• Journal of Korean Society on Water Environment
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• v.34 no.5
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• pp.447-461
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• 2018

To realize river restoration that ecological characteristics of the river are reflected, we classified the river into four reaches of valley stream, upstream, midstream, and downstream based on substrate as well as riverbed gradient obtained from the relationship between distance from the river mouth, and above sea level. Considering that the rivers of Korea have been dominated by various and intense artificial interferences over a lengthy period, we determined cross sectional range of the river based on the geological map and clarified transformation degree by reach. Vegetation profile diagram was prepared by depicting horizontal range and vertical stratification of major vegetation appearing in a belt transect of 10 m breadth installed between weirs constructed in both sides of the river. Restoration models by river reach were prepared based on breadth of waterway, bare ground, herb, shrub, and tree dominated vegetation zones on vegetation profiles wherein a flooding regime was reflected. Species composition information collected from vegetation established in each zone was systematized to use for restoring each reach ecologically. Further, background that longitudinal reaches and horizontal zones were divided, was discussed by comparing with case studies in foreign countries. In addition, necessity of ecological restoration of the river was discussed based on degree of integrity of Korean rivers, ecological significance of riparian vegetation, and importance of reference information for ecological restoration of the river.

• Journal of Ecology and Environment
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• v.43 no.2
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• pp.98-103
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• 2019

We compared the functional traits of leaf blades and culms of common reed (Phragmites australis) in four habitat types of distinguished environments such as temperature, precipitation, water characteristics, and indices related to biomass production (montane fen, MF; riparian marsh, RM; lagoon, LG; and salt marsh, SM). We also examined the relationships between the functional traits within and among populations. Four populations showed remarkable differences in the functional traits of leaf blades and culms. MF and RM had relatively tall (> 300 cm) and thick (> 8 mm) culms bearing long leaf blades (> 40 cm), whereas LG and SM had relatively shorter and thinner culms bearing shorter leaf blades than MF and RM. Some relationships between the functional traits of leaf blades and culms showed negative or not significant correlations within the population, whereas most of the relationships between the functional traits showed positive correlations particularly when all the data from four populations was included into the correlation analysis.

• Journal of Forest and Environmental Science
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• v.33 no.3
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• pp.239-242
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• 2017

Although camera traps have been widely used to understand the abundance of wildlife in recent decades, the effort has been restricted to small sub-set of wildlife which can mark-and-recapture. The Random Encounter Model shows an alternative approach to estimate the absolute abundance from camera trap detection rate for any animals without the need for individual recognition. Our study aims to examine the feasibility and validity of the Random Encounter Model for the density estimation of endangered leopard cats (Prionailurus bengalensis) in Maekdo riparian park, Busan, South Korea. According to the model, the estimated leopard cat density was $1.76km^{-2}$ (CI 95%, 0.74-3.49), which indicated 2.46 leopard cats in $1.4km^2$ of our study area. This estimate was not statistically different from the previous leopard cat population count ($2.33{\pm}0.58$) in the same area. As follows, our research demonstrated the application and usefulness of the Random Encounter Model in density estimation of unmarked wildlife which helps to manage and protect the target species with a better understanding of their status.

• Journal of Ecology and Environment
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• v.33 no.2
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• pp.157-164
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• 2010

We evaluated the restoration effect by introducing willows as a means of controlling invasions of giant ragweed (Ambrosia trifida L.) on a riparian site. Our preliminary survey demonstrated that a problematic exotic species, giant ragweed and the representative riparian species, Salix koreensis are in competitive exclusive relationship. We planted willows at 1 m intervals on the bank of the Dongmun stream at Munsan, Paju, in Central Western Korea as an experimental restoration practice. We installed two 50 m $\times$ 5 m sized restored and non-restored for this experimental study. The non-restored plots were located on river banks, which were covered with concrete blocks and left in itself without any treatment. The height of willow was measured after each of three consecutive growing seasons and compared with the height of the giant ragweed. Although the height of Salix gracilistyla did not achieve the height of the giant ragweed, the height of S. koreensis surpassed that of giant ragweed in the third year after introduction. The results were also reflected in the relative light intensity on the herb layer of willow stand, and thereby the relative light intensities of stands, which were dominated by S. koreensis or restored by introducing S. koreensis, 1.99 $\pm$ 0.33 (%, mean $\pm$ SD) and 1.92 $\pm$ 0.50 (%, mean $\pm$ SD), respectively were lower than those in the stands treated by S. gracilistyla, 3.01 $\pm$ 0.43 (%, mean $\pm$ SD). The giant ragweed stands receive full sunlight as there are no any vegetation layers higher than the herb layer formed by the giant ragweed. As the result of Detrended Correspondence analysis ordination based on naturally established vegetation, the stands dominated by willows and giant ragweed showed different species composition between both stands. The species composition of the restoratively treated sites resembled the reference sites more than the non-treated sites. The species diversity (H') of the sites restored by introducing S. koreensis and S. gracilistyla was higher than the non-restored site dominated by A. trifida. On the basis of our results, the restoration of riparian vegetation equipped with integrated features could contribute not only to the control of exotic plants including giant ragweed but also to ensure the diversity and stability of riverine ecosystems.

