Table 2.
Changes in the content of soil nitrogen forms under different litterfall manipulation treatments in two sub-tropical forest types.
| N form | Treatment | MPPF | MCMF | |||
|---|---|---|---|---|---|---|
| Content (mg‧kg−1) | Change (%) | Content (mg‧kg−1) | Change (%) | |||
| NH4+-N | LA* | 9.66 ± 2.94 Ab | 23.21↑ | 14.07 ± 3.93 Aa | 18.24↑ | |
| LC | 7.84 ± 1.29 Ab | 0.00 | 11.90 ± 2.42 Aa | 0.00 | ||
| LR | 7.79 ± 1.01 Aa | 0.64↓ | 7.94 ± 1.88 Ba | 33.28↓ | ||
| NO3−-N | LA | 15.23 ± 4.81 Aa | 49.90↑ | 19.08 ± 8.75 Aa | 25.28↑ | |
| LC | 10.16 ± 4.45 Bb | 0.00 | 15.23 ± 6.79 Ba | 0.00 | ||
| LR | 8.17 ± 3.19 Bb | 19.59↓ | 13.00 ± 6.48 Ba | 14.64↓ | ||
| Total inorganic N | LA | 24.89 ± 4.42 Ab | 40.86↑ | 33.15 ± 5.95 Aa | 22.19↑ | |
| LC | 17.67 ± 4.94 Bb | 0.00 | 27.13 ± 4.64 Ba | 0.00 | ||
| LR | 15.97 ± 3.08 Bb | 9.62↓ | 20.73 ± 5.22 Ca | 23.59↓ | ||
*
LA, litter addition; LC, litter control; LR, litter removal; MPPF, Masson pine pure forests; MCMF, Masson pine and Camphor tree mixed forests. Values are mean ± SD. Different capital letters indicate significant differences among the same forest type column treatments. In contrast, lower-case letters indicate significant differences between the forest types under the same treatment (p < 0.05). Upper ↑ indicates a positive change, and down ↓ indicates a negative change in LA and LR treatments compared to LC treatment.