• Mycobiology
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• 제28권3호
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• pp.133-141
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• 2000

Twenty species representing five genera of arbuscular mycorrhizal fungi were isolated from twenty-four soil samples of the rhizosphere of the family Gramineae in Paekryung and Daecheong islands. A few species such as Glomus invermaius, G. marcrocapus var. marcrocarpus and Scutellospora coralloidea were recorded for the first time in Korea. The number of spores per 10g of soil was in the range of $8{\sim}337$ in Paekryung and $16{\sim}349$ in Daecheong island, respectively. The number of species per 10g of soil was $2{\sim}8$ species in Paekryung and $2{\sim}7$ species in Daecheong, respectively. Among them, G. macrocarpus var. macrocarpus was the most abundant species in both islands. The species diversity and evenness were almost similar in Paekryung and Daecheong Islands. Based on the host plants in two islands, the species diversity showed the highest value of 1.63 in Ischaemum crassipes, whereas the eveuness of species showed the lowest value of 0.35 in Eragrostis ferraginea.

• 자원환경지질
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• 제57권1호
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• pp.41-50
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• 2024

본 연구는 한반도 중서부 대청도에 발달하는 광역규모 습곡의 구조기하학적 특징과 형성 기작에 대하여 보고한다. 야외에서 획득한 구조 요소 자료를 기반으로 구조 영역별 등면적 하반구 스테레오 투영과 습곡된 지층 경계의 하향 투영을 수행한 결과, 연구지역에 발달하는 습곡은 북동 방향으로 완만하게 침강된 개방 과습곡으로 분류된다. 과습곡 날개부의 비대칭 기생습곡과 힌지부의 대칭 기생습곡은 지층과 평행한 압축작용을 경험한 이후 요굴흐름 기작이 발생했음을 의미한다. 한반도 중서부의 조산운동사에서 대청도 과습곡이 가지는 의미를 규명하기 위해 향후 습곡의 형성시기 규명이 반드시 필요하다.

• 한국자원식물학회지
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• 제25권1호
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• pp.31-47
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• 2012

본 연구는 2008년과 2010년에 걸쳐 3차례 식물상을 조사하였으며, 전체 조사된 분류군은 90과 269속 351종 3아종 43변종 6품종등 403분류군이 확인되었다. 주요 식물들로 특산식물이 서울제비꽃 등 2분류군이 확인되었고, 산림청지정 희귀 및 멸종위기 식물이 대청부채(CR) 등 8분류군, 환경부 지정 특정식물은 금방망이(V) 등 35분류군으로 나타났다. 또한 식물지리학적 분포특성에 있어 남방계 식물과 북방계식물이 함께 확인되었다. 귀화식물은 대청가시풀 등 40분류군이 확인되었으며, 한반도 미기록종인 대청지치가 새로이 발견되었다.

• 한국지형학회지
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• 제25권2호
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• pp.63-80
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• 2018

The purpose of this study was to investigate the physicochemical characteristics and formation age of sand dunes in the Okjukdong and Dajindong, Daecheong Island. As a result, most of the sand deposited in Okjukdong were composed of medium sized sand with moderately well sorted. The $SiO_2$ and $Al_2O_3$ accounted for a very high proportion of these deposits. There were some differences in characteristics between the sands in the dune and beach, whereas similar characteristics were observed among the materials (OJ-B, OJ-C and OJ-D) in the dune. In case of Dajindong, heterogeneous geochemical characteristics were found in the lower point. It was estimated that this was due to the influence of Daejin-dong black beach. Age dating results showed that uncovered dunes in Okjukdong were deposited $0.44{\pm}0.02$ ~ $0.50{\pm}0.02ka$, and sand depositsin Dajindong were formed $0.16{\pm}0.01$ ~ $0.18{\pm}0.01ka$. In both Okjukdong and Dajindong, sand deposits estimated to be formed 70 years ago, therefore it can be estimated that sand movement was active throughout the area from about hundred years ago. In this study area, the growth of sand dunes has been active in recent several decades or hundred years. It seems that there were different regions where deposits predominated over time. The source of dune sand was also different from time to time. Since the windbreak forest was established, the natural growth of sand dunes was limited, and sand nourishment was carried out by period. Therefore, in order to protect and continuously utilize coastalsand dunesin Daecheong Island, it is necessary to prepare conservation plan.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2018년도 추계학술대회
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• pp.64-64
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• 2018

