• Ecology and Resilient Infrastructure
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• v.7 no.3
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• pp.145-159
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• 2020

Wetlands are vulnerable to biological invasion by alien species, because they function as sinks that accumulate excess water, sediments, nutrients, and other contaminants from the surrounding watersheds by disturbance. In this study, to understand the status and characteristics of the alien plants based on the type of wetlands, we classified 24 ecologically outstanding wetlands and analyzed the status of alien flora. A total of 130 alien plants were found in the wetlands, accounting for 11% of the total plant species. Among them, the Asteraceae species was the most diverse, with 40 species. Erigeron annuus and Oenothera ordorata had the highest frequency of occurrence. The species richness of alien plants in the riverine and lacustrine wetlands (average: 30 species) was higher than that in the mountainous palustrine wetlands (average: 10 species). The same results were found in the naturalization index, urbanization index, and ratio of annuals and biennials, which indicate the degree of artificial interference. In the cluster analysis, the riverine and lacustrine wetlands were combined, and only the mountainous palustrine wetlands were separated. The number of alien plants is remarkably low in the mountainous palustrine wetlands, and it is considered to be the influence of Erigeron strigosus, Symphytum officinale, and Bilderdykia convolvulus, not found in the other types of wetlands. In particular, invasive alien plants such as Aster pilosus, Ambrosia trifida, Sicyos angulatus, Ambrosia artemisiifolia var. elatior were found intensively in the riverine wetlands. Therefore, it is considered that a methodical management is urgently required considering the dispersal of alien plants in the riverine and lacustrine wetlands with high artificial interference.

• Journal of Wetlands Research
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• v.16 no.4
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• pp.463-476
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• 2014

The riverine wetlands located in the riverside bring about social conflicts through confrontation between flood control value through flood control project and ecological preservation value of riverine wetland. In this study, we identified the importance of both values through analysis of economic feasibility of flood control and ecological values of riverine wetland, and tried to suggest management plans for riverine wetland considering both of flood control safety and ecological preservation through these results. For this, we calculated the expected annual flood damage of Imjin River using the multi-dimensional flood damage analysis(MD-FDA), and calculated the total value of riverine wetland using the contingent valuation method(CVM) to estimate preservation value of riverine wetland. The result of the analysis shows that the Imjin River needs flood control project and the ecological preservation of riverine wetland is also important. Therefore, the establishment of the management plan for protecting riverine wetland is also needed. As a result, the Imjin riverine wetland was classified as the area where sedimentation continues to take place, and the flood water level to rise. On the basis of the analyzed results, it is judged that the Imjin River needs flood control for public safety and ecological consideration for ecosystem preservation in the river improvement project. So, the stepwise river improvement is desirable to protect riverine wetland and minimize ecosystem disturbance. The results is expected to be made good use as the basic study for establishment of institutional river management plans considering flood control project and riverine wetland preservation in the future.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.4 no.2
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• pp.11-25
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• 2001

A wetland is an ecosystem which is the most useful and highly-energetic transition area. This study has been carried out to classify and identify the various types of wetlands in Korea. The main objective of this study are 1) defining and classifying of wetlands, and 2) identifying the wetlands characteristics, and 3) studying cases on the natural wetlands such as Han river, DMZ(Demillitarized Zone), Upo wetland and Yong(Dragon) wetland. The results as follows： 1) Development of the indices for identifying and classifying wetlands in encompassing in such as Ramsar Conference, US NWI(National Wetlands Inventory), Hydrogeomorphic system. 2) Development on the classifying method on the wetlands in the level of supersystem, system, subsystem, class and subclass. The systems include Palustrine and Riverine, and the subsystems are Seasonal, Permanent(Palustrine) and Impersistent, Lower perennial, Impersistent (Riverine). 3) Finally, we find out Young wetland is Palustrine/Permanent/Slope/Persistent, and Upo wetland consists of various types of wetlands, those are, Palustrine/Permanent/Depression/Forest Deciduous, Palustrine/Permanent/Depression/Shrub Deciduous, Palustrine/Permanent/Depression/Persistent, Palustrine /Permanent/Depression/Hydrophytes, and Lacustrine/Permanent/Openwater/Hydrophytes. The taxonomy of this study stems from identifying and classifying wetlands with indices mainly based on hydrologic features and substrates. So, it is needed that consequent studies are to be performed with various viewpoints. And the studying cases were limited because of the restricted entrance into the DMZ, And, we selected only 10 crucial sites in Han river as the subject for wetlands regulation and creation. And, for advanced studies, drawing up inventory and mapping are necessary.

