• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 2002.11a
• /
• pp.77-78
• /
• 2002

원자력시설이나 원자력발전소에서 사고가 발생하여 대기로 방출된 방사능물질은 두 가지 주요경로를 통해 인체노출이 일어난다 첫째는 지역내 대기중에 존재하는 방사성물질이 인체의 호흡이나 피부 등을 통해 체내로 흡입되는 직접적인 노출 (Direct Exposures)이고 다른 하나는 방사능물질이 대기로부터 주변의 토양에 침적하고 이러한 토양에서 재배된 오염된 농작물들 (쌀, 보리, 밀, 또는 과일, 채소)을 인간이 섭취하거나, 방사능물질에 오염된 목초로 키운 축산물(소, 돼지, 닭 등)과 이들로 생산하는 제품들(우유, 고기, 달걀 등)을 인간이 섭취함으로써 이루어지는 보다 간접적인 인체노출(Indirect Exposures)이 있을 수 있다. (중략)

• Proceedings of the Korea Society of Environmental Biology Conference
• /
• 2005.12a
• /
• pp.131-131
• /
• 2005

• Journal of Korean Society of Forest Science
• /
• v.85 no.3
• /
• pp.496-505
• /
• 1996

Soil respiration was measured every two weeks from May through November 1995 using the soda lime method in 40-Year-old Pinus rigida and Larix leptolepis plantations on a similar soil in Yangpyeong, Kyonggi Province. Treatments included control and no-roots(plots trenched and root regrowth into plots prevented). Root respiration was evaluated by comparing no-roots sub-plots to control plots. Mean soil respiration showed highly significant species effects(p<0.01) and was highest at the Pinus rigida control plot($0.38g/m^2/hr$) and lowest at the Larix leptolepis no-roots plot($0.31g/m^2/hr$). High soil respiration in Pinus rigida may be related to aboveground litter production. The annual $CO_2$ fluxes ranged from 23 to 27t/ha/yr. We found significant correlations between temperatures(air : $R^2$=0.53, soil : $R^2$=0.55) and soil respiration(p<0.01), but no significant correlations between soil moisture and soil respiration(p>0.1). Root respiration was 3% of total soil respiration. We might underestimate rapt respiration because of shallow trenches and $CO_2$measurements right after trenching. Factors controlling soil respiration including belowground litterfall(especially fine roots) inputs, litter quality should be well understood to predict soil carbon fluxes and relative contributions to total soil respiration in forest ecosystems.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2002.04a
• /
• pp.323-326
• /
• 2002

Oxygen uptake characteristics of soil microcosm added by hydrocarbon degrading bacteria screened from polluted site in Korea was studied. The degradation of TPH was enhanced by additon of nononionic surfactants. The amount of oxygen consumed was decreased at higher concentration. The degradation rate of hydrocarbon was decreased by increasing the hydrcarbon concentration.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2021.06a
• /
• pp.278-278
• /
• 2021

가뭄이 장기간 지속되어 농업적 가뭄 상태가 되면 토양의 수분이 마르기 시작하면서, 식생의 생장활동이 방해되고, 이는 식생의 광합성 활동까지 영향을 미친다. 광합성을 통해 대기 중의 이산화탄소가 흡수되고 산소 발생이 증가하는데, 광합성이 활발하지 못하면 상대적으로 대기 중의 이산화탄소 농도가 증가한다. 본 연구에서는 이러한 토양수분, 식생활동과 대기 중 이산화탄소의 농도의 관계를 다중분광센서인 MODerate resolution Imaging Spectroradiometer (MODIS) 산출물을 이용하여 분석하였다. 기존 토양수분의 경우, 마이크로파 센서를 통해 산출된 값을 활용했지만, 이는 상대적으로 공간 해상도가 조악하다는 단점을 갖고 있어서 면적이 작은 연구지역을 분석할 때에는 한계점을 갖고 있다. 이러한 문제를 해결하기 위하여 상대적으로 고해상도인 광학센서를 이용한 토양수분 산정 방법을 적용하였다. 또한, MODIS 총 일차생산량 (Gross Primary Productivity, GPP) 산출물을 이용하여 식생 호흡량과의 관계식을 통해 이산화탄소 플럭스를 계산하였다. 원격탐사 기반의 토양수분, 식생지수, 이산화탄소 플럭스를 한국에서 발생한 가뭄 기간 중, 2014년과 2015년도에 대하여 지점 관측자료인 플럭스 타워에서 제공되는 값과 비교 분석하였다. 분석한 결과 토양수분, 식생 지수, 탄소플럭스는 순차적으로 지연시간을 두고 상관성이 발생함을 확인하였다. 토양수분과 식생 지수 사이에는 1개월, 식생지수와 탄소플럭스는 0.5개월의 지연시간 후에 가장 높은 상관성을 보였다.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.26 no.2
• /
• pp.167-173
• /
• 1981

Respiration of whole seeds and seed parts isolated from four soybean varieties Essex, Pickett, Wayne and Bonus as measured at $25^{\circ}C$ during germination. The average respiration rates of cotyledons were significantly higher than those of other parts. The values were 35.7, 28.0 and $23.9{\mu}hr^{-1}$ seed$^{-1}$ for cotyledons, embyros, and hila, respectively. Bonus showed a significantly lower respiration rate than the other varieties did. The interaction of variety x seed part was not significant source of variation for respiration. This suggests that seed part and variety independently contribute to soybean seed respiration during early imbibition. The effects of imbibition time and time x variety intereaction on whole seed respiration were significant, but the variety effect was not significant. The correlation coefficient between seed moisture content and respiration after 24 hours of imbibition was significant for Bonus, but not for the other varieties tested. This suggests that Bonus may require more water for respiration during imbibition than the other varieties. There as no significant correlation of whole seed respiration rate after 24 hours imbibition with seed weight or seedling length.

