Table 1.
Effects of grassland restoration on plant and soil properties (means ± standard error)
| Year since restoration (yr) | ||||||
|---|---|---|---|---|---|---|
| Item | 1 | 5 | 10 | 15 | 25 | 30 |
| Plant properties | ||||||
| Root biomass (g m−2) | 12.4 ± 1.5 d | 19.3 ± 2.3 c | 23.5 ± 2.4 c | 37.9 ± 2.1 b | 41.7 ± 3.5 b | 57.8 ± 5.3 a |
| Root C (g kg−1) | 288 ± 24 e | 324 ± 35 d | 336 ± 26 d | 357 ± 17 c | 384 ± 28 b | 398 ± 23 a |
| Root N (g kg−1) | 0.76 ± 0.05 a | 0.74 ± 0.07 a | 0.74 ± 0.04 a | 0.75 ± 0.06 a | 0.73 ± 0.03 a | 0.62 ± 0.05 b |
| Root P (g kg−1) | 0.38 ± 0.02 a | 0.44 ± 0.03 c | 0.45 ± 0.05 c | 0.48 ± 0.04 b | 0.53 ± 0.06 b | 0.64 ± 0.05 a |
| Leaf C (g kg−1) | 439 ± 23 d | 446 ± 52 c | 458 ± 43 c | 461 ± 27 b | 467 ± 35 b | 472 ± 36 a |
| Leaf N (g kg−1) | 1.58 ± 0.24 a | 1.57 ± 0.26 a | 1.54 ± 0.18 a | 1.55 ± 0.33 a | 1.48 ± 0.41 a | 1.45 ± 0.52 a |
| Leaf P (g kg−1) | 0.28 ± 0.03 a | 0.28 ± 0.02 a | 0.30 ± 0.02 a | 0.31 ± 0.01 a | 0.32 ± 0.03 a | 0.33 ± 0.02 a |
| Soil properties | ||||||
| pH | 7.73 ± 0.23 a | 7.21 ± 0.24 b | 7.02 ± 0.18 b | 6.54 ± 0.37 c | 6.17 ± 0.21 c | 6.03 ± 0.25 d |
| SM (%) | 9.42 ± 2.14 d | 10.31 ± 2.75 c | 11.62 ± 1.95 c | 12.93 ± 3.16 b | 13.11 ± 3.15 b | 14.20 ± 2.22 a |
| SOC (g kg−1) | 9.12 ± 1.89 | 10.36 ± 2.13 | 12.52 ± 2.56 | 13.51 ± 2.34 | 15.68 ± 1.89 | 16.17 ± 2.45 |
| STN (g kg−1) | 1.22 ± 0.23 d | 1.32 ± 0.35 c | 1.35 ± 0.26 c | 1.48 ± 0.17 b | 1.53 ± 0.35 b | 1.59 ± 0.21 a |
| SAP (mg kg−1) | 23.4 ± 3.4 e | 25.8 ± 2.8 e | 36.8 ± 5.4 d | 43.2 ± 4.1 c | 62.6 ± 5.4 b | 68.7 ± 5.9 a |
| MBC (mg kg−1) | 341 ± 36 d | 355 ± 39 c | 362 ± 26 c | 389 ± 42 b | 403 ± 49 b | 422 ± 37 a |
| MBN (mg kg−1) | 87.1 ± 8.6 d | 92.1 ± 9.6 c | 98.0 ± 11.2 c | 101.1 ± 7.9 b | 109.0 ± 9.2 b | 115.2 ± 15.1 a |
| MBP (mg kg−1) | 19.2 ± 3.1 a | 18.8 ± 5.2 a | 18.2 ± 2.1 a | 17.9 ± 3.1 a | 17.6 ± 2.5 a | 17.3 ± 3.8 a |
Note: Different lowercase letters indicate a significant difference (p < 0.05) among the treatments (year since restoration) by Fisher's test following the analysis of variance.
Abbreviations: MBC, microbial biomass C; MBN, microbial biomass N; MBP, microbial biomass P; SAP, soil available P; SM, soil moisture content; SOC, soil organic C; STN, soil total N.