Effects of Elevated CO₂Concentration on Leaf Phenology of Quercus acutissima

Abstract

Effects of elevated CO 2 on leaf phenology of Quercus acutissima were examined using open-top chambers, which had ambient and elevated CO 2 concentrations (ambient × 1.4, ambient × 1.8). To analyze the effect of chamber, non-treatment block was established near outside of the chambers. In 2013, budburst, leaf unfolding, coloring, and shedding were surveyed, and spring phenology was surveyed in 2014. Thermal sum (base temperature +5 o C) of each phenological event occurred was recorded. In addition, bud samples were collected and analyzed for carbohydrate contents in March 2014. Elevated CO 2 concentration advanced budburst and leaf unfolding, and delayed shedding in 2013. However, in 2014, the temperature of the spring season was high, and there was no significant effect of elevated CO 2 concentration on spring phenology. Carbohydrates content, such as starch, total non-structural carbohydrate and total soluble sugar, were significantly increased in response to elevated CO 2 concentration. It has been proposed that elevated CO 2 concentration could extend the growing season of temperate species with increased possibility of frost damage due to early bud opening and leaf unfolding. However, our analysis showed that the increased carbohydrate concentration in bud under elevated CO 2 would reduce the possibility of early spring frost damage by acting as cryoprotectant.

The Effects of CO2 Enrichment on the Radial Growth of Pinus densiflora

“…Past studies also reported the effects of CO 2 enrichment on morphological and physiological activities of trees (Ryu et al, 2014), and phenological activity of the leaves of Q. acutissima (Seo et al, 2014). These studies indicated that different tree species have different morphological and physiological characteristics (e.g., stomatal morphology and photosynthetic capacity) depending upon CO 2 enrichment and increasing carbon dioxide concentrations extends the growing season of Q.…”