• Korean Journal of Environment and Ecology
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• v.32 no.6
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• pp.582-590
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• 2018

Although there are many studies of the effect of climate change on the breeding phenology and community diversity of amphibians, the studies of variations in reproductive population size of individual species according to climate change are still lacking. We examined the effect of climate change on the reproductive population size of Rana huanrenensis and Hynobius leechii, which bred in mountain valleys, by surveying the reproductive population of the two species between 2005 and 2012 and analyzing the correlation between the variation of the outdoor population and the surrounding climate change factors, obtained from a meteorological observatory located at 5.6 km from the study site. The size of the reproductive population of the two species commonly fluctuated with aan pproximately 3.5-year cycle. That of H. leechii, in particular, decreased significantly over eight years. The air temperature tended to more closely relate with the reproductive population size of R. huanrenensis as was the case of the precipitation with that of H. leechii. The yearly mean highest temperature and spring mean temperature variation consistently decreased over the eight years, and the latter was related with the significantly decreased size of H. leechii reproductive population. These results showed that recent climate change directly could affect the reproductive population size of amphibians, particularly H. leechii, which breeds in mountain valleys.

• Korean Journal of Environmental Biology
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• v.28 no.2
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• pp.49-55
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• 2010

There are only 10,000 Saunders' Gull's (Larus saundersi Swinhoe) surviving in the world today. But they are being threatened by coastal habitat, degradation, development pressure and disturbance by humans. Their first breeding record in Korea was in 1998 and the breeding status has been studied, however, the breeding status is not sufficient for this species. This study was performed from May 1999 to June 2009 to clarify breeding populations and trend of the Saunders' Gull population in Korea. The results indicate that the breeding population has been increasing gradually from 300 to 1,300 individuals, though disturbance increased. As threats to the breeding birds, physical environmental factors such as development and human disturbance were identified as a major threatening factors. Also, as a secondary factor, eggs and chicks are falling pray to predators. Incheon bay breeding places have been created by a landfill projects for the purpose of urban and industrial development, thus, these places will no longer be available for this species. In addition, the breeding habitat has been reduced and changed by expansions of development on the ground. Therefore, well planed management schemes should be provided for the species' breeding population to be continually breed and survive.

• Korean Journal of Environmental Biology
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• v.35 no.2
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• pp.134-142
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• 2017

Nando Island is reported as one of the biggest breeding colonies of seabirds in South Korea, and is protected as a Natural Monument. This study was conducted between July to November 2015, to investigate the breeding population of Black-tailed gulls and their habitat on Nando Island. We estimated the breeding population of Black-tailed gulls (Larus crassirostris) using nest density. The mean nest density of Black-tailed gulls was $0.51\;per\;1m^2$ ($0.51m^{-2}$), and the breeding population was approximately 26,760 individuals. The dominant vegetation was Echinochloa crusgalli and Agropyron tsukushiense var. transiens, which served as shelter and nest sites to Black-tailed gulls. The diet of Black-tailed gulls was mainly the fish, Japanese Anchovy Engraulis japonicas (48%). Other species which were found to breed on Nando Island were Streaked Sheawater (Calonectris leucomelas), Temminck's Cormorant (Phalacrocorax capillatus), and Swinhoe's storm petrels(Oceanodroma monorhis).

• Proceedings of the Zoological Society Korea Conference
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• 1996.10a
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• pp.101.2-101
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• 1996

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.499-501
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• 2000

굴을 포함한 대부분의 해양 무척추동물들은 동일종이라도 먹이조건과 온도조건에 의해 성장과 발육, 번식초기연령이나 최소번식 크기 등에 큰 차이를 보인다. 굴의 번식수단 및 생활사 를 이해하기 위해서는 번식이나 생활사에 관한 속성을 보다 수량적으로 확인하고 동시에 개체군 생태학적인 지견을 가질 필요가 있다 (윤, 1996). 대서양산 굴, Crassostre virginica에 대하여 Lee and Heffernan (1991)은 알의 지질과 단백질 조성을 밝히고 생화학적 특성을 보고하였으며, Choi et al. (1993)는 면역학적 방법을 이용하여 번식량에 대한 정량적인 연구를 보고한 바 있으나, 이와는 대조적으로 참굴 C. gigas의 알 및 번식량에 대한 연구는 미비한 실정이다. (중략)