• Ecology and Resilient Infrastructure
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• v.7 no.4
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• pp.238-247
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• 2020

This study aims to examine the causes of the rapid expansion of riparian vegetation in river channels in recent years. Accordingly, the changes in the monthly rainfall were analyzed at 19 locations over the period of 1984 to 2018. Moreover, the changes in the water levels of the target river sections of Seom River, Cheongmi River, and Naeseong River were analyzed. The results showed that rainfall increased by 30% in April and decreased by up to 49% in the May-September period since 2012. Between 2012 and 2018, when rainfall decreased, the inundation time of the floodplains of the target rivers decreased considerably. The floodplains of Seom River and Cheongmi River were not inundated since 2012 and 2013, respectively. In the case of Naeseong River, the inundation time of the low-water channel drastically decreased since 2013, and there was no inundation in 2015. Consequently, riparian vegetation settled rapidly on the floodplain without any disturbance and continued to expand. The settling and expansion of riparian vegetation reduce the flood capacity of the river channel and can also lead to the loss of the water ecosystem due to terrestrialization.

• Journal of Environmental Impact Assessment
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• v.7 no.2
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• pp.53-64
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• 1998

This study was performed to build up the ecological guidelines to grasp the structure of the vegetation change which is due to river rehabilitation. Anyway, river ecosystem and function has been destroyed owing to river development. It is important that river vegetation supplies ecological corridor and biotope. Two survey sites(Wonsungcheon and Pungseocheon)were investigated in the aspect of plant ecosystem and structure to settle the practical concept of river ecosystem. Each survey site was subdivided to five plots. The site was surveyed through the belttransect method. Wonsungcheon gets more seriously polluted as it runs to the urban area. In other words, there are On the other hand, Pungseocheon has more naturality but its downstream is under the pressure of various wood plants in the upstream area, but downstream area is dominated by naturalized plants such as Bidens frondosa, Panicum dichotomiflorum, etc. Riverbank of downstream has been changed into farm and parking lot. development. It should be preserved definitely because it still has abundant naturality and wetland which formed a biotope. The objective of the research is to find out the river retrogression and maintenance methods based on the riparian vegetation structure. To manage the river ecologically, hydrophytes should be induced partly for natural purification after the riverside is rehabilitated. The vegetation should be induced step by step to restore natural river and steady monitoring and research are required.

• Korean Journal of Environment and Ecology
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• v.32 no.1
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• pp.105-117
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• 2018

This study conducted health assessment and multivariate vegetation analysis using the riparian vegetation index in 30 sites of the Geumgang mainstream and Mihocheon to obtain practical data on the river management of the Geumgang. The result showed that the number of plant communities was 54. The flora was 75 families, 185 genera, 243 species, 2 subspecies, 21 varieties, 2 varieties, and 268 taxa. The riparian vegetation index was 38.3 (3.3; G-D1 ~ 66.7; G-U2, G-U4, and G-M3), and the health of the rivers in this area was evaluated as normal (grade C). The health of rivers was the highest in the upper stream of Geumgang mainstream and lowest in the downstream of Geumgang mainstream. The relationship between riparian vegetation index and chlorophyll-a content was low. The riparian vegetation was divided into five groups of Digitaria ciliaris colony group, Salix gracilistyla colony group, Erigeron annuus colony group, the group dominated by Humulus japonicus, Salix koreensis, Miscanthus sacchariflorus, and Phragmites japonica colonies, and the group dominated by Conyza canadensis and Echinochloa crusgalli var. echinata colonies. They had the similar health conditions. The CCA analysis showed that the environmental factors affecting the distribution of vegetation were physical factors such as vegetation area, artificial structure area, waterway area, branch width, channel width, and bank height and the biological factors such as the number of species. As such, it is necessary to maintain the health condition through continuous monitoring where the health condition is high and to apply active measures such as ecological restoration where the health condition is low.

