• Korean Journal of Ecology and Environment
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• v.42 no.3
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• pp.374-381
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• 2009

Ecological instream flow was quantitatively calculated based on the river characteristics and fish habitat in the downstream of Yongdam Reservoir. The river bed and width did not change from 1988 before the am construction to 2004 after the dam construction, but the bed sediment size was attenuated a little in 2004. According to result that investigate fishes, 4 family 11 species including Acheilognathus koreensis were collected. Among them, Zacceo koreanus of cyprinidae was dominant, and Coreoleuciscus splendidus did sub-dominant. The habitat suitability indexes were estimated for two fish species Zacco koreanus and Coreoleuciscus splendidus using Physical Habitat Simulation System (PHABSIM) considering the river characteristics. In Gamdong and Daeti sites, the optimal ecological flow for Z. koreanus and C. splendidus were $13.90\sim12.60\;m^3\;s^{-1}$ and $15.50\sim11.60\;m^3\;s^{-1}$, respectively. In contrast, the optimal flow for the two species in Bunam site were $7.00\;m^3\;s^{-1}$. The ecological instream flow in the downstream of Yongdam Reservoir was between normal and high flow rate.

• Journal of Korea Water Resources Association
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• v.38 no.9 s.158
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• pp.771-778
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• 2005

In this study, flow duration analysis was conducted at the Gumbo stage gauging station due to construction of the Youngchun dam. The flow duration characteristics were $10.49\;m^3/s$ of drought flow, $13.30\;m^3/s$. of low flow, $15.65\;m^3/s$ of normal flow, and $25.00\;m^3/s$ abundant flow before construction of Youngchun dam. But after construction of Youngchun dam, the flow duration characteristics were $2.07\;m^^3/s,\;2.89\;m^3/s,\;4.0\;m^3/s,\;9.36\;m^3/s$ and they had been deteriorated. Applying the Physical Habitat Simulation Model by Instream Flow Incremental Methodology, the Weighted Usable Area(WUA)-Discharge Curve was developed for Zacco Platypus according to the growth stages. Using the WUA-Discharge Curve, the WUA Duration Curve was developed with exceedance probability of daily flow and evaluated fish habitat conditions due to the construction of Youngchun dam. As an evaluation result, the WUA was reduced and fish habitat environment was deteriorated due to the construction of Youngchun dam during the spawning and growth period of Zacco Platypus. However the exceedence probability of the $90\;\%$, irrigation water supply from the Youngchun dam improved flow duration characteristics and Weighted Usable Area as well as fish habitat.

• Korean Journal of Medicinal Crop Science
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• v.6 no.1
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• pp.51-56
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• 1998

This study was carried out to evaluate environmental and ecological characteristics of natural habitat for cultivation of Epimedium koreanum. Habitat of E. koreanum was the slope foot of mountain descending gradually toward mostly northwest from top of mountain with slope of $2{\sim}20%$ and the altitude ranged from 60 to 400m above the sea level. Some physiochemical characteristics of habitat soil were as follows: pH, $4.1{\sim}5.8$, organic matters content, $4.9{\sim}6.6%$ and cation exchange capacity, $14.8{\sim}34.3\;me/100g$ soil, respectively. Habitats were shaded by deciduous broad-leaved tree mainly, and compared with those of naked area, relative photon flux density was $3.5{\sim}13.1%$ and relative luminance was $3.3{\sim}11.9%$ due to shading. Air temperature of habitat under shade was $4.3{\sim}6.5^{\circ}C$ lower than that of naked area. Habitat soil temperature was lower than that of naked area but temperature range was smaller than that of naked area. E. koreanum plants were growing with semishading plants under shade of tree leaf. From investigation of natural characteristics of habitat, it was concluded that E. koreanum plant would grow at place with a little change in temperature and moisture of soil which was caused by shading and mulching with litterfall of broad-leaved tree.

• Journal of the Korean Association of Geographic Information Studies
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• v.15 no.3
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• pp.91-102
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• 2012

As the basis of the environmental ecological river management, this research developed a method of habitat classification using imagery information to understand a distribution characteristics of fish living in a natural river. First, topographic survey and investigation of discharge and water temperature were carried out to analyze hydraulic characteristics of fish habitat, and the unmanned aerial photography was applied to acquire river imagery at the observation time. Riffle, pool, and glide regions were selected as river habitat to analyze fish distribution characteristics. Analysis showed that the standard deviation of RGB on the riffle is higher than pool and glide because of fast stream flow. From the classification accuracy estimation on riffle region according to resolution and kernel size using the characteristics of standard deviation of RGB, the highest classification accuracy was 77.17% for resolution with 30cm and kernel size with 11. As the result of water temperature observation on pool and glide using infrared camera, they were $19.6{\sim}21.3^{\circ}C$ and $15.5{\sim}16.5^{\circ}C$ respectively with the differences of $4{\sim}5^{\circ}C$. Therefore it is possible to classify pool and glide region using the infrared photography information. The habitat classification to figure out fish distribution can be carried out more efficiently, if unmanned aerial photography system with RGB and infrared band is applied.

