• Journal of the Korean Society of Environmental Restoration Technology
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• v.13 no.3
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• pp.46-62
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• 2010

This study was conducted to understand the water and soil properties to propose the promotion of vegetation environment at farm pond depression. We selected 8 palustrine wetlands from agricultural area after consideration of human interference, surround land use, and size of area. Water quality analysis showed that the average SS, T-N, T-P were over the limit of agricultural water quality standard level at some sites. The cause for deterioration of water quality is supposed by the long-term stagnation of water in palustrine wetland. The recommended measures to improve water quality are as follows; improving water circulation by connecting with nearby natural water, preventing oxygen depletion by dredging deposit, lowering down T-N and T-P by removing autumn plants, preventing inflow of phosphorus in fertilizer ingredients which is the main cause for high T-P. The soil contamination of the surveyed area was about the same level of average heavy metal contents in soils from 2,010 paddy fields in Korea, which was much lower than soil contamination standards. As for soil texture, sand content was 40~90% and clay content was less than 20%. The content of silt and clay in soil from community of floating-leaved:submerged hydrophytes and community of emergent hydrophytes was higher that of soil from community of hygrophytes, and the content of sand in soil from community of hygrophytes was 10% higher than underwater soil. In terms of bulk density, the average was 0.24~0.96g/$cm^3$, which was quite low, because of high content of peat and organic matter in soil of the surveyed area. As for the average content of organic matter, community of floating-leaved:submerged hydrophytes was 18.25g/kg, community of emergent hydrophytes was 16.88g/kg, and community of hydrophytes was 25.63g/kg. The range of content of T-N in soil of community of floating-leaved；submerged hydrophytes was 0.022~0.307%, and that of community of emergent hydrophytes was 0.029~0.681% and that of community of hydrophytes was 0.088~0.325%. Apart from three sites in the surveyed area, most parts were over the standards or below the standard. After this study, we will conduct and discuss the relationship between vegetation characteristics and environments, which will be used of the best practical management and restoration of wetland.

• Journal of the Korea Society of Computer and Information
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• v.6 no.1
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• pp.14-24
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• 2001

The huge and complicated plants such as nuclear power stations are likely to cause the operators to make mistakes due to a variety of inexplicable reasons and symptoms in case of emergency. Thats why the prevention system assisting the operators is being developed for. First of all. I suggest an improved fuzzy diagnosis. Secondly. I want to demonstrate that a classification system of nuclear plants accident investigating the causes of accidents foresees possible problems. and maintains the reliability of the diagnostic reports in spite of improper working in part. In the event of emergency in a nuclear plant, a lot of operational steps enable the operators to find out what caused the problems based on an emergent operating plan. Our system is able to classify their types within twenty to thirty seconds. As so, we expect the system to put don the accidents right after the rapid detection of the damage control-method concerned.

• Journal of Wetlands Research
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• v.25 no.2
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• pp.132-144
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• 2023

The use of constructed wetlands (CWs) to sequester carbon has been a topic of interest in recent studies. However, CWs have been found to be both carbon sinks and carbon sources, thus leaving uncertainties about their role in carbon neutrality initiatives. To address the uncertainties, a bibliometric and comprehensive review on carbon sequestration in CWs was conducted. Upon forming various scripts using CorText Manager, it was found that a majority of the studies focused on the effectiveness of CWs to remove nutrients, particularly nitrogen. The results of the comprehensive review revealed that high carbon concentrations and carbon sequestration rates in CW soils are dependent on the vegetation types used, the ages of the CWs, and the organic content of inflow water entering the CWs. The Typha genus was the most dominant plant genus used in the CWs from the reviewed studies and was associated with the highest carbon sequestration rates documented in this review study. Furthermore, the relatively high ability of tree species, in comparison to emergent plants, to sequester carbon was observed. Therefore, incorporating tree species into CW designs and adding them to emergent plants is seen as a potential breakthrough approach to improve the ability of CWs to sequester carbon and ultimately contribute to mitigating climate change.

