• Journal of The Korean Society of Grassland and Forage Science
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• v.10 no.3
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• pp.179-182
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• 1990

This experiment was carried out to determine the proper application time of nitrogen (N) and potassium ($K_2O$) as a additional fertilizer in corn cultivation at Taekwalyong alpine area.Two varieties of silage corn (cv. Suwon 19 and Kangwon local var.) were grown under different top dressing time (4-leaf, 7 leaf and 10-leaf stage) in 1989.Kangwon local variety produced more leaf area and higher dry matter yield than Suwon 19. However,there was no describle differences among application time of N and $K_2O$ fertilizer in both Suwon 19 and Kangwon local variety.

• Parasites, Hosts and Diseases
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• v.22 no.1
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• pp.102-108
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• 1984

This paper is the result of adult female mosquito and larval collection in U.S. Army Installations in Korea from 1979 to 1983. New Jersey light traps were operated for adult collection from May to October. The primary concern of this surveillance is to determine when to recommend insecticide spraying for mosquito control in the Army areas. The 5th Preventive Medicine Unit have developed an "index" level of female mosquitoes in a light trap similar to other U.S. Army Agencies in other parts of the world. When 10 female mosquitoes are reached on two consecutive trap-night, or 5 known vector females are collected, fogging is recommended in the trap areas. 1. Mosquito collections were conducted in 12 U.S. Army areas by operating 39 New Jersey light traps. Mosquitoes collected from the areas were identified to be 17 species comprising 3 genera. Anopheles sinensis (40%), Culex tritaeniorhynchus (31%), Aedes vexans nipponii (19 %) and Culex pipiens pallens (10%) appeared to be the most common species in the areas. 2. The species, population density and monthly appearance of adult mosquitoes were found to be almost the same in the all provinces involved. And Japanese Encephalitis vector mosquitoes, Culex tritaeniorhynchus, showed their seasonal fluctuation from July to September with a peak in August each year. 3. Larval habitats confirmed in the Army areas were categorized into 16 types as shown in Table 3. The mosquito larvae collected in those habitats were identified to be 15 species representing 4 genera. Most breeding sites in the Army areas were those which are activated during the wet season. 4. More mosquitoes were collected from the Kyungki Province than from the other Provinces. The reason for more collection of mosquitoes from military installations in the Kyungki Province appears to be the geographic characteristics surrounded by rice fields, marshes and other stagnant water areas.

• The Korean Journal of Ecology
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• v.23 no.3
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• pp.211-215
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• 2000

We have collected two species of firefly, Hotaria papariensis and Hotaria unmunsana to investigate their patterns of appearances and distributions from May to July in 1999 at 18 localities in Korea. A total of 1,096 individuals of these two species were collected: H. papariensis 584 and H unmunsana 512. The highest appearance level of adult firefly was different from each altitude. They appeared from the beginning of June to the end of June at 200 m sea level, the middle of June to the end of June at 200∼400 m, the end of June to the beginning of July at 400∼600 m and the beginning of July to the middle of July at 600∼800 m, respectively, All regions of these two species were cohabit, but Cheju-do region is the exceptional case. H papariensis was dominant at the northern parts and H unmunsana was the southern parts of Korean peninsula.

• Proceedings of KOSOMES biannual meeting
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• 2009.06a
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• pp.149-150
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• 2009

