A multitude of scientific publications have emphasized the importance of an organic carbon (C) -mineral complexation mechanism as a crucial factor in C stabilization and sequestration. Carbon-mineral complexation is strongly controlled by mineral surface area, mineralogy, pH, redox, polyvalent cations, ionic strength, and the chemical composition of organic matter. These factors vary spatially as a function of geomorphologic, hydrologic, and microbiological processes. Soil horizons and sediments with abundant Fe and Mn oxides/hydroxides have high mineral surface area and thus a high capacity to complex C, reducing its susceptibility to microbial degradation. Additionally, both sediment and hydrological fluxes transport mineral surface area in both solid and dissolved phases (i.e., Fe can be hydrologically transported in its reduced state and then oxidized to iron oxides with high mineral surface area).
At the Christina River Basin-Critical Zone Observatory (CRB-CZO), one of six observatories located in the Piedmont region of Southeastern Pennsylvania and northern Delaware and funded by the National Science Foundation, we investigate how Fe- and Mn- redox coupling affects the C cycle under varying redox conditions across a wide range of landscape positions and uses, such as floodplain forest, upland forest, and agriculture.
Lazareva, O., D.L. Sparks, A.. Aufdenkamp, K. Yoo, S. Hicks and J. Kan. (2011): Role of Fe- and Mn- Redox Coupling on the Carbon Cycle in a Mixed Land Use Watershed. CZO National Meeting, Tuscon, Arizona, May 8-12.
This Paper/Book acknowledges NSF CZO grant support.
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