Top ten OTUs (at the 97% level) responsible for dissimilarity between certain selected groups of hot spring samples.

1Phylum level for most bacteria and class level for archaea and Proteobacteria.2Contribution of each OTU to the overall dissimilarity between these two clusters.3Average abundance of each OTU in cluster (a) and cluster (b).4Thermaceae is a family in the phylum Deinococcus-Thermus and includes genus Thermus. Whereas some OTUs can be classified to genus level (Thermus), others can only be classified to the family Thermaceae.