• 한국환경과학회지
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• 제23권1호
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• pp.39-46
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• 2014

This study surveyed Abies koreana to identify the correlation between its vegetation structure according to its slope direction and seedling establishment in a bid to build basic research data on the changes and conservation of the A. koreana in Hallasan Mountain. The findings of its vegetation structure revealed that in both areas, Importance value was given to the A. koreana for its tree layer, the Taxus cuspidata for its shrub layer, and the Sasa quelpaertensis for its herb layer. However, in the Youngsil area with the tree layer, high importance was given to deciduous broad-leaved trees such as Prunus maximowiczii, Quercus mongolica, and the young species of the A. koreana in the shrub layer that can maintain the A. koreana forest's greater importance in the Jindallebat than in the Youngsil. Thus, the A. koreana forest in the Jindallebat is believed to lastlonger. The findings of correlation between the quantity of seedlings and their location by area revealed that in each tiny quadrat, the A. koreana seedling averaged 5.3 in the Youngsil and 2.9 in the Jindallebat. Both areas were all found to have a positive correlation in terms of rock exposure ratio and dead tree ratio as well as a negative correlation with regard to the cover degree of S. quelpaertensis, the canopy gap, the total vegetation, and the herb layer. It was found that the cover degree of the herb layer in the Youngsil and the S. quelpaertensis in the Jindallebat had the largest impact on the A. koreana seedlings.

• 한국수산과학회지
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• 제43권6호
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• pp.740-746
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• 2010

This study standardized the catch per unit effort (CPUE) of bigeye tuna (Thunnus obesus) caught by the Korean longline fishery in the Pacific Ocean. The study used a general linear model (GLM) to standardize the CPUE using catch and effort data aggregated by year, month, and $5{\times}5$ degrees of latitude and longitude in the tropical Pacific Ocean from 1982 to 2008 (except for 1988 and 1989). Explanatory variables in the GLM analysis included year, month, subtropical area, and number of hooks between floats (HBF). The study area and HBF were subdivided into three subtropical areas and six classes, respectively. During the study period, the standardized CPUE was significantly related to the nominal CPUE. The standardized CPUE declined sharply, as compared to the nominal CPUE, after the mid 1990s. In particular, the decline in the standardized CPUE in all subtropical areas in the 2000s was clearer than that of the nominal CPUE.

• Animal Bioscience
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• 제35권6호
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• pp.847-857
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• 2022

Objective: The effects of maternal undernutrition during midgestation on muscle fiber histology, myosin heavy chain (MyHC) expression, methylation modification of myogenic factors, and the mammalian target of rapamycin (mTOR) signaling pathway in the skeletal muscles of prenatal and postnatal goats were examined. Methods: Twenty-four pregnant goats were assigned to a control (100% of the nutrients requirement, n = 12) or a restricted group (60% of the nutrients requirement, n = 12) between 45 and 100 days of gestation. Descendants were harvested at day 100 of gestation and at day 90 after birth to collect the femoris muscle tissue. Results: Maternal undernutrition increased (p<0.05) the fiber area of the vastus muscle in the fetuses and enhanced (p<0.01) the proportions of MyHCI and MyHCIIA fibers in offspring, while the proportion of MyHCIIX fibers was decreased (p<0.01). DNA methylation at the +530 cytosine-guanine dinucleotide (CpG) site of the myogenic factor 5 (MYF5) promoter in restricted fetuses was increased (p<0.05), but the methylation of the MYF5 gene at the +274,280 CpG site and of the myogenic differentiation (MYOD) gene at the +252 CpG site in restricted kids was reduced (p<0.05). mTOR protein signals were down-regulated (p<0.05) in the restricted offspring. Conclusion: Maternal undernutrition altered the muscle fiber type in offspring, but its relationship with methylation in the promoter regions of myogenic genes needs to be elucidated.