영산강 하구둑에 의해 폐쇄내만의 조건을 가진 영산강 하구역에서 식물플랑크톤의 계절변동을 파악하고자 2008년에 계절별로 7개 정점에서 조사하였다. 영산강 하구역에서 출현한 식물플랑크톤 개체수는 14$\sim$34,958cells/mL의 범위를 보였다. 조사시기별로는 7월에 평균 10,796cells/mL가 출현하여 조사기간 중 가장 많은 출현 개체수를 보였고, 이어서 9월(평균 3,327cells/mL), 5월(평균 590cells/mL), 11월(평균 34cells/mL) 순으로 감소하여 조사시기별 출현개체수의 변동이 매우 심하였다. 규조류는 모든 조사시기에 걸쳐 최고의 점유율을 나타내었고 11월을 제외하면 전체 개체수의 90%이상을 차지하고 있어 규조류가 영산강 하구역의 식물플랑크톤 생물량을 좌우하고 있는 종임을 알 수 있었다. 영산강 하구역에서 출현한 식물플랑크톤의 제 1 우점종은 5월에 Eucampia zodiacus(83.1%), 7월에 Chaetoceros curvisetus(24.2%), 9월에 Pseudo-nitzschia delicatissima(94.3%), 11월에는 Chroomnnas류(33.6%)로 변화하였다. 5월과 9월은 한 종이 전체 식물플랑크톤 개체수의 80% 이상을 차지하는 극우점양상을 보여주었고, 7월에는 C. curvisetus, Skeleton듬 costatum 및 Chaetoceros sp. 등이 유사한 점유율로 우점하고 있었다. 영산강 하구역의 식물플랑크톤 종다양성지수는 0.228$\sim$2.260의 범위로 소수의 우점종에 의해 전체 군집의 분포양상이 결정되는 전형적인 연안, 하구수역의 군집 특성을 보이고 있었다.

• Korean Journal of Environmental Biology
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• v.29 no.1
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• pp.11-16
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• 2011

Distribution characteristics of two dominant paracalanids of the family Paracalanidae on temperature and salinity were studied in the brackish and coastal waters from the West and South coasts of Korea. Bestiolina coreana mainly occurs in a range of 29.8~31.3 psu salinity and temperature of more than about $20^{\circ}C$, while Paracalanus parvus s. l. mainly occurs in a range $17{\sim}20^{\circ}C$ temperature and more than 30 psu salinity. The fact clearly indicates that temperature and salinity was a major factors in spatio-temporal distribution between these two paracalanids.

• Korean Journal of Veterinary Research
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• v.13 no.2
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• pp.161-163
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• 1973

In order to observe the time of the first appearance of Bowie positive pepsinogen granules in the gland cells of the chicken proventriculus, histological examination was performed on the chicken embryo proventriculus at 7, 10, 14, 18, 19, 20 and 21 days postincubation. The first appearance of Bowie positive pepsinogen granules in the gland cells of the chicken proventriculus was at 21 days postincubation.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.10a
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• pp.39-40
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• 2001

제주도 주변해역은 계절에 따라 다양한 이질수괴(대마난류계수, 황해지층냉수계수, 중국대륙연안수, 한국남해연안수 등)가 출현하고 있으며 이들 여러수괴의 분포상태에 따라 고등어, 전갱이, 방어, 삼치 등과 같은 여러 회유성 어종이 시기별 출현상황이 달라지고 있다(노, 1985; Nakao, 1977; 김ㆍ노, 1994; 김, 1995). 그중 방어(Yellow tail, Seriola quinqueradiata, TEMMINCK et SCHL-ECEL)는 제주도 주변해역에는 추ㆍ동계가 되면 제주도 북서쪽 추자도 주변어장을 시작으로 제주해협의 화도(속칭:관탈도)를 거쳐 제주도 남서부 마라도로 연결되는 방어어장이 매년 형성되며 특히, l1∼12월 사이의 어획량은 전국 방어 채낚기어업의 어획량의 대부분을 차지하고 있을 정도로 그 규모가 매우크다. (중략)

• Korean Journal of Environmental Biology
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• v.27 no.2
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• pp.205-215
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• 2009

