Invasive species can reap benefits from extreme weather

Extreme weather may wreak havoc around the world, but some non-native plants and animals can benefit from disasters, raising risks for already threatened native species, according to a new study published Monday.

Invasive species, often transported by human activity, are thought to play a major role in global extinction rates and catastrophic declines in biodiversity that threaten the well-being of people and the planet.

Heat waves, droughts, floods and other extreme events accelerated by global warming may give often destructive invasive species an unwanted advantage, researchers found.

Harmful invaders experienced positive impacts from extreme weather in about a quarter of cases, nearly twice as much as native populations, according to the study published in the journal Nature Ecology & Evolution.

Native species were also more likely to suffer negative consequences from weather disasters.

“Extreme climate events may facilitate the establishment or spread of non-native species and these two processes may combine to pose significant threats to biodiversity under ongoing global change,” said lead author Xuan Liu of the Chinese Academy of Sciences. Beijing.

The study found that invasive species were only vulnerable to heat waves and storms. But native fauna on land and in freshwater are negatively affected across several factors, including survival rates, reproduction and body size, by all but cold spells of extreme weather in freshwater.

The researchers looked at hundreds of previously published studies on the responses of 187 non-native animal species and 1,852 native animal species to extreme weather patterns in different environments.

They found that differences in responses to unusual weather across species could be due to native species dying out during extreme weather conditions, leaving a gap for invasive species to exploit.

For example, severe droughts increase the salt content of the water, killing off native invertebrates and fish, while providing the opportunity for more salt-tolerant species to move in.

Invasive species are also known for rapid growth rates and a greater competitive advantage that may allow them to recolonize faster.

Only in the case of marine animals have both indigenous and non-indigenous populations been relatively immune to extreme weather, although native molluscs and corals are vulnerable to heat waves.

Invasive species are not a new problem, but they are a growing problem.

The intergovernmental Scientific Advisory Committee of the United Nations Convention on Biological Diversity revealed in a landmark report in September that invasive species are increasing at an “unprecedented rate” globally, costing more than $400 billion annually in damage and lost income.

She added that invasive species spread primarily as wanderers in global trade and have played a significant role in 60 percent of all documented plant or animal extinctions.

(If you have specific expertise and would like to contribute, or if you have a topic of interest that you would like to share with us, please email us at Nature@cgtn.com.)