• Ecology and Resilient Infrastructure
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• v.4 no.1
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• pp.44-53
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• 2017

In order to investigate the response in fauna and biological communities of terrestrial insects to the vegetation encroachment on the sandbar, species composition, species diversity, functional species traits and community structure of land-dwelling insects sampled by a pit-fall trap were compared at the bare and vegetated sandbar of a typical sand-bed stream, the Naeseong Stream, Korea. Species diversity of the insects was increased but their density was decreased as the riparian vegetation encroached at the sandbar. In particular, indicator species of bare sandbar such as Cicindela laetescripta and Dianemobius csikii, were found at the bar sandbar. The insect communities were clearly classified at the bare and vegetated sandbar according to coverages of riparian plants. The food web of the bare sandbar was composed of detritus - detritivore and scavenger - predator consisted mainly of Coleoptera. On the other hand, the food web of the vegetated sandbar was composed of plants - sucking and chewing herbivore - parasitoid and predator. These results showed that biodiversity of terrestrial insects was increased, food web was changed from grazing to detritus food chain, and insect fauna specific bare sandbar disappeared as the riparian vegetation invaded on the sandbar of a sand-bed stream.

• Journal of Wetlands Research
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• v.22 no.2
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• pp.59-65
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• 2020

The purpose of this study is to determine the origin of organic matter on sediment at Sindu-ri tidal flat. Grain size, organic matter, C/N ratio and the 13C and δ15N ratio were measured at three stations (Stn. A, B, C) of the tidal flat. As a result, the spatial variation in sediment properties showed that organic matter was related positively to the sediment mud content. Organic matters originating from marine particulate organic matter (marine POM) and fish farm particulate organic matter (fish farm POM) showed sedimentation of organic matters at Stn. A, sandy tidal flat, though terrestial plant (TP) and benthic microalgae (BMA) did at Stn.C, muddy tidal flat. Meanwhile, Stn. B, the intermediate property of Stn. A and C, was affected by marine POM and BMA. Furthermore, it was revealed that the amount and origin of organic matters in the sediments depended on spatial variation, and the factors were different from the stations. Particularly, at the Stn. C, the sediment showed high concentration of TOC in terrestrial organic matter and smaller size particles (< 63 ㎛). These facts suggest the many small size particles and organic matter will affect the sediment environmental condition in the Stn. C.

• Applied Biological Chemistry
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• v.46 no.4
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• pp.376-379
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• 2003

The aerial parts of tile Garland (Chrysanthemum comnarium L.) were extracted in MeOH and solvent fractionated with EtOAc, n-BuOH and water, successively. EtOAc fractions gave three steroid compounds through application of silica gel column chromatographies. The chemical structures of the steroids were determined by the interpretation of several spectral data, including NMR and MS as $stigmast-5-en-3{\beta}-ol\;(1,\;{\beta}-sitosterol),\;stigmast-4-en-6{\beta}-ol-3-one$ (2), $stigmast-4-en-6{\alpha}-ol-3-one$ (3). Compounds 2 and 3 have been so far reported only in the aquatic plants, were isolated for the first time from the land plants.

• Proceedings of the Speleological Society Conference
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• 1995.09a
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• pp.39-44
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• 1995

