Evolution by a team from the Chinese Academy of Sciences, suggests that these sudden, violent changes in conditions could help fundamentally reshape ecosystems.
In a statement, the team said that research on the effects of extreme weather on ecosystems, while still in its early stages, was “critically important” to our ability to understand the effects of global warming on biodiversity.
The researchers, led by Xuan Liu, an ecologist at the Academy of Sciences, analyzed 443 studies that examined the responses of 1,852 native species and 187 non-native species – from terrestrial, freshwater and marine habitats – to extreme weather.
On average, non-native species tend to show more positive responses to extreme weather, or at least, less negative responses. For example, when non-native wild species take a major hit in population numbers from a disaster, the impacts on native wild species can sometimes be far-reaching, with native populations also losing geographic distribution and struggling to recover.
According to the analysis, local terrestrial fauna tended to be highly vulnerable to heat waves, cold spells and drought, while local freshwater fauna were generally vulnerable to most events except cold spells. However, non-native terrestrial animals are generally only affected by heat waves, while non-native freshwater animals tend to suffer only from storms. Non-native marine animals were largely indifferent to most disturbances.
One reason non-native species may tolerate extreme weather more easily is that species capable of quickly establishing populations in exotic environments tend to be those with high reproductive rates, behavior and physiology, said Giovanni Vimercatti, an ecologist at the University of California, California. Adaptability and higher tolerance to disturbances. University of Fribourg in Switzerland, who was not involved in the research.
These are exactly the types of animals that are able to benefit when extreme weather wipes out a large range of native fauna. In these cases, Dr. Vimerkati said, in contrast to the common story of invasive species outright out-competing native species, they may simply prove to be “more resistant to extreme events and willing to take over after the fact.”
Other outside researchers praised the study, but expressed cautionary notes about its conclusions. It’s an important research step, but it also highlights some important research biases, since most of the studies the team examined came from North America or Western Europe, leaving ecological impacts across the world, said Laura Merson, editor-in-chief of the journal Biological Invasions. The rest of the world has not been studied.
“The results might change if more data from those missing areas could be included and this study could be made more of an evenly distributed global study in terms of non-native and native species included,” Dr Merson said. “I would suggest interpreting the results of this paper with those gaps in mind.”
Jeff Diez, an ecologist at the University of Oregon who was not involved in the study, also sounded a note of caution about drawing firm long-term conclusions. Although not all change is benign or natural, ecosystems are constantly changing, he said, and natural disasters often help keep abundant species in check and allow other species to persist.
“Were the responses measured in the basic studies long enough to capture meaningful new changes in the system, or are they just transient dynamics after a perturbation, a common phenomenon in nature?” Dr. Diez said. “We don’t know.”
According to a September report by the United Nations Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services, thousands of invasive species introduced into new ecosystems around the world cause more than $423 billion in losses to the global economy every year. . By harming nature, disrupting food systems and threatening human health.
One takeaway from the study is the importance of monitoring areas recently exposed to extreme weather events and focusing management efforts on aiding the rapid recovery of native species, Dr. Vemerkati said.
“Promoting recovery, avoiding extinction, or helping native species known to be vulnerable to extreme events could give native species enough time to evolve and adapt to new weather patterns caused by climate change,” he said.
