FIG 1.

Phylogeny of the V3 region of archaeal 16S rRNA type sequences from the Ribosomal Database Project (29). The phylogenetic positions of the OTUs discovered from pyrosequencing are indicated. The bars represent the abundances of each of the OTUs in HRFI samples (white) and LRFI samples (black). Dots at internal branches indicate bootstrap support greater than 80%. A detailed version of the full phylogeny with all species names is shown in Fig. S5 in the supplemental material. The relationships from only within the Methanobacteriales are shown in Fig. 2.