• Asian-Australasian Journal of Animal Sciences
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• v.12 no.4
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• pp.629-632
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• 1999

Constructed wetlands are being used for the removal of nutrients from livestock wastewater. However, natural vegetation typically used in constructed wetlands does not have marketable value. As an alternative, agronomic plants grown under flooded or saturated soil conditions that promote denitrification can be used. Studies on constructed wetlands for swine wastewater were conducted in wetland cells that contained either natural wetland plants or a combination of soybeans and rice for two years with the objective of maximum nitrogen reduction to minimize the amount of land required for terminal treatment. Three systems, of two 3.6 by 33.5 m wetland cells connected in series were used; two systems each contained a different combination of emergent wetland vegetation: rush/bulrush (system 1) and bur-reed/cattail (system 2). The third system contained soybean (Glycine max) in saturated-soil-culture (SSC) in the first cell, and flooded rice (Oryza sativa) in the second cell. Nitrogen (N) loading rates of 3 and $10kg\;ha^{-1}\;day^{-1}$ were used in the first and second years, respectively. These loading rates were obtained by mixing swine lagoon liquid with fresh water before it was applied to the wetland. The nutrient removal efficiency was similar in the rush/bulrush, bur-reed/cattails and agronomic plant systems. Mean mass removal of N was 94 % at the loading rate of $3kg\;N\;ha^{-1}\;day^{-1}$ and decreased to 71% at the higher rate of $10kg\;N\;ha^{-1}\;day^{-1}$. The two years means for above-ground dry matter production for rush/bulrushes and bur-reed/cattails was l2 and $33Mg\;ha^{-1}$, respectively. Flooded rice yield was $4.5Mg\;ha^{-1}$ and soybean grown in saturation culture yielded $2.8Mg\;ha^{-1}$. Additionally, the performance of seven soybean cultivars using SSC in constructed wetlands with swine wastewater as the water source was evaluated for two years, The cultivar Young had the highest yield with 4.0 and $2.8Mg\;ha^{-1}$ in each year, This indicated that production of acceptable soybean yields in constructed wetlands seems feasible with SSC using swine lagoon liquid. Two microcosms studies were established to further investigate the management of constructed wetlands. In the first microcosm experiment, the effects of swine lagoon liquid on the growth of wetland plants at half (about 175 mg/l ammonia) and full strength (about 350 mg/l ammonia) was investigated. It was concluded that wetland plants can grow well in at least half strength lagoon liquid. In the second microcosm experiment, sequencing nitrification-wetland treatments was studied. When nitrified lagoon liquid was added in batch applications ($48kg\;N\;ha^{-1}\;day^{-1}$) to wetland microcosms the nitrogen removal rate was four to five times higher than when non-nitrified lagoon liquid was added. Wetland microcosms with plants were more effective than those with bare soil. These results suggest that vegetated wetlands with nitrification pretreatment are viable treatment systems for removal of large quantities of nitrogen from swine lagoon liquid.

• Korean Journal of Environment and Ecology
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• v.30 no.2
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• pp.155-164
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• 2016

In this study we analyzed the spatial and temporal distribution and preferred habitat type of the Kentish plover (Charadrius alexandrinus) based on the 3rd National Ecosystem Survey. Kentish plovers were observed in 97 maps out of a total 842 maps (11.8%) between 2006 and 2012, mainly along the western and southern coasts of Korea. They were also observed in the eastern coast of Korea, inland rivers (Han, Geum, Nakdong, Seomjin, and Yongsan River), the western and eastern coast of Jeju island, and Daecheong Island in the Yellow Sea. The observations were mainly made during the spring breeding season and migration seasons in spring and autumn. The occurrence of kentish plovers was positively influenced by the area of water and wetland according to the middle classification level of land cover type analysis and the area of coastal wetlands in the detailed classification level of land cover types. Most (90%) of the kentish plovers recorded maps had coastal wetlands. Kentish plovers were known to be susceptible to change of habitat. As the occurrence of kentish plovers could be associated with the habitat-change of coastal wetlands and it is possible to estimate the number of individuals, it is recommended that kentish plovers be used as a bioindicator species for the ecological assessment of ecosystem in intertidal zones.

