Figure 2.

Correlations between altitude and bacterial genera. Bacterial genera were included in the list when (1) the correlation between altitude and relative abundance of genera was in the same direction in both transects based on Spearman’s rho correlation, (2) average relative abundance >0.1% across all samples, and (3) at least named bacterial family was assigned to search for oxygen requirements. The brackets [ ] indicate recommended taxonomy. Red color indicates Ecuador transect and blue color indicate Bolivia-Brazil transect. Filled patterns show obligate anaerobes and open pattern show non-anaerobes (i.e. facultative anaerobes, aerotolerant anaerobes, microaerophiles, and obligate aerobes). Oxygen requirements were assigned to each genus based on Bergey’s Manual of Systematics of Archaea and Bacteria and recent literature. Fisher’s combined p-values of the Spearman’s rho raw p-values are indicated: * p < 0.1, ** p < 0.05, *** p < 0.0001. After Bonferroni correction (alpha = 0.05/17 = 0.003), only the two Prevotella genera were significant.