Invasive fire ant populations have been expanding across eastern North America, but new research suggests the insects may also be helping to spread invasive plant species.
Researchers found the European fire ant (Myrmica rubra) distributes the seeds of both domestic and invasive plant species, the University of Toronto reported.
"Ecologists think invasive species might help each other to spread, but there are few good examples. They talk about 'invasional meltdown,' because ecosystems could be very, very rapidly taken over by invasive species if invaders help each other out," said evolutionary biologist Megan Frederickson, one of the authors of the study, published Dec. 24 in the journal Proceedings of the Royal Society B. "Our results suggest that invasional meltdown could be happening right under our noses, here in Ontario."
To make their findings the researchers created artificial ecological communities inside 42 plastic children's swimming pools. Each pool was also filled with soil and three native and one invasive species of wildflower, as well as either invasive fire ants or native woodland ants.
"The pools with the invasive ant were overrun by the invasive plant, but pools with the native ant had lots of native plants," said study co-author and ecologist Kirsten Prior.
The team observed the invasive ants moved seeds from all four wildflower species, but the invasive plant was better at taking advantage of the dispersal. The researchers noted that since humans tend to move species around the globe, most ecosystems now contain invasive specimens, many of which have the potential to change their entire makeup.
"Our finding that multiple invasive species can accelerate invasion and cause ecosystems to become dominated by invasive species is a troubling one. Invasive species are a leading threat to natural ecosystems, and can have impacts on society. Research on how ecosystems become invaded and the consequences of invasion is important. It sets us on the right path to develop solutions to reduce the spread and impact of these harmful species," Prior said.