$\bigcirc$ 동굴생물은 식물과 동물, 미생물로 크게 구분되지만 태양광선이 완전히 차단된 동굴내 환경에서는 동굴 동물들이 주종을 이루고 있다. $\bigcirc$ 동굴내의 동물에 관한 연구는 1966년 고씨동굴, 용담굴을 시발로 고수굴, 천동굴, 노동굴, 백룡글, 대이굴, 환선굴 등 강원도내에 분포하는 동굴 중 약 30% 정도는 동물을 포함한 생물상이 조사되었다. $\bigcirc$ 강원도의 동굴동물로서 확인된 것은 9강 30목 141종이며 강별로는 곤충강이 9목 50종 주형강이 4목 49종 갑각강이 6목 18종의 순으로 우세하고 목별로는 거미목이 15과 39종, 톡토기목이 7과 20종, 딱정벌레목이 8과 15종으로 우세한 편이다(남, 1987). $\bigcirc$ 동굴생물에 관한 연구는 육상생태계와 격리된 환경에서 생리, 생태적 적응을 통한 종의 분화나 유전, 진화문제를 추구하며 지하생태계와 육상생태계의 생물적인 유연관계 규명에 중요한 분야로 인정되며 아울러 독특한 특성을 지닌 동굴생물의 생존을 위한 방안과 노력이 일부동굴의 개방 및 개발에 앞서 더욱 구체적으로 모색되고 증대되어야 한다. $\bigcirc$ 동굴환경의 주요 특성은 첫째 햇빛에 차단되어 암흑상태이며, 둘째 내부습도가 높고 기온이나 수온의 년중변화가 심하지 않고, 셋째 먹이연쇄에 필수적인 영양공급원이 제한되어 있다. 따라서 광합성작용으로 성장하는 녹색식물은 태양광선이 유입되는 곳이나 인공조명시설 지역을 제외한 곳에서는 서식이 불가능하고 대형동물이나 초식동물은 생존이 어렵다. $\bigcirc$ 동굴내에는 환경에 적응하는 종들만이 서식할 수 있고 이들을 생태적 특성에 따라 세가지로 구분 할 수 있다. 환경적응 요인으로는 광도, 습도, 온도 영양공급원과 섭식장소, 수중생물의 경우는 특히 수온, 수량 영양원등이다.(중략). 본 연구의 접근방법으로는 ASRS의 개념적인 Reference Model을 수립하고 이 Reference Model에 대한 Formal Model로 DEVS(Discrete Event System Specification)을 이용하여 시스템을 Modeling하였다. 이의 Computer Simulation을 위하여 DEVS형식론 환경에서의 Simulation Language인 DEVSim ++ⓒ를 이용하여 시스템을 구현하였다.. 실형 결과로는 먼저 선형 상미분방정식의 예로 mass-damper-spring system, 비선형 상미분방정식의 예로는 van der Pol 방정식, 연립 상미분방정식의 예로는 mixing tank problem 등을 보였으며, 그의 공학에서 일어나는 여러 가지 문제들도 다루었다.화물에 대한 방어력이 증가되어 나타난 결과로 여겨지며, 또한 혈청중의 ALT, ALP 및 LDH활성을 유의성있게 감소시키므로서 감잎 phenolic compounds가 에탄올에 의한 간세포 손상에 대한 해독 및 보호작용이 있는 것으로 사료된다.반적으로 홍삼 제조시 내공의 발생은 제조공정에서 나타나는 경우가 많으며, 내백의 경우는 홍삼으로 가공되면서 발생하는 경우가 있고, 인삼이 성장될 때 부분적인 영양상태의 불충분이나 기후 등에 따른 영향을 받을 수 있기 때문에 앞으로 이에 대한 많은 연구가 이루어져야할 것으로 판단된다.태에도 불구하고 [-wh]의미의 겹의문사는 병렬적 관계의 합성어가 아니라 내부구조를 지니지 않은 단순한 단어(minimal $X^{0}$ elements)로 가정한다. 즉, [+wh] 의미의 겹의문사는 동일한 구성요 소를 지닌 병렬적 합성어([$[W1]_{XO-}$ $[W1]_{XO}$ ]$_{XO}$)로 그리고 [-wh] 의미의 겹의문사는 중복된 발은을 지닌 한 단어로 ([W]$_{XO}$

• Proceedings of the Speleological Society Conference
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• 1994.05a
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• pp.106-110
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• 1994

