Abstract: In this paper, the possible changes in carbon budget of forest ecosystems in Northeast China under the future climatic scenario were simulated by using the forest carbon budget model for China (FORCCHN) driven by the simulated future output data from FGOALS model. The results showed that under A1B (balanced development scenario) and in 2003〖KG-*2〗-〖KG-*7〗2049, the net primary productivity (NPP) and soil respiration rate of Northeast China forest ecosystems had an increasing trend, and the increment of soil respiration rate would be far higher than that of NPP (13443% vs. 1084%). The forest ecosystems in Northeast China would still be an obvious carbon sink, but their carbon-absorbing capability would be decreasing. Nevertheless, the total mount of absorbed carbon dioxide would be still increasing. All of these illustrated that from 2003 to 2049, the forest ecosystems in Northeast China would play an active role in reducing greenhouse gases concentration and in mitigating the impact of climatic change.

Key words: SO₂, Wheat, Salicylic acid, Ethylene, Hydrogen peroxide