• Korean Journal of Ecology and Environment
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• v.55 no.3
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• pp.231-243
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• 2022

Anthropogenic disturbances on freshwater ecosystem are known to degrade biodiversity, especially on fish assemblage. In this study, we have conducted fish surveys to identify impact of a bridge construction on fish assemblages. A total of eight study sites were surveyed in the Danjang and the Dong Stream in southern part of South Korea from June to November in 2021. The fish samplings were carried out five times, using cast-nets(10×10 mm mesh size), scoop-nets(4×4 mm, 5×5 mm mesh size), set-nets (10×10 mm mesh size), and fish traps (3×3 mm mesh size), along with the Stream/River Ecosystem Survey and Health Assessment by the Ministry of Environment of Korea and basic water quality measurement. Also, we applied the species diversity index and length-weight relationship regressions on certain species to identify interspecific growth rate differences in accordance with study sites. As a result, a total of 782 individuals, 23 species and 10 families were collected. The dominant species was Zacco Koreanus and relative abundance was 50.89%. When applying the length-weight relationship regressions on certain species, the 'b' value for Z. Koreanus was lower at the downstream points than at the upstream points of the construction site. In addition, when comparing to the results of the past survey, relative density of demersal fish at the upstream and downstream points decreased from 26% to 1.4%, and from 18% to 6.3%, respectively. In conclusion, it is considered that bridge construction negatively affects the habitat of fishes, especially on demersal fishes. Therefore, appropriate conservation efforts such as installation of silt protector and sand sedimentation pond are needed to alleviate the disturbance in habitat such as occurrence of turbidity and destruction of micro-habitats.

• Korean Journal of Environment and Ecology
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• v.20 no.3
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• pp.331-339
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• 2006

Inhabitant patterns of the legally protected species and the characteristics of fish fauna in the Pyeongchang River, Korea, were studied from April to July 2004 by selecting 6 sites. The number of fish samples in this period were 2,448 in 35 species of 9 families. A total of nineteen endemic species (54.29%) were presented and those were Hemibarbus mylodon and Acheilognathus signifer. The highest frequency was shown in Zacco korean us (34.84%) and Pungtungia herzi (10.25%) and Coreoleuciscus splendidus (6.86%) were the next. In addition, The highest biomass was found in Z. koreanus (5,580.2g) and Coreoperca. herzi (1.241.2g) and C. splendidus (1,207.0g) were the next. When comparing the distribution of the legally protected species in within the Han River system, the highesting distributions were determined in the Pyeongchang and Dong River (6 species). The ratio of individuals in the Pyeongchang River was shown to be higher (10.62%) than that of other lakes and streams. In conclusion, more precise protection and protective plans were needed in order to maintain the lake ecology in good status because the Pyeongchang River is relatively well protected from the anthropogenic disturbance in the legally protected species including the endemic species.

• Korean Journal of Environment and Ecology
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• v.23 no.6
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• pp.516-527
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• 2009

We assessed fish fauna and habitat suitability indexes in the Geum river basin. Field monitoring was conducted for ecological and habitat condition assessment at 23 sites from October 2007 to March 2009. The habitat suitability indexes established for dominant fish species using the monitoring data were employed to assess riverine health conditions such as composition ratio of fish species, richness and dominance indexes, bio-diversity(dominance index, diversity, evenness and richness), and water depth, velocity and substrate size. Twenty-one species(42%) including Rhodeus uyekii and Pseudopungtungia nigra were found endemic out of the 50 species in 11 families sampled during this study period. The most frequently found one was Zacco platypus(34.3%) followed by Z. koreanus(10.2%) and Coreoleuciscus splendidus(8.4%). For Z. platypus, the dominant fish species in the basin, the favored habitat conditions were estimated to be 0.1~0.9 m for water depth, 0~0.9m/s for flow velocity and silt(<0.1mm)~cobbles(100.0~300.0mm) for substrate size, respectively. Overall, it was concluded that the Geum river basin has been relatively well protected from the anthropogenic disturbance for the legally protected species including the endemic species studied in this study.

