Figure 7. The number of PCRs in which a particular taxon is observed vs the average abundance of that taxon within each PCR. Each data set comprises 5000 subsampled reads and incorporates a minimum read cutoff of five. Sequence abundance is plotted as log-transformed counts of the number of reads per PCR assigned to a particular taxon, averaged across the PCRs in which that taxon is observed. We find a positive correlation between the number of PCR replicates in which a taxon is observed. Each dot represents an individual taxon and is colored according to site.