DISSERTATION RESEARCH: Earthworm invasions as drivers of soil carbon sequestration in north temperate forests

Regents Of The University Of Michigan - Ann Arbor, Ann Arbor MI

Investigators

Abstract

The uptake and storage of carbon in North American temperate forests is an important ecosystem service, locking up a portion of the carbon that would otherwise accumulate in the atmosphere as carbon dioxide, a potent greenhouse gas. Forests in the northern hemisphere take up many million tons of carbon annually and store about half of it in soils. Various factors can affect rates of forest carbon storage, including invasive species, which can dramatically change above and below-ground processes. One such invader that has tremendous potential to affect carbon storage in forest soils is the exotic earthworm, whose burrowing and feeding are central to soil function and soil carbon distribution. Human activities of the past century have led to introductions of several earthworm species into North American temperate forests. Although there has been a lot of recent research on earthworm invasions, no single study has examined changes in all pools of soil carbon that may be impacted. Further, no other study has examined how interactions among different earthworm species will affect carbon storage. This project will answer unresolved questions regarding changes in forest carbon storage in response to invasions involving multiple earthworm species. This research will have important implications for assessments of exotic earthworm invasion impacts on forest carbon balances in temperate regions. Further, results will improve our understanding of biological invasions on temperate forests and their impacts on forest environmental, economic, and cultural values. The project also has an important international collaboration component that involves researchers in France, where these worms invaded forests long ago. Outcomes will have implications for science policy. For example, there are no current restrictions on the importation of exotic earthworm species to the U.S., nor is there current legislation designed to limit their further spread.