Abstract:To investigate the short-term effect of nitrogen (N) deposition on soil respiration (Rs) of a Pinus tabulaeformis plantation on Taiyue Mountain, a simulated nitrogen deposition experiment was conducted. Field work was carried out on Shanxi Taiyue mountain form July to August 2015. Simulated N deposition was conducted three times with the level of 100 kg hm-2 a-1 in the same plot, while using the LI-COR8150 automatic soil carbon flux observation system to monitor soil respiration dynamics. The dynamic change of soil respiration rate and its relationship with soil temperature and humidity before and after nitrogen application were studied. The results showed that the three nitrogen deposition events showed the same pattern. The soil respiration reached a maximum in 1 day after N treatment, then decreased. Rs tended to be stable during the third day after N deposition; the ANOVA showed that there were no significance differences in mean soil respiration before and after N treatment for the first and the second treatment (P>0.05). However, average soil respiration increased significantly from 1.99 μmol m-2 s-1 to 3.39 μmol m-2 s-1 during the third treatment (P<0.05). This indicated that nitrogen treatment showed a continuous effect on soil respiration. The relationship between soil respiration and soil temperature (Rs=aebT) was extremely significant (P<0.001), and nitrogen deposition increased the determination coefficient R2 of Rs=aebT for a short time. The soil temperature at 5 cm depth could explain 60%-69% of the variation in soil respiration. As time passes, nitrogen deposition decreased the determination coefficient R2 of Rs=aebT. The soil temperature at 5 cm depth could explain 14%-59% of the variation in soil respiration. Furthermore, the nitrogen deposition increased the Q10. Moreover, the two-variable model (Rs=aebTWc) with soil temperature and moisture appeared to have good precision when used to predict soil respiration compared with the one-variable model. The soil temperature and soil moisture at 5 cm depth could explain 49%-91% of the variation in soil respiration. In the background of global change, studying the effects of simulated N deposition on soil respiration and Q10 can provide a theoretical basis for further simulation and prediction of carbon cycling and carbon storage in the warm temperate forests worldwide.