• Korean Journal of Ecology and Environment
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• v.46 no.3
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• pp.332-342
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• 2013

We collected zooplankton from May to October, 2011, with the aim of understanding the zooplankton community distribution and food web interaction between the open water and littoral (aquatic plants) zones in two small reservoirs with different land covers (Sobudang, Myeongdong). Small-sized reservoirs are more abundant in South Korea, and a total of 51 and 65 species of zooplankton were identified at the two small reservoir (Sobudang and Myeongdong), where zooplankton densities were more abundant in the littoral zone than in the open water zone. Cladocerans and copepods densities were also higher in the littoral zone, in contrast, rotifers showed higher densities in the open water zone (t-test, P/0.05). Epiphytic zooplankton dominated at the littoral zone (Lecane, Monostyla, Alona and Chydorus) because aquatic plants provided refuge spaces for attachment. Some rotifers (e.g. Brachionus, Keratella and Polyarthra) were more abundant in the open water zone because of their small size, which might help them to go unnoticed by predators. In two-way ANOVA, rotifers related to two reservoirs or habitat space (littoral zone and open water zone), but cladocerans and copepods showed a statistically significant relationship on only two reservoirs. The results of stable isotope analysis showed that zooplankton in the littoral zone tended to depend on organic matter attached to aquatic plants as a food source, which indicates the avoidance of competition of zooplankton with other macro-invertebrates (e.g. Damselfly larva, Cybister brevis and Neocardina denticulate). As a result, zooplankton community distribution is determined by not only habitat space (aquatic plant zone and open water zone) but also by food source (phytoplankton).

• Journal of Environmental Impact Assessment
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• v.24 no.3
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• pp.287-299
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• 2015

If the Nakdong River estuary is to be sustainable, land use management practices need to consider bird habitat requirements, especially given that the area serves as an important migratory bird sanctuary. In this study, bird habitats found in the Nakdong River estuary were classified into 11 different types including Phragmites australiss, mud flat, farmland, open surface in freshwater, sand bar, riparian forest, Scirpus planiculmis, waterway, construction, grasslands, and open surface in sea or brackish water. Taking into consideration the regional characteristics, habitat properties, and landscape indices, a total of 12 study sites were analyzed. Mud flat, construction, farmland, and P. australis account for 80% of the total land area. The high area ratio of construction and farmland to other types of habitat revealed a high amount of historical human activity and intervention in the area. Both patch numbers as well as patch density were high in West Nakdong River, Samrak Waterfront, Maekdo River, and Daejeo Floodgate, with these areas showing the greatest fragmentation as well. Total numbers of species and individuals had a positive correlation with the area and the number of habitat types. Findings suggest that protecting the habitat area, especially in S. planiculmis, is the most important factor for bird habitat management and that future development could result in habitat loss, having a profoundly adverse impact on bird populations. Therefore, it is important that the total area should be carefully protected by land use regulations in order to ensure that the Nakdong River estuary maintains its functional integrity as a migratory bird sanctuary.

• Journal of Environmental Impact Assessment
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• v.24 no.2
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• pp.175-189
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• 2015

The objective of this study was to analyze characteristics of distribution of amphibian species and the affecting ecological factors. For the study, habitat environment factors were determined and applied to a habitat suitability model for the data collected from the Seom River in Hoengseong County and Wonju City, Gangwon Province, Korea between March 2013 to October 2013. The analyzed amphibian species were Rana nigromaculata, Hyla japonica, Rana dybowski, and Rana rugosa Temminck and Schlegel, and a logistic regression model was used with the pseudo-absence data. The result of the model analysis suggests that the major factors for Rana nigromaculata are distance to vegetation and rock and that for Hyla japonica is waterway. Rana dybowski and Rana rugosa Temminck and Schlegel have similar habitat characteristics, but the latter is shown to be dominant due to its wider habitat preference. According to the species richness model, the analyzed amphibian species are shown to have tendency to move between valleys or streams. This study quantitatively analyzed habitat environment characteristics using species distribution model, however, there is a limitation in terms of analysis on food factor and connectivity with other species. Combined with additional density or habitat analysis on birds or fish, this study can lead to more comprehensive analysis on biological environment factors.

• Proceedings of the Korean Aquaculture Society Conference
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• 2003.10a
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• pp.138-138
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• 2003