• Journal of People, Plants, and Environment
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• v.23 no.3
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• pp.293-304
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• 2020

Background and objective: This study was carried out to assess the relationship between the internal and external environments and the ecological items in five sites with a high level of artificial use intensity prior to the establishment of Geumgang River riparian ecological belts. Methods: The sites were classified into forest type, cultivated land type and urbanized type in accordance with their respective locational types. Ecological items including plant ecology such as proportion, naturalization index and urbanization index of native species were analyzed and animal ecology such as the number of species and population of wild birds, amphibians and reptiles, mammals, and butterflies and dragonflies, which are indicator insects, were investigated. In addition, species diversity indices of wild birds, butterflies and dragonflies found in all the subject lands were computed. Results: Among the plant ecological items, the ratio of native species in the forest type was higher than 90%, which was a satisfactory level, while the naturalization and urbanization indices were less than 10%. The number of species in the animal ecological characteristics was reduced in the order of forest type, cultivated land type and urbanized type. As the results of correlation analysis, the internal area of the planted area showed a negative correlation with the total of individuals. The area of grasslands showed a positive correlation with the number of dragonfly species and the total number of individuals, thereby illustrating that wet grasslands have positive effects. The area of surrounding forests, as an external environment, had a negative correlation with the urbanization index (UI) but a positive correlation with the inhabitation of butterflies and the total number of species. Conclusion: The results confirmed the need for more diversified special compositions including planted land, grassland, wetland, bodies of water and waterways within the subject land in the wetland ecological belt along with the need for surrounding forest location and preservation from the perspective of purchase and restoration of land for enhancement of wider biodiversity in the future.

• Journal of Wetlands Research
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• v.10 no.3
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• pp.133-139
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• 2008

Urban streams are degrading functional role due to development and pollution. This study chose the representative stream of Do-rim and identified flora and fauna. The ecological survey aimed at identifying indicator of urban streams for measuring urban healthiness and we discussed the possibility of wetland conservation area. From the beginning of Dorim stream to An-yang mixture we were successfully identified 113 species of plants, 9 of mammals, 23 of birds, 4 of amphibians, 2 of reptiles and 2 of fish species. Terrestrial insects were 71 species. The wetland vegetation is quite various and we suggested 4 different vegetation zones (aquatic vegetation zone, emergent zone, riparian-meadow zone, riparian-woodland zone) depending on distance from the flowing water stream and vegetation characteristics for urban stream management.

• Journal of the Korean Institute of Landscape Architecture
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• v.27 no.2
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• pp.58-68
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• 1999

This study was carried out to verify the distribution patterns of Salix gracilistyla and Phragmites japonica communities known as obligatory riparian species according to physical factors such as micro-landforms, substrates, etc., at Soo-ip stream corridor. Firstly four vegetation types - Salix gracilistyla dominant type, Phragmites japonica dominant type, mixed type of two species, and mixed type of two species to other species, were classified by cluster analysis based on UPGMA-Euclidean distance. Also these vegetation types showed many different distribution patterns in response to the longitudinal and lateral view along the stream corridor and substrate composition. Salix gracilistyla was major component of dominant vegetation types developed at attack point of bending reach and on substrates composed of rock fragments, but contrastly Phragmites japonica was most important component of dominant vegetation types at point bar of bending reach and floodplain, and on substrates composed of soil materials. Secondly the species and environment biplot form CCA strongly supported the vegetation types divided by classification. Namely Salix gracilistyla was closely correlated with rock fragments and steep slope, which is resistant to physical action even though located near running water. But Phragmites japonica showed a high correlation with soil particles sedimented at floodplain by divergent flow.