Comparison of bacterial community structure in Fermilab soils vs. other soils in the Earth Microbiome Project database. (a) Proportion of operational taxonomic units (OTUs) present in both composite Fermilab soils (unfertilized and fertilized treatments) and soils in the EMP10k database from various biomes. Letters indicate significantly different overlap for that treatment among biomes (P<0.05 based on one-way ANOVA followed by means separation by least significant difference). Sample sizes: Grassland = 337, Forest = 261, Agriculture = 696, Tundra = 136, Permafrost = 66, Desert = 104, Other = 172. (b) Principal coordinates analysis with 10 randomly selected representatives from Fermilab and soils from terrestrial biomes in the EMP database. Biomes were identified from user-generated metadata.