• Korean Journal of Ecology and Environment
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• v.47 no.3
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• pp.194-201
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• 2014

To elucidate which climate factors and what periods affect the time of breeding migration of Gori salamanders (Hynobius yangi), we have investigated relationships between the 5-years breeding monitoring data from 2006 to 2010 which had obtained in both natural and translocated breeding sites at Bongdae mountain, Gijang-gun, Busan-si and the matched climate data obtained from the weather station, approximately 25 km apart from the sites. Mean average and mean lowest temperatures during one month before the first breeding migration were related with the time of first female migration in the translocated site. Mean temperature variation and mean precipitation during 60~120 days before the first breeding migration affected the time of 30% male appearance at the natural site and the time of 30% female appearance at both natural and translocated sites. Climate factors were more closely related with female appearance than male and at the translocated site than at the natural site. Our results show that changes in mean temperature variation and mean precipitation rather than mean average temperature might more significantly affect the breeding migration of salamanders, female breeding migration is more closely related with climate factors, and the salamanders translocated could be more affected by climate changes than those in natural populations.

• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.81-81
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• 2001

최근 적절한 사양관리를 위해서 유중 요소태질소 수준(MUN)과 유단백을 이용하여 사료 내 에너지와 단백질의 균형을 평가하는 지표로 활용하고 있으며 요소태질소 수준이 정상보다 크게 높거나 낮았을 때 번식능력이 저하되기 때문에 번식효율의 지표로서 활용되고 있다. 따라서 본 연구에서는 우유내 요소태질소 수준이 번식장애에 미치는 영향을 조사하여 요소태질소 수준을 번식장애의 진단지표로 활용하고자 실시하였다. 본 실험에 공시된 우유시료는 경기도 안성시와 이천시에 소재한 낙농목장에서 사육중인 조사두수를 대상으로 개체당 약 30~50$m\ell$의 우유를 채유하고 냉장보관하여 실험실로 운반하였다. 우유의 분석은 유성분분석기(Fosscomb : 4000, Fossmatic 5000, Denmark)를 이용하여 우유의 일반성분인 유지방, 유당, 유단백, 무지고형분, 총고형분, 빙점, 유중요소태질소, 구연산과 체세포를 동시에 분석하였다. 번식장애우의 진단은 낙농가가 번식장애우로 분류한 개체를 대상으로 직장검사 및 초음파 진단기를 이용하여 진단하였다. MUN준에 따른 공태일수의 조사 결과 MUN수준이 7이하 군의 공태일수가 88.98$\pm$120.68로 7-16의 92.20$\pm$105.39와 16이상의 94.42$\pm$87.51보다 다소 낮은 결과를 나타냈다. 또한 번식장애우의 발생빈도와 유성분 분석결과를 살펴보면 낙농가가 번식장애우로 분류한 68두를 진단한 결과 발정발견을 하지 못하여 번식장애우로 분류된 두수가 30두(44.1%)와 비정상두수 38두(55.9%)로 나타났으며 비정상 두수 중 난포난종이 19두(27.9%)로 영구항체6두(8.8%), 자궁내막염(10.3%), 자궁축농증 6두(8.8%)보다 많은 것으로 나타났다. 번식장애우의 유성분 분석결과 자궁축농증이 있는 개체의 유단백 평균이 3.43$\pm$0.35로 다른군에 비해 높았으며 영구항체가 있는 개체군의 MUN수준이 7.73$\pm$8.58로 다른군의 10.84$\pm$4.92, 10.89$\pm$7.38와 10.61$\pm$5.52에 비해 낮게 나타났다.

