• Korean Journal of Remote Sensing
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• v.23 no.6
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• pp.575-581
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• 2007

Suaeda japonica is the one of halophyte species which is widely spread in the Ganghwado tidal flat. Halophyte affects to the vertical development of wetland by enhancing the adhesion force of sediments. If demineralization of tidal flat proceeds, the colony of halophyte moves to the seaside where has relatively high salinity content. The change of halophyte zonation can be an environmental indicator to understand the landization of tidal flat. To interpret the spectral characteristics of halophyte, we measured the reflectance of suaeda japonica, reed and sediment around Donggumdo tidal flat in Ganghwado. First and second-derivation analysis was applied to these transformed spectra in order to identify which spectral ranges were distinguished with different coastal wetland vegetation and artificial structures. From the result, red reflectance peak of suaeda japonica were appeared at 600-650nm and greed reflectance peak of reed were appeared at 500-570nm. Spectra of sediments were continuously increased from 350-550nm without any absorption by chlorophyll. These reflectance were easily identified among the spectra of halophyte.

• Korean Journal of Environment and Ecology
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• v.26 no.3
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• pp.367-373
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• 2012

Population ecology (Ecological characteristics) of Squalidus japonicus coreanus from the Namhan River(Yangpyeong-gun Yangpyeong-eup Changde-ri), Gyeonggi-do, Korea were investigated from January to December 2011. Short barbel gudgeon inhabits habitats run of the lower river. The stream bed was mostly covered sand. Their current velocities were 0.14~1.38m/sec and depths were 80~120cm. The sex ratio of female to male was 1 : 0.82. It is presumed that the spawning season is from June to July and water temperatures were $18.5{\sim}24.3^{\circ}C$. Sexually matured individuals appeared over the two year of age. Frequency analysis of total length indicated that the group with 34~50mm in total length was one year old, the 51~74mm was two years old, and the group over 75mm was three years old. The average number of eggs in the ovaries was estimated as 1,871 per matured female. Stomach content of S. japonicus coreanus were Cyanophyta, Chlorophyta, Bacillariophyta, Rotatoria, Crustaceae, Copepoda, Ephemeroptera, Diptera, and Nematoda. omnivorous, mainly feeds on benthic invertebrates such as chironomidae larvae.

• Korean Journal of Ichthyology
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• v.22 no.3
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• pp.162-167
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• 2010

Ecological characteristics of Orthrias nudus from the Eoron Stream, Gangwon-do, Korea were investigated from January to December 2009. O. nudus inhabits mainly riffles of the upstream and mid-upstream stretches of Eoron Stream, which were composed of boulder and cobble bottoms. The current velocities in these habitats were 0.42~1.34 m/sec and depths were 15~46 cm. The sex ratio of female to male was 1 : 0.98. It is presumed that the spawning season is from April to June when water temperatures were $15{\sim}19.2^{\circ}C$. Sexually mature individuals appeared to be over one year of age. Frequency analysis of total length indicated that the group 58~99 mm in total length is represented by one-year-old individuals, and the group over 100 mm by two-year-old individuals. The average number of eggs in the ovaries was estimated as 4,119 per mature female. Stomach contents of O. nudus were composed of aquatic insects such as Ephemeroptera, Trichoptera and Diptera.

• Proceedings of the Korea Society of Environmental Biology Conference
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• 2005.12a
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• pp.22-35
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• 2005

내분비계 장애물질 (Endocrine Disruptors: EDs)이란 ‘내분비 기능에 변화를 일으켜, 생체 또는 그 자손의 건강에 위해한 영향을 미치는 외인성 물질’로서 세계야생생물보호기금 (World Wildife Fund: WWF)의 목록에는 67 여종, 일본 후생성에서는 142 여종의 물질을 내분비계 장애물질로 분류하고 있다. 이렇게 분류된 내분비계장애물질 가운데에는 많은 종류의 농약이 포함되어 있으며, 이들이 자연상태계에 미치는 영향에 대한 많은 보고가 있다. 양서류는 먹이연쇄의 중위포식자로 내분비계 장애물질의 순환 및 생채축적 회로에서 중요한 위치를 갖는다. 또한 농경지나 계류 등에 서식하며 산란하는 습성이 있다. 이러한 서식지는 농약 등에 노출받기 쉬우므로 환경오염평가 대상동물로 중요하다. 본 연구에서는 국내에서 사용되고 있는 제초제, 살충제 등이 양서류 발생에 미치는 영향을 평가하고, 이들 물질에 의한 노출을 평가할 수 있는 biomarker 유전자를 발굴하고자 하였다. 우리나라 전역에 많이 분포하는 무당개구리(Bombina orientalis)의 초기 배아발생 과정에서 이들 농약을 처리하였을 때, 물질의 종류에 따라 정도의 차이는 있으나 농도 의존적으로 배아 및 올챙이의 치사율이 높게 나타났다. 또한 농약은 배아 및 올챙이의 기형을 유발하였다. 기형의 종류는 농약에 따라 서로 상이한 형태로도 나타났으나, 특히 몸통휨 또는 꼬리휨등의 척추골 기형이 많이 나타났다. 환경 위해성 평가 biomarker 유전자로서 골격계 형성에 관여하는 Sox9 유전자를 선택하였다. 무당개구리에서 처음으로 Sox9 유전자를 동정하였으며, 농약을 처리한 실험군에서의 Sox9 유전자의 발현 양상은 대조군에 비하여 높게 나타났다. 본 연구결과 생태계에서 내분비계 장애물질의 위해성 평가를 위해 양서류 초기배아의 치사 및 기형의 정도를 관찰하는 방법이 유효할 것으로 사료된다. 또한 야생동물의 biomarker 유전자를 발굴과 이를 이용한 위해성 평가는 더욱 정밀한 평가법으로 유용할 것이다.

