Plant-soil interactions shape the identity and persistence of soil organic carbon in invaded ecosystems: implication for legacy effects

1. Introduced, invasive plants can alter local soil chemistry and microbial communities, but the underlying mechanisms and extent of these changes are largely unknown. Based on characteristics associated with invasiveness in plants, it was hypothesized that introduced species that produce large amounts of litter with distinctive secondary compounds can a) alter the chemistry of both extractable and bulk carbon in the soil, b) shift microbial communities towards microbes better able to metabolize the compounds in the litter, and c) cause soil carbon chemistry and microbial communities to shift to relatively uniform, novel states at multiple sites. 2. Composition of phenolics in senescent tissues (leaves and roots) of Polygonum cuspidatum was compared to the composition of extractable phenolics and non-extractable bulk organic carbon in soils under and adjacent to large, long-established stands of P. cuspidatum at four sites in the eastern U.S. Rates of degradation of phenolics, activitie...