• Korean Journal of Environment and Ecology
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• v.22 no.2
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• pp.152-158
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• 2008

This survey was conducted to analyze the effect of road construction near the group breeding places of the egrets and herons located at Palhyun-ri, Daegu, on their breeding during four years from 2003 to 2006. With the number of the individuals of the whole egrets and herons have been decreased due to the three-year road construction work(2003-2005). When the road construction was temporally stopped in 2006, the number of individuals of egrets and herons except Cattle egret Bubulcus ibis increased and partocilarly, the Gray heron Ardea cinerea was found to have been influenced the most by this construction in comparison with other egrets and herons. The number od individuals of large egrets, little egrets and herons was found to decrease during the construction period. After cutting off the nest trees and removing some parts of the breeding site, the herons and egrets tended to move their nesting place from roadsides to the inside of the breeding area. Trees for the nests decreased due to the increase in fellen trees caused by bird nests per tree increased gradually. As for the formation ratio of trees for the nests, the ratio of pine trees lowered yearly while that of acacia and oak trees was increasing during the survey.

• Journal of Ecology and Environment
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• v.29 no.6
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• pp.545-550
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• 2006

Ten supernormal clutches of little terns Sterna albifrons and seven clutches having mixed eggs by little terns and kentish plovers Charadrius alexandrinus were recorded during the breeding seasons of 2003$\sim$2005 at Ganwol lake, Hongsung-gun, Chungcheongnam-do, Korea. The frequency of egg retrieval by Little Terns was higher after the second egg laying regardless of the clutch size and incubation stage. The frequency of egg retrieval was high at all incubation stage. When experimental eggs were placed within 15 cm from the nests, the percentage of egg retrieval was highest (almost 100%). However the percentage dropped rapidly over 35$\sim$55 cm range and finally to zero at 60 cm distance. Little terns retrieved all kinds of eggs set near their nests regardless of its kind or size. This study suggests that egg retrieval by little terns may be a source of the nest with supernormal and mixed egg clutch observed in this species.

• Weed & Turfgrass Science
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• v.2 no.2
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• pp.191-197
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• 2013

Two medium-leaf ecotypes (CY6069, CY6097) belonging to one species (Zoysia japonica) of Korean lawngrasses were selected in sod production fields in Jang Seong, Korea. They were reported to have distinct morphological and growth rate characteristics different from the preferred medium-leaf type zoysiagrass in Korea. This study was conducted to define further the genotypic difference at the molecular level and to develop DNA marker based on the specific DNA fragment. Polymorphic DNA fragments were first explored by using randomly amplified polymorphic DNA (RAPD) primers, which were then converted into PCR-based sequence characterized amplified region (SCAR) markers. The CY6069-specific primer set amplified about 550 bp successfully, while the CY6097 marker produced the expected 690 bp band, by which those markers were nominated by CY6069_550 and CY6069_690 SCARs, respectively. Together with the reported morphological and other phenotypic features, the SCAR markers confirmed in this study will be useful to identify those medium-leaf zoysiagrass genotypes when they are cultivated with other vegetatively propagated warm-season turfgrasses in sod farms.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2021.04a
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• pp.28-29
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• 2021

애기똥풀(Chelidonium majus L. subsp. asiaticum H.Hara)의 지상부는 백굴채라고 불리며 항암, 항균 등의 효능을 가지고 있어 예로부터 약용으로 이용되었다. 그러나 천연 약용소재로 개발가치가 높음에도 불구하고 실생묘의 대량 확보를 위한 종자번식 관련 연구가 전무한 실정이다. 본 연구에서는 애기똥풀의 발아 및 휴면 특성을 분석함으로써 추후 종자번식을 위한 기초자료를 제공하기 위해 수행되었다. 실험재료로 사용된 애기똥풀 종자는 2019년 6월 경상북도 봉화군에서 채종하였으며 정선 후 건조상태로 실온(25℃)에 보관하였다. 종자의 1000립중은 0.57±0.01g이며, 배종비는 0.21±0.12로 조사되어 형태적으로 미성숙한 배를 가지고 있다. 종자의 활력은 테트라졸륨 검정을 통해 79%로 확인되었다. 종자의 기본 함수율은 7.64±0.25%였으며, 침지 2일 차에 최대함수율(32.6±0.34%)에 도달하였다. 초기 발아검정은 25/15℃ (light/dark, 16/8h)챔버에서 명조건과 암조건으로 구분하여 30일간 진행하였으며, 암조건은 알루미늄 호일로 광을 완전히 차단하고 최종 발아율만 조사하였다. 발아율을 조사한 결과, 명조건은 0.75±0.80%, 암조건은 5.50±1.55%로 조사되어 형태적인 휴면과 생리적인 휴면을 모두 갖는 것으로 판단하였다. 애기똥풀의 생태적인 환경을 고려하여 12주의 Summer temperature(S12, 25/15℃, 16/8h)로 층적하고 연속하여 Autumn temperature(A, 15/10℃, 16/8h)를 4주(A4)와 8주(A8)로 달리하여 종자의 휴면타파를 유도하였다. 층적 후 발아율은 모두 증가되었으며, S12-A4(54%)는 S12-A8(24.5%)에 비해서 휴면타파에 효과적이었다. 휴면타파 효과의 증진을 위해 층적처리한 종자를 500ppm의 GA₃와 GA₄₊₇에 각 24시간동안 4℃에서 침지시킨 뒤 동일한 조건에 파종하였다. GA₃가 처리된 S12-A4는 발아율이 82.0%, S12-A8는 30.8%로 유의적으로 증가하였으나 GA₄₊₇ 처리는 S12-A4(48.5%)와 S12-A8(21.3%)에서 발아율 향상 효과가 없었다. 결론적으로 애기똥풀의 휴면타파를 위해서 12주의 Summer temperature와 4주의 Autumn temperature 변온층적과 추가 GA₃ 처리가 휴면타파를 위한 효과적인 처리방법으로 판단된다.

