Pan-Gi Kim

Long-term Climate Change Research Facility for Trees: CO 2 -Enriched Open Top Chamber System

The open-top chamber (OTC) system is designed for long term studies on the climate change impact on the major tree species and their community in Korea. In Korea Forest Research Institute (KFRI), the modified OTC system has been operating since September 2009. The OTC facility consists of six decagon chambers (10 meters in diameter by 7 meters high) with controlled gas concentration. In each chamber, a series of vertical vent pipes are installed to disperse carbon dioxide or normal air into the center of the chamber. The OTC is equipped with remote controlled computer system in order to maintain a stable and elevated concentration of carbon dioxide in the chamber throughout the experimental period. The experiment consisted of 4 treatments: two elevated levels ( and ambient ) and two controls (inside and outdoors of the OTC). Average operational rate was the lowest (94.2%) in June 2010 but increased to 98% in July 2010 and was 100% during January to December 2011. In 2010~2011, concentrations inside the OTCs reached the target programmed values, and have been maintained stable in 2011. In 2011, concentrations of 106%, 100% and 94% of target values has been recorded in control OTC, -enriched OTC and -enriched OTC, respectively. With all OTC chambers, the difference between outside and inside temperatures was the highest () at 10 am to 2 pm. Temperature difference between six OTC chambers was not detected. The relative humidity inside and outside the chambers was the same, with minor variations (0~1%). The system required the highest amount of for operation in June, and consumed 11.33 and 17.04 ton in June 2010 and 2011, respectively.

Effects of Fertilization on Physiological Parameters in American Sycamore (Platanus occidentalis) during Ozone Stress and Recovery Phase

American sycamore seedlings were grown in chambers with two different ozone concentrations (-free air and air with additional ) for 45 days. Both the control and the chambers included non-fertilized and fertilized plants. After 18 days of fumigation, seedlings were placed in a clean chamber for 27 days. Seedlings under ozone fumigation showed a significant decrease in pigment contents and photosynthetic activity, and a significant increase in lipid peroxidation. Fertilization enhanced physiological damage such as the inhibition of photosynthetic activity and the increase of lipid peroxidation under ozone fumigation. During the recovery phase, the physiological damage level of seedlings increased with ozone fumigation. In addition, physiological damage was observed in the fertilized seedlings. Superoxide dismutase (SOD) and glutathione reductase (GR) activities of -treated seedlings increased up to 33.8% and 16.3% in the fertilized plants. The increase of SOD activity was higher in the fertilized plants than in the non-fertilized plants. Negative effects of ozone treatment were observed in the biomass of the leaves and the total dry weight of the fertilized sycamore seedlings. The -treated seedlings decreased in stem, root and total dry weight, and the loss of biomass was statistically significant in the fertilized plants. In conclusion, physiological disturbance under normal nutrient conditions has an effect on growth response. In contrast, in conditions of energy shortage, although stress represents a physiological inhibition, it does not seem to affect the growth response.

Photosynthetic Inhibition in Leaves of Ailanthus altissima under O 3 Fumigation

We investigated the enect of on the photosynthetic characteristics of tree of heaven (Ailanthus altissima) that is naturalized plant and used as restoration plant for contaminated area. Two-year-old seedlings were planted to pots and transferred into closed chamber. Photosynthetic pigments contents and photosynthetic characteristics were measured every three weeks under 100 pub fumigation. There was no visible foliar injury by exposure and contents of photosynthetic pigments did not show significant differences between control and -treated seedlings. Also there were no significant differences in stomatal conductance, and water use efficiency. But photosynthetic rate and apparent quantum yield (AQY) of treated seedlings were reduced after nine weeks of ozone fumigation. In addition, the reduction of carboxylation efficiency and photorespiration were observed in the leave of treated seedlings after six weeks. In accordance with our result, carbon fixation system of A. altissima was most sensitive to stress to evaluate physiological damage induced by .

