Figure 3.

Two-dimensional hierarchical clustering (average linkage) analysis of iTag OTUs based on non-parametric Spearman's rank correlations. Abundances were rank-transformed within each resampling. Average neighbor clustering of average rank correlation was used to order OTUs and samples. Only OTUs that were observed in >95% of re-sampled datasets are shown. Sampling sites are shown in color at the top of the graph along with dendogram showing clustering relationship between the sampled aRNA or DNA where SukS samples are in blue, SukB in green, and Siq in orange. The presence of different Archaeal OTUs are shown by colored bars, with those samples represented by aRNA shown with a gray background. Different archaeal phyla are indicated by different shades of blue to purple colors. Different groups of Euryarchaeota (All methanogen-related OTUs, Thermoplasmatales, and ANME OTUs were also indicated by different colors magenta, dark purple, and pink, respectively. Taxonomic affiliation was confirmed by phylogenetic analysis of their closest neighbors (mostly > 97% identity) in the Silva Database (123).