• Journal of Wetlands Research
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• v.2 no.1
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• pp.31-40
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• 2000

The flora, vegetation structure and physico-chemical characteristics of surface sediment were investigated in Paksil-nup wetland of Hapcheon-gun, Gyeongsangnam-do, Korea in 1990~1998. Ranges of the surface sediment characteristics such as pH, conductivity, organic matter, total nitrogen, available phosphorus, exchangeable K, exchangeable Ca, exchangeable Mg, and exchangeable Na were 4.36~4.34, $19.0{\sim}1260.0\;{\mu}mho\;cm^{-1}$, 0.01~6.35%, 0.001~0.14%, 0.01~0.31 mg/l00g, 1.01~13.98 ppm, 16.75~143.80 ppm, 0.93~14.85 ppm and 0.21~3.86 ppm, respectively. Percentages of the particle size such as sand, silt, and clay were 13.0~93.3%, 5.4~71.7%, and 0.5~37.5%, respectively. The flora of the study area was composed of 72 families, 182 genera, 223 species, 36 varieties and 2 form or total 261 kinds, and those were 45 kinds of vascular hydrophytes and 216 kinds of vascular hygrophytes. The life form of vascular hydrophytes was classified as 27 kinds (60%) of emergent plants, 8 kinds (18%) of submerged plants, 6 kinds (13%) of free-floating plants and 4 kinds (9%) of floating-leaved plants, respectively. The importance value of Salix nipponica was highest as 123.78 in the shrub and tree layers, and that of Trapa japonica was highest as 16.69 in the herb layer. The vegetation type was divided into two groups according to the association analysis. The vegetation of the littoral zone was classified into 7 associations according to the cluster analysis based on the coverage data. These results showed significant differences with those of stand ordination by correspondence analysis based on the species composition and by PCA based on the sediment properties. Factors affecting the distribution of the vascular hydrophytes and hygrophytes were the gradient of particle size, altitude, and water depth.

• Journal of Wetlands Research
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• v.19 no.3
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• pp.327-334
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• 2017

The flood pulse in streams enhances the biodiversity and ecosystem services of the channel-floodplain ecosystems by exchanging water, nutrients, sediments and organisms. However, the lateral connectivity in most streams of Korea has been disrupted by the levee constructions for the purpose of flood control and land use of floodplains. To compare the characteristics of floodplain vegetation according to existence of lateral connectivity in streams, we investigated the geomorphological and soil environmental factors and structures and distribution of vegetation in the floodplains connected and isolated by levee to the channel in Cheongmi Stream, Seom River, Hwangguji Stream, Mangyeong River, Gomakwon Stream, and Boseong River, Korea. In comparison of soil environments, moisture and clay contents were higher in the isolated floodplain than in the connected floodplain. According to the result of principal component analysis (PCA) using environmental data, the environments of the connected floodplain and the isolated floodplain were separated by soil moisture contents, soil texture and distribution altitude of the vegetation. The results of detrended correspondence analysis (DCA) using vegetation data showed that the isolated floodplain was dominated by the hydropythic communities of diverse life form and that the connected floodplain was dominated by the hygrophytic communities that endure disturbance. In conclusion, it is thought that the vegetation of the floodplain changed to the lentic wetland vegetation dominated by diverse hydrophytes as the floodplain was isolated from the channel by artificial levees.

• Journal of Wetlands Research
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• v.11 no.1
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• pp.39-48
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• 2009

Wetland plants are an important component for wetland design and construction because they determine functions of wetlands through interactions with the abiotic environment such as wetland soil and hydrology as well as with other wetland organisms. In this study, germination experiments with soils from a natural wetland that contain seeds of wetland plants were conducted in wetland mesocosms to investigate the applicability of natural wetland soils for introducing and establishing wetland plants into constructed wetlands. Seven species were germinated in the experiment, with two new species that were not found in the field survey of wetland plants in the West Nakdong River area, Korea. The number of plant individuals germinated in submerged conditions (15 individuals) was much greater than that in waterlogged conditions (2 individuals). In experiments in which soils from a natural wetland and a wetland construction site were mixed at different ratios, the largest number of plant individuals was observed in the condition with 100% natural wetland soil. The highest growth was observed at 50% natural wetland soil for Hydrilla verticillata and 100% for Ceratophyllum demersum. These results suggest that 1:1 mixture of soils from natural wetland wetlands and wetland construction sites would provide an appropriate condition for secure establishment of submerged plants in constructed wetlands.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.1003-1007
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• 2007