Effects of Elevated CO 2 Concentration and Temperature on Physiological Characters of Liriodendron tulipifera

This study aimed to investigate the growth and physiological characters of Liriodendron tulipifera seedlings in responses to two different levels of elevated air temperature and CO2 concentration. The seedlings were grown in environment-controlled growth chambers with two combinations of air temperature and CO2 conditions: (1) 22 o C + ambient CO2 380 µmol mol �1 and (2) 27 o C + 770 µmol mol �1 . Physiological characters such as growth, photosynthesis, and water use efficiency, were monitored for 85 days. The seedlings under the elevated treatment showed a greater amount of growth in tree height, compared with those under the control. Regarding the characteristics of assimilatory organs, the elevated treatment resulted in a greater amount of total leaf area, leaf unfolding, and dry weight per leaf area. No significant differences were found in photosynthesis capacity between the two treatments. The increase in water use efficiency with increased intercellular CO2 partial pressure appeared overall lower in the seedling under the elevated treatment, compared with those under the control. The total leaf area of the seedlings under the elevated treatment was larger than that under the control, indicating a higher amount of photosynthesis. In addition, an increase of root growth was noted under the elevated treatment. A resistance mechanism of water stress may be attributed to a higher amount of organ growth as well as the tree height under the elevated treatment than the control.

Effects of Elevated Atmospheric CO 2 and Nitrogen Fertilization on Growth and Carbon Uptake of Yellow Poplar Seedlings

To investigate the responses of yellow poplar (Liriodendron tulipifera L.) seedlings to the interactive effects of the elevated atmospheric level and nitrogen addition, we measured biomass, photosynthetic pigments, photosynthesis, and the contents of nitrogen (N) and carbon (C) from the seedlings after 16 weeks of the treatments. Yellow poplar seedlings were grown under the ambient () and the elevated (560 and ) CO2 concentratoins with three different N addition levels (1.2, 2.4, and ) in the Open Top Chambers (OTC). The dry weight of the seedlings enhanced with the increased N levels under the elevated concentrations and the increment of the dry weight differed among the different N levels. Photosynthetic pigment content of the yellow poplar leaves also increased with the increase of the concentration levels. The effects of the N levels on the photosynthetic pigment content, however, were significantly different among the levels. Photosynthetic rates were affected by the levels of and N concentrations. Stomatal conductance and transpiration rates increased with increasing concentration. The carboxylation efficiency of the seedlings without N addition increased under the higher concentrations whereas that with N addition decreased under the elevated concentrations. Nitrogen and carbon uptake in leaf, stem, and root increased with the elevated concentration level and N addition. In conclusion, under the elevated concentrations, physiological characteristics and carbon uptake of the yellow poplar seedling were improved and increased with N addition.

Photosynthetic Responses of Populus alba×glandulosa to Elevated CO 2 Concentration and Air Temperature

This study was conducted to investigate the photosynthetic characters of Populus alba×glandulosa cuttings in response to elevated CO2 concentration and air temperature for selecting tree species adaptive to climate change. The cuttings were grown in environment controlled growth chambers with two combinations of CO2 concentration and air temperature conditions: (i) 22 C + CO2 380 μmol mol (control) and (ii) 27C + CO2 770 μmol mol −1 (elevated) for almost three months. The cuttings under the elevated treatment showed reduced tree height and photosynthetic pigment contents such as chlorophyll and carotenoid. In particular, the elevated treatment resulted in a marked reduction in the chlorophyll a closely associated with CO2 fixative reaction system. Different levels of reduction in photosynthetic characters were found under the elevated treatment. A decrease was noted in photochemical reaction system parameters: net apparent quantum yield (7%) and photosynthetic electron transport rate (14%). Moreover, a significant reduction was obvious in CO2 fixative reaction system parameters: carboxylation efficiency (52%) and ribulose-1,5-bisphosphate(RuBP) regeneration rate (24%). These results suggest that the low level of photosynthetic capacity may be attributed to the decreased CO2 fixative reaction system rather than photochemical reaction system.

