extremely significantP < 0.01
The COD Mn , COD, Chl a, TP, TN, and NO 3 -N levels at Taizishan were higher than those at other monitoring sites, and the differences in COD Mn , TN, NO 3 -N and Chl a were significant ( P < 0.05) or extremely significant ( P < 0.01) (Table 1 ).