• Journal of Ecology and Environment
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• v.43 no.4
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• pp.461-468
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• 2019

Background: This study aimed to identify NO₃^--N sources using the stable isotope δ¹⁵N in Chydorus sphaericus (OF Müller), to investigate hydrological characteristics and nutrient states in artificial wetlands near the Nakdong River. Chydorus sphaericus is dominant in wetlands where aquatic plants are abundant, occurring in high density, and is sensitive to wetland water pollution, making it suitable for identification of NO₃^--N sources. Results: NO₃^--N sources for each wetland were strongly dependent on hydrological characteristics. Wetlands with sewage or rainfall/groundwater as their main sources had high levels of NO₃^--N, whereas wetlands with surface water as their main input had comparatively lower levels. Since wetlands with sewage and rainfall/groundwater as their main water sources were mostly detention ponds, their inputs from tributaries or the main river stream were limited and nutrients such as NO₃^--N easily become concentrated. Changes in NO₃^--N levels at each wetland were closely associated with δ¹⁵N of C. sphaericus. Interestingly, regression analysis also showed positive correlation between δ¹⁵N of C. sphaericus and NO₃^--N level. Conclusions: We conclude that the nitrate stable isotope (δ¹⁵N) of C. sphaericus can be used to elucidate the hydrological characteristics of riverine wetlands. This information is important for maintenance and conservation of artificial wetlands at the Nakdong River.

• Journal of Ecology and Environment
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• v.30 no.3
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• pp.251-255
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• 2007

Self-thinning was measured in Salix communities on Bam Island in Seoul at various age stages. $D^2H$ was used to estimate tree biomass, where D is stem diameter at breast height or 10 cm height for plants with height <1.5 m, and H is height. A log-log plot of density versus $D^2H$ and correlation analysis indicated a significant relationship between density and biomass with equation 'log $D^2H$ = -1.27 log N + 7.06'. This indicates that self-thinning affects biomass in the Salix community with -1.27 as the thinning coefficient. If we assume a thinning exponent -3/2, then the allometric coefficient of the equation, log w = a log $D^2H$ + b, is 1.18. This is much higher than that for any other species studied in Korea. There were statistically significant relationships between age and density and between age and basal area and these relationships suggest guidelines for transplantation of willows and for the assessment of Salix community restoration projects in riverine wetlands based on standard density, basal area, and age. The results of this study may also increase understanding of succession processes in Salix community restoration in riverine wetlands.

• Korean Journal of Ecology and Environment
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• v.45 no.2
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• pp.252-260
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• 2012

The wetlands have eco-sociological values because their functions have proven to be useful to human society. Many countries are working to conserve and protect the wetland ecosystems. However, many wetlands have disappeared or have been fragmented due to a natural and/or anthropogenic disturbance. These isolated wetlands appear to work best in the landscape, as a spatially distributed system. We have analyzed the spatial-social distribution patterns of wetlands in Gyeongsangnam-do Province (GNP). We examined the frequency distribution of wetland sizes, the distances to the nearest wetlands, the shapes of the wetlands, land-use patterns, land owners, and official land values were confirmed as social characteristics for each wetland. A total of 146 wetlands (3,598.85 ha), including 76 riverine wetlands (1,955.60 ha), 49 palustrine wetlands (1,282.28 ha) and 21 mountain wetlands (1,282.28 ha) were identified in GNP. Most wetlands left for use to drainage were small (<2 ha) and located in agricultural areas. However, small and isolated wetlands were clustered, according to the location, indicating that these wetlands can be connected to each other using the linear riverine wetlands and water channels in agricultural areas. This is extremely valuable in maintaining the biodiversity, such that any loss of small wetlands will cause a direct reduction in the connectedness among populations of the remaining species. Due to most wetlands belonging to the nation or businesses, being classified as reservoirs (water storage areas), and consequently, degradation of wetlands will progress due to grand-scale engineering works. Therefore, wetland policy and ecologically sensitive laws and policies should be developed in order to promote the wise-use for wetlands.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.3 no.1
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• pp.13-22
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• 2022

In this study, we investigated the water quality and fish community of the Gudam Wetland, a riverine wetland in the middle-upper reaches of the Nakdong River, during March-October 2020. The main results were as follows: average annual flow rate: 45.0±23.7 m³/s, flow velocity: 0.4±0.3 m/s, water depth: 1.4±0.4 m, water temperature: 17.5±0.8℃, pH: 7.8±0.2, electrical conductivity: 121.6±19.0 ㎲/cm, dissolved oxygen concentration: 11.4±0.9 mg/L, suspended solids concentration: 3.8±2.0 mg/L, and the water quality was classified as Ia (very good). A total of 754 individual fish belonging to 4 orders, 7 families, and 19 species were investigated. Cyprinidae was the dominant group, with 13 species. The dominant species was Zacco platypus (39.3%), followed by Pseudogobio esocinus (17.5%). There were 8 (42.1%) endemic Korean species and 1 exotic species, Micropterus salmoides. Four species were carnivores, six were insectivores, and nine were omnivores. Regarding tolerance to environmental changes, 6 species were tolerant, 11 had intermediate tolerance, and 2 were sensitive. Fish community analysis revealed dominance of 0.57, diversity of 2.04, evenness of 0.69, and richness of 2.72, indicating a diverse and stable fish community. The fish assessment index showed that the assessment class was B (average 62.5), which was higher than that of major streams of the Nakdong River (class C). For sustainable conservation of the Gudam Wetland, management strategies such as minimizing aggregate collection and preventing inflow of non-point pollutants are required.

