Jason W Stuckey, Christopher Goodwin, Jian Wang, Louis A Kaplan, Prian Vidal-Esquivel, Thomas P Beebe, Donald L Sparks
Minerals constitute a primary ecosystem control on organic C decomposition in soils, and therefore on greenhouse gas fluxes to the atmosphere. Secondary minerals, in particular, Fe and Al (oxyhydr)oxides-collectively referred to as "oxides" hereafter-are prominent protectors of organic C against microbial decomposition through sorption and complexation reactions. However, the impacts of Mn oxides on organic C retention and lability in soils are poorly understood. Here we show that hydrous Mn oxide (HMO), a poorly crystalline δ-MnO2 , has a greater maximum sorption capacity for dissolved organic matter (DOM) derived from a deciduous forest composite Oi , Oe , and Oa horizon leachate ("O horizon leachate" hereafter) than does goethite under acidic (pH 5) conditions...
February 13, 2018: Geochemical Transactions