Alteration of Leaf Surface Structures of Poplars under Elevated Air Temperature and Carbon Dioxide Concentration

Effects of elevated air temperature and carbon dioxide () concentration on the leaf surface structures were investigated in Liriodendron tulipifera (yellow poplar) and Populus tomentiglandulosa (Suwon poplar). Cuttings of the two tree species were exposed to elevated air temperatures at (day/night) and concentrations at 770/790 ppm for three months. The abaxial leaf surface of yellow poplar under an ambient condition ( and 380/400 ppm) had stomata and epicuticular waxes (transversely ridged rodlets). A prominent increase in the density of epicuticular waxes was found on the leaves under the elevated condition. Meanwhile, the abaxial leaf surface of Suwon poplar under an ambient condition was covered with long trichomes. The leaves under the elevated condition possessed a higher amount of long trichomes than those under the ambient condition. These results suggest that the two poplar species may change their leaf surface structures under the elevated air temperature and concentration condition for acclimation of increased photosynthesis.

Growth, Physiological Responses and Ozone Uptake of Five Betula Species Exposed to Ozone

The objectives of this study were to examine the physiological responses to ozone and to measure ozone uptake rates of Betula species exposed to relatively high concentration of pollutants. At the end of the growing season, photosynthesis, pigments contents, antioxidants (SOD and GR) and ozone uptake rates were measured or estimated at the leaves of five Betula species (Betula costata, B. davurica, B. platyphylla var. japonica, B. schmidtii and B. ermanii) exposed to 100ppb ozone concentration. On the termination of the experiment, growth effects were determined by measuring leaf area and dry weights of leaf, stem and root. Ozone treatment showed the significant reduction the leaf area and dry weight of four Betula species, except for B. ermanii. Shoot / root (SR) ratio of five species represented two different types. SR ratio of B. costata and B. davurica were lower than control, in contrast, SR ratio of B. platyphylla var. japonica, B. schimidtii and B. emani, were higher than that of control. The photosynthetic responses of five species were different in responses to ozone exposure. Four species, except for B. emanii, maintained or increased the stomatal conductance, but B. emanii decreased both stomatal conductance and photosynthesis. SOD activities of five species decreased by the ozone exposure, especially B. ermanii showed the largest reduction, GR activities of B. platyphylla var. japonica and B. schmidtii increased, B. costata and B. emanii decreased. Instantaneous ozone uptake rate was the highest at the leaves of B. ermanii and B. costata, ozone uptake per seedling was the highest at the leaf of B. schmidtii and B. emanii. It was concluded that B. costata, B. davurica and B. platyphylla var. japonica, appeared the growth reduction and visible ozone injury, were sensitive species to ozone, and B. schmidtii with the increased antioxidant activity and B. ermanii without the growth reduction were relatively resistant species to high ozone concentration at the early growing stage.

Adaptation of Betula schmidtii Seedling in Coal-mine Field with Different Sewage Sludge Treatment Methods

We tested the field adaptation of Betula schmidtii on the abandoned coal-mine soil with sludge amendment methods for promoting physiological activity of B. schmidtii seedlings under several environmental stress. Sewage sludges were amended to coal-mine soil with B. schmidtii seedlings which grown in the mixture of artificial soil and composted sludge soil before transplanting (before-fertilized treatment, BF) and fertilized with composted sludge after transplanting (after-fertilized treatment, AF). The percent of establishment of seedlings for AF (80.7%) was lower than that for BF (92.7%). Nitrate reductase activity and photosynthetic pigment content were higher in AF than in BF, but malondialdehyde (MDA) content and superoxide dismutase (SOD) activity were lower in AF than in BF These results represent that after-fertilized seedlings increase resistance against physiological stress at field condition using nitrogen source of composted sludge. On the contrary, before-fertilized seedlings were susceptible to environmental stress on abandoned coal-mine soil by exhausting of nitrogen source from composted sludge.