Table 4. C pools of different biomass components in P. tabulaeformis forests.
Components | Young | Middle-aged | Immature | Mature | ||||
(Mg C ha–1)(%) | (Mg C ha–1)(%) | (Mg C ha–1)(%) | (Mg C ha–1)(%) | |||||
Total tree | 62.4±9.6d | 90.3±2.4a | 96.4±4.5c | 93.3±0.6a | 133.8±18.7b | 94.1±0.9a | 177.0±11.8a | 95.2±0.5a |
Aboveground | 50.8±7.8d | 73.4±1.9a | 86.8±3.8c | 84.0±0.8b | 117.8±15.9b | 82.8±0.5b | 161.2±10.8a | 86.8±0.5b |
Tree stem | 28.6±4.4d | 41.4±1.1b | 69.9±3.0c | 67.6±0.8c | 95.1±12.5b | 66.9±0.2c | 125.8±11.1a | 64.5±3.3c |
Stem wood | 23.8±3.8d | 34.4±1.1c | 64.0±2.9c | 62.0±0.6d | 86.7±11.2b | 61.0±0.2d | 113.6±10.5a | 58.3±3.3d |
Stem bark | 4.8±0.7c | 6.9±0.2f | 5.9±0.2c | 5.7±0.2g | 8.3±1.3b | 5.9±0.1g | 12.2±0.9a | 6.2±0.1f |
Branch | 11.8±1.9b | 17.1±0.6d | 9.3±0.6c | 9.0±0.2e | 9.0±0. 2c | 6.4±0.8fg | 15.9±1.2a | 8.2±0.2f |
Needle | 9.4±1.5b | 13.5±0.5e | 7.2±0.2c | 6.9±0.2f | 10.0±1.3b | 7.1±0.0f | 13. 1±1.1a | 6.7±0.3ef |
Pine cone | 1.0±0.1b | 1.4±0.2hi | 0.4±0.0b | 0.4±0.0j | 3.7±2.0b | 2.5±1.0i | 6.440±0.8a | 3.5±0.6g |
Roots | 11.7±1.8b | 16.9±0.6d | 9.6±0.7b | 9.3±0.2e | 16.1±2.8a | 11.3±0.5e | 15.8±2.3a | 8.1±1.0e |
Total understory | 1.5±0.4a | 2.2±0.5h | 0.8±0.5b | 0.8±0.6ij | 1.2±0.3ab | 0.9±0.1jk | 0.9±0.2ab | 0.5±0.1i |
Total shrub | 0.2±0.2a | 0.3±0.2i | 0.3±0.3a | 0.3±0.3j | 0.4±0.3a | 0.3±0.2kl | 0.4±0.3a | 0.2±0.1i |
Shrub foliage | 0.0±0.0b | 0.0±0.0j | 0.0±0.0ab | 0.0±0.0j | 0.0±0.0b | 0.0±0.0l | 0.1±0.0a | 0.0±0.0i |
Shrub branch | 0.1±0.1a | 0.1±0.1j | 0.1±0.2a | 0.2±0.2j | 0.1±0.1a | 0.1±0.1l | 0.2±0.1a | 0.1±0.1i |
Shrub root | 0.1±0.1a | 0.2±0.2j | 0.1±0.1a | 0.1±0.1j | 0.3±0.3a | 0.2±0.2kl | 0.2±0.1a | 0.1±0.1i |
Total herb | 1.3±0.5a | 1.9±0.7hi | 0.5±0.3b | 0.5±0.3j | 0.8±0.1ab | 0.6±0.1jkl | 0.5±0.5b | 0.3±0.3i |
Aboveground herb | 0.4±0.2a | 0.6±0.3hi | 0.1±0.1a | 0.2±0.1j | 0.2±0.1a | 0.1±0.0kl | 0.2±0. 2a | 0.1±0.1i |
Belowground herb | 0.9±0.2a | 1.3±0.4hi | 0.4±0.2b | 0.4±0.2j | 0.6±0.1ab | 0.5±0.1kl | 0.3±0.3b | 0.2±0.2i |
Forest floor | 5.1±0.8c | 7.5±2.2f | 6.2±1.4bc | 6.0±1.1g | 7.1±0.5ab | 5.1±0.9h | 7.9±0.2a | 4.1±0.3g |
Undecomposed | 3.1±0.4b | 4.6±1.3g | 4.0±1.0ab | 3.9±0.8h | 4.4±0.6a | 3.1±0.7i | 4.6±0.2a | 2.4±0.2gh |
Semi-decomposed | 1.4±0.3b | 2.0±0.6h | 1.5±0.3b | 1.4±0.2i | 1.9±0.4ab | 1.4±0.4j | 2.3±0.2a | 1.2±0.1h |
Full decomposed | 0.6±0.2a | 0.9±0.4hi | 0.7±0.2a | 0.7±0.2ij | 0.8±0.4a | 0.6±0.3kl | 0.9±0.3a | 0.5±0.2i |
Data are presented as the mean value ± the standard deviation (SD). Mean values of C stocks within a row and mean percentages of C stocks of biomass components within a column followed by different lowercase letters are both significantly different at p<0.05.