• Atmosphere
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• v.24 no.3
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• pp.303-315
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• 2014

Terrestrial ecosystem plays the important role as carbon sink in the global carbon cycle. Understanding of interactions of terrestrial carbon cycle with climate is important for better prediction of future climate change. In this paper, terrestrial carbon cycle is investigated by Hadley Centre Global Environmental Model, version 2, Carbon Cycle (HadGEM2-CC) that considers vegetation dynamics and an interactive carbon cycle with climate. The simulation for future projection is based on the three (8.5/4.5/2.6) representative concentration pathways (RCPs) from 2006 to 2100 and compared with historical land carbon uptake from 1979 to 2005. Projected changes in ecological features such as production, respiration, net ecosystem exchange and climate condition show similar pattern in three RCPs, while the response amplitude in each RCPs are different. For all RCP scenarios, temperature and precipitation increase with rising of the atmospheric $CO_2$. Such climate conditions are favorable for vegetation growth and extension, causing future increase of terrestrial carbon uptakes in all RCPs. At the end of 21st century, the global average of gross and net primary productions and respiration increase in all RCPs and terrestrial ecosystem remains as carbon sink. This enhancement of land $CO_2$ uptake is attributed by the vegetated area expansion, increasing LAI, and early onset of growing season. After mid-21st century, temperature rising leads to excessive increase of soil respiration than net primary production and thus the terrestrial carbon uptake begins to fall since that time. Regionally the NEE average value of East-Asia ($90^{\circ}E-140^{\circ}E$, $20^{\circ}N{\sim}60^{\circ}N$) area is bigger than that of the same latitude band. In the end-$21^{st}$ the NEE mean values in East-Asia area are $-2.09PgC\;yr^{-1}$, $-1.12PgC\;yr^{-1}$, $-0.47PgC\;yr^{-1}$ and zonal mean NEEs of the same latitude region are $-1.12PgC\;yr^{-1}$, $-0.55PgC\;yr^{-1}$, $-0.17PgC\;yr^{-1}$ for RCP 8.5, 4.5, 2.6.

• The Korean Journal of Ecology
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• v.28 no.5
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• pp.265-270
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• 2005

In order to investigate the organic carbon distribution, net primary production, annual litter production, organic carbon in litter layer, soil organic carbon and soil respiration were studied in an oak forest, Kongju, Chungnam Province in Korea. Net primary production was estimated to 15.84 ton $C{\cdot}ha^{-1}{\cdot}yr^{-1}$. The amount of carbon allocated to leaf and reproductive organ, branch, stem and root was 1.71, 4.03, 7.34, 2.76 ton $C{\cdot}ha^{-1}{\cdot}yr^{-1}$ respectively. Annual litter production was 5.21 $ton{\cdot}ha^{-1}{\cdot}yr^{-1}$, which amounted to 2.35 ton $C{\cdot}ha^{-1}{\cdot}yr^{-1}$. Average amount of organic carbon in litter layer (L+F) was 6.06 ton C/ha, and that of L layer decreased from winter through summer. Soil organic carbon decreased along the soil depth. Average amount of soil organic carbon in this oak forest was 165.19 ton C/ha. The amount of carbon evolved through soil respiration was 11.24 ton $C{\cdot}ha^{-1}{\cdot}yr^{-1}$. Net amount of 4.60 ton $C{\cdot}ha^{-1}{\cdot}yr^{-1}$ was absorbed from the atmosphere by this oak forest.

• Journal of Plant Biotechnology
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• v.32 no.4
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• pp.313-319
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• 2005

The effects of various carbon sources on the secretion of hGM-CSF, total protein and protease into the medium were investigated in transgenic tobacco cells. The dry cell weight (11.2 g/L) and wet cell weight (310.8 g/L) were highest at 30 g/L glucose after 5-day culture but, the dry cell weight (13.4 g/L) and wet cell weight (480 g/L) were highest at 30 g/L sucrose after 10-day culture. The total protein (110.3 mg/L), protease activity (3950 U/L) and total secreted hGM-CSF (56 mg/L) were highest at 30 g/L sucrose after 10-day culture. Stabilization of the total secreted protein and hGM-CSF in various carbon source concentrations was determined. Total secreted protein was most stabilized in the medium containing sucrose. However, the loss of the total protein was increased with the concentrations of high level in medium containing sorbitol, mannitol, fructose, and glucose. hGM-CSF was more stabilized in the medium containing sucrose than in the medium containing sorbitol, mannitol, fructose, glucose.

