Plus their is no discussion of controlling of the earthworms. Such as voles,moles,skunks,birds,toads,etc. This study started in 2000 and is ongoing. This article was to make people aware the ramifications of introducing a non-native species. Regardless it being plant,insect,bird or animals.
One article I read said that natural predators are not capable of controlling the spread of the invasive earth worms. If they could they wouldn't have become a big problem in Minn.
[QUOTE]When earthworms invade a forested area, they consume the forest floor, and herbaceous plant diversity and tree seedling density decrease dramatically. Heavily impacted stands have been observed with only one species of native herb and virtually no tree seedlings remaining.
"Ninety-nine percent of the populations of native plant species normally found in hardwood forests, including large-flowered trilliums, yellow violets, and Solomon's seal, are destroyed in affected areas," said Frelich, a research associate in forest resources. "In many areas, the remaining bare soil is simply eroding away."
Although it is not possible to reverse the continued migration of the earthworms, there are things people can do to help the forests recover.[QUOTE]