• Journal of Environmental Science International
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• v.23 no.12
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• pp.2057-2069
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• 2014

This study was carried out to estimate the BVOCs emissions with the emission factors which reflected the native conditions of forests in Jeju Island. This study made effective use of the previous data for the weather data and the emission rate of each organic volatile component measured at 10 species of conifers and broad leaved trees. The CORINAIR method and the grid system of $1km{\times}1km$ for whole area of Jeju Island were adopted in calculating the BVOCs emission emitted from forest. The vegetation information for Jeju Island was referred to GIS and a government report. By the results of BVOCs emission for Jeju Island, the 85% of monoterpene emission was emitted from conifers and the others was from broad leaved trees. Most of monoterpene emission was attributed to Pinus thunbergii and Cryptomeria japonica. The broad leaved trees greatly contributed to the isoprene emission and Quercus serrata played a dominant role in emission of isoprene. The total amount of BVOCs emission was estimated as $3612ton\;yr^{-1}$ in Jeju Island. The 51.1% of total emission was contributed to conifers, the 44.9% to broad leaved trees, and the 4.0% to grassland. Of total emission of BVOCs, monoterpene accounted for 32.3%, isoprene for 28.0%, and OVOCs for 39.7%. The BVOCs emission estimated by this study was less than that estimated by other previous study. This means that it is important to survey the emission rate at native conditions and gather the detailed information for various species of vegetation on target region.

• Journal of Environmental Science International
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• v.24 no.2
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• pp.207-219
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• 2015

The purpose of this study is to show the geographical distribution and the temporal variation of the emission amount of biogenic volatile organic compounds(BVOCs) emanated from forests at Jeju Island. The total emission amount of BVOCs calculated by using the CORINAIR Methodology is $3612ton\;yr^{-1}$ at Jeju Island. More than half of BVOCs emissions is come from coniferous forest, and 45 per cent from broad leaved forest. The others is attributed to grassland. Of total emission of BVOCs, isoprene accounts for 28 per cent, monoterpene for 32 per cent, and other VOCs for about 40 percent, respectively. It can be shown that $3000{\sim}10000kg\;yr^{-1}$ of BVOCs is emitted at the zone with dense forest from an altitude of 500 m to the top of Mt. Halla, and less than $1500kg\;yr^{-1}$ at the zone an altitude of below 500 meters. The monoterpene emission is more than $1500kg\;yr^{-1}$ due to the existence of a colony of Abies koreana at the place with more than 1500 meters and a community of Pinus thunbergii and Cryptomeria japonica at the elevation of 500~700 m. In the case of isoprene emission, there is $1500{\sim}3000kg\;yr^{-1}$ at the zone of an elevation from 700 m to 1500 m due to dense broad leaved forest and very little of its emission at an elevation of more than 1500 meters because there is hardly broad leaved trees grown. In this study, emission of BVOCs according to the altitude above sea level is estimated under the situation of lack of the data for broad leaved tree. More detailed data and information for the distribution of broad leaved trees are needed in order to calculate more realistic BVOC emission.

• Journal of Korean Society for Atmospheric Environment
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• v.28 no.1
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• pp.77-85
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• 2012

In this study, emission rates (ER) of biogenic volatile organic compounds (BVOCs) were measured by varying levels of photosynthetically active radiation (PAR). An appropriate plan for ozone reduction according to increasing ecology area ratio in future metropolitan areas was suggested. Several trees were selected as representative tree species in urban areas. Emission rates and composition ratios of monoterpene and isoprene emitted from these trees were estimated and compared. As a result, it was found that emission rates of BVOCs were considerably different depending on tree species. Especially, BVOCs emitted from Platanus orientalis and Quercus mongolica could significantly affect ozone increase in the metropolitan area, because the emission rates were several thousands to ten thousand times higher than those emitted from Zelkova serrata and Prunus serrulata. Furthermore, it was observed that emission rates of BVOCs by species increased maximum up to 10 times when PAR, which has close relations with temperature, rose. It was concluded that tree species such as Zelkova serrata et al., was appropriate for metropolitan areas since the species has low ozone potential and good landscape. Suppose this type of trees are planted on purpose in the urban areas, better ambient air quality will be promised in the future.

