Brought inadvertently to the United States more than a century ago in plants imported from Japan, the earthworms are common in areas where people live, including Clarke County.
But now they're moving into wild forests like the Smokies, and scientists fear the voracious worms could disrupt the forests' ecological balance from the bottom up, consuming the leaf layer of soil that's a key part of the forest life cycle.
Just how much risk they pose isn't clear, Callaham said.
They don't look much different than other earthworms - 5 or 6 inches long, a little fatter than most.
But in maple forests in Minnesota where the worms have taken up residence, the leaf litter - decaying leaves and other plant material - has disappeared where the worms have invaded, Callaham said.
Layers of leaf litter that took 100 years to build up have disappeared in months, along with big and little creatures that lived in the litter.
Some plant species also seem to be declining in the worms' wake, and some scientists fear that could be the first evidence of bigger changes the worms are wreaking on the maple forests, Callaham said.

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OnlineAthens.com | News | Invasive Asian earthworms hooked on destruction 11/05/07