Table 2.
Repeated-measures analysis of variance for the main and interactive effects of grazing (G) and sampling date (D) on dissolved organic C (DOC, mg kg−1) and N (DON, mg kg−1), the ratio of DOC and DON (DOC/DON ratio), nitrate N (NO3 −-N, mg kg−1), ammonium N (NH4 +-N, mg kg−1), the ratio of NH4 +-N and NO3 −-N (NH4 +-N/NO3 −-N ratio), soil available N (SAN, mg kg−1), and belowground root biomass (BGB, kg m−2) in an alpine meadow at three elevations (i.e., 4313 m, 4513 m, and 4693 m) on the Tibetan Plateau (n = 4).
| Elevation | Model | DOC | DON | DOC/DON ratio | NO3 −-N | NH4 +-N | NH4 +-N/NO3 −-N ratio | SAN | BGB |
|---|---|---|---|---|---|---|---|---|---|
| 4313 m | G | 0.77 | 1.65 | 0.46 | 27.10** | 26.05** | 1.05 | 95.61*** | 0.00 |
| D | 26.25*** | 4.80* | 5.00* | 57.55*** | 10.47** | 8.95** | 29.95*** | 2.79 | |
| G × D | 2.64 | 1.46 | 0.29 | 11.02** | 3.00 | 2.16 | 7.13* | 1.45 | |
|
| |||||||||
| 4513 m | G | 0.00 | 2.23 | 5.51 | 7.29* | 13.99** | 0.04 | 16.50** | 1.52 |
| D | 35.53*** | 4.38* | 0.40 | 51.70*** | 29.87*** | 12.29*** | 57.31*** | 2.74 | |
| G × D | 3.15 | 3.81 | 3.49 | 1.85 | 2.05 | 0.51 | 3.07 | 0.98 | |
|
| |||||||||
| 4693 m |
G | 0.00 | 0.16 | 0.12 | 0.82 | 0.27 | 0.08 | 0.65 | 0.64 |
| D | 1.33 | 3.67 | 3.03 | 9.24** | 15.27*** | 0.94 | 15.78*** | 3.85 | |
| G × D | 3.41 | 1.24 | 0.04 | 1.79 | 6.95** | 0.30 | 5.67* | 0.95 | |
*, **, and ***means P < 0.05, P < 0.01, and P < 0.001, respectively.