• Korean Journal of Remote Sensing
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• v.39 no.5_3
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• pp.1043-1060
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• 2023

An acceleration of climate change in recent years has led to increased attention towards 'blue carbon' which refers to the carbon captured by the ocean. However, our comprehension of marine ecosystems is still incomplete. This study classified and analyzed global marine eco-provinces using k-means clustering considering carbon cycling. We utilized five input variables during the past 20 years (2001-2020): Carbon-based Productivity Model (CbPM) Net Primary Production (NPP), particulate inorganic and organic carbon (PIC and POC), sea surface salinity (SSS), and sea surface temperature (SST). A total of nine eco-provinces were classified through an optimization process, and the spatial distribution and environmental characteristics of each province were analyzed. Among them, five provinces showed characteristics of open oceans, while four provinces reflected characteristics of coastal and high-latitude regions. Furthermore, a qualitative comparison was conducted with previous studies regarding marine ecological zones to provide a detailed analysis of the features of nine eco-provinces considering carbon cycling. Finally, we examined the changes in nine eco-provinces for four periods in the past (2001-2005, 2006-2010, 2011-2015, and 2016-2020). Rapid changes in coastal ecosystems were observed, and especially, significant decreases in the eco-provinces having higher productivity by large freshwater inflow were identified. Our findings can serve as valuable reference material for marine ecosystem classification and coastal management, with consideration of carbon cycling and ongoing climate changes. The findings can also be employed in the development of guidelines for the systematic management of vulnerable coastal regions to climate change.

• Korean Journal of Remote Sensing
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• v.28 no.1
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• pp.145-157
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• 2012

In this study, we simulated a carbon flux model, so called Vegetation Integrated Simulator for Trace gases (VISIT) using Spatio-temporal Environmental Information, to estimate carbon budgets of vegetation ecosystem in South Korea. As results of the simulation, the model estimated that the annual-average gross primary production (GPP), net primary production (NPP) for 10 years were $91.89Tg\;C\;year^{-1}$, and $40.16Tg\;C\;year^{-1}$, respectively. The model also estimated the vegetation ecosystems in South Korea as a net carbon sink, with a value of $3.51Tg\;C\;year^{-1}$ during the simulation period. Comparing with the anthropogenic emission of South Korea, vegetation ecosystems offsets 3.3% of human emissions as a net carbon sink in 2007. To estimate the carbon budget more accurately, it is important to prepare reliable input datasets. And also, model parameters should be calibrated through comparing with various independent method. The result of this study, however, would be helpful for devising ecosystem management strategies that may help to mitigate global climate change.

• Journal of Wetlands Research
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• v.15 no.4
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• pp.471-476
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• 2013

The operating conditions of sludge disposal for sanitary paper manufacturing wastewater treatment plant were monitored on the basis of daily check sheets during the 3 years of operation. Generated wastes were mainly composed of 79% of sludge, 14% of ash, 5% of waste synthetic resin and 2% of etc. Maximum sludge was produced to 233 ton and the average was 113 ton daily, where the primary sludge occupied 85% and 15% for the secondary sludge. The concentration of coagulant for sludge dewatering was extremely exceeded and the additional experiment such as jar-test was required for the establishment of proper dosage. Presently, the generated sludges were partially treated outside and were also partly handled inside. In the future, most sludges will be expected to be treated to recycling material for the iron industry.

• Korean Journal of Environmental Biology
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• v.31 no.2
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• pp.105-112
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• 2013

Environmental parameters and phytoplankton community structure were investigated at four sites of Yeongsan River between April 2010 and December 2011. The standing crops of the phytoplankton ranged from $275cells{\cdot}mL^{-1}$ to $58,600cells{\cdot}mL^{-1}$ with an average of $5,850cells{\cdot}mL^{-1}$. The dominant species were Cyclotella sp., Stephanodiscus sp., Aulacoseira granulata, Scenedesmus quadricauda, Pediastrum biwae, Coelastrum sp., Aphnizomenon sp., and Oscillatoria sp.. The most dominant species was Stephanodiscus sp.. The concentration of chlorophyll-a ranged from $2.3mg{\cdot}m^{-3}$ to $164.2mg{\cdot}m^{-3}$. The phytoplankton community structure of the survey area was influenced by temperature and rainfall.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.273-273
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• 2022

