• 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.

• Korean Journal of Environmental Biology
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• v.26 no.3
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• pp.170-176
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• 2008

Organic carbon distribution and carbon budget of a Quercus variabilis forest in the Youngha valley of Mt. Worak National Park were investigated. Carbon in above and below ground standing biomass, litter layer, and soil organic carbon were measured from 2005 through 2006. For the estimation of carbon budget, soil respiration was measured. The amount of carbon allocated to above- and below-ground biomass was 56.22 and 13.90 ton C ha$^{-1}$. Amount of organic carbon in annual litterfall was 2.33 ton C ha$^{-1}$ yr$^{-1}$. Amount of soil organic carbon within 50 cm soil depth was 119.14 ton C ha$^{-1}$ 50 cm-depth$^{-1}$. Total amount of organic carbon in this Q. variabilis forest was 193.96 ton C ha$^{-1}$. Of these, 61.43% of organic carbon was allocated in the soil. Net increase of organic carbon in above- and below-ground biomass in this Q. variabilis forest was estimated to 7.68 ton C ha$^{-1}$ yr$^{-1}$. The amount of carbon evolved through soil respiration was 6.21 ton C ha$^{-1}$ yr$^{-1}$. Net amount of 1.47 ton C ha$^{-1}$ yr$^{-1}$ was absorbed from the atmosphere by this Q. variabilis forest.

• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.1
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• pp.77-82
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• 2000

Seven constructed and three natural tidal flats were compared to evaluate state-of- the-art of creation and restoration technology for tidal flats. parameters studied were physico-chemical and biological characteristics of soils and rate of respiration. The natural tidal flats had higher contents of silts, nitrogen and organic matter compared to the constructed ones. The natural ones had reductive Bone below 2 cm whereas the constructed ones had oxidative zone from the surface to below 20 cm. The bacterial population in the soil of the constructed tidal flats was one to two magnitudes lower than that in the natural ones. Biomass of macrobenthos and microbial respiration rate, however, were not different significantly between the natural and the constructed tidal flats. The purification capacity by diatom+bacterial+meiobenthos and macrobenthos in the constructed tidal flats was higher than that in the natural ones due to deeper permeable layer for purification in the constructed tidal flats. There was an exceptional constructed tidal flat with similar physico-chemical and biological characteristics to natural ones. Shearing stress to the surface of the tidal flat by the flow of seawater was as low as that of natural ones. These hydraulic conditions seemed to be a controlling factor on structures and functions of tidal flats. The control of hydraulic condition seemed to be one of the most important factors to create natural-like tidal flats.

• Korean Journal of Environment and Ecology
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• v.26 no.6
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• pp.902-910
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• 2012

This study has been carried out to determine the effects of disturbances from wild boar grubbing on the functions of ecosystem. The experiments was performed in Mt. Jumbong of Long-term Ecological Research Sites of the Ministry of Environment. We measured soil physical properties, soil respiration($CO_2$), microbial biomass C, and soil enzyme activities from both disturbed and control plots. The disturbance sites were divided into two parts, mounds and pits. Soil organic matter contents were highest value at the control plots and lowest at the pit plots, respectively at 20.22% and 15.52%. The soil bulk densities were highest at the pit plots. Soil microbial biomass C and $CO_2$ evolution were significantly higher at the control plots compared to the disturbed plots. The results were positively correlated with soil organic matter contents. The cellulase activity and invertase activity in the soil showed similar pattern as the microbial biomass C and $CO_2$ evolution results. The cellulase activity and invertase activity in the soil were positively correlated with soil microbial biomass C. Soil organic matter contents seemed to affect the soil enzyme activities. The nitrate reductase activities were highest at the pit plots, which showed positive correlation with soil bulk density. The study results showed that the grubbing disturbances by wild boars induced the changes in soil properties, which affected soil microbial activities.

• Journal of Soil and Groundwater Environment
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• v.9 no.1
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• pp.12-27
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• 2004

The contamination pattern of indoor air was simulated when groundwater dissolving benzene was used for household activities. Indoor exposure scenario consisted of inhalation, ingestion, and dermal absorption. Physiologically based pharmacokinetic (PBPK) model was used to analyze how benzene exposed to human body was distributed in internal organs. Main exposure pathways contributing total internal dose were inhalation and ingestion while the contribution of dermal absorption was very small. Man showed higher exposure rate than woman due to his higher breath rate. For a short-term exposure, benzene concentration in venous blood of SPT, RPT and liver changed rapidly while slowly did in venous blood of adipose tissue at a low concentration. For a long-term exposure, woman accumulated about 2.1 times higher than man. Most of benzene exposed to human body was removed by exhalation and metabolism at lung and liver, respectively. For inhalation and ingestion, the benzene removals by exhalation were 69.8 and 48.4%, respectively. Relative importance of removal mechanism was different according to the inflow displacement of benzene. The results obtained from this study would help understand exposure, distribution, and removal phenomena and make plans for the reduction of the health risk associated with the contaminated groundwater by various organic compounds.

