Fig. 8.

Rarefaction analysis of ntcA sequences for clone library and culture isolate sequences. In each panel, dotted lines are the average number of OTUs observed for 1000 sampling iterations for each number of sequences sampled. a Rarefaction curves for each clone library sample. b Rarefaction curves of culture isolate sequences for each enrichment sample. Color indicates time of year and gray shaded areas indicate 95 % confidence intervals. c Comparison of clone library (blue circles) and culture isolate (red triangles) rarefaction curves (same data as plotted in panels a and b) for sampling up to 30 sequences. OTU designation was at 10 % dissimilarity level