Table 2.
Copy numbers of soil microbial functional nitrification and denitrification genes in grasslands.
| Gene copies g−1 soil | AOA* | AOB* | narG* | nirK* | nirS | nosZ | nosZ clade II | |
|---|---|---|---|---|---|---|---|---|
| Tibet | Baingoin | 4.2E8 ± 4.1E7c | 1.3E6 ± 7.9E5a | 5.1E6 ± 4.7E5cd | 3.0E6 ± 5.6E5cd | 3.0E5 ± 4.2E4b | 3.2E4 ± 2.1E3c | 6.3E6 ± 5.3E6ab |
| Nagqu | 6.6E8 ± 2.6 E7d | 5.9E7 ± 2.2E7b | 4.5E6 ± 6.0E5cd | 5.0E6 ± 1.2E6de | 3.6E5 ± 1.6E4b | 1.9E5 ± 3.8E4d | 1.6E7 ± 4.5E6b | |
| Hezuo | 9.0E8 ± 7.6 E7e | 2.6E8 ± 4.8E7d | 1.8E7 ± 2.5E6e | 8.1E6 ± 1.4E6e | 1.6E6 ± 9.7E4c | 4.3E5 ± 2.2E4f | 1.8E7 ± 1.1E6b | |
| Haibei | 9.6E8 ± 3.2 E7e | 1.5E8 ± 1.2E7c | 1.4E7 ± 2.5E6e | 1.3E7 ± 1.8E6f | 1.3E6 ± 2.4E5c | 5.1E5 ± 3.9E4g | 2.4E7 ± 1.3E7b | |
| Inner magnolia | Duolun | 1.6E4 ± 8.0 E3a | 3.9E7 ± 1.2E7b | 1.1E6 ± 9.7E5b | 5.3E5 ± 1.1E5b | 1.6E6 ± 5.4E5c | 1.7E4 ± 4.0E3b | 4.7E6 ± 1.9E6ab |
| Sonid Zuoq | 3.2E5 ± 7.4 E4a | 0.0 ± 0.0a | 7.9E3 ± 2.6E2a | 1.9E3 ± 6.0E2a | 1.8E3 ± 1.8E2a | 0.0 ± 0.0a | 5.1E3 ± 2.2E2a | |
| Xilin Hot | 1.9E8 ± 1.8 E7b | 7.0E7 ± 2.9E7b | 6.8E6 ± 1.4E5d | 2.2E6 ± 1.2E6bc | 2.3E5 ± 5.2E4b | 6.8E5 ± 3.0E4h | 7.6E6 ± 3.0E6ab | |
| Hulunbuir | 2.2E8 ± 4.7 E6b | 1.6E6 ± 1.0E6a | 3.1E6 ± 2.0E5bc | 1.3E6 ± 2.1E5bc | 3.6E6 ± 4.2E5d | 3.3E5 ± 2.8E4e | 5.7E6 ± 3.3E6ab |
The values represent means ± 1 SEM (n = 4) and followed by a different letter are significantly different between different sites (p < 0.05). With * mark means that there is a significant difference between Tibet and Inner Mongolia via the Mann–Whitney U test (p < 0.05).