Abstract: In order to understand the bamboos interspecific differences in  physiological responses to elevated atmospheric O₃ concentration and in O₃ stress tolerance under the background of climatic change, and to provide theoretical evidences for bamboo cultivation, open-top chambers (OTCs) were employed to approach the effects of elevated O₃ on the leaf photosynthetic pigment content, soluble protein content, lipid peroxidation, and anti-oxidation system of Phyllostachys edulis and Oligostachyum lubricum. Five treatments were installed, i.e., filtered air, ambient air, 50 nl O₃·L^-1, 100 nl O₃·L^-1, and 150 nl O₃·L^-1. After treated with increasing concentration O₃ for 90 days, the leaf chlorophyll and carotenoid contents of the two bamboo species were decreasing, with the decrements being larger for Ph. edulis, while the leaf MDA content and POD activity were increasing, with the increments being larger for Ph. edulis than for O. lubricum. The leaf SOD activity of Ph. edulis ad a decreasing trend, while that of O. lubricum decreased after an initial increase. The leaf soluble protein content of Ph. edulis had an increasing trend, whereas that of O. lubricum was in adverse. Low concentration (≤50 nl·L^-1) O₃ had less damage to the two species, but high concentration (≥100 nl·L^-1) O₃ decreased their leaf photosynthetic pigments content and SOD activity and increased their leaf MDA content and POD activity significantly, resulting in the hindering of photosynthetic pigments synthesis, the accelerated leaf aging, the intensified membrane lipid peroxidation, as well as the destruction of leaf cell membrane structure and of anti-oxidation system functions of the two bamboo species. Principal component analysis showed that O. lubricum had a stronger capability of O₃ stress tolerance, as compared to Ph. edulis.

Key words: Mt. Qinling, Quercus aliena var. acuteserrata stands, Nutrient elements, Accumulation, Distribution