Yup. Non-native animals can be a problem.

So this article suggests that the northeast forests should be earthworm-less?

For more information, try the following search in google. I think the ones from the University of Minnesota are especially informative.

Google search on forests earthworm duff

This site is a good one.

Claire

Here is a link that might be useful: Contain those crawlers!

wow this is insane

What's insane about it?

It seems perfectly reasonable to me to think that the soil conditions that are optimal for crops are not necessarily optimal for forests. It also seems perfectly reasonable to me that if you introduce an invasive species into an ecosystem that had evolved without that species, it could wreak havoc on it. There are many examples of this happening. Some invasive species are introduced intentially, with high expectations for good results, and many others are introduced entirely by accident. But the results are often very unfortunate.

its insane in a "whoa i never even knew that" kind of way

They say that we had plenty of earthworms here 10,000 years ago b4 the last iceage.
They're just making a comback.

Nah, different types of worms. It's the difference between the Nathan's hot dog eating contest

hot dog gobblers

and a decorous High Tea.

High Tea

Claire

The problem with earthworms "making a comeback" is that they are coming back to northern forests with much different vegetation and soil conditions than when they were swept away by glaciers.

They are beginning to make an impact on our very thin topsoil here in the Adirondack wood as they spread.

As a gardener, I have mixed feelings when I see the critters in my garden.

Wayne

Wayne:

Do you know if the earthworms that are spreading into the Adirondack woods are natives coming up from the south? Or are they non-natives spreading from suburbs/gardens/fishing holes?

What I'm wondering is whether all worms are dangerous in the northern woods or if it's just the more voracious aliens.

(I'm trying not to let my head drift off into contemplation of alien worms abducting humans to slave in their tunnels....)

On the serious side, I read somewhere recently that oaks have been spreading north relatively recently and the fact that they retain some leaves in the winter is related to a slow adaptation to a colder climate. Northern forests have survived the decimation of the American chestnuts, and then the elms, and other trees have taken their place.

Oaks presumably coexisted in the south with native earthworms. The question is whether a slow change to a native earthworm ecosystem would be viable in northern forests. That's opposed to a too fast change related to the alien earthworms (that presumably evolved in a different forest).

I realize that this is just a hypothetical question since the non-native earthworms vastly outnumber the natives up north.

Claire

My understanding is that it's a really fast occurence. Introductions have been traced from fishing lakes as bait is left or released at the end of the day. This is in stark contrast to a slow movement or migration from one area to another; it's starting in many places at once deep past where they "belong".

Maples are potentially susceptible here, as they rely on deeper litter layer. They're also subject to any climate warming.

Claire,

The belief here is that these are introduced European invaders, not a native species making the slow trek north since the glaciers have left.

The efforts here are in education, especially to discourage their spread through excess fishing bait as pablo_nh mentioned.

Wayne

Here is a link that might be useful: An earthwork survey, Huntington Wildlife Forest

Good link, Wayne.

Thanks,
Claire

This is really nothing new but apparently this reporter found the 1996 research and decided to write a story about it. In some eco systems worms may be deterimental while in others they are beneficial. In some eco systems some worm species may be more detrimental than other worm species. A blanket statement that worms do not belong in North America is simply wrong.

>This is really nothing new..
True, but since many people aren't aware of the issue, it is beneficial to raise it now and then.

>A blanket statement that worms do not belong in North America is simply wrong.

Very true. I didn't see any making that statement, but if they did, you would be correct.

Wayne

I think the statement being made is most of Northern North America does not need worms..?

Which would make sense since thats where the glacier went down to.

I'm guessing that people cause more eco problems than worms.

it all adds up

>I'm guessing that people cause more eco problems than worms.

"Worms don't kill forests. People with worms kill forests."
(Sorry, a little joke I couldn't resist.)

Below is a map showing the extents of the glaciers into the US. While two thirds of North America was covered during the Pleistocene years, including all of Canada, most of the US remained glacier-free, and presumably, a refuge for native earthworms.

Wayne

Here is a link that might be useful: Map of glaciers.

There's a hole in that map, somewhere around the Great Lakes, where it seems there was no glaciation. Does anyone know anything about the conditions there? or why the glaciers skipped it?

Claire

That's known as the "Driftless Area" and is a huge area that the glacier flowed around. It's mostly in Wisconsin. I think the terrain is more rugged then in the surrounding area but there may be other climatic reasons for it.

I wonder if ancient species of worms exist there?

Wayne

Wisconsin's Glacial Legacy(pops)
http://www.nps.gov/archive/iatr/expanded/history.htm

Couple theories(pops) as to why the driftless area escaped glaciation, highland and porosity of bedrock
http://pascals-puppy.blogspot.com/

Very interesting links! I know in New England there were several lobes of the Wisconsin glacier, but I didn't know that lobes could be forced to diverge and leave unglaciated areas in between, for whatever reason.

The issue of bedrock porosity affecting glacier movement (prevents skidding on melted icewater) is also new to me. Lots of new ideas here.

Thanks,
Claire

Glad to help Claire :)

A blanket statement that worms do not belong in North America is simply wrong.

But that's not what the writer of the Boston Globe article, nor the researchers interviewed have stated. What they have stated is that the forests in what had been glaciated areas (ie., the forests northeast of New Jersey) evolved earthwormless, and developed into ecosystems where a thick duff layer always existed, and so had a variety of organisms that depended (& still depend) upon that duff layer for existence.

The earthworms destroy that duff layer, radically altering the forest by diminishing its habitat quality.