• Korean Journal of Agricultural and Forest Meteorology
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• v.24 no.1
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• pp.48-61
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• 2022

South Korea is quite vegetation rich country which has 63% forests and 16% cropland area. Massive NOx emissions from megacities, therefore, are easily combined with BVOCs emitted from the forest and cropland area, then produce high ozone concentration. BVOCs emissions have been estimated using well-known emission models, such as BEIS (Biogenic Emission Inventory System) or MEGAN (Model of Emission of Gases and Aerosol from Nature) which were developed using non-Korean emission factors. In this study, we ran MEGAN v2.1 model to estimate BVO Cs emissions in Korea. The MO DIS Land Cover and LAI (Leaf Area Index) products over Korea were used to run the MEGAN model for June 2012. Isoprene and Monoterpenes emissions from the model were inter-compared against the enclosure chamber measurements from Taehwa research forest in Korea, during June 11 and 12, 2012. For estimating emission from the enclosed chamber measurement data. The initial results show that isoprene emissions from the MEGAN model were up to 6.4 times higher than those from the enclosure chamber measurement. Monoterpenes from enclosure chamber measurement were up to 5.6 times higher than MEGAN emission. The differences between two datasets, however, were much smaller during the time of high emissions. More inter-comparison results and the possibilities of improving the MEGAN modeling performance using local measurement data over Korea will be presented and discussed.

• Journal of Korean Society for Atmospheric Environment
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• v.28 no.5
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• pp.485-494
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• 2012

The purpose of this study is to monitor the flux of $CO_2$ and BVOCs (biogenic volatile organic compounds) between the atmosphere and forest. The main research activities are conducted at Taehwa Research Forest (TRF), managed by the College of Agriculture and Life Sciences at Seoul National University. The TRF site is located 60 km north-east from the center of Seoul Metropolitan Area. The TRF flux tower is in the middle of a Korean Pine (Pinus Koraiensis) plantation ($400m{\times}400m$), surrounded by a mixed forest. Eddy covariance method was used for $CO_2$ flux above the forest and REA (Relaxed eddy accumulation) method applying eddy covariance was used for BVOCs flux. BVOCs flux that was measured in spring (from May 16 to 18) had distribution of 84 to $2917{\mu}g/m^2{\cdot}h$. Especially, it showed that d-limonene being strong reactivity composed the largest fraction of monoterpene. Ambient $CO_2$ concentration measured in Mt. Taehwa was 399 ppm and observed $CO_2$ fluxes between the atmosphere and forest suggested that during the day, $CO_2$ is absorbed by plants through photosynthesis and released during the night.

• Journal of Forest and Environmental Science
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• v.34 no.2
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• pp.153-161
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• 2018

Ozone absorbs ultraviolet light which is harmful to life. However, the recent increase of ambient ozone level due to climate change is becoming the cause of stimulating human eyes, affecting respiratory system, and damaging crops. In this paper, a study was conducted at the Taehwa Research Forest (TRF) of Seoul National University with the purpose of analyzing the characteristics of forest air chemistry based on the measurement of BVOCs emitted from forests and investigating the correlation of BVOCs with ozone generation. The results showed that levels of isoprene and MVK (Methyl Vinyl Keton)+MACR (Methacrolein) were high in summer, but level of monoterpene was high in spring. Ozone level was high from the middle of May to the middle of June, which was before the rainy season. Comparison of the correlation between ozone and isoprene during the measurement period at the TRF showing limited NOx showed that the $R^2$ was correlated with a low value of about 0.4. However, when the isoprene was actively produced from 6:00 AM to 6:00 PM, correlation analysis showed that $R^2$ was about 0.9, while monoterpene started to increase in the afternoon, and decreased level of ozone at night. Correlation analysis showed negative correlation. Forests have two characteristics: not only the formation of ozone but also the decomposition of ozone.

• Korean Journal of Agricultural and Forest Meteorology
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• v.17 no.3
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• pp.217-226
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• 2015

To investigate the distributions of BVOCs (Biogenic Volatile Organic Compounds) from mountain near mega city and their role in forest atmospheric, BVOCs and their oxidized species were measured at a 41 m tower in Mt. Taehwa during May, June and August 2013. A proton transfer reaction-mass spectrometer (PTR-MS) was used to quantify isoprene and monoterpenes. In conjunction with BVOCs, $O_3$, meteorological parameters, PAR (Photosynthetically Active Radiation) and LAI (Leaf Area Index) were measured. The average concentrations of isoprene and monoterpenes were 0.71 ppbv and 0.17 ppbv, respectively. BVOCs showed higher concentrations in the early summer (June) compared to the late summer (August). Isoprene started increasing at 2 PM and reached the maximum concentration around 5 PM. In contrast, monoterpenes concentrations began to increase 4 PM and stayed high at night. The $O_3$ maximum was generally found at 3 PM and remained high until 5 PM or later, which was concurrent with the enhancement of $O_3$. The concentrations of BVOCs were higher below canopy (18 m) than above canopy, which indicated these species were produced by trees. At night, monoterpenes concentrations were negatively correlated with these of $O_3$ below canopy. Using MEGAN (Model of Emissions of Gases and Aerosols from Nature), the emissions of isoprene and monoterpenes were estimated at 1.1 ton/year and 0.9 ton/year, respectively at Mt. Taehwa.