• Journal of Ecology and Environment
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• v.29 no.5
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• pp.469-478
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• 2006

The composition changes of litters were investigated to figure out the effects of the decomposition of Humulus japonicus on nutrient circulation and decomposition process in the riverine wetlands: Tan stream and Amsa-dong. Litterbags (mesh size 1 mm and 5 mm) were installed to monitor mass and nutrient changes of 5 types of litters: H. japanicus only, Miscanthus sacchariflarus only, Phragmites communis only, mixed litters including H. japonicus, and mixed litters without H. japonicus for 7 months. It was shown that k (decay rate) of the H. japanicus ($2.68{\sim}3.12$) was higher than that of M. sacchariflorus ($1.83{\sim}2.16$) and P. communis ($0.02{\sim}1.18$). The mass and organic remainings of the mixed litters including H. japonicus at Tan stream were $47.0{\sim}55.1%\;and\;47.0{\sim}54.9%$ and those of the litterbags without H. japanicus were $49.2{\sim}65.4%\;and\;47.1{\sim}57.5%$, respectively. This result indicated that the nutrient circulation was faster at H. japanicus community than others. Ca, Na, Mg, K, P, C, N and H contents reduced to around $40{\sim}80%$ of original. However, Na concentration increased up to $407{\sim}584%$ at 100 days and decreased to $248{\sim}498%$ at the end of the experiment. Decomposition rates were similar between 1 mm and 5mm mesh size litterbags and this implies that plant litters in studied areas decomposed mainly by microbes rather than small animals. This study revealed that the fast growth of H. japonicus was resulted from fast decomposition in part: positive feedback of nutrient cycling.

• Journal of Wetlands Research
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• v.25 no.2
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• pp.111-120
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• 2023

In Korea, wetland policies are currently being pursued through long-term plans such as nationwide wetland surveys and wetland conservation basic plans. However, most policies focus on understanding the status of wetlands, such as their area, distribution, and biodiversity, and there is a lack of awareness regarding the need to conserve and manage wetland ecosystems as a single organism. Therefore, this study aims to identify potential riverine wetland sites that can be ecologically connected by considering functional aspects such as floodplain, biodiversity, habitat provision, and tourism resources. This study attempted to select a candidate site that could potentially provide ecological connectivity with three wetlands in the Nakdonggang River water system : Upo Wetland, Hwapocheon Wetland, and Junam Reservoir. 63 wetlands and 7 candidate sites located in 15 subwatersheds of the Nakdonggang River were analyzed, and the most suitable candidate site for ecological connectivity was selected based on the calculated scores. A suitability analysis was conducted using 9 evaluation factors to evaluate candidate sites, and the scoring method, using quantile, was applied to these factors. As a result, Upo2(Hopo) was selected as the most suitable site for ecological connectivity, receiving the highest score 36. Therefore, it is believed that Upo2(Hopo) can serve as a floodplain, habitat, biodiversity enhancer, and tourism resource while being the most suitable for ecological connectivity.

• Journal of Wetlands Research
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• v.18 no.4
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• pp.378-385
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• 2016

This study aims to suggest the framework of functional assessment on lotic area based on HGM(Hydrogeomorphic) approach targeting Wetland Protected Areas which are in the type of river channel, and to set up the fundamental data as a reference wetland. A total of 10 factors in terms of hydrology, biogeochemistry, plant habitat and animal habitat was analyzed based on the original approach of HGM and each Functional Capacity Index(FCI) of those factors was calculated. As the result of the modified FCI analysis, Damyang riverine wetland which is with artificial river bank had high values in the variables of area ratio of actual vegetation in the foreland, the number of plant per area and the area ratio of Salix spp., and those values were highly reflected on the factors of Nutrient Cycling(947,668.00), Species Richness and Maintain Characteristic Plant Communites(6.39) and Maintain Spatial Structure of Habitat(11.00). The Hanbando wetland which is keeping the natural bank had higher values in the variables of structural scale and species diversity, and the those values were highly reflected on the factors of Energy Dissipation(17,805.16), Subsurface Storage of Water(0.54), Removal of Imported Elements and Compounds(103,052.73), Maintain Characteristic Detrital Biomass(2.31), Maintenance of Interspersion and Connectivity (6.50), Species Diversity of Benthic macro-invertebrates(1.60) and Species Diversity of Vertebrate & Species Number of Other Animals(2.52/ 151.50), compared to the Damyang Riverine Wetland.