• Communications for Statistical Applications and Methods
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• v.22 no.6
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• pp.575-587
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• 2015

The development in data collection techniques results in high dimensional data sets, where discrimination is an important and commonly encountered problem that are crucial to resolve when high dimensional data is heterogeneous (non-common variance covariance structure for classes). An example of this is to classify microbial habitat preferences based on codon/bi-codon usage. Habitat preference is important to study for evolutionary genetic relationships and may help industry produce specific enzymes. Most classification procedures assume homogeneity (common variance covariance structure for all classes), which is not guaranteed in most high dimensional data sets. We have introduced regularized elimination in partial least square coupled with QDA (rePLS-QDA) for the parsimonious variable selection and classification of high dimensional heterogeneous data sets based on recently introduced regularized elimination for variable selection in partial least square (rePLS) and heterogeneous classification procedure quadratic discriminant analysis (QDA). A comparison of proposed and existing methods is conducted over the simulated data set; in addition, the proposed procedure is implemented to classify microbial habitat preferences by their codon/bi-codon usage. Five bacterial habitats (Aquatic, Host Associated, Multiple, Specialized and Terrestrial) are modeled. The classification accuracy of each habitat is satisfactory and ranges from 89.1% to 100% on test data. Interesting codon/bi-codons usage, their mutual interactions influential for respective habitat preference are identified. The proposed method also produced results that concurred with known biological characteristics that will help researchers better understand divergence of species.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.3
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• pp.747-756
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• 2015

Brown alga Undaria peterseniana has been interested in the commercial scale aquaculture for warm water species development in southern coastal area of Korea. However, this species was classified an endangered species caused by a decrease in habitat and natural population. In this study, inhabit characteristics of U. peterseniana was investigated in their natural habitat of Ulleung Island, Korea. The U. peterseniana population was occurred dense patches at 20~30m depth. Total length of the alga reached 1.0~2.0m and the largest width ranged 10.0~35.0cm during the study. In 2013, habitats of this species increased two sites compared with the previous year and their distribution extended to low depth (10m) of coastal area. In long-term data, seawater temperature revealed a continuous increment by strong going north of East Korea Warm Current or Ulleung Warm Eddy turning around the coast of Ulleung Island. It suggested that habitat extension of U. peterseniana may be caused by suitable settlement condition and increase of warm water around the coastal area. Current studies of this species may be continuously required in the possibility of fisheries resources as aquaculture species and index species of increment of water temperature at the fixed monitoring site in East Sea. This is the first study to research ecological feature U. peterseniana population at the natural habitat of Ulleung Island.

• Journal of the Korean Institute of Landscape Architecture
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• v.47 no.1
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• pp.76-87
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• 2019

The purpose of this study was to evaluate the performance of and to derive future maintenance-management measures of the constructed alternative habitat for the Kaloula borealis at the University of Seoul, examining the period between 2015-2017. The research was constructed in 2014 and in a $191m^2$ area. The performance evaluation was divided into maintaining the habitat of the target species, maintaining the population and reproduction rates of the target species, maintaining the habitat of the wild species, the resilience of natural ecosystems, and the harmony with the surrounding environment. In terms of maintaining the habitat of the target species, soil collected from the existing habitat of the Kaloula borealis and was the depth was increased to 30cm in the alternative habitat. An artificial water supply was required every year during the supporting the spawning and hatching of other amphibians along with the Kaloula borealis. The sources of water of the alternative habitat were both rain and tap water, as it cannot be maintained naturally. Additionally, the Kaloula borealis thrived because it inhabited the research site and the average temperature was $26.2^{\circ}C$ from April-June, which is when the Kaloula borealis spawns. In terms of maintaining the population and reproduction rates of the Kaloula borealis, they were evaluated to have stable rates of reproduction. In terms of maintaining the habitat of the wild species, studies on vegetation and the structure of the characteristics of prey or predators will be needed. Also, alien species, such as Humulus japonicus and Bidens frondosa needed to be removed to maintain the wetland ecosystem of the wild species. In the assessment of the resilience of the natural ecosystems, the mud was monitored, noting the changes in the depth of water, with steps taken to reduce the leakage of water. The mud collected from the Haneul Pond wetland, which is located around the research site was piled up. Also, partial mowing management and the inducement of a natural vegetation colony was required for vegetation management. It was also necessary to create porous spaces, such as old trees and tree branches to create a habitat with hiding places and feeding and spawning places for small organisms. In terms of the harmony with the surrounding environment, the following threat factors needed to be managed: amphibian roadkill by vehicles and pedestrians and artificial draining due to nearby user access. Based on the monitoring results, alternative habitat management measures presented the promoting various waterside structures, in which amphibians can spawn and hide in, managing the water environment consistently, managing the vegetation, focused on the habitat of the wild species, and managing the surrounding environment for the habitat. The creation of an alternative habitat should be managed through monitoring, reflecting the characteristics of the changes in the site. Also continuing efforts are also needed to improve the habitat of the target species.

