Invasive Eurasian earthworms are colonizing formerly worm-free regions of northern North America. We studied the effects of invasion by Lumbricus terrestris and other European Lumbricidae in mature Acer saccharum and Tsuga canadensis dominated stands in northern Michigan. L. terrestris is unique in that, using deep vertical burrows it removes litter from the forest floor and transfers it directly into deeper soil layers (> 20 cm). This activity and that of other functional earthworm types alters soil physical and chemical properties and root distribution. The result is the loss of a classic northern Spodosol upper profile, with organic horizons consumed and mineral soil exposed. Across an earthworm invasion front, high densities of L. terrestris resulted in an 84% reduction in organic horizon carbon, and a 13% increase in mineral soil carbon, for an overall reduction of 1,487 g C/m² (33%). High L. terrestris densities also decreased cumulative soil CO₂ efflux during the growing season by 22%, increased total root biomass by 19%, altered vertical root distribution patterns, and reduced C:N ratios by an average of 12% across soil depth. Cation concentration (mg/kg) and content (mg/m²) showed variable results by soil depth and earthworm colonization intensity. While some of these trends are explained by mass loss in Oi to Oa horizons driving a reduction of nutrient content, these losses are often offset by gains in deeper mineral soil horizons. This study illustrates the effects that invasive organisms can have on ecosystem C storage, C distribution and nutrient availability. Whether these lead to a long-term decrease or increase in soil C will depend on the balance between earthworm consumption of labile C and production of relatively stable physically and chemically protected C. Future research will attempt to determine this balance for soils of varying texture.