• The Korean Journal of Ecology
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• 제18권3호
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• pp.353-366
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• 1995

To study the relationship between the germination response and geographical distribution, the seeds of Rumex acetocella were collected from nine sites (Taegwallyong, Alps lodge, Kans'ong, Sokch'o, Chumunjin, Suwon, Taechon, Sukgok, Mokpo) of different latitudes and altitudes. The populations of Rumex acetocella were subdivided into four groups based on the characteristics of the seed germination. The first group of Rumex acetocella (Taegwallyong, Alps lodge) germinated rapidly in early spring, the second group (Suwon, Teachon) in late summer through early autumn, and the third group(Sukgok, Mokpo) slowly in late autuman with various conditions. The thermal time values needed for the germination rate of 10% to 60% for these three groups indicated that the germination rate was low at the lower latitude, while it was increased as the latitude elevated. The population of the fouth group (Kansong, Sokcho, Chumunjin) showed the narrow optimum temperature range of germination response and the highest thermal time value to germinate 10% to 30% of seeds. The seeds in the high latitude region with relatively mild winter germinated synchronously in early autumn. These different germination responses of Rumex acetocella to geographic variations were thought to be an ecological strategy to survive in different environmental conditions.

• 한국작물학회지
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• 제54권2호
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• pp.143-158
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• 2009

This experiment was carried out to examine ecological response and soybean quality as affected by environmental cultivation for producing high seed quality in domestic soybean variety. The results are as follows: Under equal cumulative temperature condition, soybean plants grown in Muju showed longer days to flowering, which was an effect of the long day-length on high latitudes, and longer duration of reproductive stage as a result of low temperature within that period. Considering apparent seed quality, 100 seed weight of soybeans grown in Muju was heavier than Miryang. Ratio of seed crack and disease-damaged seeds was lower in Muju, and these parameters decreases as planting was delayed. The protein contents did not show significant difference in terms of altitude and planting date, however, crude oil contents were higher in Miryang. An opposite trend was observed in C18:1 and C18:3. In the fatty acid composition, the proportion of C18:1 decreased as seeding date was delayed, and was higher in Miryang. Opposite observations were obtained from C18:3. The anthocyanin contents were highest on June 10 planting and higher in Muju than in Miryang. Isoflavone content was higher as seeding date was delayed and is similar accross seeding dates in Muju. As a summary, for high seed quality production the optimum planting date was June 10, and Muju was more suitable region than Miryang.

• Ocean and Polar Research
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• 제25권4호
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• pp.607-615
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• 2003

Many organisms are known to survive in icy environments. These include both over wintering terrestrial insects and plants as well the marine fish inhabiting high latitudes. The adaptation of these organisms is both a fascinating and important topic in biology. Marine teleosts in particular, can encounter ice-laden seawater that is approximately $1^{\circ}C$ colder than the colligative freezing point of their body fluids. These animals produce a unique group of proteins, the antifreeze proteins (AFPs) or antifreeze glycoproteins (AFGPs) that absorb the ice nuclei and prevent ice crystal growth. Presently, there are at least four different AFP types and one AFGP type that are isolated from a wide variety of fish. Despite their functional similarity, there is no apparent common protein homology or ice-binding motifs among these proteins, except that the surface-surface complementarity between the protein and ice are important for binding. The remarkable diversity of these proteins and their odd phylogenetic distribution would suggest that these proteins might have evolved recently in response to sea level glaciations just 1-2 million years ago in the northern hemisphere and 10-30 million years ago around Antarctica. Winter flounder, Pleuronectes americanus, has been used as a popular model to study the regulation of AFP gene expression. It has a built-in annual cycle of AFP expression controlled negatively by the growth hormone. The signal transduction pathways, transcription factors and promoter elements involved in this process have been studied in our laboratory and these studies will be presented.

