invasive earthworms?

[Sigene]

Just google a bit and you find lots of sites on how terrible and invasive earthworms are. I find it hard to believe that earthworms present in many areas (especially in glaciated areas of N. America) are european or asian imports. Is this really true? It just doesn’t make sense to me.
What is the earliest documentation of earthworms in the new world?
Is there good scientific evidence that the non-native earthworm invasion is true and WIDESPREAD (not just some small glen in Minnesota)?

I expect there may be some worms that are imports, but the websites seem to imply that all worms are invasive, did I read this wrong?

[astro]

I thought you were drnking, but it’s true.

New information!

[Shagnasty]

National Geographic had a special issue devoted the first Jamestown colony about a year ago. It noted that the colony’s biggest environmental impact by far was the introduction of European earthworms to the New World. The introduction of rooting pigs was another. National Geographic claimed that this impact alone cannot be overstated in terms of the ecology the New World.

[jayjay]

That’s just weird. In the gardening world, earthworms are like gold…they make all soils better for the purposes of growing garden plants. Hearing anyone call them invasive or bad just feels really weird.

[Darryl_Lict]

I’m not sure about all earthworms, but I know that introduced earthworms are a real problem.

@Wikipedia

Only two genera of Lumbricid earthworms are indigenous to North America while introduced genera have spread to areas where earthworms did not formerly exist, especially in the north where forest development relies on a large amount of undecayed leaf matter. When worms decompose that leaf layer, the ecology may shift making the habitat unsurvivable for certain species of trees, ferns and wildflowers.

I heard that one of the big problems is fisherman dumping non-indigenous bait worms. Just wait until the Giant Australian Earthworms take over your yard!

[Savannah]

Hm. I love worms for the lovely soil they create in the garden (and my dog loves dead ones in the driveway…) and always think of them as wonderful things. But somewhere I’m getting a glimmer of something I read about earthworms actually altering the environment of coastal forests and being an introduced species that isn’t always welcome.

[Byzz]

Wow, I never knew earthworms could be bad. In England, there is a big problem with non-native flatworms. They eat the earthworms and the absence of earthworms is devastating to farmland. It’s amazing what effects a little thing like a worm can have.

[Capt_B.Phart]

@Byzz

It’s amazing what effects a little thing like a worm can have.

Darwin would have agrred

Darwin considered earthworms as one of our planet’s most important caretakers. “I doubt,” he said, “whether there are many other animals which have played so important a part in the history of the world, as have these lowly organized creatures.”
Not bad for an animal that’s deaf, blind, and spineless.

[twickster]

It’s not all earthworms, or earthworms everywhere – but they’re not good in certain ecosystems, like forests, as Darryl Lict’s link suggests. Gardeners should be aware of this, since certain types of gardens (like shade gardens with lots of trees) will not benefit, and may be harmed, by the introduction of earthworms.

In more fertile, active ecosystems, however, earthworms are generally good – they process biomass and aerate the soil.

[robz]

Here’s a good book on worms:

The Earth Moved: On the Remarkable Achievements of Earthworms, Amy Stewart

Light reading for a the general public. Has a discussion on the invasive problem.
Bob Z
NE Pa