Variation characteristics of aggregate composition, SOC in aggregates, Feo in aggregates, and Fec in aggregates in QRS under various anthropogenic land use activitie

QRS represents a pre-Holocene paleosol that developed under warm and humid climatic conditions. A series of QRS pedons, influenced by anthropogenic land use activities, were sampled including sparse forest grassland, grassland, woodland, and cultivated land. According to the principle proposed by Brewer (1976), the Btr2 horizon in the buried QRS, which had the lowest degree of weathering in the profile, was selected as the reference basis. By utilizing the Soil Reconstruction Method and using Ti as the stable element, the gains and losses of aggregates, SOC in aggregates, Feo in aggregates, and Fec in aggregates were calculated for 0–30 cm layer in the QRS under different anthropogenic land use activities compared to the buried one.