• Fisheries and Aquatic Sciences
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• v.27 no.6
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• pp.337-345
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• 2024

This study looked at some biometric and reproductive aspects of the Common carp (Cyprinus carpio) - the overexploited fish species in the Geray Reservoir as a foundation to develop an efficient fisheries management strategy. 50 fish samples (20 to 44 cm and 130 to 2,400 g) were collected between October and May 2022 using a cast net with a mesh size of 6 cm. The ratio of male to female C. carpio (1:0.52) was deviating from the anticipated 1:1 ratio. The absolute fecundity of C. carpio was relatively low (12,375 to 31,392 eggs). Gonadosomatic index varied from 0.01 to 4.6 (male) to 0.24-12.75 (female), and the spawning period of C. carpio extended from December to January. The length-weight relationships for males (TW = 0.0009TL^3.87) and females (TW = 0.0007L^3.97) indicate that C. carpio had positive allometric growth; which may have been caused by unsuitable habitat conditions and overfishing. There is a need to develop fisheries management like implementing integrated conservation efforts and reducing wetland farming. For this, this information provides a baseline data.

• Journal of Ecology and Environment
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• v.34 no.2
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• pp.223-235
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• 2011

Juncus effusus is mostly found in freshwater wetlands and is widely used for landscaping and creating artificial wetlands due to its high ecological value. J. effusus tends to dominate during the early stage (3-10 years) of the second succession in abandoned paddy fields. This study focused on the environmental characteristics of J. effusus to create habitat for an endangered species, Nannopya pygmaea, which lives in wetlands dominated by J. effusus. Considering the distribution of J. effusus and N. pygmaea, 63 quadrats at eight wetlands were investigated between May and June 2006 during the critically dry period. Fifty-three species from 28 families co-occurred with J. effusus, and Persicaria thunbergii was the most abundant (63.5%). The optimal ranges of distribution (ORD) for the water variables were water depth, -2 to 10 cm; dissolved oxygen, 0.99-3.55 mg/kg, conductivity (CON), 23.40-115.40 ${\mu}s/cm$, total dissolved solid, 12.53-57.60 mg/L; pH, 5.00-6.87; $K^+$, 0.11-1.46 mg/L; $Ca^{2+}$, 1.53-5.85 mg/L; $Na^+$, 3.16-7.47 mg/L; $Mg^{2+}$, 0.11-1.96 mg/L; $NO_3$-N, < 0.001-0.072 mg/L; $NH_4$-N, 0.005-0.097 mg/L; and $PO_4$-P, 0.006-0.047 mg/L. ORDs for the soil variables were water content, 1.05-2.96%; loss-on ignition method (LOI), 5.07-7.81%; CON, 23.70-59.70 ${\mu}s/cm$; pH, 4.40-5.16; extracted (e) $K^+$, 4.34-15.73 cmol/kg; $eCa^{2+}$, 31.56-191.56 cmol/kg; $eNa^+$, < 0.01-2.61 cmol/kg; eMg, 0.04-19.82 cmol/kg; $eNO_3$-N, 0.514-1.175 mg/kg; $eNH_4$-N, 0.033-0.974 mg/kg, $ePO_4$-P, 0.491-11.552 mg/kg; total nitrogen, 0.016-0.200%; and total carbon, 1.06-2.37%. The appearance of rush during early succession indicated relatively lower levels of these physicochemical parameters, and that ORDs should be maintained for the J. effusus community.

• Journal of Wetlands Research
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• v.6 no.2
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• pp.65-71
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• 2004

The most significant effect of excess water in wetlands is the isolation of the soil from the atmosphere and the prevention of O2 from diffusing into soil. The blockage of atmospheric O2 induces biological and chemical processes that change soil from oxidized into reduced state. When dry soil develop into hydric soil, redox potential is dropping. The redox potential is a indicator of hydric soil and affect chemical function of wetlands. To reveal characteristics of wetland soil, redox potential was measured in Jinkwannaedong ecological conservation area from May in 2003 to March in 2004. Redox potentials in May ranged from 5 mV at 25 cm depth to 200 mV at 10 cm depth. It decreased to about -200 m V at all depths and continued until October. In winter, redox potential was slowly increased; it was the highest at 5 cm depth and lowest at 20 cm depth. Annual variations of redox potential in 20 cm depth showed the same pattern at 5 sites; low in growing season and high in non-growing season. This results indicates that soils of study sites are in hydric state and methanogenesis is occurring in Jinkwannaedong ecological conservation area.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.2
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• pp.225-241
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• 2007