• Korean Journal of Agricultural and Forest Meteorology
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• v.25 no.1
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• pp.48-59
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• 2023

Ground-level ozone affects human health and plant growth. Ozone is produced by chemical reactions between oxides of nitrogen (NOx) and volatile organic compounds (VOCs) from anthropogenic and biogenic sources. In this study, two different land cover and emission factor datasets were input to the MEGAN v2.1 emission model to examine how these parameters contribute to the biogenic emissions and ozone production. Four input sensitivity scenarios (A, B, C and D) were generated from land cover and vegetation emission factors combination. The effects of BVOCs emissions by scenario were also investigated. From air quality modeling result using CAMx, maximum 1 hour ozone concentrations were estimated 62 ppb, 60 ppb, 68 ppb, 65 ppb, 55 ppb for scenarios A, B, C, D and E, respectively. For maximum 8 hour ozone concentration, 57 ppb, 56 ppb, 63 ppb, 60 ppb, and 53 ppb were estimated by scenario. The minimum difference by land cover was up to 25 ppb and by emission factor that was up to 35 ppb. From the modeling performance evaluation using ground ozone measurement over the six regions (East Seoul, West Seoul, Incheon, Namyangju, Wonju, and Daegu), the model performed well in terms of the correlation coefficient (0.6 to 0.82). For the 4 urban regions (East Seoul, West Seoul, Incheon, and Namyangju), ozone simulations were not quite sensitive to the change of BVOC emissions. For rural regions (Wonju and Daegu) , however, BVOC emission affected ozone concentration much more than previously mentioned regions, especially in case of scenario C. This implies the importance of biogenic emissions on ozone production over the sub-urban to rural regions.

• Journal of Environmental Science International
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• v.21 no.6
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• pp.713-724
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• 2012

Emission rates of biogenic hydrocarbon emitted from broad-leaved trees grown at Jeju Island were estimated using a dynamic enclosure method. Leaf temperature, PAR and relative humidity were monitored during the sampling time. The emission rates of isoprene and monoterpene were measured for five plants(Carpinus laxiflora, Quercus serrata, Styrax japonicus, Quercus acutissima, Quercus crispula) during the sampling period at the Halla mountain sites. Among five tree species, the highest isoprene emission rate of 10.60 ${\mu}g\;gdw^{-1}hr^{-1}$ was observed for Quercus serrata. The seasonal emission rates were the highest during summer and the emission of isoprene was highly affected by light and temperature variations. The highest emission rate of isoprene was occurred between 13:00 and 14:00, but isoprene was not emitted in nighttime because of the absence of light.

• Journal of Korean Society of Forest Science
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• v.110 no.4
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• pp.543-553
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• 2021

This research focused on the investigation of isoprene and terpene emissions from 30 major urban tree species. We conducted sampling using a specific dynamic enclosure system between August and September 2020. Seedlings less than three years old were enclosed in a chamber consisting of a 400 L transparent Tedlar bag. The air-flows from the chamber's outlet were sampled using Tenax-filled sorbent tubes in the presence of standard conditions (temperature: 30℃, PAR: 1,000 μmol/m²/sec). A thermal desorption GC/MS system was used to analyze 38 BVOC compounds (isoprene, monoterpene, sesquiterpene, oxygenated monoterpene, and sesquiterpene). Isoprene emitters included Phyllostachys bambusoides, Quercus serrata, Daphniphyllum macropodum, and Buxus Koreana. Monoterpene emitters included Pinus rigida, Acer pictum subsp. mono, Larix kaempfer, Magnolia denudata, Metasequoia glyptostroboides, Pinus koraiensis, Pinus densiflora, and Abies holophylla. The monoterpene emission profiles were dominated by α-pinene, myrcene, limonene, β-pinen, and sabinene, while caryophyllene and farnesene were the prominent sesquiterpenes. Predominant oxygenated monoterpene compounds were also discovered as pulegone, borneol, menthol, eucalyptol, and nerol, while caryophyllene oxide were the prominent oxygenated sesquiterpenes. Sesquiterpenes and oxygenated sesquiterpenes had relatively lower contributions for all species.