우리나라 전남 동부 연안에서 확인된 해마 서식지를 대상으로 해마 이외의 혼재 유영 어류에 대한 생태 조사를 실시하였다. 조사는 전남 동부 연안의 해마의 서식이 확인된 수역에서 임의의 3 정점 (A, B, C)을 지정하여 채집하였다. 해마 채집 및 혼재 어류상 조사에는 소형 선박을 이용하였으며, 길이 45m, 폭 5m, 망목 크기 6~8mm의 어구를 사용하여 서식 생물을 채포하였다. 그리고 1회에 어획된 전 어종을 한 조사군으로 설정하였고 채집된 해마와 혼재 어종에 대해서는 각 어종별 분류키를 이용하여 분류하였다. 그리고 해마와 혼재 어류에 대해서는 0.1mm 범위에서 전장과 체장을 측정하였으며, 1mg 범위에서 체중을 측정하였다. 임의로 선정한 각 조사 정점별 채집된 해마와 혼재 어류상은 다음과 같다. 확인된 서식지는 전남 동부의 여수와 고흥 연안으로 각 지역별로 서식하고 있는 해마의 종류는 다소 차이가 있었는데 조사 정점 A와 B에서는 산호 해마 hippocampus sp. of. japonicus만이 관찰된 반면, 정점 c에서는 산호해마, 가시해마 Hippocampus sp. of. histrix, (참)해마 Hippocampus sp. cf. coronatus의 3종이 모두 관찰되었고 채집된 개체수도 정점 A와 B에서 1개체씩만이 관찰된 반면 정점 C에서는 5개체가 채집되어 다른 조사 정점에 비교하여 종의 수 및 개체수에서 매우 높은 결과를 나타내었다. 각 조사 정점별 관찰된 유영 어류상은 정점 A에서는 7종, 정점 B에서는 6종 그리고 정점 C에서는 12종의 어류가 관찰되었고, 이들 중 해마를 제외한 혼재 어종 수는 정점 A, B 및 C에서 각각 6종, 5종, 9종이 관찰되었다. 혼재 어종 중 감성돔, 복섬, 두줄 망둑, 실비늘치, 주둥치는 조사정점 A, B, C 모두에서 관찰되었다. 이 결과는 해마의 서식장 또는 산란장이 되는 조사 정점 C (36개체)가 다른 조사 정점 A (53개체)와 B (67개체)에 비교하여 해마의 어린 치어 또는 해마 성체를 포식할 수 있는 포식자의 개체수가 현격하게 낮기 때문인 것으로 판단된다. 그러나, 임의의 3 조사 정점에서 혼재 어종의 출현 종 수를 비교한 결과에서는 오히려 정점 A에서 6종, 정점 5에서 5종 그리고 정점 C에서 8종으로 나타나 정점 C에서 다소 높은 혼재 어종 수가 관찰되었다. 결국 해마의 서식지 주변 혼재 어종 특히, 혼재 어종의 개체수가 많을수록 해마의 서식 밀도를 감소시킬 가능성이 있는 것을 알 수 있었다. 한편, 다른 조사 정점에 비교하여 정점 C에서 출현 종 수가 높음에도 불구하고 출현 개체수가 매우 낮은 이유로 혼재 어종도 자어 또는 치어 시기에 해마 성체의 먹이로서 이용되었을 가능성도 배제할 수 없을 것으로 판단된다. 2003년 9월 (2일간)에 우리나라 전라남도 동부 연안에서 채집된 해마는 하루 오전과 오후 조석에 맞추어 4회에 걸쳐서 총 30여회 투망 작업한 결과 3종 62개체가 채집되었다.

• Korean Journal of Environment and Ecology
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• v.30 no.4
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• pp.676-683
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• 2016

This study was conducted using the Wild -Tracker (WT-300, GPS-Mobile Phone Based Telemetry KoEco) to understand the habitats of the spot-billed duck wintering in urban and rural areas and provide the results as the basic data for the protection and management of the habitats of the waterbirds in Korea. Study areas consisted of the Anseong stream in Gyeonggi-do and the Sansu reservoir in Haenam. Five spot-billed ducks were captured by region, and we attached Wild-Tracker to each of the spot-billed ducks. We analyzed the tracking location data using ArcGIS 9.x and calculated Kernel Density Estimation (KDE) and Minimum Convex Polygon (MCP). The average home-range measured by MCP was $250.8km^2$(SD=195.3, n=5) in Anseong and was $89.1km^2$ (SD=69.6, n=5) in Haenam. 50% home-range measured by KDE was $21.8km^2$ (SD=26.9, n=5) in Anseong and $3.5km^2$ (SD=2.2, n=5) in Haenam, indicating a narrow home range in Haenam. During the winter season, both wetland and paddy field were mostly used as habitats in Anseong and Haenam. While the paddy field utilization rate was high in the daytime in Haenam, it was high in the nighttime in Anseong. By late winter, Haenam's day time paddy field utilization rate and Anseong's night time paddy field utilization rate increased.

• Korean Journal of Environment and Ecology
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• v.4 no.1
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• pp.51-62
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• 1990

This study was to investigate the user's effects on the avifauna in Sokri Mountain National Park. The survey was carried over 4 districts which were divided with main trail(valley, ridge), subtrail(ridge), un-used trail (valley) by line transect method from December 1989 to October 1990. The observed birds were 36 species and 570 individuals, these consist of 23 species for residents. 7 species for summer visitor. 2 species for winter visitor, 4 species for passage migrant. The average density of birds was 2.35 ea/ha., and main dominant species were Parus major minor, Porus palustris hellmayri, Parus varius varius and Sitta europaea amurensis in order. The observed frequency of wild birds was 3.4 times/km in average. No. of species, species diversity and observed frequency of summer and autumn were lower than winter and spring in 4 survey routes. Therefore, from now, in Sokri Mountain National Park manegement, the enjoyment oriented activities will be regulated and control of trail use on main trail are necessary during breeding periods of wild birds protection, especially in summer.