혼합층(Mixed layer)은 온도가 일정한 수심층으로, 해수표면에 작용하는 바람의 영향으로 인하여 해수가 위아래로 섞여 형성된다. 이러한 혼합층은 영양염의 순환과 산소의 공급 등과 함께 일차생산량을 결정하는 중요한 요인이 될 수 있으며 혼합층 두께의 변동은 양식 산업에 영향을 미칠 수 있다. 최근에는 기후변화로 인한 해수면 상승 및 해수온 상승 등이 지속되고 있으며, 이러한 현상은 해양생태계의 변화를 초래하여 수산업의 피해를 유발할 수 있다(강원연구원, 2017). 이에 국립수산과학원, 기상청, 국립해양조사원 등 유관기관에서는 정선해양 수온 관측 및 해수순환모델을 이용하여 혼합층의 분석을 수행하고 있으나 격자 구축 및 초기·경계장 설정의 한계가 존재하여 정밀하고 정확한 혼합층 분석에는 어려움이 있다. 이에 본 연구에서는 비정형격자를 사용하여 격자 구축에 제약이 없는 SCHISM (Semi-implicit Cross-scale Hydroscience Integrated System Model)을 이용하여 우리나라 연안해역의 계절변화 및 기후변동성에 따른 혼합층 두께의 변화를 검토하고자 한다. 연구대상지는 서해·동해·남해를 포함한 우리나라 전체 연안 해역(위도: 32°N ~ 39°N, 경도: 124°E ~ 132°E)으로 선정하였으며, 격자크기 100 ~ 3,000 m인 삼각격자로 격자를 구축하였다. 혼합층을 분석하기 위하여 수직격자 층은 50층으로 SZ(Sigma Z coordinate system)좌표계를 사용하였다. 초기·경계장은 FES(Finite Element Solution)2014, HYCOM(Hybrid Coordinate Ocean Model) 및 대기모델 결과를 이용하여 설정하였다. 수치모형 검증을 위하여 수온관측소에서 수심별 측정한 수온 값과 SCHISM 결과 값을 비교하였고, 상대오차가 약 10% 이내로 나타나 모형의 정확도를 확인하였다. 최종적으로 해수면 상승 및 해수온 상승 시나리오를 고려하여 계절별 연안해역의 혼합층 두께의 변화 양상에 대하여 검토하였다. 향후에는 보다 정밀한 대기모델과의 혼합모형 구축 및 다양한 수심 별 관측자료를 활용한다면 실무에서 적용 가능한 혼합층 분석 및 수산업 피해 발생 지역에 대한 피해저감 대책 수립이 가능할 것으로 판단된다.

• Journal of Wetlands Research
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• v.11 no.3
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• pp.61-70
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• 2009

Seasonal changes of flora, vegetation structure, and primary production for the vascular plants were investigated in the disturbed bank, Daedaejae, one of the reinforced bank of Upo wetland, in Changnyeong-gun, Gyeongsangnam-do, Korea from October 2005 to October 2006. The flora of the whole study area, the fabricated and the non-fabricated bank area were composed of 78, 72, 75 taxa, respectively. Among all of them, hydrophytes, hygrophytes, and mesophytes were 3, 33, and 42 taxa, respectively. The naturalized plants were 20 taxa, which was 25.6% of 78 taxa distributed in the study area. Dominant species of the fabricated and the non-fabricated bank area was Equisetum arvense and Trifolium repens, respectively. Importance values of the naturalized plants such as Erigeron annuus, Humulus japonicus, Astragalus sinicus and Ambrosia artemisiifolia var. elatior were relatively high in both area. The species diversity indices(H') were 1.010~1.450, and those were relatively high in October and low in March in both area. Those of the non-fabricated bank area was higher than the fabricated bank area during the whole study period. The similarity indices(CCS) between two kinds of banks were 0.359~0.456, and was lowest in March and highest in August, the culmination period of the vascular plants. Net primary production in the fabricated bank area was $417.1\;g/m^2$, and those of Phragmites communis, Oenothera odorata, Miscanthus sacchariflorus were 179.5, 84.0, and $66.1\;g/m^2$, respectively. Net primary production in the nonfabricated bank area was $392.7\;g/m^2$, and those of Erigeron canadensis, Miscanthus sacchariflorus, and Phragmites communis were 102.5, 87.4, and $81.6\;g/m^2$, respectively.

• Korean Journal of Medicinal Crop Science
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• v.7 no.3
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• pp.218-228
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• 1999

This study was conducted to obtain the information on dry matter productivity in Angelica gigas Nakai for establishing the cultivation method. Cultivation methods such as direct seeding on Mar. 31, Apr. 15 and Apr. 30, and transplanting of $8^{\frac{1}{2}}$, 9, 12 months old seedling were investigated. There were similar tendencies in changes of agronomic characters for all cultivation methods. Dry weight started to increase from 120 DAS. Direct seedling showed vigorous growth for aerial part, whereas transplanting showed better underground part. The quadratic polynomial was suitable to dry weight of root after 120 DAS (or DAT) .Short growing time had higher RGR and NAR independent of cultivation method but Direct seeding on Mar. 31 and transplanting of 9 months old seedling had the highest CGRs. LAI was positively correlated with CGR, and CGR had the highest value as $6.74\g/m^2/day$ when LAI was 1.97. RGR and NAR increased as mean temperature was increased and showed the highest value around . The highest net production of leaf and petiole was obtained at 20 and$23^{\circ}C$, respectively.