Table 1.
Physicochemical properties, microbial abundances and potential bacterial respiration determined in soil samples of the studied layers A14 (upper), A16 (intermediate) and A18 (lower). For each variable, mean values followed by different letters are significantly different (p ≤ 0.05).
| A14 | A16 | A18 | |
|---|---|---|---|
| Soil physicochemical properties | |||
| pH | 6.5–7.0a | 6.5–7.0a | 6.5–7.0a |
| SOM (%)1 | 3.03b | 2.19a | 2.43ab |
| TOC (%)2 | 1.76b | 1.27a | 1.41ab |
| N (%) | 0.07a | 0.08a | 0.09a |
| TOC/N | 24.04b | 15.41a | 15.12a |
| PLFA-based microbial abundance | |||
| Total abundance (μg PLFA g−1 dry soil) | 515.72a | 387.60a | 411.25a |
| Bacteria (B) (μg PLFA g−1 dry soil) | 289.22a | 180.24a | 130.95a |
| Actinobacteria (μg PLFA g−1 dry soil) | 59.09a | 36.49a | 20.59a |
| Fungi (F) (μg PLFA g−1 dry soil) | 18.93a | 26.09a | 26.75a |
| F/B | 0.07a | 0.15ab | 0.20b |
| qPCR-based microbial abundance | |||
| Bacteria (B) (16S rRNA gene copy number g−1 dry soil) | 1.45 × 107a | 1.52 × 107a | 1.62 × 107a |
| Archaea (A) (16S rRNA gene copy number g−1 dry soil) | 8.70 × 105a | 8.85 × 105a | 1.32 × 106b |
| Fungi (F) (18S rRNA gene copy number g−1 dry soil) | 2.25 × 104a | 3.57 × 104a | 8.25 × 104a |
| A/B | 0.83a | 0.83a | 0.85a |
| F/B | 0.59a | 0.63a | 0.62a |
| Potential bacterial respiration | |||
| gtlA (gene copy number g−1 dry soil) | 7.73 × 103b | 4.57 × 103a | 3.76 × 103a |
1SOM, soil organic matter.
2TOC, total organic carbon.