Iron-bound Organic Carbon Distribution in Freshwater Wetlands with Varying Vegetation and Hydrological Regime

Iron (Fe) oxides have attracted much attention due to their role as optimal minerals for long-term soil organic carbon (SOC) sequestration. However, little is known about Fe-bound organic carbon (OC) characteristics in wetlands of Yangtze-Huaihe Basin. Here, we determined Fe-bound OC contents in topsoil (0–5 cm) and subsoil (10–20 cm) in seven wetlands with varying vegetation and hydrological regime, and analyzed influencing factors and pathway. Fe-bound OC contents ranged 2.14 31.2 mg/g in topsoil and 2.00 15.8 mg/g in subsoil, and contributed 8.33