• Journal of Astronomy and Space Sciences
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• 제30권4호
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• pp.231-239
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• 2013

To identify seasonal and latitudinal variations of F2 layer during magnetic storm, we examine the change of daily averages of foF2 observed at Kokubunji and Hobart during high (2000~2002) and low (2006~2008) solar activity intervals. It is found that geomagnetic activity has a different effect on the ionospheric F2-layer electron density variation for different seasons and different latitudes. We, thus, investigate how the change of geomagnetic activity affects the ionospheric F2-layer electron density with season and latitude. For this purpose, two magnetic storms occurred in equinox (31 March 2001) and solstice (20 November 2003) seasons are selected. Then we investigate foF2, which are observed at Kokubunji, Townsville, Brisbane, Canberra and Hobart, Dst index, Ap index, and AE index for the two magnetic storm periods. These observatories have similar geomagnetic longitude, but have different latitude. Furthermore, we investigate the relation between the foF2 and the [O]/[$N_2$] ratio and TEC variations during 19-22 November 2003 magnetic storm period. As a result, we find that the latitudinal variations of [O]/[$N_2$] ratio and TEC are closely related with the latitudinal variation of foF2. Therefore, we conclude that the seasonal and latitudinal variations of foF2 during magnetic storm are caused by the seasonal and latitudinal variations of mean meridional circulation of the thermosphere, particularly upwelling and downwelling of neutral atmosphere during magnetic storm.

• 대한원격탐사학회지
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• 제34권1호
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• pp.1-15
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• 2018

Passive microwave sea surface temperatures (SST) were validated in the Northwest Pacific using a total of 102,294 collocated matchup data between Global Precipitation Measurement (GPM) / GPM Microwave Sensor(GMI) data and oceanic in-situ temperature measurements from March 2014 to December 2016. A root-mean-square (RMS) error and a bias error of the GMI SST measurements were evaluated to $0.93^{\circ}C$ and $0.05^{\circ}C$, respectively. The SST differences between GMI and in-situ measurements were caused by various factors such as wind speed, columnar atmospheric water vapor, land contamination near coastline or islands. The GMI SSTs were found to be higher than the in-situ temperature measurements at low wind speed (<6 m/s) during the daytime. As the wind speed increased at night, SST errors showed positive bias. In addition, other factors, coming from atmospheric water vapor, sensitivity degradation at a low temperature range, and land contamination, also contributed to the errors. One of remarkable characteristics of the errors was their latitudinal dependence with large errors at high latitudes above $30^{\circ}N$. Seasonal characteristics revealed that the errors were most frequently observed in winter with a significant positive deviation. This implies that SST errors tend to be large under conditions of high wind speeds and low SSTs. Understanding of microwave SST errors in this study is anticipated to compensate less temporal capability of Infrared SSTs and to contribute to increase a satellite observation rate with time, especially in SST composite process.

• The Korean Journal of Ecology
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• 제14권4호
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• pp.379-398
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• 1991

In order to investigate the ecotypic variations of pulsatilla koreana nakai distributed in korea, 8 local populations of the plant were selected in accordance with latitude and compared on the differences of leaf shape, elongstion, stomatal distribution and dhlorophyll content. The incised angle of the plant is 38。32' in cheju, showing a great difference as compared with 23。77'-30。 32' of the other sites. as to the incised rate, mt. togyu and cheju representsed relatively high values of 49.04% and 48.21% the parted leaved individuals were only observed along the warm current coastal area including cheju, sokcho and sunchon and were 54(62.8%), 2(2.5%) and 3(3.3%) in the sites, respectively. Especially, the individuals consisting of only parted learves were 5(5.8%) in cheju alone and none of the other sites showed such individuals at all. So p. cernua distributed in cheju and p. koreana in inland area can be considered to beecotypic variations of the same species from the upper investigations. According to the elongations of leaf and rachis, the local populations could be classified into 3 types, such as warm current coastal area type(cheju,sunchon and sokcho),southern inland area type(andong, chungju and mt. togyu)and central inland ara type(mt. komdan and hongchon). The dentate numbera of 39.80-43.73 in the warm current area were also different from those of 87% in mt.togyu and 15% in hongchon, while opposite leaflets account for 100% in the other sites. The content of chlorophyll ranged from 0.609 mg/g. d.w.(cheju)to 0.924 mg/g.d.w.(hongchon), showing an increasing trends as the latitudes grow higher. The number of stomata on the low epidermis is much larger than that on the upper epidermis in the whole area. But both aspects showed an increasing tendency, too as the latitude becomes higher.

