• Korean Journal of Environmental Biology
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• v.31 no.4
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• pp.440-447
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• 2013

The ecological health, based on the Index of Biological Integrity (IBI) and Qualitative Habitat Evaluation Index (QHEI) was evaluated in 10 stream sites of Southern Han River. Eleven parameters of 12 parameters (Karr 1981) were modified for the application of regional Korean circumstance. The ecological health, based on IBI grade, was in "good condition" and the IBI score ranged from 33 to 47. Nine parameters of the original 12-parameter metrics in QHEI model (Plafkin et al. 1989) were applied in the habitat assessment. The mean QHEI model values were judged as "partially supporting" and ranged from 75 (non-supporting) to 109 (supporting). Comparative analyses revealed that values of IBI and QHEI models were greater in Gj stream than Ig- and Dn streams. The analysis of fish compositions showed that the proportions of insectivore, omnivore, and carnivore were 61.9%, 19%, and 9.5%, respectively. According to tolerance guild analysis, sensitive species and tolerant species were 76.1% and 4.7%, respectively, indicating a healthy trophic state in terms of food chain. The analysis by habitat guild type indicated that riffle benthic species dominated (57.1%) when compared to water column species (28.5%). The introduced species and individuals with diseases or external abnormality were not observed. Overall, the model values of IBI and QHEI suggested that the ecological health was maintained well in this upstream region.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.5
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• pp.427-434
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• 2023

Oysters are an important organism, accounting for an average of 76% of shellfish aquaculture production. In this study, optimal habitat was searched for by calculating the Habitat Suitability Index (HSI) using water temperature, salinity, hydrodynamics, DO, SS and Chl.a in Jaran Bay. As a result, the inside of Jaran Bay was found to be a more suitable habitat than the outside with a wide entrance and rapid hydrodynamics. Oyster production and HSI showed a significant correlation (0.710, p<0.05). Hydrodynamics helps the growth of aquaculture organisms, such as food supply through seawater exchange in the bay, which showed a high correlation (0.709, p<0.05) with oyster production. It was found to have a greater effect on habitat suitability than Chl.a. The results of this study are expected to be helpful for the efficient conservation, use and management of coastal fisheries.

• The Journal of the Acoustical Society of Korea
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• v.27 no.1
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• pp.33-39
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• 2008

Void fraction of air bubble in the seagrass bed by photosynthesis was estimated with sound speed dispersion. A field experiment was conducted at Seagrasss bed of which bottom type is sandy mud and 120 kHz CW waveform was transmitted to obtain backscattered signals from seagrass bed. The differences of the arrival time of received signal from seagrass bed were observed between day and night. The diurnal variation of arrival time was caused by sound speed dispersion of air bubble generated by photosynthesis of seagrass.

• Korean Journal of Agricultural Science
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• v.30 no.1
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• pp.41-58
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• 2003

This study was conducted to investigate bird community and to suggest a proper way how to manage protect bird community in Gap stream. The survey was carried out over four sections by the line transect method and point counts method from September 2001 to August 2002. Natural stream region as Gasuwon Bridge - Mannyeon Bridge are observed birds were 11 orders 29 families 67 species, Artificial stream region as Mannyeon Bridge - Daedeok Bridge are observed birds were 6 orders 10 families 30 species, Daedeok Bridge - Wonchon Bridge are 8 orders 12 families 28 species, Wonchon Bridge - Gap Stream Bridge are 8 orders 18 families 40 species. All the observed birds in artificial stream region are 8 orders 19 families 47 species. Number of species in natural stream region was higher than artificial stream region owe to a various habitat environment such as forest, cultivated land, streamside forest, sandy plain, gravelly field, reedy field etc. and can not add with the interface and the usage of the human. Number of species in artificial stream region was lower than natural stream region owe to a simple habitat environment and the water ecosystem is severed with embankment block and grass plot with the land ecosystem. The furtherance of various habitat environment which considers the ecosystem like the natural stream as the water ecosystem is joined together with the land ecosystem is desired to attract various wildbirds in Gap stream. The design is desired with the maintenance of the stream to consider the stream corridor which plays ecological important role as connect the fragment habitats.

• Korean Journal of Agricultural and Forest Meteorology
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• v.23 no.1
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• pp.55-67
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• 2021

Hornbeams (Carpinus spp.), which are widely distributed in South Korea, are recognized as one of the most abundant species at climax stage in the temperate forests. Although the distribution and vegetation structure of the C. laxiflora community have been reported, little ecological information of C. tschonoskii is available. Little effort was made to examine the distribution shift of these species under the future climate conditions. This study was conducted to predict potential shifts in the distribution of C. laxiflora and C. tschonoskii in 2050s and 2090s under the two sets of climate change scenarios, RCP4.5 and RCP8.5. The MaxEnt model was used to predict the spatial distribution of two species using the occurrence data derived from the 6th National Forest Inventory data as well as climate and topography data. It was found that the main factors for the distribution of C. laxiflora were elevation, temperature seasonality, and mean annual precipitation. The distribution of C. tschonoskii, was influenced by temperature seasonality, mean annual precipitation, and mean diurnal rang. It was projected that the total habitat area of the C. laxiflora could increase by 1.05% and 1.11% under RCP 4.5 and RCP 8.5 scenarios, respectively. It was also predicted that the distributional area of C. tschonoskii could expand under the future climate conditions. These results highlighted that the climate change would have considerable impact on the spatial distribution of C. laxiflora and C. tschonoskii. These also suggested that ecological information derived from climate change impact assessment study can be used to develop proper forest management practices in response to climate change.