• Korean Journal of Environment and Ecology
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• v.35 no.1
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• pp.24-36
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• 2021

Countries around the world, including the Republic of Korea, are participating in efforts to preserve biodiversity. Concerning species, in particular, studies that aim to find potential habitats and establish conservation plans by conducting habitat suitability analysis for specific species are actively ongoing. However, few studies on mid- to long-term changes in suitable habitat areas are based on accumulated information. Therefore, this study aimed to analyze the time-series changes in the habitat suitable area and examine the otters' changing pattern (Lutra lutra) designated as Level 1 endangered wildlife in Gangwon-do. The time-series change analysis used the data on otter species' presence points from the 2nd, 3rd, and 4th national natural environment surveys conducted for about 20 years. Moreover, it utilized the land cover map consistent with the survey period to create environmental variables to reflect each survey period's habitat environment. The suitable habitat area analysis used the MaxEnt model that can run based only on the species presence information, and it has been proven to be reliable by previous studies. The study derived the habitat suitability map for otters in each survey period, and it showed a tendency that habitats were distributed around rivers. Comparing the response curves of the environmental variables derived from the modeling identified the characteristics of the habitat favored by otters. The examination of habitats' change by survey period showed that the habitats based on the 2nd National Natural Environment Survey had the widest distribution. The habitats of the 3rd and 4th surveys showed a tendency of decrease in area. Moreover, the study aggregated the analysis results of the three survey periods and analyzed and categorized the habitat's changing pattern. The type of change proposed different conservation plans, such as field surveys, monitoring, protected area establishment, and restoration plan. This study is significant because it produced a comprehensive analysis map that showed the time-series changes of the location and area of the otter habitat and proposed a conservation plan that is necessary according to the type of habitat change by region. We believe that the method proposed in this study and its results can be used as reference data for establishing a habitat conservation and management plan in the future.

• Journal of Ecology and Environment
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• v.33 no.3
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• pp.237-244
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• 2010

In this study, we evaluated the distribution, habitat characteristics, and diet of two Korean freshwater turtle species (Chinemys reevesii, Pelodiscus sinensis) and an invasive turtle species (Trachemys scripta elegans) in the area surrounding the Seomjin River and the Nam River. We surveyed basking turtles in multiple locations along a 48-km stretch of the Seomjin River and in 99 reservoirs distributed along the Seomjin and Nam rivers from June to September, 2009. We observed 8 and 6 red-eared turtles in 3 reservoirs and at 3 sites in the Seomjin River, respectively, and 33 Reeve's turtles in 9 reservoirs. There were also 28 and 16 mud turtles detected at 15 sites along the Seomjin River and in 8 reservoirs, respectively. Among the 14 biotic and abiotic habitat characteristics that might influence the abundance of freshwater turtles in reservoirs, only the distance between a reservoir and the nearest residential areas was correlated negatively with abundance. With regard to the diet, all Reeve's and red-eared turtles investigated were determined to forage on water snails. Some turtles also foraged on vegetation and aquatic invertebrates. Additionally, we found fish in the stomach of one of the Reeve's turtles, and dragonflies in the stomachs of two red-eared turtles.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.21 no.3
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• pp.83-98
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• 2018

This study was conducted on rare plants distributed in Chungnam area from April, 2012 to November, 2017. The rare plant populations that are emerging are: Utricularia pilosa, Jeffersonia dubia, Iris ruthenica, Tipularia japonica, Calanthe discolor, Parasenecio pseudotaimingasa, Ranunculus kazusensis, Berchemia racemosa, Pogonia minor and Glehnia littoralis. According to the criteria of the International Union for Conservation of Nature (IUCN), plant resources in the rare species category were one important type (CR), three hazardous species (EN) and six vulnerable species (VU). As a result of analyzing characteristics of ecological environment and threats, five types of habitat types, two aquatic areas, two types of flatland and coastal sand dune distribution types were analyzed. The decreasing tendency of the rare plant populations in the surveyed area is judged to be artificial disturbance and habitat destruction rather than climate or environmental change. Considering the characteristics of habitat, conservation measures should be prepared for each population.