STORY PRODUCED BY THE CAPITAL NEWS SERVICE
By Georgia Hill
In a recent study measuring the body size and growth patterns of invasive earthworms in the Huron Mountains, researchers uncovered their role in disrupting forest ecosystems.
Contrary to popular belief, the majority of earthworms in North America are invasive species, unintentionally introduced during European colonization, according to the U.S. Department of Agriculture.
These non-native worms have a significant impact on ecosystems, especially in the Great Lakes region, where they affect soil structure, nutrient cycling and biodiversity.
The study by researchers at Governors State University in Illinois examined the body mass and length of three invasive species and found distinct differences in the ecological roles and impacts each has on the forest systems in the Huron Mountains.
The largest species was identified as a major driver of soil disturbance and nutrient distribution. The smallest species was connected to fine-scale decomposition, while the mid-sized species disrupted multiple soil layers, balancing the traits of the other two species.
The study’s lead researcher, Xiaoyong Chen, said the findings will help scientists better predict how these invasive species spread and persist.
According to Chen, eradicating all non-native invasive earthworms is not a realistic goal. However, understanding where they are and how they affect the environment will further research and management efforts.
Chen is collaborating with other researchers on an earthworm ecology project to further investigate the ecological impact of these invaders.
“We always hear about earthworms being good for the soil and productivity for plants, but as it turns out, too many of them actually causes a lot of loss of nutrients like carbon and nitrogen,” said Tim Gsell, a microbiology professor at Governors State and one of Chen’s project colleagues.
According to Gsell and Governors State environmental biology professor John Yunger, invasive earthworms speed up the breakdown of organic matter, releasing carbon dioxide and other greenhouse gases while depleting the soil’s carbon and nitrogen — nutrients essential for native plant growth.
“In the UP, around the Huron Mountains, 70% of the land is occupied by invasive earthworms,” Chen said. “Only in a small isolated area, where the lake is, there aren’t any.”
While the researchers don’t report any immediate concrete solution, one removal method used for worm collection and sampling is effective in very small areas.
“We use a mustard solution to get the earthworms to come to the surface,” said Gsell. “When we soak the soil, their mucus membranes get irritated and they want to get out of there as fast as they can.”
Using a yellow mustard and water solution, the researchers soak the soil for about 20 minutes and then collect the irritated worms at the surface.
While using this method on a larger scale is unrealistic, it is effective for collecting worms from smaller areas.
For now, the researchers say they’re focused on addressing the problem by learning as much as they can about invasive worms to inform management efforts.
