Table 1A.

Diversity estimates from 16S rRNA amplicon libraries: 454 tag sequences.

Sample	Reads	Nobs	Singletons	Chao1∗	Shannon	Simpson evenness	Equitability
Day 9E	3148	74	24	109 (86–170)	3.21	0.017	0.52
Day 13E	2892	98	30	123 (107–160)	3.96	0.012	0.60
Day 76E	2309	118	45	201 (155–301)	4.49	0.009	0.65
Day 293E	2568	168	54	230 (199–292)	5.31	0.006	0.72
Basalt	4732	132	43	188 (158–255)	3.69	0.010	0.52
Day 9C	2993	144	58	216 (181–285)	4.05	0.008	0.56
Day 13C	2003	82	39	156 (114–256)	3.31	0.015	0.52
Day 283C	2510	151	62	224 (189–290)	4.63	0.007	0.64

^∗The ranges shown are 95% confidence intervals.