Abstract: The study with open-top chamber showed that at 500 μmol CO₂·mol^-1, the soil respiration rate under Pinus koraiensis and P. sylvestriformis decreased significantly, probably due to the slow diffusion of increased soil surface CO₂ concentration. The soil surface CO₂ concentration at 500 μmol CO₂·mol^-1 was significant higher than that in the control chamber and un-chambered field, with an increment of 40～150 μmol CO₂·mol^-1. The soil surface CO₂ concentration of P. sylvestriformis in the control chamber was higher than that on unchambered field, but the difference was not significant, while a significant difference was observed in P. koraiensis. The total nitrogen and total organic carbon contents in P. sylvestriformis soil at 500 μmol CO₂·mol^-1 had no significant difference with those in the control chamber and on unchambered field, while their contents in P. koraiensis soil were significantly lower on unchambered field than those in the control chamber and at 500 μmol CO₂·mol^-1. Elevated CO₂ and the microenvironment of open-top chamber had little effect on the soil temperature at 3 cm depth.

Key words: Antheraea yamamai, Teste, Growth and development, High temperature