This study was conducted to investigate the effects of elevated air temperature and atmospheric CO₂ concentration on the growth and physiological characteristics of two-year-old seedlings of three representative species (Abies koreana, Pinus densiflora, and Quercus serrata) in Korea based on a climate change scenario. Our study used a temperature gradient chamber (TGC; aC-eT) and CO₂-temperature gradient chamber (CTGC; eC-eT) to simulate climate change conditions under ambient and elevated CO₂ concentration and air temperature. Net photosynthetic rate (Pn) and biomass were measured and carboxylation efficiency (CE) and biomass allocation were calculated to examine the physiological responses of the seedlings. A. koreana and P. densiflora were negatively impacted by warming but Pn and CE increased under the eC-eT condition while Q. serrata showed decreased Pn and CE during the second year. There were significant differences in total biomass in P. densiflora, but showed no differences in Q. serrata. Shoot/root ratio in Q. serrata showed a significant increase under the aC-eT condition. Our results highlight that further investigation of species‐specific physiological responses and carbon allocation under artificial climate conditions is needed.

Climate change alters vegetation patterns, pushing subtropical forests further north. These forests play a crucial role for carbon neutrality efforts due to their significant CO₂ assimilation potential. This study investigated CO₂ assimilation rate along with growth, morphological, and physiological traits in 23 half-sib families of Quercus acuta and 26 half-sib families of Q. glauca, two prominent East Asian evergreen broadleaf species. Q. acuta exhibited significantly higher growth rates, with diameter at breast height (DBH) and aboveground biomass exceeding those for Q. glauca by 12.1% and 69.9%, respectively (p < 0.001). Leaf traits, including leaf mass pear area (LMA), leaf nitrogen, and chlorophyll content, were also greater in Q. acuta, showing 24.5%, 45.8%, and 15.6% higher values (p < 0.001). While photosynthetic traits were similar, Q. acuta exhibited a 12.7% higher intrinsic water-use efficiency (_iWUE) (p < 0.01). Among half-sib families, marginal differences were observed in growth traits (p < 0.1), and significant differences in leaf morphology and physiological traits (p < 0.05) were observed. A positive correlation was found between growth and physiological traits associated with the CO₂ assimilation rate in Q. acuta, but not in Q. glauca. These findings highlight the potential of Q. acuta and Q. glauca for supporting future carbon neutrality efforts and provide traits supporting carbon uptake, valuable for selecting tree species with enhanced carbon sequestration potential.