Contemporary Mobilization of Legacy Pb Stores by DOM in a Boreal Peatland

• DOI: 10.1021/acs.est.7b06577
• Publication Date: 2018-02-28T15:21:24Z
• Authors: Jeff D. Jeremiason; Erin I. Baumann; Stephen D. Sebestyen; Alison M. Agather; Emily A. Seelen; Benjamin J. Carls...; Meghan M. Funke; James B. Cotner
• Keywords: Mobilization

We examined how different landscape areas in a catchment containing northern ombrotrophic peatland and upland mineral soils responded to dramatic decreases atmospheric deposition of lead (Pb). Pb concentrations the outflow stream from measured 2009-2015 indicated continued mobilization export derived historic inputs bog. In contrast, surface peat runoff have declined response reductions deposition. Relative early 1980s, streamflow decreased only ∼50%, while subsurface by more than 90%. Water level fluctuations slow-accumulating allowed dissolved organic matter (DOM) continue mobilizing deposited decades earlier. Strong correlations between carbon (DOC) bog porewaters demonstrate mobility related DOM production. Peat stores 2016 were less or equal those reported 1980s despite dry mass inventory increasing 60-80%. Much loss stored can be accounted for peatland.