Climate change and Cognettia sphagnetorum: effects on carbon dynamics in organic soils

1. A microcosm experiment was performed to test the impacts of Cognettia sphagnetorum on carbon leaching in a cambic stagnohumic gley soil. 2. Leaching of dissolved organic carbon (DOC) was significantly enhanced by C. sphagnetorum, with the greatest effect being found in the upper, 0-6 cm, soil layers. The ratio of DOC to dissolved organic nitrogen (DON) in the leachate decreased in faunated systems, indicating that the enchytraeids were mobilizing carbon from organic matter with a low C to N ratio. 3. The vertical distribution of the enchytraeids had an effect on the production of DOG, and this vertical distribution is affected strongly by climate. It is proposed that increases in DOC found in a field soil-warming experiment with the same soil are largely a result of changes in the vertical distribution of these organisms.