Worms can be too much of a good thing

Capital News Service
LANSING — Wriggly soil-dwellers may not have the bad rep of some of their invasive counterparts but they do have the power to change entire ecosystems.
“It’s ingrained into our education that earthworms are good,” said Chuck Elzinga, assistant professor of biology at Michigan State University. “But the more earthworms you have, the worse it is.”
Now a recent study has found that an abundance of earthworms decreases the small plant matter scattered on the forest floor. By eating away at what scientists call “fine root biomass,” worms can significantly change the forest. The good news is that when worms decompose matter and convert it into carbon dioxide, the levels of the greenhouse gas will not necessarily increase with more worms in a given area. For now, worms are not a serious threat to climate change.

Earthworm Invaders

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.