Table 1.

Summary of the 15 groups into which we binned the 202 samples

Group nameDescription#S#OG ResidPD ResidSNET
Nonsaline cultured (Nc)Cultured from diverse nonsaline environments including soil, lake water, lake sediment, and air11545−0.88** −1.87** Embedded Image Embedded Image
Soil surface (Nso)Soils of diverse types (agricultural, rainforest, temperate forest, grass pasture, and desert) and geographical regions; some polluted (PCB, HC)313,560−0.76** −0.61 Embedded Image Embedded Image
Nonsaline submerged (Nsu)Soils that are submerged and potentially anoxic including subsurface soils, a rice paddy, and polluted and pristine wetland soils, aquifers, and sediments from a cave104900.410.30 Embedded Image Embedded Image
Nonsaline sediment (Nse)Sediment from nonsaline lakes and reservoirs77080.60* 1.77** Embedded Image Embedded Image
Nonsaline water (Nw)Rivers and lakes from diverse geographical regions and trophic level. Samples taken from various depths281,208−0.340.26 Embedded Image Embedded Image
Nonsaline endolithic (Nen)Scraped from cave walls with and without artificial lighting, epi and endolithic limestone in Mexico, and an acidic endolithic community in Yellowstone National Park72390.200.03 Embedded Image Embedded Image
Nonsaline springs (Nsp)Thermophilic springs from Yellowstone National Park and Thailand (sediment and growth slide) and a microbial mat in a cave sulfidic spring51500.56* 0.02 Embedded Image Embedded Image
Saline cultured (Sc)Cultured from diverse saline environments including marine ice, sediment, and coastal water, a salt marsh, and a hypersaline stromatolite9279−0.23−1.0 Embedded Image Embedded Image
Saline sediment (Sse)Sediment from diverse saline environments including meromictic lakes, coastal and deep sea sediments, brackish to hypersaline water, active and inactive hydrothermal vent sites, gas hydrate mounds, salterns, and springs381,9790.54** 0.70** Embedded Image Embedded Image
Saline water-anoxic (Swa)Water from anoxic saline environments including meromictic Mono Lake (California), the anoxic zone of the Cariaco Basin, and deep hypersaline basins in the Mediterranean Sea84020.190.69* Embedded Image Embedded Image
Saline water-subsurface (Swb)Water from subsurface samples between 10 and 4,000 M depth, from diverse geographical locations and mostly open ocean16999−0.057−0.08 Embedded Image Embedded Image
Saline water-surface (Sws)Water from surface saline water, mostly from coastal samples of diverse geographical location but also the Sargasso Sea10713−0.15−0.77 Embedded Image Embedded Image
Saline ice (Smi)Marine ice from the Arctic and Antarctic.278−0.002−0.30 Embedded Image Embedded Image
Saline-misc (So)Miscellaneous saline environments including within gas hydrate mounds, salt marsh grasses, stromatolites, hypersaline mats, basalt, and hydrothermal vent colonizers161,4640.83** 0.14 Embedded Image Embedded Image
Mixed (M)Environments with mixing of water from saline and nonsaline sources including estuaries and an intertidal hotspring4170−0.330.29 Embedded Image Embedded Image
  • #S is the number of samples representing each group, #O is the number of OTUs represented in the samples, and G Resid and PD Resid are the average residuals for regression of G and PD values against sampling effort (Fig. 3 and SI Fig. 5). A negative/positive residual means that the point fell below/above the overall regression line, and is indicative of low/high comparative diversity. Significantly different residual averages are marked with “**” (“*” indicates that the value is sufficiently different that it would likely become significant with a larger sample size). The symbols that represents the samples in Fig. 1 (SN) and Fig. 2 (ET) are also indicated. Detailed information on the samples in each group is in SI Data Set 1.