• Korean Journal of Environment and Ecology
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• v.28 no.6
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• pp.705-714
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• 2014

This text was analyzed and investigated the aerial part plants and buried seed plants at coniferous forest and broadleaved forest in Yesan-gun, in order to offer the basic data of potential natural vegetation change on secondary forest. Plants of buried seed germination were consisted of 29 taxa in coniferous forest (28 species, 1 varieties, of 27 genus, 20 families) and 36 taxa in broadleaved forest (34 species, 2 varieties, of 32 genus, 18 families). Family classification of buried seed plant was the most in Compositae, and emergent plot frequency was the highest of Cyperus amuricus in coniferous forest and Crepidiastrum sonchifolium in broadleaved forest. The soil depth of the most plants appearance was 0~10 cm in coniferous forest and 0~5 cm in broadleaved forest, and the soil depth of the most population appearance was 0~2 cm in coniferous forest and broadleaved forest. Population of buried seed germination was decreased according as soil is deep. Crepidiastrum sonchifolium was a plant that population of buried seed germination is the most. Similarity index of the aerial part plants and buried seed plants was low as 0.22, and coniferous forest and broadleaved forest was 0.40.

• 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.

• Journal of Wetlands Research
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• v.9 no.2
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• pp.45-55
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• 2007

Flora, actual vegetation map, distribution area by the life form, primary productivity and annual primary production by the vascular hydrophytes and hygrophytes were investigated in the Upo wetland, Changnyeong-gun, Gyeongsangnam-do, Korea from May 2005 to March 2006. The flora of Upo, Mokpo, Sajipo, Jokjibyeol, Topyeongcheon upstream, and Topyeongcheon downstream were composed of 263, 233, 244, 182, 190, and 178 taxa, respectively. The flora of total study area was 85 families, 224 genera, 287 species, 42 varieties, 4 form, or total 333 taxa. Among them, hydrophytes, hygrophytes, and others were 38, 108, and 187 taxa, respectively. The life form of the vascular hydrophytes was classified as 20 taxa of emergent plants, 6 taxa of floating-leaved plants, 5 taxa of free-floating plants, and 7 taxa of submersed plants, respectively. There were 27 plant communities including pure population, mixed population, and etc. It is also found that Trapa japonica-Ceratophyllum demersum community occupies 60.64 ha, the largest area, and Salvinia natans-Ceratophyllum demersum community 32.91 ha, Zizania latifolia community 30.05 ha, and that the area of free-floating plants was the largest as 172.6 ha(47.9%) on the basis of life form. Total annual primary production of the vascular hydrophytes and hygrophytes was 1,383.3ton. That of the emergent hydrophytes was the most as 564.1 ton(40.8%), and those of the free-floating, floating-leaved, and the submersed were 484.1 ton(34.9%), 146.7 ton(10.6%), and 1.3 ton(0.5%), respectively, and the hygrophytes was 182.1 ton(13.2%). Since most plant species are fairly adapted to the present marsh environment, bad influences and change of species composition are expected by the artificial influences on the wetland such as fragmentation, reclamation, and introduction of the exotic species. Therefore, schemes and counterplans for the conservation and preservation of the marsh are demanded.

• 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.

• Journal of Korean Society on Water Environment
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• v.25 no.5
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• pp.713-719
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• 2009

