• Journal of the Korean Institute of Landscape Architecture
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• v.40 no.1
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• pp.43-56
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• 2012

The purpose of this study was to propose management strategies through aesthetic landscape assessments for landscape units in the Han River riparian(HRR) area. First, this research reclassified the HRR into "natural," "artificial," "agricultural," and mixed landscape types and selected 37 representative case areas(about $1km{\times}1km$). This study found 71 landscape units in consideration of topography and land surface classification. Landscape assessment consisted of landscape quality and landscape integration assessment. The criteria for assessing landscape quality were "naturalness," "interest," "uniqueness," and "landscape function." "Landscape quality" was ranked into five grades using a matrix. The landscape integration assessment consisted of an inner integration assessment in each landscape unit and outer integration assessment among landscape units. As a result of the field study, case sites were found to have 4,288 landscape units and an area of $42.8km^2$. The forest area was found to have the most space with $11,580,905m^2$(27.1%), while the wet lands had just $52,348m^2$(0.1%). In the landscape quality assessment, about 30.5% of the total area consisted of landscape units that scored highest in "naturalness". In the landscape integration assessment, about 39.3% of the total area consisted of landscape units which scored highest in "integration", denoting visual interrelation and harmony. The existence of disparities in landscape quality in accordance with the form of the landscaping was determined using a Oneway ANOVA, with "naturalistic" landscaping scoring the highest and "artificial" landscaping scoring lowest. This study may contribute to making the HRR area a more ecologically sound and visually attractive landscape space. It is recommended that the aesthetical and ecological value of the landscape unit should be assessed simultaneously in the future.

• The Korean Journal of Ecology
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• v.16 no.4
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• pp.377-395
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• 1993

Habitat types, community structure and population characteristics of Koelreuteria paniculata were investigated in Mt. Wolak, Chungbuk and Naesokdong, Daegu, which are natural habitats of the species in inland region of Korea, and its origin was discussed. Habitats of Koelreuteria paniculata were classified to 3 types: sand bar formed by the sands flooded in the course of flow of the mountain stream (Type 1). crevice on the rock bed within the mountain stream (Type 2) and crevice of the rock around the edge of mountain stream (Type 3). Most Koelreuteria paniculata communities in Mt. Wolak site were composed of 3 layers of subtree layer, shrub layer and herb layer and that of Daegu site was 4 layers including tree layer. In the floristic composition of the Koelreuteria paniculata community, plants occurring frequently in the wet and open site, such as Zelkova serrata and Fraxinus rhynchoph-vlla showed high frequency. Frequency distribution of diameter at ground surface of Koelreutrria paniculata showed reversed J-shaped type. It was supposed that expansion of Koelreuteria paniculata community in Mt. Wolak site might be accomplished by the flow of the stream. Many saplings capable of becoming a successor of mature trees in Daegu site in near degenerating phase were established on the forest floor of the Koelreuteria paniculata community. From this result, it was supposed that these saplings originated from the seeds dispersed from a seed tree might form the Koelreuteria paniculata community of the next generation. On the other hand, the origin of Koelreutevia paniculata in inland sites was explained by two hypotheses: the one was that Koelreuteria paniculata might be transplanted by human and the other was that the present site might be native habitat of the community.

• Korean Journal of Ecology and Environment
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• v.40 no.1
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• pp.50-60
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• 2007

Ten taxa of green algae collected at 8 stations of reservoirs and one of aerial habitat were reported newly in Korea. They belong to 7 genera, 2 species, 6 varieties and 2 forms and include one taxon of Scenedesmus, Actinotaenium, Euastrum, Hyalotheca, Staurastrum and Teilingia respectively, 4 taxa of Cosmarium. The Korean green algae, including these newly reported ones, totals to 1,131 taxa, and classified as 1 class, 10 orders, 34 families, 140 genera, 728 species, 318 varieties and 85 forms. Actinotaenium cucurbita var. cucurbita f. rotundatum cultured in this study was appeared to be variable in the size of isthmus. In the Korean taxa of Cosmarium lapponicum var. granulatum, C. portianum var. orthostichum and Euastrum denticulatum var. rectangulare, cell sizes were shown smaller than previously reported ones. Five taxa including Cosmarium lapponicum var. granulatum were occurred in the eutrophic states, and Cosmarium decedens, previously reported as present in the freshwater area, was collected at the aerial habitat in this study.

• Korean Journal of Ecology and Environment
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• v.45 no.1
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• pp.123-128
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• 2012

We aimed to estimate the accumulated degree days required for the development of $Cloeon$ $dipterum$ (Ephemeroptera: Baetidae) in an experimental tub under field conditions from August 7 to October 10 in 2011. After 4 days in a tub setting, a dead female adult was found on the water surface at which oviposition had presumably occurred. Adults emerged from 39 days to 61 days after the oviposition date. The total number of emerged adults was 229, and the sex ratio (number of females : total population) was 0.45, although not statistically significant ($p$ >0.05). The males generally emerged earlier than females. Assuming that the basal temperature ($T_b$) value is $0^{\circ}C$, we estimated the number of accumulated degree days required for the development of $C.$ $dipterum$ to be $1,221.8{\pm}116.0$ DD (mean${\pm}$SD). Since the annual number of accumulated degree days in the reference wetland was measured to be 5,650.0 DD, we estimated that $C.$ $dipterum$ is multivoltine, with a maximum of 4 cohorts in 1 year in natural habitats.

