Fig. 3.

Dynamic changes of the estimated NST during the succession of the groundwater microbial communities in response to emulsified vegetable oil injection. NST was calculated based on (A) Jaccard and (B) Ružička metrics using null model algorithm PF. In null model PF, the probabilities of taxa occurrence are proportional to the observed occurrence frequencies, and taxon richness in each sample is fixed as observed (19). When using abundance-based metric, Ružička, null taxa abundances in each sample are calculated as random draw of the observed number of individuals with probability proportional to regional relative abundances of null taxa in the sample (26). W8 is the control well on which the vegetable oil had no or minimal impact. See SI Appendix, Figs. S3–S5, for results of other null model algorithms and similarity metrics.