• 한국환경과학회지
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• 제24권11호
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• pp.1371-1384
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• 2015

This study analyzes the characteristics of Western North Pacific (WNP) tropical cyclone (TC) activity and large-scale environments according to the Western Pacific (WP) teleconnection pattern in summer. In the positive WP phase, an anomalous cyclone and an anomalous anticyclone develop in the low and middle latitudes of the East Asia, respectively. As a result, southeasterlies are reinforced in the northeast area of the East Asia including Korea and Japan which facilitates the movement of TC to this area, whereas northwesterlies are reinforced in the southwest area of the East Asia including South China and Indochina Peninsula which blocks the movement of TC to this area. Due to the spatial distribution of this reinforced pressure system, TCs develop, move, and turn more to the northeast of WNP than those in the negative WP phase. Consequently, the characteristics of this TC activity in the positive WP phase are associated with the location of upper tropospheric jet further to the northeast. Meanwhile, TCs in the negative WP phase mainly move to the west from Philippines toward south China and Indochina Peninsula. Furthermore, due to the terrain effect caused by the high passage frequency of TCs in the mainland China, the intensity of TCs are weaker than those in the positive WP phase.

• The Korean Journal of Ecology
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• 제16권4호
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• pp.515-526
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• 1993

한반도 남부 지역에 분포하는 아까시나무(Robinia pseudo-acacia L.)종자의 생태학적 형질변이를 추적하기 위하여, 북위34$^{\circ}$18'~38$^{\circ}$36'사이에 위치한 15개 지역(대진, 속초, 강릉, 수락산, 홍천, 광릉, 남한산성, 충주, 예산, 안동, 전주, 달성, 창원, 목포, 완도)을 선정하여 채종한 종자를 재료로, 단백질 패턴 및 정량 분석을 실시하였다. SDS-PAGE에 의한 단백질 패턴 분석결과, 전 지역데 걸쳐 총 35개의 밴드가 분리되었으며 최고 분자량은 142,232 daltons, 최저 분자량은 17,258 daltons였다. 분리된 단백질 밴드 수를 지역별로 비교한 결과, 대진, 속초가 32개로 가장 많은 반면, 홍천과 달성은 23개로 가장 적었으며, 대체로 고위도로 갈수록 증가하는 경향을 나타냈다. 각 단백질 밴드의 유무에 따라 지역에 따른 단백질 패턴의 차이를 비교해 본 결과, 중북부 동해안형(대진, 속초, 강릉)과 중부형(수락산, 홍천, 광릉, 남한산성, 충주) 및 남부형(에산, 안동, 전주, 달성, 창원, 목포, 완도)등 3가지 지역 유형이 구분되었다. 단백질 패턴의 지역간 유사도 지수(Jaccard 계수)를 근거로 UPGMAdp 의한 cluster analysis 결과, 중북부 등해안형(속초, 강릉), 중북부 I형(수락산, 홍천), 중북부 II형(남한산성, 충주, 대진), 중북부III형(광릉), 중남부형(예산, 달성, 전주) 및 남부형(안동, 창원, 목포, 완도)등 6개 유형이 식별되었다. 분리된 단백질 밴드 가운데, 모든 지역세어 No.12밴드(78,162daltons)가 가장 높은 염색 강도를 나타냈고, No.11.12.13.과No.23~28 밴드 역시 비교적 높은 염색강도를 보였다. 전체적으로 총 단백질 함량이 높은 창원, 목포, 완도 등 남부형 지역에서 특히 높은 염색 강도를 나타냈다. 총 단백질 함량은 각 지역별로 최저9.68mg/g(수락산)에서 최고17.30mg/g(전주)에 이르는 다양한 수치를 나타냈으며, 대체로 저위도로 갈수록 증가하는 경향을 보였다.

