• Korean Journal of Soil Science and Fertilizer
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• v.43 no.2
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• pp.242-251
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• 2010

In comparison with other terrestrial ecosystems, rice paddies are unique because they provide the primary food source for over 50% of the world's population, and act as major sources of global methane. The present paper summerizes a long-term field study that combine carbon isotopes, and canopy-scale flux measurements in an irrigated rice paddy, in conjugation with continuous monitoring of environmental, and vegetational factors. Both $CO_2$, and methane fluxes were largely influenced by soil temperature, and moisture conditions, especially across drainage events. Soil-entrapped $CO_2$, and methane showed a gradually increasing trend throughout growing season, but rapidly decreased upon flood water drainage. These variations in flux were well correlated with changes in concentration, and isotope ratio of soil $CO_2$, and methane, and of atmospheric $CO_2$, and methane within, and above the canopy. The isotopic signature of the gas exchange process varied markedly in response to change in contribution of soil respiration, belowground storage, fraction of $CO_2$ recycled, magnitude, and direction of $CO_2$ exchange, transport mechanism, and fraction of methane oxidized. Our results clearly demonstrate that stable isotope analysis can be a useful tool to study underlying mechanisms of gas exchange processes under natural conditions.

• Korean Journal of Environmental Biology
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• v.36 no.1
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• pp.50-61
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• 2018

The current study aimed to review the research trends on forest liming by age, country, and research topics, and seeks to summarize the effects of forest liming on soil, vegetation and water system in forest ecosystems. The recent goals of forest liming have been changed in response to changes in the acid deposition, and related studies have been mainly carried out in Europe and North America, where there is noted a massive forest decline, which was subsequently caused by acid rain. Most forest liming studies are noted to have focused on soil responses, however, the number of studies on the responses of vegetation and water system according to a literature review on the subject were relatively small. Meanwhile, forest liming influenced whole forest ecosystems through interaction between the soil, vegetation and water system as associated with the relevant regions. The changes in soil pH, base saturation, and cation exchange capacity by forest liming were noted as different depending on the soil layer and elapsed time after liming. The responses of vegetation to forest liming were shown in above- and below-ground plant growth and plant nutrient concentration, and also were noted to have varied depending on the available regional plant species and noted specific soil conditions. The chemical properties of the water system were changed similarly to those in the soil, leading to notable changes as seen in the planktons and available fish species in the region. Finally, these results could be used to plan further studies on forest liming, which would significantly benefit regional studies to promote the preservation of the species noted for protection in the region.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2002.05b
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• pp.388-389
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• 2002

옥상지반의 무기질계 토양종류와 야생초화류별 식물생육생태를 파악하고자 본 실험을 수행한 결과 초기 발아정도는 버미큘라이트에서 우수한 것으로 나타났으며, 초장과 피복율의 경우도 1, 2차 실험기간동안에는 버미큘라이트가 우수했으나 3차 이후부터는 오히려 펄리아트 처리구에서 효과적인 것으로 확인되었다. 다음으로 야생초화류의 토양종류별 생육특성을 실험한 결과 대체적으로 민들레, 벌개미취, 마타리, 큰달맞이의 생육상태가 우수한 것으로 나타났다.

• The Microorganisms and Industry
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• v.16 no.1
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• pp.18-20
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• 1990

현재 전세계적으로 10,000여개 이상의 실험실에서 생물공학적인 연구가 진행중에 있고, 200여개 이상의 회사에서 생물공학을 이용한 제품이 만들어지고 있다.(Saftlas, 1984). 이와같은 제품으로 생물농약(예, 모기억제에 사용되는 Bacillus thuringiensis var. israelensis 등)이라든가 insulin, 성장호르몬, lymphotoxin및 항암제등의 의약품(Saftlas, 1984)과 식물품종개량제(예, 질소 공정의 vector로 사용되는 Agrobacterium tumerfaciens의 Ti Plasmid)(McDanial, 1981 ; Shaw, 1986) 등이 있다. 그러나 최근 미생물 생태분야에서는 이와같이 만들어진 미생물들 (genetically engineered microorganisms : GEMs)이 자연 생태계에 유출되었을때 야기될 가능성이 있는 biohazaed에 대하여 관심이 집중되고 있다. (Curtiss, 1976 ; Sharples, 1983 ; Rissler, 1984). 토양환경에서 GEM이 유전물질을 전달항 수 있는 기작은 크게 conjugation, transduction, transformation 등이 알려지고 있다. 여기서는 주로 토양환경에서 transformation에 의한 유전물질의 전달과정에 대한 최근 연구동향을 간단히 기술하고자 한다.

