LAUSR

It is estimated that the quantity of organic carbon (OC) in soils exceeds the amount of OC in the atmosphere and vegetation pools combined. Given the current changes in climate, the fraction of OC sequestered in soils and sediments is more sensitive to decomposition and release as CO2 in the atmosphere. Evidence implies that sorption and association of dissolved OC with inorganic soil components, i.e., soil minerals, is a key mechanism that contributes to stabilization and retention of OC in soils. Studies have shown a direct correlation between sorption of dissolved OC and soil mineral surface properties and their surface area. In addition, properties of organic compounds such as their chemical structure and functional groups play a significant role in the interaction of dissolved organic species with mineral surfaces. Association of OC with minerals via ligand exchange reactions, polyvalent tertiary bonding, or complexation with metal ions, is found to be preferential and dependent on the organic compounds’ functional groups.