Regulatory Effects of Elevated Carbon Dioxide on Growth and Biochemical Responses to Ozone Stress in Chinese Pine (Pinus tabulaeformis Carr.).

This study examined whether carbon dioxide (CO) might alleviate ozone (O) injury to the dominant coniferous forest species of northern China, Pinus tabulaeformis Carr. After 90 days O exposure, biomass and net photosynthetic rate (Pn) decreased significantly by 24.44 % and 42.89 % compared with the control. A significant increase in malondialdehyde (MDA) was shown, suggesting cell membrane damage and oxidative stress. However, the positive responses of biomass dry weight, antioxidative enzymes and soluble sugar contents under elevated CO alone and the combination of elevated CO and O were observed, indicating that CO could ameliorate O-induced injury. The study provided increasing evidence that moderately elevated CO levels may have a beneficial effect on the forest ecosystem to respond to global climate change.