Invasive earthworms threaten forest diversity
European earthworms in Canadian forests are eating tree seeds
Much of the harm they cause is the result of seed predation, as well as the removal of the leaf cover that many plants rely on, in order to take root. The worms are eating the seeds of tree species, such as yellow birch and black cherry, as well as seeds of many wild flowers.
In an experimental area, the researchers found that over a two week period, 73 percent of seeds had been removed from the soil surface or pushed too deeply underground to germinate.