• Journal of Ecology and Environment
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• 제46권3호
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• pp.161-171
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• 2022

Background: Epilobium hirsutum L. is designated as an endangered plant in South Korea located in Asia, due to the destruction of its habitats through the development of wetlands. Therefore, in this study, in order to find a light condition suitable for the growth and ecophysiological responses of Epilobium hirsutum L., those of this plant under treatment with various light qualities in a smart farm were measured. Results: In order to examine the changes in the physiological and growth responses of Epilobium hirsutum L. according to the light qualities, the treatment with light qualities of the smart farm was carried out using the red light: blue light irradiation time ratios of 1:1, 1:1/2, and 1:1/5 and a red light: blue light: white light irradiation time ratio of 1:1:1. As a result, the ecophysiological responses (difference between leaf temperature and atmospheric temperature, transpiration rate, net photosynthetic rate, intercellular CO₂ partial pressure, photosynthetic quantum efficiency) to light qualities appeared differently according to the treatments with light qualities. The increase in the blue light ratio increased the difference between the leaf temperature and the atmospheric temperature and the photosynthetic quantum efficiency and decreased the transpiration rate and the intercellular CO₂ partial pressure. On the other hand, the white light treatment increased the transpiration rate and intercellular CO₂ partial pressure and decreased the temperature difference between the leaf temperature and the ambient temperature and photosynthetic quantum efficiency. Conclusions: The light condition suitable for the propagation by the stolons, which are the propagules of Epilobium hirsutum L., in the smart farm, is red, blue and white mixed light with high net photosynthetic rates and low difference between leaf temperature and atmospheric temperature.

• Journal of Ecology and Environment
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• 제31권4호
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• pp.261-267
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• 2008

Growth and photosynthetic responses of one $C_3$ and two $C_4$ plants in the family Chenopodiaceae in three $CO_2$ concentration $([CO_2])$ conditions-low (about $243{\mu}mol\;mol^{-1}$, LC), present (about 378, PC), and high (about 465, HC)-were investigated in open top chambers. The relative growth rate (RGR) and net assimilation rate in the $C_3$ plant, Chenopodium album, increased with increasing $[CO_2]$, though the RGR was not enhanced significantly in the HC condition. The leaf area ratio and leaf weight ratio of the $C_3$ plant drastically decreased with increasing $[CO_2]$, suggesting that the $C_3$ plant invests more biomass to leaves in lower $[CO_2]$ conditions. The two $C_4$ plants, Atriplex glauca and A. lentiformis, showed relatively small changes in those growth parameters. These photosynthetic-pathway-dependent responses suggest that growth patterns of $C_3$ and $C_4$ plants have been altered by past increases in atmospheric $[CO_2]$ but that there will be relatively little further alteration in the future high-$CO_2$ world.

• 한국기후변화학회지
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• 제7권1호
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• pp.77-84
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• 2016

Seedling stage is particularly important for tree survival and is easily influenced by warming. Therefore, air temperature being increased due to climate change may affect physiological traits and growth of seedlings. This study was conducted to investigate the physiological and growth responses of Larix kaempferi seedlings to open-field experimental warming. 1-year-old and 2-year-old L. kaempferi seedlings were warmed with infrared lamps since April 2015 and April 2014, respectively. The seedlings in the warmed plots were warmed to maintain the air temperature to be $3^{\circ}C$ higher than that of the control plots. Physiological responses (stomatal conductance, transpiration rate, net photosynthetic rate and total chlorophyll content) and growth responses (root collar diameter (RCD), height and biomass) to experimental warming were measured. Physiological and growth responses varied with the seedling ages. For 2-year-old L. kaempferi seedlings, stomatal conductance, transpiration rate and net photosynthetic rate decreased following the warming treatment, whereas there were no changes for 1-year-old L. kaempferi seedlings. Meanwhile, total chlorophyll content was higher in warmed plots regardless of the seedling ages. Net photosynthetic rate linked with stomatal conductance also decreased due to the drought stress and decrease of photosynthetic efficiency. In response to warming, RCD, height and biomass did not show significant differences between the treatments. It seems that the growth responses were not affected as much as physiological responses were, since the physiological responses were not consistent, nor the warming treatment period was enough to have significant results. In addition, multifactorial experiments considering the impact of decreased soil moisture resulting from elevated temperatures is needed to explicate the impacts of a wide range of possible climate change scenarios.

