Earthworm Invaders

By CHRIS SYMONS
Capital News Service
LANSING – Compost box heroes, or the root of all ecological evil? Earthworms in Great Lakes forests are not what they seem. Trilliums are smaller, algal blooms are more common and hummingbird populations are decreasing. All of these are worsened by non-native earthworms in Great Lakes soil, according to a new study that identified four key minerals that earthworms remove from soil and that native plants need to grow. The loss of calcium, magnesium, potassium and phosphate reduces the richness of the soil and limits what plants the soil can support, said the study by scientists at the U.S. Forest Service, University of Minnesota, Stroud Research Center and U.S. Geological Survey and published in the journal “Ecosystems.”
The impacts of the earthworms are visible in a variety of places, said Tara Bal, a research assistant professor at Michigan Technological University’s School of Forest Resources and Environmental Science.