• Journal of Wetlands Research
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• v.26 no.3
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• pp.285-297
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• 2024

This study, conducted in Geolpo-dong and Gamjeong-dong near Gimpo-Hangang New Town, examines an area adjacent to the Han River estuary, a major wintering ground for migratory birds. Over 59 surveys from October 2015 to March 2022 in four representative rice fields (sites A-D) recorded 44,942 individuals from 32 genera and 72 species. Site D, a large area near the Han River, exhibited high species diversity. Despite lower diversity in areas under development (sites A, B, C), ongoing species influx and utilization persist. The study focuses on Anser fabalis, a species predominantly utilizing rice fields, and identified their distribution characteristics. The analysis revealed 162 instances of population influx, with over a 30-fold increase observed across 39 surveys conducted over a 30-month period (October to March, '15~'22). The area, a key wintering site for migratory birds of Janghang Wetland, about 5 km from feeding sites, is heavily utilized by migratory geese, indicating the region's high value considering migration distance and anticipated continuous bird influx despite urban expansion. Therefore, future developments should preserve ecological corridors and connected stepping stone habitats to not only preserve existing habitats but to secure alternative feeding sites, ensuring smooth movements and mitigating habitat loss.

• Korean Journal of Environment and Ecology
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• v.30 no.3
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• pp.335-343
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• 2016

Of the Nak-dong Jeongmaek, five mountains, viz. Mt. Baek-byeong, Mt. Chil-bo, Mt. Baek-am, Mt. Un-ju, Mt. Go-heon, which are considered to well represent the natural environmental characteristics of Nak-dong Jeongmaek as well as its various terrain, were selected for this study. Two fixed plots were selected as sample study areas of each type of bird habitats and surveyed from May to October in 2015. According to the results of the survey conducted in the five mountains of Nak-dong Jeongmaek, a total of 47 species with 1,163 individuals birds was identified. The largest variety of species occupying a particular habitat type was found in the forest road and the ridge with 31 species. Also, the number of individuals was highest in the valley with 471 individuals. According to the results of nesting guild analysis of the vein (Pearson Chi-Square test, ${\chi}^2=13.377$, p = 0.037) by each Nak-dong Jeongmaek habitat type, the communities that belong to the canopy nesting guild showed a high frequency in development land and the valley while the communities that belong to the hole nesting guild showed a high frequency on the forest road and ridge. The results of Pearson Chi-Square test (${\chi}^2=15.555$, p=0.004) showed that the communities that belong to Bush foraging guild were most frequent in the development area and the community that belong to canopy foraging guild were most frequent inthe valley, the forest road and the ridge. These findings show that different habitat types of Nak-dong Jeongmaek support a great variety of birdlife by providing diverse and excellent resources.

• Korean Journal of Environment and Ecology
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• v.37 no.6
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• pp.450-463
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• 2023

The objective of this study is to derive the core habitat of the Kirengeshoma koreana Nakai utilizing Habitat Suitability Index (HSI) and Maximum Entropy (MaxEnt) models. Expert-based models have been criticized for their subjective criteria, while statistical models face difficulties in on-site validation and integration of expert opinions. To address these limitations, both models were employed, and their outcomes were overlaid to derive the core habitat. Five variables were identified through a comprehensive literature review and spatial analysis based on appearance coordinates. The environmental variables encompass vegetation zone, forest type, crown density, annual precipitation, and effective soil depth. Through surveys involving six experts, importance rankings and SI (Suitability Index) scores were established for each variable, subsequently facilitating the creation of an HSI map. Using the same variables, the MaxEnt model was also executed, resulting in a corresponding map, which was merged to construct the definitive core habitat map. Out of 16 observed locations of K. koreana, 15 were situated within the identified core habitat. Furthermore, an area historically known to host K. koreana but not verified in the present, Mt. Yeongchwi, was found to lack a core habitat. These findings suggest that the developed models exhibit a high degree of accuracy and effectively reflect the current ecological landscape.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2003.05a
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• pp.40-40
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• 2003

망둑어과 어류는 매우 유사한 형태를 지니고 있으며, 매우 넓게 서식지가 중복되고 있어 근연종간 자원 이용 따른 경쟁 은 매우 클것이다. 망둑어과 어류의 근연종간 자원의 분할 이용에 대한 연구는 간단한 먹이 생물의 분석 등에 대해서만 알려져 있을 뿐 서식지의 분할 이용과 서로 다른 섭이전략에 따른 공존에 대한 연구는 없었다. (중략)

• Proceedings of KOSOMES biannual meeting
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• 2017.11a
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• pp.192-192
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• 2017