Starting with the European settlers, humans have introduced earthworms from Europe and Asia into North American forests. These
introductions continue through the transport of soil that contains non-native earthworms, such as during construction and through the
release of non-native earthworms used for fishing. The effects of non-native earthworms are especially large in forests that did not have
any native earthworms. For example, forests of the Great Lakes region did not previously have earthworms until humans introduced them.
When non-native earthworms are introduced, the thick layer of leaves, known as leaf litter, covering the ground disappears quickly,
thereby altering biogeochemical cycles.
What is a possible negative consequence of introducing the non-native earthworms to forests in the Great Lake regions?
A. The earthworms reduce the resources available to other animals that eat dead plant matter.
B.The earthworm decreases the
energy flow from one tropic level to the next.
C. The earthworms provide an additional food source for primary consumers.
D. The earthworms burrow,
which reduces the nutrients, flow of air, and water underground.