• Journal of Ecology and Environment
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• 제43권3호
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• pp.305-313
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• 2019

Background: This research aims to study the effect of climate change on the phenology, growth, and physiological traits of Silene capitata Kom., a Korean endangered species II. This study increased $CO_2$ concentration in a closed glass greenhouse, with the daily mean temperature and $CO_2$ concentration respectively being $4.61^{\circ}C$ and 93.63 ppm higher than the outside temperature (ambient conditions, control). The seeds of S. capitata were sown in control and treatment environments in March 2013 while seedlings were transplanted into individual pots in May 2013. To research phenological changes, the first day of the flowering and ripening of the plants transplanted in 2013 and first day of leafing in 2014 were observed. The growth and physiological responses of mature leaves were also studied in 2013. Results: There was no difference in the first day of flowering, but the first day of ripening was earlier in the treatment group than the control group. There was no difference in the number of rosette leaves between the two groups, but leaf area was wider in the treatment group than the control group. Transpiration rate and stomatal conductance were higher in the treatment group than the control group, chlorophyll content decreased, and photosynthetic rate and water use efficiency were the same for both groups. As a result of simple regression analysis among the transpiration rate, stomatal conductance, photosynthetic rate, and water use efficiency, stomatal conductance increased when transpiration rate increased. Stomatal conductance increased with photosynthetic rate in the control unlike in the treatment group. The photosynthetic rate and water use efficiency increased with transpiration rate in the control group unlike in the treatment group. Furthermore, water use efficiency increased as photosynthetic rate increased in both groups. Conclusion: Due to high $CO_2$ concentration, the photosynthetic rate was no longer controlled by the stomata, which appeared to suppress the excessive production of photosynthetic products by reducing chlorophyll content. It is believed that the phenological responses of S. capitata under climate change conditions will advance and that stable growth will be difficult in regions lacking moisture due to the high transpiration rate.

• The Korean Journal of Ecology
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• 제18권2호
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• pp.265-273
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• 1995

Net photosynthetic rate (Pn) of Quercus mongolica leaves was determined under the controlled O₃concentrations of 0, 20, 30, 40, 50 or 60 ppb at every 10 min for 7 hr. Under the fumigation of the different O₃concentrations the relative net photosynthetic rate (RNPR) of the leaves decreased rapidly until 1 hr and thereafter decreased slowly. At below 20 ppb O₃the decrease of the RNPR was scarce but at above 20 ppb O₃the RNPR was inversely proportional to O₃concentration on a logarithmic curve. The RNPR at 60 ppb O₃, for example, was reduced 30％ less than that without O₃. Under the different O₃concentrations fumigated for the short period of time the Pn dependent upon PPFD was depicted as saturation equation and Pn dependent upon temperature as quadratic equation. Results of this study suggest that short-term low O₃of less than 60 ppb concentration may lead to reductions of Pn in Q. mongolica leaves.

• 한국농림기상학회지
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• 제10권4호
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• pp.141-148
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• 2008

피음처리에 의한 네 참나무 수종(신갈나무, 졸참나무, 상수리나무, 굴참나무)의 광합성 반응 특성을 조사하기 위하여, 차광막으로 전천광을 35%, 55%. 75% 차광 처리한 조건과 전광조건에서 엽생장과 엽록소함량을 측정하고 광-반응 곡선과 A-Ci 곡선을 통하여 광합성계의 특성을 조사하였다. 그 결과, 굴참나무와 상수리나무는 엽생장, 엽록소함량, 순양자수율을 증가시키고 엽록소 a/b와 탄소고정효율을 감소시켜 빛의 흡수량과 광합성에 대한 이용효율을 높이는 적응 반응을 나타냈다. 신갈나무는 굴참나무와 상수리나무와 같은 경향의 적응반응을 보였지만 광합성 광화학계 활성의 저하로 낮은 광합성 능력을 나타냈다. 졸참나무는 가장 낮은 내음성 적응반응을 나타냈다.

• Plant Breeding and Biotechnology
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• 제5권4호
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• pp.363-370
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• 2017

In this study, Quercus acutissima seedlings were subjected to drought for 30 days then analyzed to determine their response to water deficit. The growth phenotype, chlorophyll fluorescence response, fresh weight, dry weight, photosynthetic pigment levels, soluble sugar content, and malondialdehyde (MDA) were measured to evaluate the effects of drought on plant growth and physiology. The growth phenotype was observed by infrared (IR) digital thermal imaging after 30 days of drought treatment. The maximum, average, and minimum temperatures of drought-treated plant leaves were $1-2^{\circ}C$ higher than those of the control. In contrast, the fresh and dry weights of the dehydrated leaves were generally lower than those of the control. There were no significant differences between treatments in terms of chlorophyll a, chlorophyll b, total chlorophyll, and carotenoid levels. Nevertheless, for the drought treatment, the $F_v/F_m$ and $F_v/F_o$ ratios (chlorophyll fluorescence response) were lower than those for the control. Therefore, photosynthetic activity was lower in the dehydrated plants than the control. The drought-stressed Q. acutissima S0536 had lower soluble sugar (glucose and fructose) and higher MDA levels than the controls. These findings may explain the early growth and physiological responses of Q. acutissima to dehydration and facilitate the selection of drought-resistant tree families.