최근 기상이변, 불투수층의 증가와 배수체계개선 등의 요인으로 인한 홍수량의 증대로 하도방어 위주의 현재 홍수방어체제는 지속적인 치수사업의 시행에도 불구하고 오히려 하류에서의 홍수가 격심해지는 등 상당한 어려움에 직면하고 있다. 따라서 최근의 유역종합치수계획에서는 천변저류지 등에 의한 면적 개념의 2차원적 홍수량 분담을 통한 피해의 잠재성을 경감시키고자 하는 방안들이 제시되고 있다. 이러한 기술적 수요의 증가에 따라 낙동강유역종합치수계획, 삽교천유역종 합치수계획 등에서는 중규모 이상의 천변저류지가 검토되었지만 이러한 예는 대하천유역이므로 홍수피해가 빈발하는 농촌지역의 중소규모 하천에서는 계획된 적이 없다. 지금까지 지속적인 하천개수사업으로 2004년말 현재 하천연장 기준으로 전국의 하천 개수율은 78%에 이르고 있다. 이 중 국가하천과 지방1급하천은 약 15%로서 개수율이 약 90%이상으로 높고, 지방2급하천은 약 85%를 차지하나 대부분은 농촌지역에 위치하여 약 70% 미만의 낮은 개수율을 나타내고 있으므로 향후 중소규모유역의 지방2급하천에서 하천개수가 지속적으로 추진될 것이다. 현재 하천정비기본계획이 미수립된 하천구간에 대하여 하도계획시 제방축제에 의한 경제성이 미미한 일부 구간에 무제부의 소규모 아지늪을 조성하고, 홍수파의 전파속도를 저감하여 하류의 홍수집중을 경감시키고 유수 에너지를 감소시키며 아울러 본천의 유수환경과는 다른 습지로서의 정수환경을 창출하여 하천생태계의 다양성을 확보하는 방안도 있을 것이다. 본 연구에서는 경남 하동군에 위치하는 지방2급하천인 주교천에 약 $4000m^2$의 소형 습지(아지늪)를 2004년 3월에 조성하고 2006년 11월에 습지의 어류 및 수생식물에 대한 모니터링을 실시하여 아지늪의 하천생태의 다양성의 달성도를 평가하였다. 또한 주교천에서 홍수량의 증가에 따른 홍수류의 유속 변동과 그에 따른 에너지의 변화를 고찰하기 위하여 HEC-RAS를 적용하고 주교천 아지늪 주변의 수리학적 거동을 고찰하였다.

• Journal of Wetlands Research
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• v.11 no.3
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• pp.49-59
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• 2009

Seasonal changes of the growth characteristics and biomass of Scirpus fluviatilis, a aquatic emergent vascular plant, were investigated to reveal the phenology and the population dynamics and to provide the fundamental resources for the restoration counterplan of the wetland vegetation in the littoral zone of the Upo wetland, Changnyeong-gun, Gyeongsangnam-do, Korea from March 2006 to November 2006. Scirpus fluviatilis was distributed commonly in Upo, Mokpo, Sajipo, Jokjibyeol, and Topyeongcheon upstream and downstream of Upo wetland, and the density was highest in Mokpo. Distribution range for the water depth was 9~49cm, and the highest shoot density in 26~49cm, and the mean shoot density was $119/m^2$, and the mean shoot length was 122.3cm on May 28. The number of the tuber was $104.5/0.25m^2$, and the living tubers were 84.2%. The mean fresh biomass of the living tubers was 3.0g, and those of 1~4g was most as 57.9%. Germination rates of the living tubers was 43.8%, and the maximum rate was in 7~9g and more than 10g. In the pot cultivation, the shoot density of the germinated tubers and the dormant tubers were highest as 13.5 and 9.7, respectively in early August. In the field study, the shoot density had few change before typhoon damage, while the density increased abruptly in November after flooding accompanied with the typhoon 'Ewiniar'. The shoot length in the pot cultivation and in the field study were 100~116cm and 60~170cm, respectively in the growth-end. Biomass allocation rates into the stem, leaf, flower, and underground parts were 8.9%, 6.6%, 0%, and 84.5%, respectively in the pot cultivation of the germinated tubers, and those of the dormant tubers were 7.1%, 7.1%, 0%, and 85.8%, respectively. The tuber number increased to 1.4~4.1 times by the growth-end, so it is concluded that Scirpus fluviatilis is mostly propagated by the vegetative reproduction.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.12
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• pp.657-667
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• 2015

