Abstract:
Objective Decomposition of Moso bamboo (Phyllostachys edulis (Carr.) H.de Lehaie) leaves and carbon and nutrient cycling of Moso bamboo forest are closely related. The research on atmospheric nitrogen deposition and global warming environmental changes on Moso bamboo leaves decomposition aims at providing a theoretical basis for the current countermeasures of bamboo forest management. Method The original leaves and powdery leaves of Moso bamboo (through the 2 mm sieve) was tested at three factors and two levels of completely randomized trial, i.e. added nitrogen (5 mg·g-1) and controls without nitrogen, cultivated temperature at 12℃ and 28℃, original leaves and powdery leaves, cultured in incubator for 78 days, the CO2 emissions were measured periodically by the sealed alkali absorption method, and the rate of decomposition were calculated. Result The effects of nitrogen fertilizer treatment, temperature and leaf shape and their interactions on the decomposition rate of Moso bamboo litter leaves were different at different periods. On the whole, the decomposition rate of Moso bamboo litter leaves were faster in pre-cultured (0-23 d) and mid-cultured (24-48 d) than that in post-cultured (49-78 d). The added nitrogen treatment inhibited the decomposition rate of original leaves at 12℃ in mean, while it had no significant effects on those of the two morphological leaves at 28℃. The temperature sensitivity (Q10) of original leaves decomposition rate increased by the treatment of added nitrogen, but the effect of added nitrogen on the Q10 of powdered litter leaves was not significant. Meanwhile, the Q10 of original bamboo litter decomposition rate was higher than that of powdery litter leaves. In addition, the C/N of bamboo leaf litter increased significantly after culture, and the increase in the powdery bamboo leaves with the nitrogen addition was more dominant. Conclusion The effects of nitrogen deposition on litter decomposition of Moso bamboo are related to cultivation temperature and leaf morphology. In summary, the impact of litter decomposition is numerous, so the study on the response of litter decomposition to global climate change should not only focus on its chemical and biological mechanism, but also on the physical process and its regulatory potentials.