Table 2.

β-Diversity among environment types.

	Aquaria + biofilters	Caves	Coastal sediments	Coral + sponges	Groundwater	Hot springs	Hydrothermal vents	Lakes + rivers	Marine sediments	Seas	Soils	Ocean water column	Wastewater treatment
Aquaria + biofilters		0	0.053	0.087	0.045	0	0.042	0	0.090	0.077	0	0.094	0.037
Caves	0		0.007	0	0	0.058	0	0	0.015	0	0.007	0	0
Coastal sediments	0.008	0.001		0.129	0.058	0.117	0.037	0.167	0.229	0.033	0.221	0.099	0.097
Coral + sponges	0	0	0.007		0	0	0.054	0	0.081	0.067	0	0.113	0.016
Groundwater	0	0	0.006	0		0.031	0	0.125	0.039	0	0.048	0	0.029
Hot springs	0	0.014	0.005	0	0		0	0.233	0.084	0	0.182	0.013	0.109
Hydrothermal vents	0	0	0	0.007	0	0		0	0.206	0.095	0	0.158	0
Lakes + rivers	0	0	0.014	0	0.014	0.018	0		0.118	0	0.205	0.015	0.157
Marine sediments	0.009	0	0.018	0.002	0.003	0.01	0.022	0.015		0.044	0.092	0.136	0.076
Seas	0	0	0.001	0.008	0	0	0.008	0	0.003		0	0.179	0
Soils	0	0	0.022	0.001	0.004	0.008	0	0.021	0.014	0		0.006	0.090
Ocean water column	0.005	0	0.006	0.020	0	0.002	0.016	0.002	0.009	0.017	0.001		0.044
Wastewater treatment	0	0	0.005	0	0	0.008	0	0.010	0.009	0	0.005	0.003

Values represent the Jaccard similarity index for (above the diagonal) amoA nucleotide OTUs at the 90% identity level and (below the diagonal) unique AmoA protein sequence types.