• Korean Journal of Environment and Ecology
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• v.22 no.5
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• pp.521-529
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• 2008

This research conducted a survey on waterbirds visiting this area four times by season from February to October in 2007 to look into the habitat use of waterbirds, to do a value and grade testing of the tidal flat by dividing the foreshore on Muan Bay located in Jeollanam-do into four areas (Dongam, Guro, Bokryong and Wangsan tidal flats). The survey results revealed that there existed a total of 15,755 individuals of 54 species including 2 species of grebes, 7 species of herons, 7 species of dabbling ducks, 6 species of diving ducks, 20 species of waders, 3 species of gulls and 9 other species and this survey also observed 9,291 individuals of the wading birds as a dominant group on Muan Bay. In these classified groups, the gulls and waders were observed to mostly use Dongam tidal flat as their habitat, while the group using Guro tidal flat as their habitat was mostly grebes, dabbling and diving ducks. As a result of UPGMA clustering analysis in consideration of the species and number of individuals, there appear the close similarities between Dongam and Bokryong tidal flats and so do Guro and Wangsan tidal flats. Taking a look at the grading of tidal flats by setting up ecological indexes, such as diversity index, abundance index, and dominance index, etc. legally reserved species and maximum number of individuals as a standard, the rank for the value and importance degree of Bokryong tidal flat appeared higher than that of the other three tidal flats. Like this, the gradation of tidal flats according to waterbirds are judged to able to suggest objective data on the issue of proper judgment and designation of valuable tidal flat areas and its subsequent effective preservation and management.

• Korean Journal of Ecology and Environment
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• v.45 no.4
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• pp.444-452
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• 2012

We conducted a comprehensive monitoring for freshwater food web in a wetland system (Jangcheok Lake), from May to October, 2011. Monthly sampling for zooplankton, fish as well as organic matters, was implemented. In order to understand the food web structure and energy flow, we applied stable isotope analysis to the collected samples, based on ${\delta}^{13}C$ and ${\delta}^{15}N$ values of epiphytic particulate organic matter(EPOM) and particulate organic matter (POM), epiphytic and planktonic zooplankton, fish (Lepomis macrochirus). In the study site, epiphytic and planktonic zooplankton was 24 and 30 species, respectively, and coincidence species between epiphytic and planktonic zooplankton were 20 species. Epiphytic zooplankton were more abundant during the spring and early summer (May to July); however, planktonic zooplankton were more abundant during the autumn (September to October) season. Stable isotope analysis revealed that fish and epiphytic zooplankton had seasonal variations on their food sources. EPOM largely contributed epiphytic zooplankton in spring (May), but increasing contribution of POM in autumn (September) was detected. However, planktonic zooplankton depended on only POM in both seasons. Fish utilized both epiphytic and planktonic zooplankton, but small sized (1~3 cm), fish preferred epiphytic zooplankton, where as larger sized (4~7 cm) fish tended to consume planktonic zooplankton, and epiphytic zooplankton had important role in energy transfer. This pattern was clear when results of spring and autumn stable isotope analysis were compared. From the results of this study, we confirmed that wetlands ecosystem supported various epiphytic and planktonic zooplankton species, they depend on other food items, respectively. L. macrochirus also showed a difference of food source according to the body size, they depend on seasonal density change of zooplankton. In particular, epiphytic zooplankton was very important for growth and development of young fish in the spring.

• Korean Journal of Ecology and Environment
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• v.49 no.4
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• pp.279-288
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• 2016

Stable Isotope Analysis(SIA) of carbon and nitrogen is useful tool for the understanding functional roles of target organisms in biological interactions in the food web. Recently, mixing model based on SIA is frequently used to determine which of the potential food sources predominantly assimilated by consumers, however, application of model is often limited and difficult for non-expert users of software. In the present study, we suggest easy manual of R software and package SIAR with example data regarding selective feeding of crustaceans dominated freshwater zooplankton community. We collected SIA data from the experimental mesocosms set up at the littoral area of eutrophic Chodae Reservoir, and analyzed the dominant crustacean species main food sources among small sized particulate organic matters (POM, <$50{\mu}m$), large sized POM (>$50{\mu}m$), and attached POM using mixing model. From the results obtained by SIAR model, Daphnia galeata and Ostracoda mainly consumed small sized POM while Simocephalus vetulus consumed both small and large sized POM simultaneously. Copepods collected from the reservoir showed no preferences on various food items, but in the mesocosm tanks, main food sources for the copepods was attached POM rather than planktonic preys including rotifers. The results have suggested that their roles as grazers in food web of eutrophicated reservoirs are different, and S. vetulus is more efficient grazer on wide range of food items such as large colony of phytoplankton and cyanobacteria during water bloom period.