A closed flux chamber system was used for measuring major greenhouse gas (GHG) emission from tideland and/or wetland soils in estuarine area at Saemankum, Kunsan in southwestern Korea during from months of February to June 2006. Hourly averaged GHG soil emissions were measured two to three times a day during the ebb tide hours only. Site soils were analyzed for soil parameters (temperature, pH, total organic contents, N and C contents in soil) in the laboratory. Soil GHG fluxes were calculated based on the GHG concentration rate of change measured inside a closed chamber The analysis of GHG was conducted by using a Gas Chromatography (equipped with ECD/FID) at laboratory. Changes of daily, monthly GHGs' fluxes were examined. The relationships between the GHG emissions and soil chemical contents were also scrutinized with respect to gas production and consumption mechanism in the soil. Soil pH was pH $7.47{\pm}0.49$ in average over the experimental period. Organic matter contents in sample soil was $6.64{\pm}4.98\;g/kg$, and it shows relatively lower contents than those in agricultural soils in Kunsan area. Resulting from the soil chemistry data, soil nitrogen contents seem to affect GHG emission from the tidal land surface. The tidal soil was found to be either source or sink for the major GHG during the experimental periods. The annual average of $CH_{4}\;and\;CO_{2}$ fluxes were $0.13{\pm}0.86\;mg\;m^{-2}h^{-1}\;and\;5.83{\pm}138.73\;mg\;m^{-2}h^{-1}$, respectively, which will be as a source of these gases. However, $N_{2}O$ emission showed in negative flux, and the value was $-0.02{\pm}0.66\;mg\;m^{-2}h^{-1}$, and it implies tidal land surface act as a sink of $N_{2}O$. Over the experimental period, the absolute values of gas fluxes increased with soil temperature in general. Averages of the ambient gas concentration were $86.8{\pm}6.\;ppm$ in $CO_{2},\;1.63{\pm}0.34\;ppm\;in\;CH_{4},\;and\;0.59{\pm}0.15\;ppm\;in\;N_{2}O$, respectively. Generally, under the presence of gas emission from agricultural soils, decrease of gas emission will be observed as increase in ambient gas concentration. We, however, could not found significant correlation between the ambient concentrations and their emissions over the experimental period. There was no GHG compensation points existed in tide flat soil.

• The Korean Journal of Quaternary Research
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• v.25 no.2
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• pp.25-37
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• 2011

The purpose of this study is to assume the particular area of hills where it is highly possible for historical site to be buried in the viewpoint of geomorphology and based on this to suggest excavation-recommended area. Namely, this writer is to understand the dwelling site type of ancient people who had resided there at that time for the object of 'Ohnju region urban development business site' (referred as investigation area hereinafter) and considering the characteristics of micro-landform of hills which are distributed in investigation area and is to recommend the area where it is highly possible for historical site to be buried. The result of analysis is like the following. (1) Dwelling site types of ancient people who might have resided in the whole area of investigation region are discovered to be largely 'low hills+wetland' of Type-I and 'alluvial fan(or river terrace+wetland' of Type-II. (2) In investigation area if the area which has high possibility of distribution of historical site namely, excavation-recommended area is looked as based on micro-landform unit of hills, they are Crest slope and Crest flat. Individual area ratios which Crest slope and Crest flat occupies in investigation area are 12.9% and 10.2% respectively and the rankings are 3 and 6 each. And excavation-recommended areas in valley plain(or bottomland) of investigation area are in the vicinity of 'distal end' or 'buried distal end'of small scale alluvial fan.

• Journal of Environmental Impact Assessment
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• v.26 no.6
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• pp.385-403
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• 2017

This study showed the national ecosystem classification for the spatial standards of ecosystems-based approaches to the risk assessments and adaptation plan. The characteristics of climate change risk assessment, implement national adaptation plans, and ecosystem/habitat classification status was evaluated. Focusing on the land cover classification widely utilized as spatial data for the assessments of biodiversity and ecosystem services in the UK and other countries in Europe, the applicability of the national land cover classification for climate change risk assessments was reviewed. Considering the ecosystem classification for climate change risk assessment and establishing adaptation measures, it is difficult to apply rough classification method to the land cover system because of lack of information on habitat trend by categorization. The results indicated that forest ecosystems and agro-ecosystem occupied 62.3% and 25.0% of land cover, respectively, of the entire country. Although the area is small compared with the land area, wetland ecosystem (2.9%), marine ecosystem (0.4%), coastal ecosystem (0.6%), and urban ecosystem (6.1%) can be included in the risk assessments. Therefore, it is necessary to subdivide below the medium classification for the forest and agricultural land, as well as Inland wetland, which has a higher proportion of habitat preference of taxa than land area, marine/coastal habitat, and transition areas such as urban and natural ecosystem.

• Journal of the Korean association of regional geographers
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• v.7 no.1
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• pp.35-50
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• 2001