• The Korean Journal of Ecology
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• v.28 no.6
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• pp.417-431
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• 2005

Soils of Korea experienced with long-term acidic deposition have been exhaustively leached exchangeable base cation (BC) for plant nutrient comparable with soils of forest decline areas in Europe and N. America. Ratios of $BC/Al^{3+}$ of most soils are below than 1, which value is critical load for plant growth. Acid soil applied with dolomitic liming is increased as much as 20% and 244% in concentrations of $Ca^{2+}$ and $Mg^{2+}$, respectively, as well as shrub leaves increase much cation uptake by 1 year later. Ions of $NO_3^-$ and $NH_4^+$ in acid rain are absorbed by the canopy acted as the sink but f is leached out from the canopy to throughfall as the source at Gwangneung forest with a little of acidic deposition, however, such sink and source functions are not found at Kwanaksan forest because of so much deposition. In coniferous and deciduous forested watershed ecosystems ions of $K^+$, $Cl^-$, $NO_3^-$ and $SO_4^{2-}$ from throughfall are retained in forest floor but ions of $Na^+, $Mg^{2+}$ and $Ca^{2+}$ are leached from the floor to streamwater.

• Journal of Wetlands Research
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• v.19 no.1
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• pp.144-154
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• 2017

The riparian vegetation is one of corridor type ecosystems, an ecotone and able to improve the ecological soundness by structural and functional link. And they act as habitats, sources and sinks of species, conduits, filters and barriers. This study was carried out to develop the vegetation model for the fluctuation areas of lake reservoirs consider of hydrologic and soil environments according to the vegetation structure of the reference ecosystem. To develop the case study, 2 sites within 10degree slope of the Daecheong Lake were selected. The riparian vegetation models were built by the results of GIS analysis, remote satellite analysis, field survey results, consider of water level, flooded frequency, soil and topographic index, land cover or land use etc. 1) study area varied from FWL to -5m of NFWL, 2) slope 10% below, 3) vegetations flooded below 100days yearly are Salix koreensis, Salix chaenomeloides, Salix gracilistyla, 4)land cover type classified wildlife grassland, abandoned paddy field, cropland according to landuse (or landcover), 5)finally model was constructed as ecological landscape forest. The model designs were suggested by 2 types in Daecheong lake reservoir. The model for the riparian vegetation corridors could be the basic and useful data to improve the ecological and landscape properties.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.82-82
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• 2022

최근 지구온난화로 인한 전 세계적 기후변화가 일어나고 있으며, 이러한 지구온난화 방지 대책으로 탄소의 중요성과 탄소중립을 선언하는 국가가 증가하고 있다. 탄소의 중요성이 증가함에 따라 유역 내의 탄소 중립이 중요 이슈로 떠오르고 있다. 유역 내 탄소 저장원으로는 숲, 하천, 토양 등이 존재하나 하천의 경우 탄소의 저장이 곧 수질 오염과 연결이 되기에 바람직한 방안이 될 수 없다. 그러나 토양의 경우 방대한 양의 탄소를 저장하기에 적합한 기능을 하기에 다른 저장원들에 비해 중요한 저장원으로 대두되고 있다. 토양탄소의 경우 일반적으로 유기물과 무기물의 형태로 토양에 저장된다. 이중 토양유기탄소는 장기간 토양 속에서 대기와의 탄소 조절 역할을 하기에 중요 요인으로 대두되고 있다. 하지만 기후변화로 인한 국지성 호우 및 무분별한 개발 등이 증가함에 따라 유역 내 토양 생태계의 변화가 일어나고 있으며, 이에 따른 유역 내 토양유기탄소 또한 손실이 일어나고 있다. 따라서 본 연구에서는 토양의 특성과 모델을 활용하여 유역단위 토양유기탄소량의 변화량을 산정하여 비교 및 분석을 하고자 한다. 이를 위해서 토양유기탄소의 모의가 가능한 APEX 모델을 활용하였으며, 선정된 연구 대상 지역의 토양 특성 자료를 활용하여 입력자료 전처리를 진행 후 모의를 진행하였다. 이후 선행연구 및 보고서를 통한 실측자료를 기반으로 모델 매개변수 보정을 진행하였으며, 보정된 결과를 통해 유역에 대한 토양유기탄소를 산정을 진행하였고 기간별 변화의 차이를 분석하였다. 해당 연구를 통해 유역 내 잠재되어있는 토양유기탄소량 정량화 등의 연구에 활용될 수 있을 것으로 기대한다.