• Korean Journal of Ecology and Environment
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• v.42 no.1
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• pp.26-31
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• 2009

Ecological characteristics of Cobitis pacifica inhabited in the Yeongok Stream, Gangwon-do, Korea was investigated from May 2006 to August 2007. The major habitat was composed of sand bottom with current velocities of $0.23{\sim}0.56m\;sec^{-1}$ and depths of $20{\sim}50cm$. The sex ratio of female to male was 1 : 0.93. It was presumed that the spawning season was the period of water temperatures of $25{\sim}27^{\circ}C$. Sexually matured individuals appeared over the two years of age. Frequency analysis of body length indicated that the group with $40{\sim}59mm$ in body length was one-year-old, the group of $60{\sim}89mm$ was two-years-old, the group of $90{\sim}109mm$ was three-years-old, and the group of over 110 mm was four-years-old. The average number of eggs in the ovaries was estimated as 809 per matured female. Main prey items were Ephemeroptera and Diptera.

• Korean Journal of Environment and Ecology
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• v.30 no.4
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• pp.745-750
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• 2016

Morphological characteristics and population characteristics of the Rhynchocypris kumgangensis were investigated at Taehwa River from April 2014 to April 2015. This is the first record on R. kumgangensis not only from Guksu stream (the upstream region of Taehwa River, Ulsan-si Ulchu-gun Beomseo-eup Kuksu-ri) but also from the stream flowing into the Gangneungnamdae stream, in the southern part of East Sea, Korea. The morphometric characteristics of R. kumgangensis in the Taehwa River and the Han River are very similar except that the population at Taehwa River showed shorter caudal peduncle length than caudal peduncle depth when compared with the population at Han River. In terms of meristic character the population at Taehwa River showed fewer numbers of scales at the lateral line, above the lateral line and below the lateral line. Other than that, the two populations showed the same meristic characters. The fish cohabiting with R. kumgangensis mainly composed of Zacco platypus (25.2%), Rhynchocypris oxycephalus (24.1%) and Zacco koreanus (21.8%). Length frequency distribution analysis indicated that the length of the group ranged between 45~65 mm and the average length was 54.3 mm. Calculation of the length-weight relation of R. kumgangensis showed the value of constant a as 0.000002 and b as 3.34, and the Condition factor (K) was 1.10 an on average.

• The Korean Journal of Quaternary Research
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• v.5 no.1
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• pp.1-13
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• 1991

The distribution of cryophilous arctic-alpine and alpine plants in Korea is reviewed in connection with palaeoenvironment, along with a discussion to their origins, patterns of migration, and their refugia. At present, the estimated number of Korean arctic-alpine and alpine species is 419, and this includes 75 arctic-alpine species, 239 alpine species and 105 Korean endemic alpine species. The disjunctive distribution of cryophilous arctic-alpine and alpine plants is likely to be due to first, the downslope and southward expansion of those species towards the Korean peninsula as a primary refugia from the arctic region as the Pleistocene glacial phases approached, and then their subsequent isolation upslope in mountain areas toward a secondary refugia as the interglacial and post-glacial climatic ameliorations followed; secondly, the expansion of forest tree communities on lowland and montane areas subsequent to the end of the Pleistocene has had the effect of dividing formerly high mountains as a result of the increased competition; and thirdly, the general disapperance or restriction of available habitats for arctic-alpine and alpine species because of post-glacial climatic amelioration. The existence of 139 alpine species exclusively in the north of Korea may be due to the following reasons; first, frequent exchanges of alpine floras with other neighbouring East Asian regions would have been facilitated; secondly, there are numerous high mountains available for the alpine plants to survive and prosper during the post-glacial period; thirdly, the existence of easy accesses between mountains within the north, which has enabled alpine floras to migrate when necessary; and finally, the availability of diverse environments and habitats for the alpine flora of the north. However, the continued survival of those species in Korea at the world's or East Asia's southernmost limits of their distribution for many species is in danger if global warming associated with the greenhouse effect takes place.