Since remotely sensed images of coastal wetlands are very sensitive to spatial resolution, it is very important to select an optimum resolution for particular geographic phenomena needed to be represented. Scale is one of the most important factors in spatial analysis techniques, which is defined as a spatial and temporal interval for a measurement or observation and is determined by the spatial extent of study area or the measurement unit. In order to acquire the optimum scale for a particular subject (i.e., coastal wetlands), measuring and representing the characteristics of attribute information extracted from the remotely sensed images are required. This study aims to explore and analyze the scale effects of attribute information extracted from remotely sensed coastal wetlands images. Specifically, it is focused on identifying the effects of scale in response to spatial resolution changes and suggesting a methodology for exploring the optimum spatial resolution. The LANDSAT TM image of Sunchon Bay was classified by a supervised classification method, Six land cover types were classified and the Kappa index for this classification was 84.6%. In order to explore the effects of scale in the classification procedure, a set of images that have different spatial resolutions were created by a aggregation method. Coarser images were created with the original image by averaging the DN values of neighboring pixels. Sixteen images whose resolution range from 30 m to 480 m were generated and classified to obtain land cover information using the same training set applied to the initial classification. The values of Kappa index show a distinctive pattern according to the spatial resolution change. Up to 120m, the values of Kappa index changed little, but Kappa index decreased dramatically at the 150m. However, at the resolution of 240 m and 270m, the classification accuracy was increased. From this observation, the optimum resolution for the study area would be either at 240m or 270m with respect to the classification accuracy and the best quality of attribute information can be obtained from these resolutions. Procedures and methodologies developed from this study would be applied to similar kinds and be used as a methodology of identifying and defining an optimum spatial resolution for a given problem.

• Journal of the Korean association of regional geographers
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• v.14 no.4
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• pp.279-289
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• 2008

The purpose of this paper is to search for geomorphological landscape resources of Goryeong-gun, to provide fundamental data for their management through mapping their distribution, and to present their conservation and application plan. The results are as follow: Firstly, geomorphological landscape resources in mountain area are Misungsan and Jusan mountain of Goryeong-up, Sangbiri valley of Deoggok-myeon, and isolated hill of Gaejin-myeon. Secondly, geomorphological landscape resources in riparian area are natural wetlands such as Jinchonneup of Bu-ri Gaejin-myeon, Hochonneup and Dalseongseupji of Hochon-ri Dasan-myeon, Bongsanneup of Bongsan-ri Ugok- myeon; artificial wetlands following the construction of weir such as riparian wetland of Oe-ri Goryeong-up and Banun-ri Gaejin-myeon; meander core and abandoned channel of Banun-ri Gaejin -myeon, river cliffs such as Naegok-ri Goryeong-up and Weolo-ri Ugok-myeon; sand bars and braided channel of Yajeong-ri Ugok-myeon. Thirdly, Jinchonneup swamp area of Bu-ri Gaejin-myeon have characteristics of typical floodplain landform, and its conservation conditions is relatively satisfactory, and its accessibility to metropolis is great, so it is a good place to construct eco-park. And construction of inquiry learning place at Banun-ri Gaejin-myeon will increase the opportunity to observe environmental changes following incised meander cutoff and ecological affirmative functions of a weir.

• Journal of Wetlands Research
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• v.12 no.2
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• pp.59-65
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• 2010

Wetlands are a well known ecosystem which have high spatial-temporal heterogeneity of chemical characteristics. This high heterogeneity induces diverse biogeochemical processes, such as aerobic decomposition, denitrification, and plant productivity in wetlands. Understanding the dynamics of dissolved organic carbon (DOC) and inorganic nitrogen in wetlands is important because DOC and inorganic nitrogen are main factors controlling biological processes in wetlands. In this study, we assessed spatial distribution of DOC and inorganic nitrogen with relation to the different hydrology and vegetation in created wetlands. Both DOC and nitrate contents were significantly higher in vegetated areas than open areas. Different water levels also affected DOC contents and their quality. Average DOC contents were $0.37mg{\cdot}g^{-1}$ in deep riparian (DR) and $0.31mg{\cdot}g^{-1}$ in shallow riparian (SR). These results appeared to be related to the interaction between carbon supply by vegetation and microbial decomposition. On the other hand, inorganic nitrogen contents were not affected by water level differences. This result indicates that presence/absence of vegetation could be a more important factor than hydrology in the spatial dynamics of inorganic nitrogen. In conclusion, we observed that vegetation and hydrology differences induced spatial distribution of carbon and nitrogen which are directly related to biogeochemical processes in wetlands.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.27 no.3
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• pp.158-172
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• 2022

The distribution of seabirds was investigated in 24-34 major coastal wetlands in Korea from 2015 to 2019. During the study period, seven orders, 16 families, and 111 species were observed, and the largest number of species (51-89 species) was recorded in 2018. 92,821-265,783 individuals per year were observed with the largest number in 2018. The largest number of species (55-72 species) was observed in the southern sites of Jeollado, and the largest number of individuals (annual average of 62,542 individuals) was found in Chungcheong regions. The largest number of seabird species (68 species) was observed at the Suncheon Bay site in 2016, and the largest number of individuals (95,399 individuals) was observed at Biin and Jangan sites in 2018. In terms of the habitat type of seabirds, at the family level, shorebirds appeared most frequently with an average of 38%, followed by waterfowl, wading birds, seabirds, and raptors. With regard to legally protected species, eight protected marine species, 19 endangered wildlife species (Level I: six species, Level II: 13 species), and twelve natural monument species were observed. Overall, there was a significant difference in the number of species and individuals of seabirds in the Korean coastal wetlands during the research period. This suggests the importance of conducting systematic and continuous seabird surveys and developing a conservation policy considering habitat characteristics.