Fig. 4
From: Anaerobic microsites have an unaccounted role in soil carbon stabilization
The effect of particle size-induced variations in the extent of anaerobic microsites on the microbial oxidation of different carbon pools. a Changes in total carbon across the diffusion-limited domain within the reactor. b Changes in dissolved, particulate, or mineral-associated organic carbon pools in the aerobic and anaerobic zone. Dissolved (DOC), particulate (POC), and mineral-associated organic carbon (MAOC) are listed in order of decreasing bioavailability. c Changes in carbon oxidation state in reactor experiments. The changes in oxidation state are calculated as the ratio of the absorbance of carboxyl (288.35 eV) to that of aromatic C (285.05 eV) in spectra obtained by near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. Changes in carbon pools and oxidation state are shown relative to a time-zero control (t 0). Particle size variations to manipulate the extent of anaerobic microsites are shown in red (coarse = 150–250 µm) and blue (25–45 µm). Error bars denote the standard error of the mean calculated from four replicate reactors
