Original data on root-soil interactions governing soil organic nitrogen dynamics under acid rain and nitrogen deposition

Acid deposition and nitrogen (N) enrichment are major environmental stressors under anthropocene change, exerting severe negative impacts on N cycling in forest ecosystems. Fine roots, as the primary input source of soil organic nitrogen (SON), their decomposition process play a critical role in the formation and turnover of SON; However, how fine root decomposition mediates changes in root substrates and the soil microenvironment, thereby influencing SON dynamics under acid rain and N deposition, is still poorly understood. Here, we established an acid rain-nitrogen deposition simulation platform in subtropical Cunninghamia lanceolata plantations and conducted experiments using substrate regulation, environmental regulation, and in situ decomposition experiments to explore the interactive effects of fine root substrates and soil environments on SON dynamics.