• 한국환경생태학회지
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• 제35권3호
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• pp.237-255
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• 2021

제비동자꽃(Lychnis wilfordii (Regel) Maxim.)은 주로 고위도의 이탄습지에 분포하는 전문종이다. 우리나라에서는 2개 지역에 고립되어 분포한다. 본 연구에서는 생육지 특성, 생장특성 및 자가화합성 그리고 안정적인 개체군을 유지하고 있는 용늪습지보호지역에서 개체군의 지속에 관여하는 내적 동태를 평가하였다. 분포지의 식생환경은 용늪습지보호지역과 평창군 대관령면 분포지 사이에 뚜렷한 차이가 있었다. 화분매개충의 방문에 의해 종자의 생산이 촉진되기는 하지만 자가화합성을 함께 소유하였다. 토양의 유기물함량이 높은 조건에서 다수의 겨울눈을 생성하였고, 줄기 수, 열매 수가 최대에 달하였다. 그렇지만 유기물함량이 낮은 조건에서도 생장하고 개화하여 종자를 생산하였다. 용늪습지보호지역에서 제비동자꽃은 고층습원에는 분포하지 않았고 뚝사초가 형성하는 사초기둥이 발달한 저층습원에 분포하였다. 제비동자꽃은 이 공간에서도 사초기둥의 상단부에 주로 분포하였다. 따라서 뚝사초가 형성하는 사초기둥의 생성, 성장 및 소멸은 이 공간에 분포하는 식물의 정착, 성장, 소멸과 밀접한 연관이 있는 것으로 판단되었다. 현재 용늪습지보호지역은 제비동자꽃이 분포하는 사초기둥이 발달한 공간이 넓게 분포하고 있고 소멸과 재정착의 과정이 잘 이루어지는 것으로 평가되었다. 그러므로 현재와 같은 생태적 과정이 잘 유지된다면 용늪습지보호지역의 제비동자꽃 개체군은 오랜 기간에 걸쳐 지속 가능할 것으로 예상되었다.

• 한국지구과학회지
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• 제44권2호
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• pp.135-147
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• 2023

인공위성 관측 유의파고는 기후변화에 대한 해양의 반응을 이해하는데 널리 활용되므로 장기간의 지속적인 검증이 필요하다. 본 연구에서는 1992년부터 2016년까지 25년 동안 북태평양과 북대서양에서 9종의 인공위성 고도계 관측 유의파고의 정확도를 평가하고 오차 특성을 분석하였다. 위성 고도계와 부이 관측 유의파고 자료를 비교 분석하기 위하여 137,929개의 위성-실측 유의파고 일치점 자료를 생성하였다. 북태평양과 북대서양에서 위성 고도계 유의파고는 0.03 m의 편차와 0. 27 m의 평균제곱근오차를 보여 비교적 높은 정확도로 관측되고 있음을 확인하였다. 그러나 위성 고도계 유의파고는 지역적인 해역 특성에 따라 오차의 공간 분포 특성이 상이하였다. 실측 유의파고에 따른 오차, 위도별 오차의 계절분포 및 연안으로부터 거리에 따른 오차를 분석하여 오차 요인을 파악하고자 하였다. 대부분의 위성에서 실측 유의파고가 낮을 때 과대추정되었으며 실측 유의파고가 높을 때 과소추정되는 경향이 나타났다. 고도계 유의파고의 오차는 겨울철에 증가되고 여름철에 감소되는 뚜렷한 계절변화를 보였으며 고위도로 갈수록 변동성이 증폭되었다. 연안으로부터 거리에 따른 평균제곱근오차는 100 km 이상의 외해에서는 0. 3 m 이하로 높은 정확도를 보인 반면 15 km 이내의 연안에서는 오차가 0. 5 m 이상으로 현저하게 증가하였다. 본 연구의 결과는 인공위성 고도계 자료를 활용하여 전구 및 지역적인 해역에서 유의파고의 시공간 변동성 분석 시 각별한 주의가 필요함을 시사한다.