Moso bamboo (Phyllostachys edulis) forests are a vital resource in subtropical China, known for their high carbon (C) sequestration capacity. However, the dynamic processes of C fluxes within each component (canopy, culm, and soil) and their individual contributions, particularly during on- and off-years, remain unclear. A 2-year field experiment was conducted to investigate the dynamics of C fluxes from the canopy, culm, and soil (partitioned into heterotrophic, rhizome, and stump respiration) and their contributions to net ecosystem productivity (NEP) in a representative Moso bamboo forest in the subtropical region of China. The average annual NEP of the Moso bamboo forest was 7.31 ± 2.76 t C·ha−1. Specifically, the canopy's annual net C uptake was 17.30 ± 3.23 t C·ha−1, accounting for 237% of NEP. In contrast, C emissions from heterotrophs, culms, rhizomes, and stumps were 5.37 ± 1.20, 2.18 ± 1.05, 1.29 ± 0.04, and 1.15 ± 0.33 t C·ha−1, accounting for −73%, −30%, −18%, and −16% of NEP, respectively. The NEP, net cumulative C uptake in the canopy, and C emissions from the respiration of heterotrophs and stumps were all significantly higher during on-years when compared to off-years, whereas C emissions from bamboo culms displayed opposite trends. These findings offer a new approach for quantifying the C budgets of Moso bamboo forests and provide valuable insights into the C cycling processes in forest ecosystems.
- Article type
- Year
Open Access
Research Article
Issue
Open Access
Research
Issue
It is still not clear whether the effects of N deposition on soil greenhouse gas (GHG) emissions are influenced by plantation management schemes. A field experiment was conducted to investigate the effects of conventional management (CM) versus intensive management (IM), in combination with simulated N deposition levels of control (ambient N deposition), 30 kg N·ha-1·year-1 (N30, ambient + 30 kg N·ha-1·year-1), 60 kg N·ha-1·year-1 (N60, ambient + 60 kg N·ha-1·year-1), or 90 kg N·ha-1·year-1 (N90, ambient + 90 kg N·ha-1·year-1) on soil CO2, CH4, and N2O fluxes. For this, 24 plots were set up in a Moso bamboo (Phyllostachys edulis) plantation from January 2013 to December 2015. Gas samples were collected monthly from January 2015 to December 2015.
Compared with CM, IM significantly increased soil CO2 emissions and their temperature sensitivity (Q10) but had no significant effects on soil CH4 uptake or N2O emissions. In the CM plots, N30 and N60 significantly increased soil CO2 emissions, while N60 and N90 significantly increased soil N2O emissions. In the IM plots, N30 and N60 significantly increased soil CO2 and N2O emissions, while N60 and N90 significantly decreased soil CH4 uptake. Overall, in both CM and IM plots, N30 and N60 significantly increased global warming potentials, whereas N90 did not significantly affect global warming potential. However, N addition significantly decreased the Q10 value of soil CO2 emissions under IM but not under CM. Soil microbial biomass carbon was significantly and positively correlated with soil CO2 and N2O emissions but significantly and negatively correlated with soil CH4 uptake.
Our results indicate that management scheme effects should be considered when assessing the effect of atmospheric N deposition on GHG emissions in bamboo plantations.
京公网安备11010802044758号