FIGURE 5.

PCA ordination plots of microbial and environmental data from three soil profiles of contrasting Amazon peatlands. Samples were derived from QUI (red triangles), SJO (green circles) and BVA (blue squares) with abbreviations as in Figure 1. Methane concentration ([CH₄]), 16S rRNA gene OTU relative abundances, and mcrA gene copy number (A), and Bathyarchaeota alpha (Shannon) and beta (Unifrac) diversity indices, NO_x concentrations ([NO₂^–], [NO₃^–]) and pH (B) were evaluated against microbial distribution. We used Bathyarchaeota abundance and diversity indices as a not yet physiologically resolved close archaeal group important to evaluate but not as assumed methanogens.