TABLE 3.
Carbon isotope ratios of dissolved inorganic carbon, dissolved organic C, and total C present in Fe(III)-oxide microbial mats collected from Norris Geyser Basin, YNP, 2011 to 2013
| Carbon pool | Samplea | δ13C value (‰) (σ) (no. of samples) | Concn (mg kg−1) (σ) (no. of samples)b |
|---|---|---|---|
| DIC | OSP_B | −5.1 (0.8) (3) | 1.5 (0.8) (3) |
| BE_D | −3.2 (0.2) (4) | 2.0 (1.9) (4) | |
| GRN_D | −0.5 (2.6) (3) | 0.6 (0.1) (3) | |
| DOC | OSP_B | −21.0 (1.6) (3) | 0.8 (0.5) (3) |
| BE_D | −22.3 (1.0) (5) | 0.8 (0.7) (4) | |
| GRN_D | −23.0 (2.1) (4) | 0.6 (0.2) (3) | |
| Microbial matc | OSP_B | −15.0 (1.8) (3) | 10,200 |
| BE_D | −16.4 (1.1) (8) | 11,500 | |
| GRN_D | −16.5 (0.9) (3) | 7,600 |
a
OSP_B, One Hundred Springs Plain Spring site B; BE_D, Beowulf Spring site D; GRN_D, Grendel Spring site D.
b
Expressed as mg per liter for DIC and DOC and mg per kg (dry weight) for microbial mat C.
c
The total C level was determined on aggregate mat samples from each site during this time frame (n = 1). The range of 0.8 to 1.5% total C agrees favorably with values observed in previous studies (16).