• 한국환경복원기술학회지
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• 제17권5호
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• pp.43-49
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• 2014

Fairy Pittas use the forest around the valley and Gotjawal as breeding places. This survey was conducted to investigate the characteristic of earthworms, specifically its population density, body size around the breeding site in Gotjawal and the forest around the valley areas from the middle of July to the end of July 2013. A total of 405 individual earthworms were collected in the 100 small established quadrats, in which 315 were found in Gotjawal and 90 were found in the forest around the valley area. The density of earthworms in Gotjawal was significantly higher compared to that forest around the valley area. It was also observed that the body size of earthworms was significantly different between Gotjawal and the forest around the valley area. Proportion of number of individuals which are larger than 7cm in body size was 43%(n=135) in Gotjawal and 84%(n=76) in the forest around the valley area, respectively. Soil area was not important factor to the density of earthworms. We suggest that Gotjawal can be considered as a suitable breeding site for Fairy Pitta because of the richness of its primary food in this area.

• 대한지리학회지
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• 제42권3호
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• pp.355-367
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• 2007

지구 온난화의 영향으로 임업 뿐 아니라 농업, 수산업, 보건 등 여러 분야에서 피해가 발생하고 있어, 사회 경제 전분야에 걸쳐 기후변화에 대한 적응 대책이 필요하다. 기후변화의 영향을 평가하고 적응 방안을 마련하기 위해서는 미래 기후가 어떻게 변할것인지 미리 전망하는 일은 필수적이다. 본 연구에서는 트레와다의 기후 지역 구분 기준(최한월 평균기온이 $18^{\circ}C$ 이하이면서 월평균기온 $10^{\circ}C$ 이상인 달이 8-12개월)을 적용하여 아열대 기후 지역을 정의하고 A1B 시나리오에 근거한 아열대 기후구의 변화를 전망하기 위하여 기온 관측 자료와 모델 시나리오자료를 분석하였다. 아열대 기후에 관한 트레와다의 정의를 적용하여 현재 아열대 기후구와 미래 아열대 기후구의 변화를 전망해 본 결과 현재는 제주도를 포함한 남해안 일부 지역(부산, 통영, 거제, 여수, 완도, 목포)에 해당하던 것이 2100년에는 태백산맥과 소백산맥을 중심으로 한 산지 주변을 제외하고는 대부분 아열대 기후에 포함된다. 즉, 현재의 온난화가 지속된다면 제주도와 울릉도를 포함한 도서지역은 물론, 동해안으로는 속초, 서해안으로는 강화에 이르기까지 해안 지역을 모두 포함하며, 서울, 인천, 수원 등 대도시 지역도 아열대 기후 지역에 포함될 것이다.

• 한국자원식물학회지
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• 제34권5호
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• pp.462-469
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• 2021

본 연구는 제주도 곶자왈 지역에 자생하는 빌레나무를 대상으로 차광 처리를 통해 세 가지 수준의 차광 조건(35%, 55%, 75%)에 따른 개화 및 생장 특성을 분석하였다. 차광률 증가에 따라 개화 시기가 지연되었고, 55% 차광 처리구에서 가장 많은 개체가 개화하였으며, 개체당 화서의 수도 높게 나타났다. 차광률이 증가할수록 묘고가 감소하였고 잎과 줄기의 수는 75% 차광 처리에서 가장 낮은 것으로 나타났다. 전체 및 부위별 생물량도 차광률 증가에 따라 감소하였으며, 35% 차광 처리구에서 75% 차광 처리구 대비 지상부 생물량 2.1배, 지하부 생물량 1.7배, 총 엽면적 2.0배 높은 것으로 나타났다. 종합적으로 고려하면 빌레나무는 건전한 생육을 위하여 차광 처리가 필요하며 개화는 55% 차광 수준, 생장은 35% 차광 수준에서 가장 양호한 것으로 판단된다.