In order to understand on the seasonal dynamics of phytoplankton in the mouth parts of Gamak Bay, Korea, we investigated from one station during June 2005 to June 2006. Samples were collected every week during the high water temperature (${\geq}20^{\circ}C$), and every two weeks during the low water temperature (${\leq}20^{\circ}C$). The phytoplankton community were composed of 76 genera, 208 species in the surface layer, and 72 genera, 186 species in the bottom layer (total: 77 genera, 214 species). The number of occurring species fluctuated greatly throughout the year from 27 species (March 15, 2006) to 121 species (Aug. 16, 2005). High number of species showed between June and September (>70 species), whereas the low number of species showed during the period of the low water temperature below $20^{\circ}C$ (ca. 40 species). The predominant species were diatom Skeletonema costatum during whole year, and two naked dinoflagellates, Cochlodinium polykrikoides and Polykrikos kofoidii during high temperature seasons. However, centric diatoms, Chaetoceros curvisetus, Chaetoceros debilis and Eucampia zodiacus were dominant species during low temperature seasons. Standing crops of dinoflagellate showed great fluctuations, which were ranged from $3.0{\times}10^5\;cells\;L^{-1}$ (April 17, 2006) to $7.3{\times}10^5\;cells\;L^{-1}$ (Aug. 2, 2005) in the surface layer and from $1.5{\times}10^3\;cells\;L^{-1}$ (Nov. 9, 2005) to $3.9{\times}10^5\;cells\;L^{-1}$ (Aug. 16, 2005) in the bottom layer, and showed high during high temperature seasons such as the number of species. The fluctuations were greater in the surface layer than in the bottom layer. Moreover, the variation of Cochlodinium polykrikoides, is affected by Polykrikos kofoidii grazing.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.4
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• pp.309-314
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• 2013

Temporal and spatial variations and species composition of ichthyoplanktons were investigated by Bongo net in a sea area with the construction of artificial upwelling structure at 13, June, 21 September, and 23 September in 2012. A total of fish eggs was 4,849 ind./$1,000m^3$, and fish larvaes was 641 ind./$1,000m^3$ in the study area. The common fish eggs was Engraulis japonicus which was composed of 57.5%, and unidentified I, II, III and IV were occurred with decreased number of individuals order. For fish larvaes, Pictiblennius yatabei, Repomucenus sp.A, sp.B and Scomber japonicus were dominated, however, other species were Engraulis japonicus, Konosirus puntatus, and unidentified I, II. Temporal variations of fish eggs and larvae were remarkable differed. Higher numbers of fish eggs and larvaes were July 2012, whereas those were lower at August 2012. Spatial variations of those were also significantly differed with higher numbers were at station 2 and 3 during study periods. The total number of fish eggs and larvae was about 4 fold against numbers of those in the compared area far from study area. These results indicated that higher numbers of fish eggs and larvaes were due to influx much more nutrients and food organisms with artificial upwelling.

• Korean Journal of Environmental Biology
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• v.37 no.4
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• pp.640-651
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• 2019

The study analyzed the relationship between harmful cyanobacteria and physicochemical factors in Lake Juam from 2005 to 2018. The research locations were designated St. 1 (Juam-Dam) and St. 2 (Sinpyong). Harmful cyanobacteria was found in four genera (Microcystis sp., Anabaena sp., Aphanizomenon sp., Oscillatoria sp.). The average standing crops of harmful cyanobacteria in both locations were 2,575 cells mL^-1 and 2,557 cells mL^-1 from 2005 to 2011. Since 2012, there has been a significant decrease that the measurements were 42 cells mL^-1 and 82 cells mL^-1 from 2012 to 2018. To analyze the reason for the decrease in harmful cyanobacteria, Pearson's correlation and t-tests were performed on data collected during the summer period (June-September). Pearson's correlation showed a significantly positive correlation with total nitrogen(TN), outflow, and storage and a negative correlation with electrical conductivity. T-tests were conducted in two different periods and showed decreases in total nitrogen, electrical conductivity, and residence time. The average rainfall was decreased from 263.3 mm (2005-2011) to 219.9 mm (2012-2018) and total nitrogen was decreased from 0.912 mg L^-1 (2005-2011) to 0.811 mg L^-1 (2012-2018) and the same variability was seen in TP (total phosphorus). Therefore, it seems that the low-rainfall decreased the nutrients (TN) and variability in the TP, resulting in a decrease in harmful cyanobacteria in Lake Juam.