Cyanobacteria frequently dominate the freshwater phytoplankton community in eutrophic waters. Cyanotoxins can be classified according to toxicity as neurotoxin (Anatoxin-a, Anatoxin-a(s), Saxitoxins) or hepatotoxin (microcystins, nodularin, cylindrospermopsin). Microcystins are present within cyanobacterial cells generally, and they are extracted by the damage of cell membrane. It has been reported that cyanotoxins caused adverse effects and they are acculmulated in aquatic oganisms of lake, river and ocean. In natural, microcystins are removed by biodegradation of microorganisms and/or feeding of predators. However, in process of water treatment, the use of copper sulfate to remove algal cells caused extraction of a mess of microcystins. Microcysitns are removed by physical, chemical and biological methods according to reports. The reduction of nutrients (N and P) inflow is basic method of prevention of cyanobacteria bloom formation. However, it is less effective than investigation because nutrients already present in the eutrophic lake. In natural lake, cyanobacteria bloom are not formed because macrophytes invade from coastal lake by eutrophication. Therefore, a coastal lake has to recover to prevent of cyanobacteria bloom formation.

• Korean Journal of Environment and Ecology
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• v.32 no.3
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• pp.274-288
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• 2018

This study investigated the environmental factors and fish assemblage in 42 wetlands between spring and autumn of 2017 to evaluate the fish distribution and deduce the management strategy for improving biodiversity in created wetlands located at the Nakdong River basin. The investigation identified a total of 30 fish species and found that the most of wetlands were dominated by exotic fishes such as Micropterus salmoides and Lepomis macrochirus. Fish species such as Rhinogobius brunneus, Opsariichthys uncirostris amurensis, Zacco platypus were less abundant in the area with high density of Micropterus salmoides (static area) because they preferred the environment with active water flow. The pattern analysis of fish distribution in each wetland using the self-organizing map (SOM) showed a total of 24 variables (14 fish species and 10 environmental variables). The comparison of variables indicated that the distribution of fish species varied according to water depth and plant cover rate and was less affected by water temperature, pH, and dissolved oxygen. The plant cover rate was strongly associated with high fish density and species diversity. However, wetlands with low plant biomass had diversity and density of fish species. The results showed that the microhabitat structure, created by macrophytes, was an important factor in determining the diversity and abundance of fish communities because the different species compositions of macrophytes supported diverse fish species in these habitats. Based on the results of this study, we conclude that macrophytes are the key components of lentic freshwater ecosystem heterogeneity, and the inclusion of diverse plant species in wetland construction or restoration schemes will result in ecologically healthy food webs.

• Journal of Wetlands Research
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• v.14 no.1
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• pp.121-130
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• 2012

This study is to investigate the removal rates of nutrient in water, the biomass of water plants, and the total amounts of T-N and T-P uptakes by water plants to evaluate the ecological characteristics of the constructed wetland for treatment of livestock wastewater in Yangji-ri, Nonsan-si from June through November 2011. During the experimental period, the monthly plant biomass of constructed wetland in July were the highest as 669.4 kg, while the lowest in November as 200.1 kg. The research showed that the average nitrogen and phosphorus contents in aboveground and underground biomass of Phragmites australis were $21.9{\pm}0.6{\sim}32.1{\pm}1.5mg/g$, $15.1{\pm}5.5{\sim}24.9{\pm}5.7mg/g$, $1.5{\pm}0.3{\sim}2.4{\pm}0.2mg/g$ and $1.6{\pm}0.6{\sim}2.5{\pm}0.6mg/g$, respectively. The maximum amount of T-N and T-P uptake by Phragmites australis were 28.0 kg in July and 2.5 kg in June, respectively, while the minimum amount of T-N and T-P uptake by Phragmites australis were 9.7 kg and 0.7 kg in November, respectively. The removal rates of T-N and T-P in constructed wetland for treating livestock wastewater were 23.0 % and 59.1 %, respectively. The results of this study is expected to deduce the circulation of contaminants and nutrient in the wetland afterwards.

