Table 1. Diversity metrics of rarified bacterial and archaeal 16S rRNA 454-pyrotag sequences.

Sample	Chao1a	Chao1 (lower bound)b	Chao1 (upper bound)b	ACEc	Simpsond	Singletonse	Doubletonse
Distal plume	394.53	273.32	628.27	443.80	0.58	91.78	15.96
Proximal plume	806.71	626.34	1093.50	911.07	0.57	198.93	38.47
Uncontaminated	1722.58	1507.22	2007.66	1849.08	0.96	481.80	126.04

^aSpecies richness (Chao, 1984).

^bConfidence intervals (Chao et al., 1992).

^cSpecies richness (Chao et al., 2000).

^dSpecies diversity (Simpson, 1949).

^eSingeltons are species with only one individual. Doubletons are species with only two individuals (Colwell and Coddington, 1994).