|Northern Maple forest without earthworms.|
Within recent decades however, earthworms began showing-up in these formerly glaciated soils of the north. This might not seem that weird until you realize that earth worms travel an average of 5 or 6 yards a year. Over 11,000 years that equals only about 40 miles, which is a ridiculously slow rate that wouldn't have even allowed them to travel across an entire state. Even if you double or triple that distance it doesn't even come close to the distance the worms would need to travel to show up in these northern forests. So how did they move thousands of miles in just a few decades? The only explanation is that humans carried them. Fishermen and gardeners are especially notorious for carrying earthworms long distances. As a result, worms were accidentally introduced to new locations hundreds of miles away from the nearest native worms.
|Northern Maple forest with earthworms.|
Fortunately, earthworms have not taken over every single forest in these northern areas. Also fortunate is the fact that worms only travel about 6 yards a year. This means, if people quit transporting worms to new areas in the north, populations of worms aren't going to expand much.
Great Lakes Worm Watch