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

Abstract

Summary• Here we investigated photosynthetic traits of evergreen species under a deciduous canopy in a temperate forest and revealed the importance of CO 2 assimilation during winter for annual CO 2 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 CO 2 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 CO 2 assimilation among species are strongly modified by species-specific photosynthetic traits during the winter under deciduous canopy trees.Key words: deciduous canopy trees, the growth season, photosynthetic capacity, nitrogen content, daily CO 2 assimilation, winter CO 2 assimilation.

Photosynthetic ecophysiology of evergreen leaves in the woody angiosperms – a review

“…Saplings of six understory evergreen species in central Japan showed an early winter decline and a late winter recovery of photosynthetic capacity, with Camellia japonica and Ilex pedunculosa maintaining as much as ca. 50% and 25% of their respective summer capacities even during the coldest period in January (Miyazawa and Kikuzawa 2005b). When integrated over the whole year, assimilation during the 4.5 months of winter in three of these six species exceeded that during the rest of the year, illustrating the advantages of an evergreen life strategy under a deciduous forest canopy.…”

“…Where temperature allows, winter CO 2 uptake may be an important contribution to the annual CO 2 budget, e.g. because of favorable moisture conditions in Mediterranean vegetation (Varone and Gratani 2007) or abundant light in the understory of temperate deciduous forests (Miyazawa and Kikuzawa 2005b). Saplings of six understory evergreen species in central Japan showed an early winter decline and a late winter recovery of photosynthetic capacity, with Camellia japonica and Ilex pedunculosa maintaining as much as ca.…”

Climate-growth variability in Quercus ilex L. west Iberian open woodlands of different stand density

“…Severe drought and excessive heat seem to cause a decrease in future growth during the next year because of poor bud formation and/or carbohydrate accumulation during the previous autumn. The absence of frosts would favour late autumn-winter photosynthesis and increase carbohydrate storage for future growth (Miyazawa and Kikuzawa, 2005). This might be the reason for the positive correlation of minimum temperatures in November and December of the previous year.…”

The need for a canopy perspective to understand the importance of phenotypic plasticity for promoting species coexistence and light‐use complementarity in forest ecosystems

“…Temporal differentiation in light-use among species also occurs at longer time scales, such as during succession in a tropical secondary forest (Selaya et al 2008). In many temperate forests of Japan, evergreen and deciduous trees coexist, and the difference in leaf habit and timing of leaf flushing may represent temporal differentiation among species (see, e.g., Maeno and Hiura 2000; Miyazawa and Kikuzawa 2005). At a shorter time-scale, the diurnal pattern of photosynthesis tends to vary among coexisting species.…”