Fig. 4

Principal coordinates analysis (PCoA) plots of representative genes based on weighted-Unifrac distance. Ellipses represent 95% confidence intervals. The colors of functional gene names represent the metabolic processes in which they participate. a SSU rRNA gene. b mcrA for anaerobic oxidation of methane (orange). c dsrA for dissimilatory sulfate reduction (green). d cysH for assimilatory sulfate reduction (yellow-green). e narG for denitrification (light blue). f nifH for nitrogen fixation (blue). Overall P values are annotated on the plots, while pairwise P- and F- values are compiled in Data S3