Canopy modification of base cations deposition in a subtropical broadleaved forest: Spatial characteristics, canopy budgets and acid neutralizing capacity

•TF or SF base cations fluxes had no significant differences between UP and LP.•Relative contributions of DD and CE to NTF were different at the two slope plots.•NTF K+ flux was dominated by CE regardless of slope position.•NTF Ca2+ and Mg2+ fluxes were dominated by DD in UP, while CE in LP.•ANC and ALK of TF and SF were significantly higher compared to BP.