• Korean Journal of Ichthyology
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• v.22 no.2
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• pp.90-95
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• 2010

Blue devil (Pomacentrus caeruleus, also called Chrysiptera cyanea) is widespread in the Indo-Pacific Ocean and very popular all over the world as an aquarium fish because it is so easy to keep in a marine aquarium. However, tank-breeding techniques are not completely known. In this study, we reared blue devil and investigated its spawning ecology, as a necessary precursor for successful artificial-tank breeding. We investigated the spawning volume according to time with two types of calendars: solar and lunar. Rearing conditions were set at 30 ppt salinity, $27^{\circ}C$ water temperature, in two aquariums with water volumes of 80 and 125 L. We successfully bred P. caeruleus in this artificial-tank system. The aquarium fish formed a spawning harem with one male and more than two females. We harvested about 113,580 eggs in 44 spawning episodes by two spawning harems during the 11-month period from December to October. They showed a peak season of spawning volume and time in May and June. We confirmed the two peak points in spawning volumes and times, which coincided with the first quarter and last (third) quarter of the lunar phases of the moon.

• The Korean Journal of Ecology
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• v.4 no.3_4
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• pp.68-79
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• 1981

We discovered following on our surveys to the island six times in May, August (1978), in April, May, June, July (1979). There are 73 families, 158 genera, 189 species, 31 varieties over Tracheophyta Fuller & Tippo. Till early or middle age of Lee Dynasty, the island's dominant plants was evergreen broad-leaved trees, mainly consisted with Camellia japonica L. and Castanopsis cuspidata Schot, var. sieboldii Nakai but due to the population growth and increased exiles constant ground burnt off fr cultivation, the number of evergreen broad-leaved trees was decreased and that of P. densiflora S. et Z. replaced position. That is to say, the island was dominated by the flora of the subtropical zone era, but it has been complicated by flora of the temperate zone whose reproductivity is more vivid, in modern era. Recently Pinus thunbergiana Franco, Robinia pseudo-acasasia L. Amoroha fructicasia L. invaded and reserved inthe island. During a decade of the end of Japanes rule and after liberation about all of Pinus densiflora S. et Z. were cut downed, and after that, under the Forest Bureau, there have being sucessed to Pinus thunbergiana France. Camellia japonica L. other 20 species of evergreen broad-leaved trees are distributed in Island Wi, a tutelary shrine of Dae Ri, a mountain at the back of a village of Chi Do Ri and a mountain at the back of Jin Ri administrative office of a township. The special plants of the island are 1) state of Lycoris aurea Herb which of foun in a ridge between fields and forest around Jin Ri and 2) stock of Cmbidium virescens Lindly bloomed under the Pinus densiflora forest of Keun Tan Chi Do.