• Korean Journal of Environmental Biology
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• v.19 no.4
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• pp.232-238
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• 2001

Effects of atmospheric nitrogen deposition on terrestrial ecosystems were reviewed and discussed in this paper. The amount of nitrogen deposition has increased rapidly in Europe, North America and Korean due to industrialization, increase in fossil fuel combustion(automobiles in particular), and intensive agricultural activities. Nitrogen input through such deposition may enhance primary productivity at early stage, but it could cause nitrogen saturation and hence deterioration of forests of disturbance of systems in the long term. Mechanisms of the deterioration of forests by nitrogen deposition include nutrients imbalance, soil acidification, and immobilization of toxic ions. In addition, nitrogen deposition may impede the decomposition rates of soil organic matter, and induce eutrophication in aquatic ecosystems by enhanced leaching of nitrate. Finally, I propose several topics in relation to nitrogen deposition, which warrant further studies in Korea.

• Korean Journal of Environmental Biology
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• v.22 no.3
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• pp.381-386
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• 2004

To develop accurate and predictive global carbon cycle models, it is important to understand the change of accumulated carbon for many ecosystems according to successional stage. In this study, I measured total biomass, litter and soil organic matter contents through an aerial photo and field observation. As a result, accumulated organic matter contents per unit area (kg $m^{-2})$ of three communities composed at grassland were 7.00 kg $m^{-2}$, in Solidago altissima community, 9.18 kg $m^{-2}$, in Imperata cylindrica community, and 12.68 kg $m^{-2}$, in Miscanthus sinensis community, respectively. Accumulated total organic matter contents was high in Miscanthus sinensis community at later succession stage but soil carbon was low. In Miscanthus sinensis community, highly accumulated organic matter contents was resulted from increasing of biomass comparison with that of the other two communities. The pattern of accumulated organic matter contents was changed by changing of the dominant community due to progressing in succession. The accumulated carbon in temperate grassland will be increased with progressing in succession.

• Journal of agriculture & life science
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• v.50 no.1
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• pp.117-124
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• 2016

Researches on soil microbial community are increasing to assess ecosystem responses to anthropogenic disturbances and to provide an indicator of ecosystem recovery. Microbial communities are able to respond more rapidly to environmental changes than plants and therefore they may provide an early indication of the ecosystem recovery trajectory. This study was conducted using 16S rRNA gene pyrosequencing of soil samples to compare soil bacterial community composition between artificially covered soils of the Baedudaegan ridgeline and their adjacent forest soils in two restoration project sites, Ihwaryeong and Yuksimnyeong, which were completed in 2012 and 2013, respectively. Richness of the Phylum level was 29.3 in Ihwaryeong and 32.3 in Yuksimnyeong. Significant difference in the richness between artificial restored soils and adjacent forest soils(p<0.01) was observed, however no significant difference was observed for site location and soil depth. Acidobacteria(37.3%) and Proteobacteria(31.1%) were more abundant than any other phylum in collected soil samples. Also, we found the significant difference in the relative abundance of the two abundant phyla between artificially restored soils and their adjacent forest soils (Proteobacteria, 38.1% in restored soils vs 24.2% in adjacent forest soils, p<0.01; Acidobacteria, 55.4% in restored soils vs 19.2% in adjacent forest soils, p<0.001). The results support the previous researches indicating that soil bacterial community composition is affected by nutritional status of soils and that Acidobacteria is also strongly influenced by pH, thus favoring soils with lower pH. This study could be utilized to monitor and evaluate restoration success of forest soil environment quantitatively.