Most people don’t think much about earthworms, but gardeners do, and most gardeners think that worms have always been in our soils, but they haven’t. Canada and the northern states of the US had no earthworms after the last glaciation until the Europeans showed up.
It is believed that earthworms first arrived in the US around the seventeenth century. It’s thought that they arrived in the soil that was used as ballast on the ships coming from England. Their arrival changed forest ecosystems forever as they chewed their way through the leaf litter on the forest floor.
Some forest ecologists blame these European earthworm immigrants for the demise of some species of salamanders and ground-nesting birds, animals that depend on the forest leaf litter for habitat. Continue reading The Introduction of Earthworms to The US