Winter photosynthesis by saplings of evergreen broad-leaved trees in a deciduous temperate forest

• Here we investigated photosynthetic traits of evergreen species under a deciduous canopy in a temperate forest and revealed the importance of CO₂ assimilation during winter for annual CO₂ assimilation. • Saplings were shaded by the canopy trees from spring through to autumn, but were less shaded during the winter months. Photosynthetic rates at light saturation (A_area) were lower during winter than during the growing season. A_area was higher in Camellia, Ilex and Photinia than in Castanopsis, Cleyera and Quercus during the winter, but differed little during summer and autumn. • Estimated daily CO₂ assimilation (A_day) was higher during the winter than during the growing season in Camellia, Ilex and Photinia but was higher than that during the growing season only at the beginning and end of winter in Castanopsis, Cleyera and Quercus. A_day was higher in Camellia, Ilex and Photinia than in Castanopsis, Cleyera and Quercus but differed little among them during the growing season. • These results reveal the importance of winter CO ₂ assimilation for the growth of Camellia, Ilex and Photinia. Furthermore, differences in annual CO₂ assimilation among species are strongly modified by species-specific photosynthetic traits during the winter under deciduous canopy trees.