Table 1.
Chemical properties and CO2 uptake activity of Miyake-jima volcanic ash deposits and reference soilsa
| Sample | Site | Sampling year (age [y]) | Water content (%) | pH (H2O) | TC (g kg−1 dry soil) | TN (g kg−1 dry soil) | CO2 uptake rate (nmol [g dry weight]−1 h−1) |
|---|---|---|---|---|---|---|---|
| Volcanic ash deposit | OY | 2004 (3.5) | 24 | 3.6 | 0.3 | 0.1 | NDb |
| 2005 (5.0) | 25 | 3.0 | 0.3 | 0.1 | 4.9 | ||
| 2007 (6.6) | 27 | 3.4 | <0.1 | <0.1 | ND | ||
| IG | 2005 (5.0) | 25 | 4.1 | 1.6 | <0.1 | 1.2 | |
| 2007 (6.6) | 16 | 4.3 | 0.7 | 0.2 | ND | ||
| Surface soil | CL | 2005 (>800) | 34 | 5.5 | 28.2 | 2.5 | −10.9c |
| 2007 (>800) | 39 | 6.1 | 41.3 | 3.7 | ND |
a
Data for chemical properties represent the means of duplicate determinations.
b
ND, not determined.
c
Negative value represents CO2 production.