Increased nitrogen deposition in a subtropical forest in China affects carbon cycling. Soil aggregates protect organic carbon from decomposition. The study added nitrogen to the soil and found that as nitrogen levels increased, certain soil parameters changed, but soil organic carbon remained stable. Microbial biomass decreased in some soil aggregate sizes with nitrogen deposition, while dissolved organic carbon increased. Overall, soil aggregates had higher concentrations of certain organic compounds compared to bulk soil. This suggests that soil aggregates play a role in stabilizing soil organic carbon under nitrogen deposition.