2.5. Linear Discriminant Analysis (LDA) Effect Size (LEfSe) Measurement

To detect bacterial taxa with a significant differential abundance between the sampling sites and the sampling periods, linear discriminant analysis effect size (LEfSe) measurement [46] was created according to the web-based tool [47]. For LEfSe, Kruskal–Wallis test by ranks were performed to detect the features (ASVs) with significant abundance, followed by LDA to evaluate the effect size of each differentially abundant ASV. Values were considered significant at p < 0.05 for both statistical methods. ASVs with markedly increased effect size were defined as those with an LDA score (log₁₀) > 3. LDA score represents the discriminant rank of the features ASVs with differential abundance within sampling periods or among sampling sites.