Feasibility of Ivy (Hedra helix) for landscaping in Seoul, Korea

Due to the global warming, Seoul in Korea seems to be plausible to grow evergreen broad-leaved trees over the cold winter. This offers the planting options to create green environment. Thus, it became worth investigating what kinds of evergreen broad-leaved plants could stand in Seoul during the winter. Ivy (Hedera helix) has been chosen in the current study which is a well-known native and ornamental plant in Europe. It grows in warm condition in general. The current study tracked H. helix which is evergreen cover plant over winter in order to evaluate the possibility for utilizing this species as a climber or cover-plant in Seoul. We found that H. helix can survive over the winter and can be utilized to create evergreen environment in Seoul. It also implies that similar kinds of plants could be tested assuming the environment of Seoul is becoming more suitable for the plants originated from the warmer sites. H. helix is an option for elaborating outdoor environments in the city that lacks of green color.

Thermal acclimation of photosynthetic activity and Rubisco content in two hybrid poplar clones

The mechanistic bases of thermal acclimation of net photosynthetic rate (An) are still difficult to discern and empirical research remains limited, particularly for hybrid poplar. In the present study, we examined the contribution of a number of biochemical and biophysical traits on thermal acclimation of An for two hybrid poplar clones. We grew cuttings of Populus maximowiczii × Populus nigra (M×N) and Populus maximowiczii × Populus balsamifera (M×B) clones under two day/night temperature of 23°C/18°C and 33°C /27°C and under low and high soil nitrogen level. After 10 weeks, we measured leaf RuBisCO and RuBisCO activase (RCA) amounts and the temperature response of An, dark respiration (Rd), stomatal conductance, (gs), maximum carboxylation rate of CO2 (Vcmax) and photosynthetic electron transport rate (J). Results showed that a 10°C increase in growth temperature resulted in a shift in thermal optimum (Topt) of An of 6.2±1.6 °C and 8.0±1.2 °C for clone M×B and M×N respectively, and an increased An and gs at the growth temperature for clone M×B but not M×N. RuBisCO amount was increased by N level but was insensitive to growth temperature while RCA amount and the ratio of its short to long isoform was stimulated by warm condition for clone M×N and at low N for clone M×B. The activation energy of Vcmax and J decreased under warm condition for clone M×B and remain unchanged for clone M×N. Our study demonstrated the involvement of both RCA, activation energy of Vcmax and stomatal conductance in thermal acclimation of An.