• Journal of Environmental Science International
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• v.31 no.9
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• pp.767-779
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• 2022

In this study, sediment cores were sampled from tidal flats (six sites) in the west and south coastal wetlands, the blue carbon stock in the tidal flat sediments was calculated, and the blue carbon stock characteristics and influencing factors were analyzed. The sediment particle size of the west coastal tidal flats was larger than that of the south coastal tidal flats, and the organic carbon content in the south coastal tidal flats was more than twice that of the west coastal tidal flats. Blue carbon stock per unit area was 28.4~36.8 Mg/ha on the west coastal tidal flats and 69.8~89.8 Mg/ha on the south coastal tidal flats, which was more than twice higher in the south coastal tidal flats than in the west coastal tidal flats. The total amount of blue carbon stock in the tidal flats was the highest in Suncheon Bay tidal flats at 153,626 Mg, and followed by Gomso Bay tidal flats at 141,750 Mg, Hampyeong Bay tidal flats at 58,420 Mg, Dongdae Bay tidal flats at 44,900 Mg, Cheonsu Bay tidal flats at 36,880 Mg, and Jinhae Bay tidal flats at 26,205 Mg. Blue carbon stock per unit area was higher in the south coastal tidal flats, but the total amount of blue carbon stock in the tidal flats was higher in the west coast. The slope of the regression function of blue carbon stock with respect to the organic carbon content in the tidal flat sediments was estimated to be about 0.05 to 0.07, and the slope of the regression function was higher in the west coastal tidal flats than in the south coastal tidal flats.

• Journal of Wetlands Research
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• v.15 no.4
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• pp.543-553
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• 2013

In Korea, there have been many studies and progresses on various types of pilot scale or commercialized field scale Best Management Practices(BMP) during the last 10 years. Runoff characteristics of diffuse pollutants from different land uses are well identified and documented. However, for the coastal area connected directly with shoreline, runoff patterns and management schemes of non-point pollution were not fully studied. Recently, coastal area is emerging as a new development axis especially in west coast side of Korea such as Incheon city and Chungnam province, thus urbanized area rapidly increased but there are no buffer zones and BMP facilities to aim at preventing direct discharge of the first flush into coastal sea and beaches. In this study, parking area in Deacheon harbor, Boryeong City in Chungnam Province was selected and rainfall runoff was monitored for two year period in order to examine run-off features from which proper type of BMP suitable for coastal area is proposed. Coastal area usually has a low ground water level and consists of plain land, so that large scale BMP such as storm water retention pond and wetland requiring great excavation works is not best management plan. In addition, monitoring study shows that storm water from the paved parking area has a high salinity compared with those in storm water from the inland. High salinity is detrimental for the vegetation. Therefore, BMP employing least vegetative cover and also in terms of maintenance is a good option such as infiltration trench and porous pavement.

• Journal of Wetlands Research
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• v.23 no.2
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• pp.122-132
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• 2021

We reviewed the methods employed in Korean tidal flat surveys to measure the local abundance of the endangered wildlife and marine protected species, the fiddler crab, Austruca lactea. A complete census for infinite population is impossible even in a limited habitat within a tidal flat, and density estimates from samples strongly vary due to diverse biological and ecological factors. The habitat boundaries and areas shift with periodicities or rhythmic activities of organisms as well as measurement errors. Hence the local abundance calculated from density and habitat areas should be regarded as transient. This conjecture was valid based on the spatio-temporal variations of the density averages, standard error ranges, and spatial distribution of the crab, A. lactea observed for 3 years (2015-2017) in Songdo tidal flat in Incheon. We proposed the potential habitat areas using the occurrence probability of 50% from logistic regression model, reflecting the importance of habitat conservation value as an alternative to local abundance. The spatial shape of potential habitat predicted from a generalized model would remain constant over time unless the species' critical environmental conditions change rapidly. The species-specific model is expected to be used for the introduction of desired species in future habitat restoration/creation projects.