• Korean Journal of Environmental Biology
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• v.27 no.1
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• pp.20-30
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• 2009

To study reproductive dynamics of a Gold-spotted pond frog (Rana chosenica) population located at Gangnae, Cheongwon, Chungbuk, Korea, we monitored the population over 207 days between April 17$^{th}$ 2007 and December 18$^{th}$ 2008 using a drift fence accompanied with 20 pitfall traps. The population was located in an agricultural wetland, compromising three small ponds. Gold-spotted pond frogs immigrated into the wetland between April 16$^{th}$ and June 17$^{th}$ and emigrated from the wetland between September 21$^{st}$ and November 12$^{th}$. Precipitation showed a positive correlation with the number of migrated frogs in Autumn 2007 and Spring 2008, but other environmental factors such as air and water temperatures and relative humidity did not show any significant relationships. In general, small frogs first migrated into and from the wetland, but the trend was not strong. Female gold-spotted pond frogs were bigger than males. During the autumn migration, small frogs of which snout-vent length was smaller than 20 mm were found, indicating that successful breeding occurred in the population. Our results could be useful to conserve this endangered species in Korea.

• Korean Journal of Environment and Ecology
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• v.35 no.1
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• pp.48-67
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• 2021

Plant species exhibit current characteristics as a result of interactions with environmental conditions. The plants of Viola sp. have selected chasmogamous flowers with vigorous vegetative propagation or development of cleistogamous flowers as an adaptation strategy. Viola websteri is distributed on the Korean peninsula and the eastern part of Jilin Province, China. The center and edge of the distribution are expected to exhibit different population-dynamics. It is necessary to investigate the cause of its current limited distribution even though V. websteri has a mixed-mating strategy. Firstly, We examined the vegetation environment of habitats and evaluated its characteristics. Growth characteristics were examined through plant phenology. We then evaluated the population structure, characteristics of chasmogamous flowers, and productivity of cleistogamous flowers. Moreover, we compared population sizes between 2014 and 2018. Most habitats were located in deciduous broadleaf mixed forests adjacent to valleys. V. websteri produced chasmogamous flowers with self-incompatibility in April-May and cleistogamous flowers in June-September. The cleistogamous flower production is a strategy ensuring seed production under uncertain environmental fluctuations; these were approximately twice as numerous as chasmogamous flowers. The population structure was distinguished into stable and very unstable regions. There were sites where the population experienced a sharp decline in the 2018 compared to that of 2014. This large decline was found in the edge populations. The habitats had different microsites depending on the natural disturbances of drought and the matrix constituting the habitat, thus supporting various plants. Ensuring the production of seeds through cleistogamous flowers, it was determined that rapid seedling re-establishment and population replenishment were possible when the natural disturbance factor was removed. Environmental factors did not equally affect all populations or individuals. Therefore, it was expected that it would be able to persisted in a long time, despite the rapid decrease in the number of individuals in the population regionally. Local extinction and re-establishment are likely to repeat according to environmental change. We propose the additional population investigation based on this works are required. We also suggest a need to assess the long-term population dynamics and the genetic characteristics of chasmogamous flowers and cleistogamous flowers to establish and implement effective conservation strategies.

• Korean Journal of Environment and Ecology
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• v.29 no.5
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• pp.703-709
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• 2015

A breeding pair of the Black-faced Spoonbill Platalea minor was firstly recorded on Chilsando Islands, Younggwang, Jeollanamdo Province in 1991. Since the mid 2000s, breeding population on the breeding sites has gradually increased. This study was conducted to identify breeding status and nest site characteristics of the species from May to August, 2013 on Chilsando Islands. We recorded number of nests, length and width of the nest base, slope around the nests, nest materials, distances from the nearest nest, presence of nest cover and nesting area. In 2013 breeding season, 25 of 49 nests produced at least one successful fledging. A total of 55 youngs were successfully fledged and number of fledging per nest was 2.20 individuals. Nesting area was $77.8m^2$ and $93.4m^2$ for Sansando and Yuksando Islet, respectively. Soil and soil mixed with tree root were preferred for substrate of nest base over rock and Brassica napus was dominantly selected as nest materials by Black-faced Spoonbills. Nest characteristics of 22 nests in Sasando and Yuksando Islet varied $49.59{\pm}6.53cm$(mean${\pm}$SD) for length of nest base, $41.00{\pm}5.82cm$ for width of nest base, $20.85{\pm}9.96^{\circ}$ for slope above the nest, $34.09{\pm}17.75^{\circ}$ for slope below the nest and $130.82{\pm}84.17cm$ for distances from the nearest nest. Fifteen pairs (68.2%) occupied where nest cover existed. Nest cover were located in front of the nest for 5 pairs, back of the nest for 9 pairs and both front and back of the nest for 1 pair.