$\bigcirc$ 동굴생물은 식물과 동물, 미생물로 크게 구분되지만 태양광선이 완전히 차단된 동굴내 환경에서는 동굴 동물들이 주종을 이루고 있다. $\bigcirc$ 동굴내의 동물에 관한 연구는 1966년 고씨동굴, 용담굴을 시발로 고수굴, 천동굴, 노동굴, 백룡굴, 대이굴, 환선굴 등 강원도내에 분포하는 동굴 중 약 30%정도는 동물을 포함한 생물상이 조사되었다. $\bigcirc$ 강원도의 동굴동물로서 확인된 것온 9종 30목141종이며 강별로는 곤충강이 9목 50종 주형강이 4목 49종 갑각강이 6목 18종의 순으로 우세하고 목별로는 거미목이 15과 39종, 톡토기목이 7과 20종, 딱정벌레목이 8과 15종으로 우세한 편이다 (남, 1987). $\bigcirc$ 동굴생물에 관한 연구는 육상생태계와 격리된 환경에서 생리, 생태적 적응을 통한 종의 분화나 유전, 진화문제를 추구하며 지하생태계와 육상생태계의 생물적인 유연관계 규명에 중요한 분야로 인정되며 아울러 독특한 특성을 지닌 동굴생물의 보존을 위한 방안과 노력이 일부동굴의 개방 및 개발에 앞서 더욱 구체적으로 모색되고 증대되어야 한다. $\bigcirc$ 동굴환경의 주요 특성은 첫째 햇빛이 차단되어 암흑상태이며, 둘째 내부습도가 높고 기온이나 수온의 연중변화가 심하지 않고, 셋째 먹이연쇄에 필수적인 영양공급원이 제한되어 있다. 따라서 광합성작용으로 성장하는 녹색식물은 태양광선이 유입되는 곳이나 인공조명시설 지역을 제외한 곳에서는 서식이 불가능하고 대형동물이나 초식동물은 생존이 어렵다. $\bigcirc$ 동굴내에는 환경에 적응하는 종들만이 서식할 수 있고 이들을 생태적 특성에 따라 세가지로 구분 할 수 있다. 환경적응 요인으로는 광도, 습도, 온도 영양공급원과 섭식장소, 수중생물의 경우는 특히 수온, 수량 영양원등이다.(중략)다. 본 연구의 접근방법으로는 ASRS의 개념적인 Reference Model을 수립하고 이 Reference Model에 대한 Formal Model로 DEVS(Discrete Event System Specification)을 이용하여 시스템을 Modeling하였다. 이의 Computer Simulation을 위하여 DEVS형식론 환경에서의 Simulation Language인 DEVSim ++ⓒ를 이용하여 시스템을 구현하였다.. 실형 결과로는 먼저 선형 상미분방정식의 예로 mass-damper-spring system, 비선형 상미분방정식의 예로는 van der Pol 방정식, 연립 상미분방정식의 예로는 mixing tank problem 등을 보였으며, 그의 공학에서 일어나는 여러 가지 문제들도 다루었다.화물에 대한 방어력이 증가되어 나타난 결과로 여겨지며, 또한 혈청중의 ALT, ALP 및 LDH활성을 유의성있게 감소시키므로서 감잎 phenolic compounds가 에탄올에 의한 간세포 손상에 대한 해독 및 보호작용이 있는 것으로 사료된다.반적으로 홍삼 제조시 내공의 발생은 제조공정에서 나타나는 경우가 많으며, 내백의 경우는 홍삼으로 가공되면서 발생하는 경우가 있고, 인삼이 성장될 때 부분적인 영양상태의 불충분이나 기후 등에 따른 영향을 받을 수 있기 때문에 앞으로 이에 대한 많은 연구가 이루어져야할 것으로 판단된다.태에도 불구하고 [-wh]의미의 겹의문사는 병렬적 관계의 합성어가 아니라 내부구조를 지니지 않은 단순한 단어(minimal $X^{0}$ elements)로 가정한다. 즉, [+wh] 의미의 겹의문사는 동일한 구성요 소를 지닌 병렬적 합성어([$[W1]_{XO-}$ $[W1]_{XO}$ ]$_{XO}$)로 그리고 [-wh] 의미의 겹의문사는 중복된 발은을 지닌 한 단어로 ([W]$_{XO}$

• Land and Housing Review
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• v.14 no.1
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• pp.83-97
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• 2023

The study aims to provide an academic basis for the preservation and restoration of abandoned paddy wetland and the enhancement of its carbon accumulation function. First, the temporal change of the wetlands was analysed, and a typological classification system for wetlands was attempted with the goal of carbon reduction. The types of wetland were classified based on three variables: hydrological environment, vegetation, and carbon accumulation, with a special attention on the function of carbon accumulation. The types of abandoned paddy wetlands were classified into 12 categories based on hydrologic variables- either high or low levels of water inflow potential-, vegetation variables with either dominance of aquatic plants or terrestrial plants, and three carbon accumulation variables including organic matter production, soil organic carbon accumulation, and decomposition. It was found that the development period of abandoned paddy analyzed with aerial photographs provided by the National Geographic Information Institute happened between 2010 and 2015. In the case of the wetland in Daejeon 1 (DJMN01) farming stopped by 1990 and it appeared to be a similar structure to natural wetlands after 2010 . Over the past 40 years the abandoned paddy wetland changed to a high proportion of forests and agricultural lands. As time went by, such forests and agricultural lands tended to decrease rapidly and the lands were covered by artificial grass and other types of forests.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.2 no.2
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• pp.78-86
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• 1997

To clarify the phytoplankton blooms in Lake Shihwa after the construction of a dyke, a study on the environmental factors, the distribution of chlorophyll-a, phytoplankton standing stocks, dominant species and primary productivity was carried out in Lake Shihwa and adjacent coastal areas from October, 1995 to August, 1996. Lake Shihwa is brackish water with mixing of freshwater from tributaries and the remaining salt water at the bottom. The dense phytoplankton bloom of average value of 168.6 ${\mu}gChl-a\;l^{-1}$ have occurred throughout the year in Lake Shihwa which is eutrophicated by the large input of nutrients from inflowing 5 tributaries and Shihwa Industrial Complex. The major organisms of algal bloom in Lake Shihwa were diatoms, Cyclotella atomus, Nitzschia sp. and Chaetoceros sp. in autumn and winter, and dinoflagellate Prorocentrum minimum and Chrysophyceae in spring and summer. The autumn and winter diatom blooms were limited by the depletion of silicate in the lake. Diatom blooms have occurred in the coastal areas adjacent to Shihwa lake from winter to summer due to the inflow of nutrient rich-water from Lake Shihwa. The primary productivities in the Lake Shihwa ranged from 2,653 mgC $m^{-2}\;day^{-1}$ to 9,505 mgC $m^{-2}\;day^{-1}$ with an average of 3,972 mgC $m^{-2}\;day^{-1}$. However, most of the high primary production was limited to the shallow euphotic zone due to the inhibition of light penetration. The primary productivities during autumn and winter were limited by the depletion of silicate. Lack of photosynthesis and the decomposition of falling organic matter under the middle of water column accelerated the depletion of dissolved oxygen in the bottom layer.