• 한국농림기상학회지
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• 제16권3호
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• pp.219-226
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• 2014

기후변화 대응 산림 관리 방법을 개발하기 위해서는 온난화에 따른 수목의 반응을 예측하는 것이 중요하다. 본 연구는 우리나라 주요 활엽수종인 거제수나무(Betula costata), 물푸레나무(Fraxinus rhynchophylla), 굴참나무(Quercus variabilis) 묘목의 실외 인위적 온난화에 대한 생장 반응을 알아보기 위하여 수행되었다. 이를 위해 적외선등을 이용하여 지속적으로 기온을 $3^{\circ}C$ 증가시킬 수 있는 실외 인위적 온난화 시스템을 구축하고, 활엽수 3개 수종을 파종한 후, 온도 증가에 대한 발아 당년 묘목의 생장, 생물량 분배 및 순광합성률의 반응을 분석하였다. 연구 결과, 거제수나무, 물푸레나무, 굴참나무 묘목의 생장은 실외 인위적 온난화 처리에 대하여 수종과 시기에 따라 서로 다른 반응을 나타냈다. 즉 거제수나무는 온난화 처리에 따라 근원경 대비 묘고 비율, 총 생물량, 지상부 대비 뿌리 중량 비율, 순광합성률 등이 감소한 반면, 굴참나무는 근원경, 묘고, 총 생물량, 순광합성률 등이 증가하였으며, 물푸레나무는 다른 수종에 비하여 생장 반응이 뚜렷하지 않았다. 시기별 반응으로는, 7월에는 모든 수종에 대하여 온난화 처리에 따른 변화가 나타나지 않았으나 11월에는 굴참나무의 근원경, 묘고, H/D율이 증가한 반면 거제수나무의 H/D율이 감소하였다. 온난화에 대한 수종별 생장 반응의 차이는 순광합성률 및 생물량 분배의 수종별 반응과 유사하게 나타나, 온도 증가에 의한 순광합성률과 생물량 분배의 수종별 차이가 생장에 영향을 미친 것으로 생각된다. 한편, 여름에 비하여 가을에 더 두드러지게 나타난 생장 반응은 온난화에 의한 식물 계절 특성의 변화에 의한 것으로 보인다. 활엽수 3개 수종에 대하여 온난화에 의한 수종 특이적 생장 반응을 밝힌 본 연구 결과는 기후변화에 대응한 산림 관리 정책 개발에 활용될 수 있을 것으로 사료된다.

• 한국산림과학회지
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• 제97권6호
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• pp.680-689
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• 2008

본 연구에서는 층층나무, 물푸레나무, 박달나무, 개벚나무, 고로쇠나무를 대상으로 차광처리를 통해 4가지 수준(상대 차광률; 전광처리구, 전광대비 65~72%, 29~40%, 7~12%)으로 광도 조건을 달리하여 광합성 특성을 조사하였다. 그 결과, 층층나무, 물푸레나무 및 박달나무는 차광처리에 의하여 광합성 능력과 엽록소 형광이 저하하여, 내음성 수준이 낮음을 시사하였다. 개벚나무는 조사 시기별 차이는 있었으나, 강피음 처리구를 제외한 나머지 세 처리구에서 좋은 광합성 능력을 나타내, 보통 수준의 내음성을 보였다. 한편 고로쇠나무는 전광대비 29~40% 처리구에서 가장 높은 광합성 능력과 엽록소 형광을 나타내, 내음성 수준이 공시수종 중에 가장 높음을 시사하였다.

• 원예과학기술지
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• 제31권6호
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• pp.677-686
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• 2013

Edible canna is a productive starch source in some tropical and semitropical regions. In these regions, water deficit stress is one of factors that limit the crop yield. In the present study, we investigated seven physiological indexes and photosynthetic responses of three edible canna (Canna edulis Ker.) cultivars ('PLRF', 'Xingyu-1', and 'Xingyu-2') under 35 days drought stress. Our results indicated that drought treatment caused visible wilting symptoms in all cultivars, especially in 'Xingyu-1'. Coupled with the increase of wilting symptoms, relative water content (RWC) and chlorophyll content decreased progressively, malondialdehyde (MDA) content gradually increased, and key antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) activities increased first and then decreased in all three cultivars. The effect of water stress was more pronounced in 'Xingyu-1' than in 'PLRF' and 'Xingyu-2', and in lower leaves than in upper leaves. In addition, 35 days drought stress also significantly reduced the photosynthetic capacity. Consistent with antioxidant parameters, photosynthetic changes of 'Xingyu-2' were less than those of the other cultivars under water deficit stress. Drought stress caused a significant increase of water use efficiency (WUE) in 'Xingyu-2', but little in 'PLRF', and obvious decrease in 'Xingyu-1'. These results indicated that 'Xingyu-2' was more tolerant to drought stress than 'PLRF' and 'Xingyu-1' by maintaining lower lipid peroxidation and higher antioxidant enzyme activities.