• Korean Journal of Environment and Ecology
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• v.32 no.6
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• pp.686-697
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• 2018

Due to the advance in remote sensing technology, it has become easier to more frequently obtain high resolution imagery to detect delicate changes in an extensive area, particularly including forest which is not readily sub-classified. Time-series analysis on high resolution images requires to collect extensive amount of ground truth data. In this study, the potential of land coverage mapas ground truth data was tested in classifying high-resolution imagery. The study site was Wonju-si at Gangwon-do, South Korea, having a mix of urban and natural areas. KOMPSAT-3A imagery taken on March 2015 and land coverage map published in 2017 were used as source data. Two pixel-based classification algorithms, Support Vector Machine (SVM) and Random Forest (RF), were selected for the analysis. Forest only classification was compared with that of the whole study area except wetland. Confusion matrixes from the classification presented that overall accuracies for both the targets were higher in RF algorithm than in SVM. While the overall accuracy in the forest only analysis by RF algorithm was higher by 18.3% than SVM, in the case of the whole region analysis, the difference was relatively smaller by 5.5%. For the SVM algorithm, adding the Majority analysis process indicated a marginal improvement of about 1% than the normal SVM analysis. It was found that the RF algorithm was more effective to identify the broad-leaved forest within the forest, but for the other classes the SVM algorithm was more effective. As the two pixel-based classification algorithms were tested here, it is expected that future classification will improve the overall accuracy and the reliability by introducing a time-series analysis and an object-based algorithm. It is considered that this approach will contribute to improving a large-scale land planning by providing an effective land classification method on higher spatial and temporal scales.

• Journal of Wetlands Research
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• v.17 no.3
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• pp.264-272
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• 2015

Understanding bird status is essential for the systematic and sustainable management of the Nakdong River Estuary, taking into consideration the relationship between ecosystems and the bird species. In this study, bird status in the Nakdong River Estuary Bird Sanctuary prior to the Four Major Rivers Project was analyzed using the bird monitoring data (2003-2011) from surveys conducted by the Busan Development Institute. The high percentage of winter visitors in terms of both species diversity (38.36%) and individual bird numbers (63.14%) suggest that the Nakdong River Estuary is an important wintering site for migratory birds. Cumulative numbers of individual birds were higher in Myungji (208,601), West Nakdong River (202,444), Eulsukdo (153,232), and Baekhap Doyodeung (150,595). The total numbers of migratory species were higher in Eulsukdo (171), Ilungdo (124), Myungji (132), and Samrak (121). Among the 232 species found in the Nakdong River Estuary, Anas platyrhynchos (17.71%) was the most common species, followed by Anas poecilorhyncha (8.85%), Larus crassirostris (6.48%), Anser fabalis (6.09%), Anas penelope (5.16%), and Calidris alpina (4.22%). Most bird taxa, except shelducks, showed annual fluctuations in individual numbers, with increasing frequency during survey periods. Of these, cormorants, swans, and gulls showed higher fluctuations than other taxa. Swans decreased drastically in numbers in 2007-2008 and 2009-2010 compared to previous years. Shore birds, gulls, wagtails, and other forest birds were also less common in 2010-2011. These results suggest that there were some environmental changes that might have affected the birds in the Nakdong River Estuary. Overall, the results suggest that habitat types affect the distribution of dominant species.

• Journal of the Korean Association of Geographic Information Studies
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• v.12 no.1
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• pp.64-72
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• 2009

The method to generate a digital elevation model(DEM) from contour lines causes a problem in which the low relief landform cannot be clearly presented due to the fact that it is significantly influenced by the expression of micro landform elements according to the interval of contours. Thus, this study attempts to develop a landcover burning method that recovers the micro relief landform of the DEM, which applies buffering and map algebra methods by inputting the elevation information to the landcover. In the recovering process of the micro landform, the DEM was recovered using the buffering method and elevation information through the map algebra for the landcover element for the micro landform among the primary DEM generation, making landcover map, and landcover elements. The recovering of the micro landform was applied based on stream landforms. The recovering of landforms using the buffering method was performed for the bar, which is a polygonal element, and wetland according to the properties of concave/convex through generating contours with a uniform interval in which the elevation information applied to the recovered landform. In the case of the linear elements, such as bank, road, waterway, and tributary, the landform can be recovered by using the elevation information through applying a map algebra function. Because the polygonal elements, such as stream channel, river terrace, and artificial objects (farmlands) are determined as a flat property, these are recovered by inputting constant elevation values. The results of this study were compared and analyzed for the degree of landform expression between the original DEM and the recovered DEM. In the results of the analysis, the DEM produced by using the conventional method showed few expressions in micro landform elements. The method developed in this study well described wetland, bar, landform around rivers, farmland, bank, river terrace, and artificial objects. It can be expected that the results of this study contribute to the classification and analysis of micro landforms, plain and the ecology and environment study that requires the recovering of micro landforms around streams and rivers.