The genus Cenchrus (Poaceae), containing ca. 97 species, is distributed throughout Australia, Africa and Indian sub-continent and which was introduced to the United States and Mexico for use in improved pasture. In Korea, especially Daecheong Island, it is one of the most hazardous invasive plant, which causes serious environmental threats, biodiversity damages and physically negative impact on humans and animals. It can cause serious damage to farms, fields and white sand beaches. However, the chloroplast (cp) genome sequences and information of Cenchrus longispinus have been not addressed, so we provide the complete cp genome of Cenchrus longispinus using next-generation sequencing technology. The size of cp genomes of this Daecheong Island species (Cenchrus longispinus) is 137,144 bp, and it shows a typical quadripartite structure. Consisting of the large single copy (LSC; 80,223 bp), small single copy (SSC; 12,449 bp), separated by a pair of inverted repeats (IRs; 22,236 bp). This cp genome contains 75 unique genes, 4 rRNA coding genes, 33 tRNA coding genes and 21 duplicated in the IR regions, with the gene content and organization are similar to other Poaceae cp genomes. Our comparative analysis identified four cpDNA regions (rpl16, rbcL, ndhH and ndhF) from three Cenchrus species, two Setaria species and one Pennisetum species which may be useful for molecular identification.

• 한국지형학회지
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• 제25권1호
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• pp.1-17
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• 2018

The characteristics and burial ages of sand sediments on the Jiduri coast in Daechung-myeon, Ongjin-gun, Incheon were investigated. Daecheong Island is the area where the characteristics of the rocky coast and sand coast are shown. Various studies have been conducted on the Okjukdong sand dune that appears in the north of the island. However, there has been no study on the sandy sedimentary topography of the Jiduri and Moraewul area in the south. The sandy sedimentary terrain of Jiduri is divided into sandy beaches, sand dunes and sand deposits along the slope including climbing dune. Overall, the depth of sandy sediments in Jiduri is not deep. The characteristics of sandy sediments and burial ages were investigated at an elevation of about 23 m above sea level at the back of Jiduli Beach and 46 m above sea level at the ridge line between Jiduri and Moraewol. From the Jiduri coast to the hillside behind, the average grain size decreases and the sorting becomes better as it moves from the intertidal zone to the beach and the foredune. This indicates the selective sand transport by the wind and can be judged by the terrain formed under the current sedimentation environment. The average grain size at the upper part of the section of JD-1 (elevation of about 23m MSL) was $1.6918{\varphi}$ of medium sand. The sorting was $0.4584{\varphi}$, skewness was -1.0491 and kurtosis was -1.2411, respectively. Particularly, the average particle size of the crosssection issomewhat uniform, but the color of the constituent material changes from brown to black. In the case of JD-2 (about 46 m MSL), the mean grain size of the section was $1.7943{\varphi}$, the sorting was 0.4931, the skewness was -1.1163, and the kurtosis was 1.2133. On the other hand, the brown and black layers of JD-1 exhibited a burial age of $0.1{\pm}0.0ka$ and the JD-2 had a burial age of $0.7{\pm}0.0ka$.