• Journal of Wetlands Research
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• v.7 no.1
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• pp.129-138
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• 2005

The flora and vegetation of Jang-cheok wetland (Gyeong-nam) was investigated from April 1. 2004 to Feburary 28. 2005. The vegetation plants collected from this area were 18 taxa : 18 species 17 genera 14 families. Hygrophtes were 2 species 2 genera 2 families. Emergent plants were 6 species 5 genera 6 families. Submersed plants were 1 species 1 genera 1 families. Floating-leaved plants were 5 species 5 genera 5 families. Free-floating plants were 2 species 3 genera 2 families. Dominance of life form was investigated Trapa japonica, Phragmites commnis, Leersia japonica by 5 dominance values and Hydrocharis dubia, Ceratophyllum dmersum were 1 dominance values. The community was investigated 5 communities : Leersia japonica community. Trapa japonica community. Nelumbo nucifera community. Miscanthus sacchariflorus community. Phragmites communis community. Dominance species(Leersia japonica) of Leersia japonica community was investigated $1,89g/m^{2}$(Dry weight) and $1,730ind./m^{2}$(Density). Doninance species(Trapa japonica) of Trapa japonica community was investigated $36,25g/m^{2}$(Dry weight) and $15.20ind./m^{2}$(Density). Dominance species(Nelumbo nucifera) of Nelumbo nucifera community was investigated $30.59g/m^{2}$(Dry weight) and $11.20ind./m^{2}$(Density). Dominance species(Miscanthus sacchariflorus) of Miscanthus sacchariflorus community was investigated $180.50g/m^{2}$(Dry weight) and $124.80ind./m^{2}$(Density). Dominance species(Phragmites communis) of Phragmites communis community was investigated $159.50g/m^{2}$(Dry weight) and $60.00ind./m^{2}$(Density). The predominant species of this area was investigated Trapa. Japonica and the other communities was only small area in the waterside area.

• Korean Journal of Plant Taxonomy
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• v.48 no.4
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• pp.249-259
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• 2018

$Iso{\ddot{e}}tes$ L. ($Iso{\ddot{e}}taceae$) is a cosmopolitan genus of heterosporous lycopods containing ca. 200 species being found in lakes, streams, and wetlands of terrestrial habitats. Despite its ancient origin, worldwide distribution, and adaptation to diverse environment, species in $Iso{\ddot{e}}tes$ show remarkable morphological simplicity and convergence. Allopolyploidy appears to be a significant speciation process in the genus. These characteristics have made it difficult to assess the phylogenetic relationships and biogeographic history of $Iso{\ddot{e}}tes$ species. In recent years, these difficulties have somewhat been reduced by employing multiple molecular markers. Here, we reconstruct the phylogenetic relationships in East Asian $Iso{\ddot{e}}tes$ species. We also provide their divergence time and biogeographic origin using a fossil calibrated chronogram. East Asian $Iso{\ddot{e}}tes$ species are divided into two clades: I. asiatica and the remaining species. $Iso{\ddot{e}}tes$ asiatica from Hokkaido forms a clade with northeastern Russian and western North American $Iso{\ddot{e}}tes$ species. In clade I, western North America is the source area for the dispersal of $Iso{\ddot{e}}tes$ to Hokkaido and northeastern Russia via the Bering land bridge during the late Miocene. The remaining $Iso{\ddot{e}}tes$ species (I. sinensis, I. yunguiensis, I. hypsophila, I. orientalis, I. japonica, I. coreana, I. taiwanensis, I. jejuensis, I. hallasanensis) from East Asia form a sister group to Papua New Guinean and Australian species. The biogeographic reconstruction suggests an Australian origin for the East Asian species that arose through long-distance dispersal during the late Oligocene.