Abstract:

In this study, the seasonal dynamic patterns of nutrients in the bulk precipitation, throughfall and stemflow were investigated in a subtropical evergreen broad-leaved forest over one year in Laoshan Natural Reserve, southern Anhui. The results showed that the concentrations of nutrients were significantly increased after rain passed through forest canopies. The mean concentration of K⁺, Ca²⁺, Mg²⁺, NH⁺₄-N, NO^-₃-N, PO^3-₄ were, respectively, 1.40 mg ·L^-1, 3.08 mg ·L^-1, 0.056 mg ·L^-1, 0.42 mg ·L^-1, 0.51 mg ·L^-1, and 6.86 μg ·L^-1 for the bulk precipitation; 3.88 mg ·L^-1, 4.69 mg ·L^-1, 0.27 mg ·L^-1, 0.44 mg ·L^-1, 0.94 mg ·L^-1 and 10.73 μg ·L^-1 for the throughfall; and 5.78 mg ·L^-1, 8.02 mg ·L^-1, 0.45 mg ·L^-1, 0.94 mg ·L^-1, 1.03 mg ·L^-1 and 19.98 μg ·L^-1 for the stemflow. The nutrient concentrations of precipitation fluctuated with rainfall intensity. The nutrient concentrations of throughfall and stemflow were affected by not only atmospheric conditions but the growth stage of trees.

Key words: forest hydrochemistry, evergreen broad-leaved forest, throughfall, stemflow