[freebeard]

Via Slashdot: Earthworms Are Invasive - and Likely Hurting Insects - in Much of North America

Earthworms' subterranean engineering isn't a problem in their native ecosystems, but in the northern half of North America, the glaciers of the last ice age wiped out virtually all soil-dwelling worms more than 10,000 years ago. The ice sheets covered nearly all of Canada, most of the northeast U.S., and much of the upper Midwest. When the ice receded, forests returned but the worms did not because they can only expand their range by a maximum of about 30 feet a year. These northerly ecosystems evolved for millennia in the absence of earthworms. Without worms munching through fallen foliage and churning the soil, these forests accumulated thick layers of leaf litter, which came to support a vast array of animals, fungi, and plants. Eisenhauer says even non-scientists can appreciate the difference.

Echoes of the last Ice Age still resounding.