Relative abundances of bacterial/archaeal groups in 16S rRNA data set. Relative abundances of bacterial/archaeal groups in 16S rRNA data set. (A) Microbial taxonomy summarized at phylum level. (B) Microbial taxonomy summarized at the class level; the legend displays only the top 15 most abundant taxa in the bar chart. Plots were generated in QIIME using abundance-filtered OTU tables with control OTUs subtracted. MH, Marble Hill; S., South; W., West. Holly M. Bik et al. mSphere 2016; doi:10.1128/mSphere.00226-16