• Korean Journal of Environment and Ecology
• /
• v.21 no.6
• /
• pp.487-493
• /
• 2007

This study was carried out to evaluate soil property between campsites located at Joongsanri, Daewonsa old, Daewonsa new, Baekmudong and their adjoining forest areas in the eastern area of Jirisan National Park. The survey results showed that there existed a significant difference(p<0.05) between the two areas in soil property, such as soil bulk density, soil hardness, soil pH, water infiltration and soil respiration rates. However, there was no difference in soil property by depth between surface soil($0{\sim}15cm$) and subsurface soil($15{\sim}30cm$) for the two areas(p>0.05). In case of soil bulk density, its values in campsites were significantly higher ($1.29{\sim}1.44g/cm^3$) than in forest areas($0.95g/cm^3$), while soil hardness was significantly lower(p<0.05) in forest areas($1.44kg/cm^2$) than in campsites($2.9{\sim}4.0kg/cm^2$). Soil pore space was significantly lower in campsites($45.7{\sim}51.4%$) than in forest areas(64.3%), and soil pH in forest areas indicated pH 5.46 and that of the campsites was distributed at the range from pH 6.49 to pH 6.38. In addition, water infiltration was significantly lower in campsites($0.79{\sim}2.06cc/sec$) than in forest areas(18.7cc/sec), while soil respiration rates were significantly higher in forest areas($0.58gCO_2/m^2/h$) than in campsites($0.13{\sim}0.34gCO_2/m^2/h$).

• Korean Journal of Environment and Ecology
• /
• v.27 no.5
• /
• pp.561-570
• /
• 2013

Organic carbon distribution and carbon budget of a Pinus densiflora forest in the Songgye 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 May 2011 through April 2012. For the estimation of carbon budget, soil respiration was measured. The amount of carbon allocated to above and below ground biomass was 52.25 and 14.52 ton C $ha^{-1}$. Amount of organic carbon in annual litterfall was 4.71 ton C $ha^{-1}$. Amount of organic carbon within 50cm soil depth was 58.56 ton C $ha^{-1}$ 50cm-$depth^{-1}$. Total amount of organic carbon in this Pinus densiflora forest was estimated to 130.04 ton C $ha^{-1}$. Amount of organic carbon in tree layer, shrub and herb layer was 4.12, 0.10 and 0.04 ton C $ha^{-1}yr^{-1}$ and total amount of organic carbon was 4.26 ton C $ha^{-1}yr^{-1}$. Amount of organic carbon returned to the forest via litterfall was 1.62 ton C $ha^{-1}yr^{-1}$. The amount of carbon evolved through soil respiration was 6.25 ton C $ha^{-1}yr^{-1}$. The amount of carbon evolved through microbial respiration and root respiration was 3.19 and 3.06 ton C $ha^{-1}yr^{-1}$. The amount of organic carbon absorbed from the atmosphere of this Pinus densiflora forest was 1.07 ton C $ha^{-1}yr^{-1}$ when it was estimated from the difference between Net Primary Production and microbial respiration.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2001.09a
• /
• pp.57-60
• /
• 2001

미생물 활성도와 그에 따른 유기물의 분해율은 미생물의 호흡률과 직접적인 관계가 있다. 본 연구는 매립종료후 경과기간이 1년인 Y 매립지와 10년인 C 매립지의 오염특성을 조사하였고, 오염토양 미생물의 산소소비속도를 이용하여 매립종료기간에 따른 오염토양의 산소소비율을 비교 평가 하고자 하였다. C 매립지의 오염토양에 대한 SCO $D_{cr}$ TOC는 Y 매립지에 비해 낮은 함량으로 나타났으나 T-N, N $H_3$-N의 함량은 큰 차이를 보이지 않았다. TOC/T-N비로 보았을 때 Y 매립지에 비해 C 매립지가 낮은 것으로 나타나 연령이 많은 경우 분해성 유기물의 함량은 적은 것으로 판단된다. 산소소비율 실험결과 Y 매립지가 산소소비율이 높은 것으로 나타났으며, C 매립지도 대조토양에 비해 높은 산소소비율을 보였다. 따라서 매립종료 후 경과기간이 10년인 매립지의 미생물의 산소소비율을 보았을 때 여전히 생물학적 안정화가 종료되지 않은 것을 알 수 있었다.

• Korean Journal of Soil Science and Fertilizer
• /
• v.45 no.2
• /
• pp.253-259
• /
• 2012

Disposal of high amount of coal combustion by-products, such as fly ash and bottom ash, is of a great concern to the country, due to the huge treatment cost and land requirement. On the other hand, those coal-ash wastes are considered to have desirable characteristics that may improve physical, chemical, and biological properties of soils. Especially, compared with fly ash, bottom ash has a larger particle size, porous surface area, and usable amount of micronutrients. In the present study, we examined bottom as a soil amendment for mitigating $CO_2$ emission and enhancing carbon sequestration in soils fertilized with organic matter (hairy vetch, green barely, and oil cake fertilizer). Through laboratory incubation, $CO_2$ released from the soil was quantitatively and periodically monitored with an enforced-aeration and high-temperature respirometer. We observed that amendment of bottom ash led to a marked reduction in $CO_2$ emission rate and cumulative amount of $CO_2$ released, which was generally proportional to the amount of bottom ash applied. We also found that the temporal patterns of $CO_2$ emission and C sequestration effects were partially dependent on the relative of proportion labile carbon and C/N ratio of the organic matter. Our results strongly suggest that amendment of bottom ash has potential benefits for fixing labile carbon as more stable soil organic matter, unless the bottom ash contains toxic levels of heavy metals or other contaminants.