Earthworm Invasion

October 2013

Earth Worm Invasion

Link: http://www.sciencedaily.com/releases/2013/10/131029133126.htm

     Earthworms are being called the most recent keystone species to be added to the list for the forests of New England. Keystone species are groups that control an ecosystem and have a disproportionate impact on other species. Although none of the worms are native to the area, the migration of a few different species of earthworms is being tracked in attempt to understand how their soil-eating ways are affecting forests and global stocks of carbon. These earthworms are also being categorized as invasive species: non-native animals and plants, carried by people into new locations, that take hold, disrupting and reshaping local ecosystems.

     Scientists at the University of Vermont are reporting sixteen earthworm species reported in the state that are all exotic: fourteen are European and two are Asian. Many of these worms are invaders, spreading quietly underground. Although there is a good amount of carbon stored in trees aboveground, a roughly equal amount of carbon is stored belowground where these earthworms are. This is because the earthworms participate in decomposition underground, and release carbon dioxide as they eat. This adds to the forest's carbon emissions, which leads to the greenhouse effect and global warming. However, earthworms do a good job spreading soil aggregates that physically protect the organic carbon inside them, forming a barrier to the microorganisms that could otherwise break it down.