Fig. 3

Effects of S addition on total PLFAs (a), relative abundance of bacteria (b), and fungi (c) groups, ratio of fungi to bacteria (F:B, d), saturated-to-monounsaturated FAs (sat:mono, e), and cyclopropyl FAs-to-monoenoic precursor (cy:pre, f). Bar indicates the mean value (± 1 standard error) for each treatment. Different lowercase letters above bars indicate significant differences among different S addition rates at the level of P < 0.05. The scatter subplot in each panel demonstrates the relationship between soil pH and corresponding variables, the linear regression is fitted when P < 0.05 (with R² and P shown). The gray area represents 95% confidence interval