Earthworm Invasions

http://www.macroevolution.net/earthworm-invasion.html

An earthworm invasion sparked by farming and fishing has been spreading into forests and previously glaciered areas in North America. These forests were evolved without the help of native earthworms. The earthworms were first brought to the area though European plant importation. In prior years hikers had noticed leaf litter layer was decreasing, and that the worms were slowly mixing into the lower layer of mineral soil. Professor, Kyungsoo Yoo, at Delaware of Plant and Soil Sciences at the University of Delaware, says that in agricultural development its important to have a mix of organic material and mineral soil, but in native forests the leaf litter layer is needed for the trees to survive. Studies have shown that tree types can change in 30 to 40 years. Although they are invading it may take awhile to make any major impact because they only increase about seven meters a year.
I think that if the worms could cause major damage that scientists should find a way to try to get rid of them. Also, if the trees are native to America that they should be kept native to America and the forests shouldnt be be changed by these foreign worms. Fishers should also not throw their worms on the ground and spread them more. They should just let them die or dispose of them some other way instead of spreading them more. I don't believe that just letting this go will be of any good to our forests. The leaf litter layer is essential to the growth of trees and if the worms are depleting that, then our forests won't be our forests anymore, they'll be foreign in time.