• Environmental and Resource Economics Review
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• v.10 no.1
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• pp.95-126
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• 2001

Functional values for wastewater treatment and atmospheric regulation in coastal wetland and rice paddy ecosystems are quantified, and an illustration is given on how to integrate biophysical parameters into a valuation framework. This is one of most controversial issues in economic analysis for wetland preservation versus wetland conversion to agricultural use. This paper includes theoretical considerations for estimating functional values of environmental ecosystems, and the integration of biophysical data and replacement cost method employed. Specific physical and geographical characteristics and data on ecosystem functions and services in coastal wetlands and rice paddies are addressed for evaluating their values in economic terms. In particular this paper indicates double counting problems and overestimation in the previous studies, and demonstrates how to avoid them and to maintain the consistency of valuation process involving a least-cost method, thus enables an accurate integration of the coastal wetland ecology and wetland economics. As a result which is far away from the previous studies, the total economic present value of wastewater assimilation by coastal wetland is estimated at 7,484,640 won/ha, and the net present value of positive effect for atmospheric regulation, negative effects for air pollution and water pollution by rice paddy is estimated at -37,934 won/ha, assuming that resources are infinitely long-lived and the annual value and the rate of discount (10%) is constant every year. In conclusion, for further reliability and validity of functional values for natural resources it is very noteworthy that a general equilibrium framework that could directly incorporate the interdependence between ecosystem functions and services would be preferred to the partial equilibrium framework.

• Journal of Wetlands Research
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• v.11 no.1
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• pp.105-113
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• 2009

Heat energy exchange is very important processes in the coastal wetland ecosystems. We observed and analyzed the net radiation flux, the sensible heat flux, the latent heat flux and the soil heat flux, which are balanced in the heat energy balance, over a reclaimed land covered with reeds at Goheung, Jeonllanamdo where is horizontally plane. The atmospheric turbulence had been measured in order to estimate the heat transfer during 5 intensive observation periods (IOPs). It was considered that the soil consists of water, fine particles, and vegetation canopy that changes color and density according to the season. We examined the characteristics of the heat flux and the vegetation effect on the air temperature control. It was noted that the heat was transported mainly by latent heat flux in the summer season and the vegetation canopy decreased the daily temperature range due to the heat storage. The air temperature was lower at the IOPs site than near urban area. This showed that the coastal wetland covered with the vegetation control the thermal environment.

• Journal of Wetlands Research
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• v.11 no.2
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• pp.29-38
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• 2009

A coastal wetland is the important area of diverse biodiversity as a transitional zone between coast and land. The results of surveying the flora were recorded as 310 taxa; 85 families, 212 genera, 278 species, 27 varieties and 5 forma. The halophytes were 14 taxa; Atriplex gmelini, Salsola komarovii, Suaeda asparagoides and so forth. The hydrophytes and hygrophytes were 23 taxa; Boehmeria spicata, Persicaria hydropiper, Persicaria japonica and so forth. The naturalized plants were 40 taxa; Fagopyrum esculentum, Rumex crispus, Chenopodium ambrosioides and so forth. The specific plants for the floral region were 28 taxa; Pteris multifida, Cyrtomium fortunei, Dryopteris erythrosora and so forth. In future, the flora of coastal wetland will be analyzed in series, and community dynamics and species composition for the halophytes will be studied.

• Journal of Wetlands Research
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• v.25 no.1
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• pp.1-13
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• 2023

Coastal shellfish in the shallow aquaculture waters form carbon contained shells as they grow. The existing researches showed that carbon flux can be improved, if the shells are re-treated by the carbon stored methods. In the present study, firstly, the mechanism and the quantitative flux of carbon dioxide in the shellfish individual have been analyzed. The re-treated methods of the useful by-product in the shellfish aquaculture, shells, have been reviewed. Finally, the potential effects to reduce the greenhouse gas has been suggested, if the shells can be properly re-treated.

• Journal of Wetlands Research
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• v.5 no.2
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• pp.33-42
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• 2003

Habitat pattern and distribution of the water birds were analyzed along the Hyungsan River on nine sites during fifteen months from January 2001 to March 2002. Water birds including 16,186 individuals and 86 species in total were observed from all the surveyed sites at the downstream of the Hyungsan river. Site 5, which has been observed 4,669 individuals and 60 species of the birds, was the most favorite habitat for the water birds in the Hyungsan River. And the diversity of water birds from the Hyungsan river showed the fewest species and individual numbers of the water birds at the site 2 located at the estuary of the river and site 3, the small reservoir for filtering of the draining water from the industrial area. The similarity between habitats in the Hyungsan river was divided of three groups by the cluster analysis with the bird species and individual numbers such as coastal area, estuary sites, and rice paddy field areas.