• Journal of Wetlands Research
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• v.22 no.1
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• pp.24-30
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• 2020

To assess the wetland systems' capability to reduce fine dust, we used an artificial wetland module of small-sized greenhouse (70cm W × 70cm L × 60cm H) which creates a closed system. Experiment was performed twice using four species in each experiment. Non-plantation, one species, or two species condition was created in each mesocosm. We measured air quality, primarily PM2.5 and PM10 at the initial open mesocosms and 1hr later since mesocosms were closed. The dry weight of vegetation was measured at the 2nd experiment. The decreased amount of PM2.5 and PM10 was 13.7±1.3 and 13.2±1.3 ㎍·m^-3hr^-1 in wetland condition and 15.0±1.4 and 13.8±1.5 ㎍·m^-3hr^-1 in dryland condition, respectively. In 2^nd experiment, the decreased amount of PM 2.5 and PM 10 in wetland condition was 13.7±1.3 and 9.2±1.5 ㎍·m^-3hr^-1, 15.0±1.4 and 8.8±1.4 ㎍·m^-3hr^-1 in dryland condition, respectively. Wetland showed higher removal effect due to its high productivity leading to more effective absorption of particulate matter. Furthermore, the aquatic characteristics of wetland system and high humidity helped purifying the air quality. This can be seen as another value of wetlands, which can be presented as one of the solutions to the problem of fine dust.

• Korean Journal of Environment and Ecology
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• v.34 no.6
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• pp.515-529
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• 2020

Constructed wetlands undergo biological and physical changes such as an increase in the proportion of arid plants due to the natural succession process after formation. It can adversely affect not only the purification function but also the habitat of species. As such, this study aims to identify environmental factors affecting biodiversity and propose management plans based on the monitoring results of physical environmental changes and the emergence of species in seven constructed wetlands selected based on the water depth and surrounding conditions among the lands purchased by the Nakdong River basin. We examined the environmental conditions and emergence of the Odonata, which is a wetland-dependent species, to predict the trend of changes in biodiversity and abundance. The results showed that the open water area decreased as the emergent plants spread to the deep water in 2015 compared to 2012 when they were initially restored to a depth of 0.2 to 1 m. While a total of 54 dragonfly species were observed, the habitat diversity, such as vegetation, water surface, and grassland, remained similar to the initial formation of the wetlands despite the expansion of the emergent plants. On the other hand, the number of Agrionidae species, which prefer areas with fewer aquatic plants, decreased between 2012 and 2015 due to the diminished water surface. The p-values of the differences in the number of species and population between wetlands by year were 2.568e-09 and 1.162e-08, respectively, indicating the statistically significant differences. The decrease in open water surface was found to have the greatest effect on the biodiversity and habitat density of dragonflies. The time-series survey of constructed wetlands confirmed that the spread of Phragmites communis, P. japonica, Typha orientalis, etc., caused a decrease in species diversity. It suggests that environmental management to maintain the open water surface area is necessary.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.8
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• pp.579-592
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• 2020

This study was designed to assess the water quality and phytoplankton community including chlorophyll a in blood cockle (Tegillarca granosa) farms in May, August and November of 2017 in the northwestern Yeoja Bay, Korea. As a result, the seasonal characteristics of water types by water temperature and salinity were clear. Nutrients were abundant in silicate throughout the season, but phosphate was scarce in spring and summer, and nitrogen sources were scarce in autumn. The species composition of phytoplankton community was a very simple distribution, and the standing crop was also very low. The annual dominant species is dominated by the diatoms, with Skeletonema costatum-ls, Nitzschia longissima in spring, Pleurrosigma normanii, Coscinodiscus gigas in summer, and N. longissima, Pseudonitschia pungens, Chaetoceros curvisetus, Eucampia zodiacus in autumn. In summer the results were different from other coastal waters of Korea. The principal component analysis(PCA) and correlation analysis showed that the characteristics of water quality and biological environments differed according to the season. Furthermore, it was determined by the supply of materials through fresh water on land, seawater congestion caused by the refueling of surface sediments with lower depth, and the balance of biological production and mineralization of organic matters in blood cockle farms.