• 한국지형학회지
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• 제24권4호
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• pp.91-101
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• 2017

The Okjukdong dune in Daecheong Island attracts national attention because of its unique landscape that is not covered by vegetation. However, there has been little knowledge on the timing of the dune formation, associated wind regime, and conservational strategies. In this study, we used OSL dating and grain size analyses to reveal the history of the dune development. In addition, we analyzed the wind regime in the dunefield which is surrounded by artificial coastal forest. The fine sand at Okjukdong underlain by a colluvial gravel layer indicates that the dune has been developed since at least 5 ka. Aeolian sands were found to be deposited around 700 years ago. The dunefield appears to have been severely eroded 30~60 years ago. The dune landscape has been destroyed after constructing a windbreak forest around the dunefield. The sand seems to be moving south and north with the season.

• 한국환경생태학회지
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• 제28권6호
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• pp.664-696
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• 2014

본 연구는 대청도와 소청도의 곤충다양성에 관한 연구를 위하여 실시하였으며 2011년 6월부터 10월까지 6회에 걸쳐 주간과 야간조사를 병행하여 실시하였다. 대청도에서 조사된 곤충은 총 9목 75과 286종이며 소청도에서 조사된 곤충은 총 8목 42과 106종으로 대청도와 소청도에서는 9목 78과 336종의 곤충이 서식하는 것으로 조사되었다. 기존 참고문헌을 포함하여 대청도와 소청도에 서식하는 전체 곤충을 정리하면 총 10목 103과 744종으로 나비목이 29과 439종으로 59%의 비율을 차지하며 우점하였고, 딱정벌레목이 27과 124종으로 16%의 비율로 조사되었다. 이 중에서 환경부 지정 멸종위기야생동물은 2종으로 애기뿔소똥구리와 왕은점표범나비가 확인되었다. 그 외 IUCN 적색목록에 포함된 종이 2종(봄처녀나비, 큰주홍부전나비), 국외반출승인대상종 25종, 고유종 5종, 한국적색목록 6종, 특정종 77종, 기후민감종이 2종으로 확인되었다. 본 조사에 새롭게 조사되어 신규등록된 곤충은 대청도에서 58과 147종이며 소청도에서 24과 43종으로 확인되었다.

• 한국수산과학회지
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• 제48권3호
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• pp.275-283
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• 2015

This study compared the sensory and nutritional characteristics of mottled skate Beringraja pulchra caught off Ulleung Island (U-MS), Korea, with those caught off Daecheong Island (D-MS). Based on their trichloroacetic acid-soluble nitrogen content, free amino acid content, and taste value, the taste of intermediate weight female U-MS was superior to that of both other U-MS and D-MS. The urea content of U-MS was higher in females than males and increased in the order heavy>intermediate>light individuals. There was, however, no difference in urea content between U-MS and D-MS. The taste and flavor characterization results suggest that the level of ammonia, which was converted from urea, influenced the quality of fermented U-DS. With the exception of the light U-DS, the other U-MS exhibited no difference in terms of hardness. The total amino acid content of U-MS was higher in females than males and increased in the order intermediate > heavy > light individuals. The total amino acid content of U-MS was also higher than that of D-MS. The major amino acids of all MSs were aspartic acid, glutamic acid, leucine, and lysine.

• 한국지형학회지
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• 제28권4호
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• pp.1-13
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• 2021

In this study is aerial photos and UAV(Unmanned Aerial Vehicle) images were used to analyzed the characteristics of depositional landform changes in the Geum river channels before and after the opening gate of Gongju weir. Based on the depositional landform classification result, the main stream and the bare land occupied most of the area in all periods, and also found that the main stream, mid-channel island, and sand bar occupied a greater degree of area increase or decrease compared to other landforms in the classification items. As a result of analyzing the characteristics of depositional landform changes before and after the opening gate of Gongju weir, it is judged that the depositional landforms have changed due to the decreased water level of the Geum river after the opening of the weir, the summer rainy season and typhoons, river stabilization after the effluence of Daecheong dam, supply and deposition of river sediments and fixation of vegetation. The results derived from this study can be used as basic data for the study of river depositional landforms and the establishment of management and conservation plans for the landforms in river channels.