• Journal of Korean Society of Forest Science
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• v.30 no.1
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• pp.50-60
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• 1976

For finding out the proper method of developing Buxus koreana var. insularis, this study was carried out in Pokil-Do, Wan-Do, Chonnam, in 1975. The ecology, morphology and characteristics of the plant were mainly investigated and analyzed. The results are summarized as follows; 1. The small islands of the southern sea of Korea; Pokil-Do, Chin-Do and So-Huk-San-Do, turn out to be the site of the natural communities of B. koreana var. insularis. 2. The growth of the plant is fairly good in the acid soil of these islands. 3. This vegetation of composed as the three-layered communities, these communities consit of Camellia, Buxus and Cares. 4. The plant is a board leaved evergreen shrub that is tolerant to shade and native to the temperate zone. 5. The size of the leaves, fruits and seeds is slightly larger than those of B. koreans. 6. As fruiting and germination of the seeds are favorable. it is easy for us to make a number of seedlings. 7. The proper times for sowing and harvesting the seeds are around the middle of July and August, respectively. 8. The seedlings is difficult to grow in the naked ground because the germinated seeds are seriously damaged by frost. 9. The plant growth per annum is about 8 to 10cm in height, 1.5mm in diameter. It is graceful looking as the branches and leaves as of the dense foliage type 10. It is possible to develop the plant in many ways, such as; ornamental plant, bee plant, sculptural and industrial materials.

• The Korean Journal of Pesticide Science
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• v.8 no.2
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• pp.117-128
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• 2004

The influence of different feeding rates of three green algae on growth and reproduction in four Korean cladocera, Daphnia sp., Daphnia obtusa, Moina macrocopa, and Simocephalus vetulus was investigated. The growth and reproduction rates of Daphnia sp. fed Chlorella vulgaris cells were significantly increased than those of daphnid fed Senedesmus subspicatus and Selenastrum carpricornutum. The total offsprings of Daphnia sp. fed $25\times10^4$ and $50\times10^4$ cells Chlorella vulgaris for 21days were $124{\pm}2.8$ and $168{\pm}22.1$, respectively. The Daphnia obtusa fed $25\times10^4$ and $50\times10^4$ cells Selenastrum carpricornutum was shown good reproduction rates, $72.2{\pm}7.9$ and $79.6{\pm}22.9$, respectively. The Moina macrocopa fed $25\times10^4$ and $50\times10^4$ cells Senedesmus subspicatus as well as Simocephalus vetulus and $25\times10^4$ and $50\times10^4$ cells Chlorella vulgaris were shown good reproduction rates. All of algae tested were sufficient as a good diet for Korean Cladocerans in this study. However, the preferred alga was Chlorella vulgaris and the optimal feeding concentrations were $2.5\times10^5\sim5\times10^5$ cells/mL, because the alga was shown most stable and generally high production rates in all cladocerans tested.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.3
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• pp.345-352
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• 1999

The sand dollar, Astriclypeus manni is commonly encountered on a subtidal sand bottom along the coast of Cheju Island. limited information has been reported on their ecology despite their natural abundance. This study reports ecology and an annual reproductive cycle of the sand dollars present at Hamdock, northern coast of Cheju Island. A. manni collected from Hamdock revealed that they are 80 to 200 mm in test diameter. Sediment Brain size analysis indicated that A. manni mostly occurs on medium (particle diameter of 500 $\mu$m) to very find sand (particle diameter of 125 $\mu$m), particularly on fine sand (particle diameter of 250 $\mu$m). Internal morphology and in situ observations on their feeding habit indicated that A. manni is a deposit feeder, feeding on organic debris contained in the sediment around its habitat. A. manni were more frequently observed near Zostrea marina bed where content of organic matter in the sediment is considered to be higher. Gonadal tissues of the male were yellow in color while female gonads appeared to be purple. Fully mature eggs, with a mean diameter of 381 $\mu$m, and sperm were observed from the histological slides of the sand dollars collected in late July to August, suggesting that A. manni spawn during July to August when water temperature reaches 20 to $25^{\circ}C$.

• The Korean Journal of Ecology
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• v.25 no.2
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• pp.93-100
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• 2002

In order to analyze the life cycle of A. artemisiifolia var. elation dormancy and some environmental factors inducing germination of the seeds were examined. The results were as follows : Dormancy of fertile seeds was broken in part within a month after seed collection in case of adequate moisture and alternating temperature was also effective in breaking dormancy. The temperature range, which allow germination was 12℃ ∼ 32℃. Optimum temperature for germination was 24℃. The seed of A. artemisiifolia var. elatior was light-independent. The difference of storage period appeared to have no particular effect on the viability of seeds at any time during the 9-month storage period. In the increasing temperature(IT) regime, A artemisiifolia var. elatior seeds started to germinate at 16℃, showing the higher temperature the greater germination rate, the final germination percentage was 99.34%. On the other hand, in the decresing temperature(DT) regime, seeds began to germinate at 20℃ with the 1.34% germination. An induced dormancy occurred at 12℃ making the 5.34% fecal germination in the DT regime. Low temperature was more effective to break dormancy than higher temperature Seeds of A. artemisiifolia var. elatior seems to be germinated in mid to late autumn or germination delayed until following spring. The above results suggest these variation of germination response in diverse environmental factors seems to be a physiological strategy to maintain their existence and to reproduce in the extreme thermal variation.