A natural wetland in the Nakdong River basin which effectively removes non-point source pollutants was investigated for 2 years to understand wetland topography, vegetation types, and water quality characteristics. The water depth of the natural wetland was in the range of 0.5~1.9 m which is suitable for the growth of non-emergent hydrophytes. The wetland has a high length to width ratio (3.3:1) and a relatively large wetland to watershed area ratio (0.057). A broad-crested weir at the outlet increases the retention time of the wetland whose hydrology is mainly dependent on storm events. The concentrations of dissolved oxygen in the growing season and the winter season showed anoxic and oxic conditions, respectively. Diurnal variations of DO and pH in the growing season were also observed due to weather change and submerged plants. COD and TP concentrations were low in the winter season due to low inflow rate and increased retention time. Increased TP concentrations in the spring season were caused by degradation of dead wetland plants. Nitrogen in the wetland was mostly in organic nitrogen form (>75%). During the growing season, ammonium concentration was high but nitrate nitrogen concentration was low, possibly due to anoxic and low pH conditions which are adverse conditions for ammonificaiton and nitrification. The results of this study can be used as preliminary data for design, operation, monitoring and management of a constructed wetland which is designed to treat diffuse pollutants in the Nakdong river watershed.

• Journal of Ecology and Environment
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• v.38 no.3
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• pp.375-381
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• 2015

We investigated the influence of summer rainfall on Pectinatella magnifica colonies in lotic ecosystems. Of the examined substrate materials, branches and aquatic macrophytes supported more colonies of P. magnifica than that by stones or artificial materials. The influence of rainfall on P. magnifica colonies differed in accordance with the type of substrate material at each study site. In the Geum River, little difference was noted in the number of P. magnifica colonies on branches before ($mean{\pm}SE$, $24{\pm}7.3$ individuals) and after rainfall ($20{\pm}8.4$ ind.); other substrate types supported fewer colonies of P. magnifica after rainfall. In contrast, in the Miryang River, rainfall had minimal effect on the number of P. magnifica colonies supported by macrophytes ($13{\pm}3.8$ and $12{\pm}4.3$ ind., respectively). Artificial material was more abundant in the Banbyeon Stream where it was able to support more colonies of P. magnifica. We found that the structure of different substrates sustains P. magnifica following rainfall. In the Miryang River, free-floating and submerged plants with a relatively heterogeneous substrate surface were the dominant macrophytes, whereas in the Geum River, simple macrophytes (i.e., emergent plants) were dominant. Therefore, we conclude that the substrate type on which P. magnifica grows plays an important role in resisting physical disturbances such as rainfall.

• Korean Journal of Ecology and Environment
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• v.39 no.1 s.115
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• pp.85-92
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• 2006

To evaluate the primary production and nutrient uptake of macrophytes in Lake Paldang, this study investigate the vegetation areas of six dominant aquatic plants including Typha angustifolia, Zizania latifolia, Phragmites australis, Trapa japonica, Nelumbo nucifera and Savinia natans, and contents of carbon, nitrogen and phosphorus of each macrophyte. Total vegetation area of six dominant aquatic plants was 1.37 $km^2$. Among them, Typha angustifolia was the most wide-distributed species which occupied the 46.7% of total vegetation area. Littoral zone of South Han river had the largest vegetation area with 0.458 $km^2$, and North Han river, Kyungan river and confluence area in the order named. The results of the contents of carbon, nitrogen and phosphorus of macrophytes showed that the carbon contents of emergent macrophytes was higher than that of other life-forms. The nitrogen content of Salvinia natans, free-floating macrophyte was highest and that of Typha angustifolia, emergent macrophyte was lowest. The phosphorus content of Trapa japonica showed the highest content of phosphorus among six macrophytes and emergent macrophytes such as Zizania latifolia and Phragmites australis showed lower contents of phosphorus than other life-forms. The annual net primary production of macrophytes in Lake Paldang, 2004, was calculated as 758.4 ton C $yr^{-1}$ and the annual net nitrogen and phosphorus uptake of macrophyte was 16,921 kg $yr^{-1}$ and 1,841.0 kg P $yr^{-1}$ respectively. Comparing the total budget of organic carbon, nitrogen and phosphorus in Lake Paldang, the amount of primary production and nutrient uptake by macrophytes take a small portion in total budget implying macrophytes do not play an important role in budget of matters in river-type lake, Lake Paldang.