| Forest restoration stages | |||||||
---|---|---|---|---|---|---|---|---|
 | F14 | F49 | F70 | UF | ||||
Soil layer | Topsoil | Subsoil | Topsoil | Subsoil | Topsoil | Subsoil | Topsoil | Subsoil |
Soil properties | ||||||||
  pH | 4.75 ± 0.07 A | 4.78 ± 0.06a | 4.43 ± 0.04 C | 4.50 ± 0.03b | 4.59 ± 0.03B | 4.57 ± 0.01b | 4.50 ± 0.04BC | 4.50 ± 0.04b |
  BD (g·cm− 3) | 1.35 ± 0.01 A | 1.47 ± 0.02a | 1.11 ± 0.01 C | 1.42 ± 0.00a | 1.27 ± 0.03B | 1.29 ± 0.02b | 1.26 ± 0.01B | 1.43 ± 0.01a |
  Sand (%) | 77.69 ± 0.35 A | 70.62 ± 0.45a | 24.08 ± 0.94 C | 19.78 ± 0.41c | 16.85 ± 0.66D | 16.23 ± 1.14d | 43.93 ± 0.87B | 45.88 ± 0.97b |
  Silt (%) | 18.17 ± 0.31 A | 23.85 ± 0.18c | 61.82 ± 1.16B | 65.38 ± 0.44a | 66.88 ± 0.69 A | 66.49 ± 0.87a | 44.75 ± 0.71 C | 43.67 ± 0.97b |
  Clay (%) | 4.14 ± 0.29 C | 5.53 ± 0.30d | 14.10 ± 0.84 A | 14.84 ± 0.26b | 16.27 ± 0.53 A | 17.28 ± 0.55a | 11.32 ± 0.72B | 10.45 ± 0.24c |
Soil microbial PLFAs (nmol·g− 1) | ||||||||
  Bacterial PLFA | 6.44 ± 0.32B | 4.10 ± 0.17b | 3.56 ± 0.39 C | 2.42 ± 0.27b | 8.75 ± 0.52 A | 2.98 ± 0.11b | 9.24 ± 0.72 A | 11.46 ± 1.07a |
  Fungal PLFA | 0.60 ± 0.03BC | 0.49 ± 0.05b | 0.42 ± 0.07 C | 0.28 ± 0.06b | 0.97 ± 0.04 A | 0.36 ± 0.02b | 0.81 ± 0.07AB | 1.42 ± 0.14a |
Soil amino sugar parameters (mg·kg− 1) | ||||||||
  GluN | 316.84 ± 29.77D | 116.65 ± 10.93d | 415.66 ± 7.28 C | 298.97 ± 12.31c | 502.64 ± 10.01B | 320.89 ± 3.82b | 598.21 ± 5.09 A | 336.84 ± 7.53a |
  MurA | 27.83 ± 4.17 | 12.83 ± 1.75b | 27.95 ± 1.39 | 21.38 ± 1.24a | 26.03 ± 2.14 | 20.87 ± 1.04a | 27.76 ± 3.50 | 20.31 ± 1.64a |
  GalN | 92.86 ± 17.68 C | 33.37 ± 3.38c | 141.06 ± 4.95B | 104.14 ± 5.57b | 152.56 ± 1.63B | 110.10 ± 2.10b | 176.67 ± 3.77 A | 133.24 ± 3.56a |