• 식물분류학회지
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• 제50권3호
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• pp.368-375
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• 2020

This study presents a survey of the bryophytes of evergreen broad-leaved forest near Baekyaki Oreum in Gujwa-Seongsan Gotjawal in the eastern part of Jejudo Island, Korea. A total of 53 taxa belonging to Bryophyta (11 families 26 genera 39 species) and Marchantiophyta (9 families, 9 genera 14 species) were determined, and the liverwort index was found to be 26.4%. The predominant life-form was the mat type. The rates of bryophytes dominating at mesic to hygric sites were higher than those of bryophytes, which were mainly observed in xeric habitats. These values indicate that the forest areas in this study area have a high density level. Upon an investigation of the substrates, bryophytes on rocks were most diverse. It was also found that volcanic rock masses of various sizes lay scattered over the study area and offer numerous micro-habitats for bryophytes. This is related to the characteristics of Gotjawal. We consider that more detailed studies should be conducted on regional scales to establish the bryophyte flora of Gotjawal and the evergreen broad-leaved forests of Jejudo Island.

• 한국지구과학회지
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• 제30권4호
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• pp.444-453
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• 2009

충북 영동 지역에 분포하는 하부 백악계 영동층군에서 식물화석이 많이 산출되었다. 영동 식물군은 이번에 처음 산출된 Pseudofrenelopsis의 자성생식기관과 웅성생식기관을 포함하여 Frenelopsis cf. alata, Pseudofrenelopsis cf. parceramosa, P. cf. varians, Brachyphyllum cf. vulgare, Pagiophyllum sp. 및 Classostrobus sp.의 5속 6종으로 구성된다. 이들은 모두 케이로레피드과에 속한다. 영동 식물군은 전기 백악기 중기-후기에 아열대의 건조한 기후 하에서 번성한 것으로 추정된다.

• 한국지구과학회지
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• 제22권2호
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• pp.105-111
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• 2001

충남 보령시 명암 지역에 분포하는 트라이아스기 후기의 아미산층으로부터 7개의 빗방울자국 표본이 발견되었다. 빗방울자국은 습윤한 아열대의 호성환경하에서 일시적 또는 계절적으로 건조한 기후에 수면의 저하시기에 형성된것으로 해석된다. 이들 빗방울자국은 하부 중생대 남포층군에서는 처음으로 발견된 것이다.

• Ocean and Polar Research
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• 제30권3호
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• pp.335-345
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• 2008

In order to study spatial variabilities and major controlling factors, we measured fugacity of $CO_2(fCO_2)$, temperature, salinity and nutrients in surface waters of the North Pacific($7^{\circ}30'{\sim}33^{\circ}15'N$, $123^{\circ}56'E{\sim}164^{\circ}24'W$) between September$\sim$October 2007. The North Pacific and the marginal sea were distinguished by $fCO_2$ distribution as well as unique characteristics of temperature and salinity. There was a distinct diurnal SST variation in the tropical North Pacific area, and surface $fCO_2$ coincidently showed diurnal variation. In the North Pacific area, surface $fCO_2$ was mainly controlled by temperature, while in the marginal sea area it was primarily dependent on alkalinity and dissolved inorganic carbon concentrations. Air-sea $CO_2$ flux showed a large spatial variation, with a range of $-6.10{\sim}5.06\;mmol\;m^{-2}day^{-1}$. The center of subtropical gyre of North Pacific acted as a source of $CO_2(3.09{\pm}0.95\;mmol\;m^{-2}day^{-1})$. Tropical western North Pacific (i.e. the 'warm pool' area and the subtropical western North Pacific) acted as weak sources of $CO_2$($1.07{\pm}1.20\;mmol\;m^{-2}day^{-1}$ and $0.50{\pm}0.53\;mmol\;m^{-2}day^{-1}$, respectively). In the marginal sea, however, the flux was estimated to be $-0.68{\pm}1.17\;mmol\;m^{-2}day^{-1}$, indicating that this area acted as a sink for $CO_2$.