From moose to spiders, diverse and interacting assemblages of creatures rely on the understory plants, forest floor and upper soil horizons of cold-temperate hardwood forests across the Great Lakes Region. We are just beginning to understand how exotic earthworm invasion may be affecting forest animals.
The loss of the forest floor and changes in the understory plant communities following earthworm invasion is associated with changes in the diversity and composition of microscopic animals, declines in macroinvertebrates, and may negatively affect the habitat and food sources for forest birds, small mammals and amphibians & reptiles. In addition, the effects of exotic earthworms seem to interact with the effects of deer browsing which may lead to even great declines in native forest plants. It seems that a cascade of effects on many organisms may follow exotic earthworm invasion that could severely impact the diversity of forested ecosystems. However, much more research is needed to demonstrate impacts if they exist and figure out what factors are driving these changes.