• Applied Biological Chemistry
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• v.40 no.5
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• pp.438-441
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• 1997

The relatedness of naturalized Bradyhizobium japonitum populations with soil physico-chemical characteristics as affected by paddy rice-upland soybean rotation cropping with conventional and none fertilization in Chilgog clay loam soils were determined as follows. The populations of B. japonicum in soils were increased from about $10^1$ in continuous paddy upto $10^1cells/g.soil$ only in one-year rotation of upland use with soybean cropping. Compared to the densities in plots of conventional fertilization, those in none fertilization were high ranging from 1.9 to 10 fold in 2-year upland use rotation and both in 3-year upland use rotation and 4-year upland use, respectively. The populations were positively correlated with soil organic matter $contents(r=0.83^*),\;Ca/K(r=0.74^*),\;and(Ca+Mg)/K(r=0.72^*)$ and were negatively correlated with soil $hardness(r=-0.73^*)$. And the soil populations increased by paddy-upland rotation resulted in superior symbiotic potentials to those in continuous paddy use in terms of nodule mass, nitrogenase activity, and soy-bean shoot dry weight.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.406-410
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• 2016

하도 식생은 흐름 및 유사의 거동에 영향을 미치며, 하도의 지형변화를 일으킨다. 또한 하천에서 생태계 서식처 형성을 하는데 영향을 주며 하천경관을 향상시킨다. 그러나 홍수시에 흐름의 저항을 증가시키고 수위를 상승하여 하천범람을 일으킨다. 따라서 홍수에 안전하고 하천 경관을 유지하면서 하천환경과 조화를 이루는 하도 식생관리 기술이 요구되고 있다. 본 연구에서는 실내실험을 통하여 유량의 변화에 따른 식생대에서 퇴적과정과 하도의 변화 과정을 분석하였다. 실내실험은 길이가 10 m이고, 수로 폭이 0.6 m인 가변형 경사수로에서 수행하였다. 식생패치는 폭이 0.28 m, 길이 1.0 m로 2.0m 간격으로 교대로 3개 설치하였다. 식생패치는 지름이 5 mm이고, 길이는 0.25 cm인 아크릴봉을 이용하여 제작되었으며, 식생 밀도는 $1.76m^{-1}$이었다. 흐름은 식생이 없는 주수로에 집중되었고, 식생대와 주수로 사이에 와류가 형성되면서 하상이 세굴되었다. 식생대에서는 흐름이 감소되면서 유사가 퇴적되었다. 식생대를 따라 교호사주가 형성되었으며, 사행이 형성되었다. 유량이 증가하면서 식생대에서 퇴적 면적은 증가하였다.

• Journal of Wetlands Research
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• v.6 no.1
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• pp.57-72
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• 2004

Macrobenthic fauna were studied on a tidal flat in Garolim Bay in July 2002, in order to understand their spatial distribution with the surface sediment types. Forty-nine stations were set on the tidal flat. A total of 147 species was sampled with the mean density of $1,140ind./m^2$ and the mean biomass of $157.2g/m^2$. The polychaetes were speices- and density-dominant faunal group with 64 species and the mean density of $791ind./m^2$. Mollusks were biomass-dominant faunal group with $132.0g/m^2$. Major dominant species were two polychaetes, Mediomastus californiensis with the mean density of $374ind./m^2$ and Heteromastus filiformis with $224ind./m^2$. Also mollusks such as Umbonium thomasi, Batillaria cumingi and Ruditapes philippinarum was relatively high in the mean density, showing the density of 45, 42, $32ind./m^2$ respectively. Especially, U. thomas was distributed in the mouth of the bay, where sediment grain size is rather coarse, and R. philippinarum at near tidal channel. Based on the cluster analysis, the macrobenthic community on the tidal flat was classified into seven station groups depending on the benthic environmental parameters(sediment types). Compared with other Korean tidal flats, species richness of Garolim tidal flats is more and less low.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.28 no.4
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• pp.143-157
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• 2023

This study confirmed the characteristics of macrobenthic community due to anthropogenic environmental changes in the Boryeong Jugyo tidal flat, where the habitat of manila clam (Ruditapes philippinarum) and mud shrimp (Upogebia major) is separated. The total number of occurring species was 55 during the study period with an average habitat density of 338 ind./m² and a biomass of 212.2 gWWt/m². The number of occuring species increased from 27 species at the upper flat to 37 species at the lower flat, and the dominant species differed by tide levels (Upper: Leonnates persica, Middle: Heteromastus filiformis, Lower: R. philippinarum). The macro-benthic community sturctures of the top 10 species using cluster analysis and nMDS were divided into two groups, focusing on Manila clam culture farm of lower flats and middle flats with high habitat density, reflecting the influence of specific species. The sediment composition of the U. major habitat space fluctuated highly, but it was maintained annually, and the sorting coefficient was 2.1 𝜑, and the proportion of the same particle size was increased. In particular, because the middle flat has a dense anthropogenic impact, a dominant species, H. filiformis dominated and revealed a relationship with the density of burrow holes of U. major, which is considered to be a biological interaction between these two macrofauna in this tidal flat.