The influences of elevated ozone (O₃) concentrations on biomass, leaf gas exchange, fluorescence parameters, and leaf physiological and biochemical traits were examined in Elaeocarpus sylvestris and Michelia chapensis seedlings under four O₃ conditions for a growing season in open-top chambers (OTCs). The four O₃ concentrations were charcoal-filtered air (CF) (20 ppb), 1 × O₃ air (40 ppb), 2 × O₃ air (80 ppb), and 4 × O₃ air (160 ppb), respectively. The significant decrease in the root/shoot (R/S) ratios of both species indicated that under O₃ stress root biomass was more negatively affected than shoot biomass for both tree seedlings. Along with the loss of chlorophyll and carotenoid contents, decrease in the superoxide dismutase (SOD), and enhanced level of lipid peroxidant, the light-saturated net photosynthesis rate (P_nmax) of E. sylvestris, the effective quantum yield of PSII photochemistry (Y(II)) and the electron transport rate (ETR) of both species decreased, suggesting that impaired photosynthesis occurred. The negative effect of O₃ on physiological and biochemical parameters was greater for M. chapensis than for E. sylvestris. As the O₃ concentration increased, the leaf mass per area (LMA) of E. sylvestris decreased, while that of M. chapensis increased. Therefore, the increased SOD activity as a hormetic-compensatory response, the increases in LMA and longer vegetative period contributed to the good adaptability and high tolerance of M. chapensis.

在4个O ₃条件下，在开放式密闭室中的生长季节，研究了Elaeocarpus sylvestris和chapensis Michele chapensis幼苗中臭氧（O ₃）浓度升高对生物量，叶片气体交换，荧光参数以及叶片生理生化特性的影响（ OTC）。四个O ₃浓度分别是木炭过滤空气（CF）（20 ppb），1×O ₃空气（40 ppb），2×O ₃空气（80 ppb）和4×O ₃空气（160 ppb）。 。两个物种的根/茎（R / S）比的显着降低表明在O _3下两种树苗的胁迫根生物量均比苗生物量受到更大的负面影响。随着叶绿素损失和类胡萝卜素含量，减少在超氧化物歧化酶（SOD），以及脂质peroxidant的增强级中，光饱和净光合速率（P _n最大）的E.樟子松，有效量子PSII光化学产率（两种物种的Y（II））和电子传输速率（ETR）均降低，表明发生了光合作用受损。的O-的负面影响₃上的生理生化参数是更大的乐昌含笑比E.樟子松。随着O ₃浓度的增加，每单位面积的叶片质量（LMA）为樟树E. sylvestris减少，而chapensis M. chapensis的增加。因此，增加的SOD活性作为一种荷尔蒙补偿反应，LMA的增加和营养期的延长，有助于chapensis的良好适应性和高耐受性。