Figure 4

Principal coordinate analysis (PCoA) of unweighted UniFrac distances of 16S rRNA genes from 36 samples (three labeled/unlabeled treatments × three rRNA fractions per treatment × two soils). The analysis was conducted on a randomly selected subset of 3990 sequences per sample. The scatterplot is of principal coordinate 1 (PC1) vs principal coordinate 2 (PC2). The percentage of the variation in the samples described by the plotted PCs is shown on the axes. All three rRNA fractions of each treatment are represented by a single color. Ellipses in solid line denote the samples from the 13C-labeled treatments for NF (circles) and N (triangles) soils. Ellipses in dotted line denote the samples from the 12C-unlabeled treatments for NF and N soils.