Diversity indices of bacteria in different treatments.

The letters attached to the values indicate the results of multiple comparisons (ANOVA with Bonferroni corrections) of mean diversity indices among treatments for each month (excluding the data of the V treatment in February): values with the same letter are not significantly different (p>0.05). Mean ± SD, n = 3, except the duplicate values (n = 2) presented for the data of the V treatment in February. S: OTU richness, E: Evenness, H: Shannon-Wiener diversity index, D: Simpson's index of diversity.