Erin Cameron gave an excellent talk to the Red Deer River Naturalists on earth worms.
One of the first surprises she gave us was that we don't have native earth worms in Alberta. Where glaciation occurred , our native earthworms were wiped out. Earthworms that we have now have come to us by various methods.
Erin Cameron is studying the effect of earthworms in the Boreal forest. The research is only just beginning. Very few answers have been found. They know that earthworms have only recently moved into the boreal forest. Earthworms have been brought in by man rather than earth worms travelling on their own to the boreal. Roads, industrial activity and fishermen have all brought earth worms into the area. They have made extensive counts along roadways and siesmic lines and find that the earth worms are have not gone very far from the roadway.
What's the worry about earth worms in the boreal? Some earth worms influence the leaf mold layer on the surface above the mineral soil. Many plants and insect life do not perform well with that layer gone. Two of the earth worm species live in the mineral soil and come to the surface and take the leaf debris into the mineral soil thus depleting the leaf mold. Other types of earth worms that function only in the leaf mold disappear.
So the big question is how the boreal forest will replace itself because of the earth worms which were not here before.?