• Korean Journal of Environment and Ecology
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• v.30 no.5
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• pp.803-809
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• 2016

In order to elucidate the ecological responses of B. latissimum under global warming situation and prepare the conservation measures, we cultivated the plant within control(ambient $CO_2+$ambient temperature) and treatment(elevated $CO_2+$elevated temperature) from 2010 to 2011. Rising $CO_2$ concentration was treated with 2 times and temperature increased with $2.0^{\circ}C$ above than control. As a result, Growth response has received more the effect of $CO_2+$Temperature rising than light, moisture, nutrients, and it was grow well in $CO_2+$temperature rise sphere when many nutrients, and it was grow well in $CO_2+$temperature rise sphere when many nutrients. No. of leaves were many number in the treated group compared to the control at a low light gradient and high nutrient gradient, leaf width was narrow in the treatment compared to the control in the middle gradient of light and nutrients. Shoot length, petiole length, lamina length was no difference between control and $CO_2+$temperature rise sphere. Based on the results of this study, in order to preserve the B. latissimum in future climate, we should be supply of nutrients(containing ${NH_4}^+$, $NO_3$, $P_2O_5$, $K_2O$, etc.) in the habitat of the B. latissimum, and must ensure that the habitat of B. latissimum is not destroyed. Also, We should be find similar area with habitat of the B. latissimum, restoring, expanding.

• Korean Journal of Ecology and Environment
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• v.55 no.1
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• pp.10-18
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• 2022

This study analyzed the relationship between the community structure of benthic macroinvertebrates and habitat changes in open estuaries among the sites included in the national estuary monitoring program. The estuary survey was conducted under the "Guidelines for Investigation and Evaluation of Biometric Networks" and classified by sea area, 80 places in the East Sea, 102 places in the South Sea, and 19 places in the West Sea were investigated. In a total of 201 open estuaries, benthic macroinvertebrates were identified with 4 phyla, 9 classes, 41 orders, 139 families, 269 species and 196 species in the East Sea, 182 species in the South Sea, and 90 species in the West Sea. The highest population densities were Insecta in the East Sea, the Malacostraca in the South Sea, and the Annelida in the West Sea. Through SIMPER analysis, species contributing to the similarity of benthic macroinvertebrates communities in each sea area were identified. Some species greatly influenced the similarity of clusters. The benthic community in the East Sea was affected by the salinity, so the contribution rate of freshwater species was high. On the other hand, the benthic communities of the South and West Seas showed species compositions are influenced by the substrate composition. As results, the benthic macroinvertebrate community in Korean estuaries was impacted by salinity and substrate simultaneously, and the close relationship with geographical distance was not observed. The result of this study is expected to be used to respond to environmental changes by identifying and predicting changes in the diversity and distribution of benthic macroinvertebrates in Korea estuaries.

• Korean Journal of Environmental Agriculture
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• v.32 no.4
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• pp.294-303
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• 2013

BACKGROUND: It is well known that rice-fields can provide excellent foraging places for birds including seasonal migrants, wintering, and breeding and hence the high biodiversity of rice-fields may be expected. However, how environmental change including climate-changes on life-history and population dynamics in birds on rice-fields has not been fully understood. In order to investigate how climate-change affects population migratory patterns and migration timing, I modeled a population dynamics of birds in rice-fields over a whole year. METHODS AND RESULTS: I applied the Lotka-Volterra equation to model the population dynamics of birds that have been foraging/visiting rice-fields in Korea. The simple model involves the number of interspecific individuals and temperature, and the model parameters are periodic in time as the biological activities related to the migration, wintering and reproduction are seasonal. As results, firstly there was a positive relationship between the variation of seasonal population sizes and temperature change. Secondly, the reduced lengths of season were negatively related to the population size. Overall, the effects of the difference of lengths of season on seasonal population dynamics were higher than the effects of seasonal temperature change. CONCLUSION(S): Climate change can alter population dynamics of birds in rice-fields and hence the variation may affect the fitness, such as reproduction, survival and migration. The unstable balances of population dynamics in birds using paddy rice field as affected by climate change can reduce the population growth and species diversity in rice fields. The results suggest that the agricultural production is partly affected by the unstable balance of population in birds using rice-fields.