Table 2.

Significant site differences between dominant bacterial classes for each sample type. Specific OTUs driving site differences are specified within classes (OTU numbers are specified within parenthesis). An arrow pointing up indicates the listed OTU had significantly higher relative abundance at the site compared with others. An arrow pointing down indicates the listed OTU had significantly lower relative abundance at the site compared with others. A negative sign indicates that either a specific OTU was not detected to explain differences among sites or the relative abundance of the OTU did not differ from other sites

Sample type	Class	OTU	Ref	Site 1	Site 2	Site 3	Vent
Leaf	Oscillatoriophycideae	o. Oscillatoriales (2)	↑	↓	↓	↓	↓
Roots	Bacteroidia	–	↓	–	–	↑	↓
	Clostridia	–	↓	–	–	↑	↓
	Oscillatoriophycideae	o. Candidatus Thiobios (2)	↑	↓	↓	↓	↓
	unknown Cyanobacterium	–	–	–	–	↓	↑
Sediment	Acidimicrobiia	o. Acidimicrobiales (152)	↑	–	–	–	↓
	Candidatus Thiobios	o. Candidatus Thiobios (46)	↓	–	–	–	↑
	Gammaproteobacteria	g. Thiothrix (16)	↓	↓	↓	↓	↑
		sp. Balneatrix balneatrix (40)	–	–	↓	–	↑
		g. Balneatrix (1368)	–	–	↓	–	↑
	Sphingobacteria	–	–	–	↑	–	↓
	Zetaproteobacteria	–	–	–	–	↑	↓