Forest type and stand age co-regulate iron-associated carbon and microbial life-history strategies in red soils

Microorganisms are important regulators of soil organic carbon (SOC) accumulation and stabilization, which is modulated by soil minerals, especially iron (Fe) oxides. Here, we analyzed soils from different forest types (coniferous forests, mixed forests, and broad-leaved forests) and stand ages (40-, 20-, and 10-year) in a subtropical acidic red soil region. SOC peaked at 20 years and declined by 40 years, while decreasing with soil depth. Free iron oxides (Fed) content was higher in mixed fores