Fig. 5

Quantitative estimates of the microbial community assembly process across sediment depths. A Variance partition analysis (VPA) revealing the relative contributions of contemporary, historical, and sedimentary parameters to the whole sediment community variations (Hellinger transformed). B Different ecological processes in assembly of microbial communities before and after damming. C Different patterns of βNTI between neighboring layers across sediment using the data of individual samples and seasonally merged samples. A quadratic model was applied for eleven merged samples. The upper and lower whiskers of each box correspondingly denote the minimum and maximum values. Median, mean values, and outliers are shown by the midline, plus dot, and black dot, respectively. The area between βNTI =  + 2 and − 2 denotes stochastic assembly