• Korean Journal of Soil Science and Fertilizer
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• v.14 no.4
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• pp.224-229
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• 1982

Effects of light intensity and temperature on photosynthesis and respiration of autogenous wild SUMBODY plants, Dystaenia takesimana, known as a prospective source of forage in Ulleung island, Korea, were investigated. Results were as follows : 1. Light saturation point at $20^{\circ}C$ was 34 to 38 klux and light compensation point was 4 to 6 klux. Apparent photosynthetic rate at light saturation was 9 to 12 mg $CO_2/dm^2/hr$. 2. Optimum temperature for photosynthesis was $20^{\circ}C$ and $Q_{10}$ values of two temperature ranges, 20 to $30^{\circ}C$ and 30 to $40^{\circ}C$, were 0.8 and 0.9 for photosynthesis, while $Q_{10}$ for respiration were 1.6 and 1.7. 3. Native plants sampled in area of higher altitude had a higher apparent photosynthtic rate at lower temperature and the plants sampled in area of mixed with bushes had lower a light compensation point. These rusults suggest that the Inland weather condition of Korea during spring and fall seasons might be. suitable for the SUMBODY growth but inadequate during summer.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.15
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• pp.115-121
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• 1974

Artificial induction of nitrogen deficiency symptoms (leaf chlorosis) with two root respiratory inhibitors(DNP and Na$_2$S) was studied and regarded to be the same characteristic to red discoloration in rice var. Tongil seedling leaves as well as adult ones. Tongil(IR 667) was shown to be more nitrogen sensitive and have more distinctive appearance of the leaf discoloration than Punggwang(a native Japonica-type varity.) Conclusions were drawn from the present data that so-called red discoloration of Tongil under the natural field conditions is brought about either by insufficient nitrogen supply in soils or certain factors which may limit at any time the root absorption of nitrogen (low temperature, toxic gases or substances, poor drainage, around roots, etc.) in soils even with ample supply of it.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2002.11a
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• pp.199-201
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• 2002

입자상 물질은 폐렴으로 인한 사망률을 증가시키며, 호흡기 및 심혈관계 질환과 관련된 외래환자 수를 증가시키고, 천식 증상을 악화시키며, 폐 기능 저하 둥을 유발한다고 알려져 있다(U.S.EPA, 2001). 황사는 발원지의 기상 및 토양상태에 따라 다르지만 한반도와 일본에서 관측된 황사의 크기는 1-10$\mu\textrm{m}$ 정도이며 중금속 성분 등 오염물질이 포함되어 있어, 시정악화, 농작물 및 활엽수의 생육장애, 인체 호흡기관으로 깊숙이 침투하여 폐 질환 유발 및 안 질환 등을 유발시켜 대기환경을 오염시킬 뿐만 아니라 인체에도 매우 유해하다. (중략)

• Korean Journal of Agricultural and Forest Meteorology
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• v.15 no.3
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• pp.186-190
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• 2013

Soil respiration in forest ecosystems play an important role in global carbon cycle. This study was carried out to determine the annual variation of soil $CO_2$ efflux for 4 years in a broadleaved deciduous forest of the Geumsan (Mt.) Long-Term Ecological Research (GLTER) site in Southern Korea. The soil $CO_2$ efflux in the GLTER site showed annual variations with the fluctuations of annual mean soil temperature, but not with those of soil water content. The annual mean soil $CO_2$ efflux except for winter season was 0.32 g $CO_2\;m^{-2}h^{-1}$ for 2008, 0.40 g $CO_2\;m^{-2}h^{-1}$ for 2009, 0.41 g $CO_2\;m^{-2}h^{-1}$ for 2007, and 0.54 g $CO_2\;m^{-2}h^{-1}$ for 2010. The lowest soil $CO_2$ effluxin 2008 was associated with the lowest soil temperature ($2.0^{\circ}C$) in comparison with those of other years ($13.0-13.5^{\circ}C$). The exponential relationships between monthly soil $CO_2$ efflux and the corresponding soil temperature at the soil depth of 20 cm were significant ($R^2$ = 0.31-0.75, P < 0.05). The results indicate that the annual variation of soil $CO_2$ efflux was attributed to the variations of soil temperature rather than soil water content in the GLTER site.

• Korean Journal of Soil Science and Fertilizer
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• v.24 no.3
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• pp.200-205
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• 1991

To evaluate cold tolerance of rice cultivars on the basis of a relationship between cold tolerance in the field test and a biochemical character, transition-temperature of respiratory activity of mitochondria(TRM) which were isolated from different parts and at different growth stages and from etiolated rice seedling was investigated, and its relationship with degree of cold tolerance(DCT) in the field experiment was studied. The results obtained were summarized as follows. 1. The transition-temperature of respiratory activity of mitochodria (TRM) isolated from etiolated seedling ($25^{\circ}C$, two week-grown in the dark) of cold tolerant cultivars tended to be low, while that of cold susceptible cultivars to be high. 2. The correlation between TRM of etiolated seedling and the degree of cold tolerance(DCT) was $r=0.8935^{**}$ in 1988 and $r=0.8236^{**}$ in 1989. The correlation coefficient between TRM of 4-leaf seedling and DCT was $0.6239^{**}$ 3. TRM of young panicle was correlated with DCT except a few varieties. 4. TRM of seedling increased with growth as $12.5^{\circ}C$, $14.5^{\circ}C$, $15.5^{\circ}C$ and $16.5^{\circ}C$ at 1, 2, 3~4 and 5weeks respectively. 5. The transition temperature of mitochondrial respiratory activity was not significantly influenced by growth stages as $15.0{\sim}16.0^{\circ}C$ in Pungsanbyeo and $17.0{\sim}18.0^{\circ}C$ in Satbyelbyeo, while it was significantly different depending upon the degree of cold tolerance(tolerant, medium, susceptible).