• Journal of Environmental Science International
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• v.22 no.8
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• pp.925-935
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• 2013

In this study, a comprehensive field monitoring was conducted to understand habitat conditions of fish species in up and downstream of Hoengseong Dam. Based on the monitoring data, riverine health conditions such as composition ratio of fish species, bio-diversity (dominance index, diversity, evenness and richness), index of biological integrity (IBI) and qualitative habitat evaluation index (QHEI) were assessed, and optimal ecological flowrates (OEF) were estimated using the habitat suitability indexes (HSI) established for three fish species Coreoleuciscus splendidus, Pungtungia herzi and Microphysogobio longidorsalis selected as icon species using the physical habitat simulation system (PHABSIM). The total number of species sampled was 20 species, and two species of Zacco platypus (30.4%) and C. splendidus (20.9%) dominated the fish community. As a result, it was revealed that IBI and QHEI values decreased from upstream to downstream along the river. The estimated IBI value ranged from 24 to 36 with average being 30.9 out of 50, rendering the site ecologically fair to good health conditions. HSI for C. splendidus were determined according to three different month in terms of season: Spring (April), Summer (August) and Autumn (October). HSI for flow velocity were estimated at 0.7 to 0.8 m/s for the Spring, 0.5 to 1.0 m/s for the Summer and 0.8 to 0.9 m/s for the Autumn. HSI for water depth were estimated at 0.3 to 0.5 m for the Spring; 0.3 to 0.5 m for the Summer; and 0.3 to 0.4 m for the Autumn. OEF was estimated at 4.2 and $6.5m^3/s$ for the Spring and Autumn, and $12.0m^3/s$ for the Summer. Overall, it was concluded that the Hoengseong Dam has been relatively well protected from the anthropogenic disturbance for the legally protected species including the endemic species studied in this study.

• 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.

• Korean Journal of Ecology and Environment
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• v.43 no.2
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• pp.271-278
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• 2010

Field monitoring was conducted for fish fauna and community assessment at 7 sites from April 2008 to October 2009 in the Chogang Stream. The number of fish samples in this period were 4,669 in 36 species of 9 families. Family Cyprinidae take 66.7 (24 species), Cobitidae, Bagridae, Centropomidae and Odontobutidae occupied 5.6%(each 2 species), respectively. Twenty species (55.6%) including Acheilognathus koreensis and A. yamatsutae were found endemic out of the 36 species. The species of Pseudopungtungia nigra, Gobiobotia macrocephala and Gobiobotia brevibarba were endangered species. The most frequently found one was Zacco koreanus (34.0%, n=1,588) followed by Z. platypus (22.6%, n=1,053) and Coreoleuciscus splendidus (13.3%, n=623). The lower reach of Chogang Stream was more abundance of species, high diversity, evenness and richness, and lower dominance index than those of the upper reach. According to the dendrogram established at 0.5 level of similarity rate, sampling stations were divided into 3 groups. They were divided into upper most stream (St. 1~St. 2), upper stream (St. 3), middle and lower stream (St. 4~St. 7). Overall, it was concluded that the Chogang Stream has been relatively well protected from the anthropogenic disturbance for the legally protected species including the endemic species studied in this study.

• The Korean Journal of Quaternary Research
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• v.6 no.1
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• pp.1-11
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• 1992

The reconstruction of the vegetational and environmental history of the Korean peninsula by the use of various fossil floral data from the Carboniferous period to the Pre-Holocene is reviewed. Though the oldest plant fossil in Korea (Neuropteris) dates back to the Carboniferous period, the first appearance of many of the present-day floristic genera indeed dates back to the Oligocene (c. 40 to 20 million years B.P.), and includes many thermophilous genera. The presence of thermophilous genera in the Oligocene at up to four degrees north of their present distributional limits implies that the climate of the Oligocene was warmer than that of today. The occurrence of similar thermophilous floristic element at up to six degrees north of their present range during the Middle Miocene suggests a maximum northward expansion of warmth-loving evergreen broadleaved vegetation for, recent Korean vegetation history. The continued occurrence of numerous present-day genera since the Oligocene period indicates a long-term stability of Korean vegetation, along with minor fluctuations within it. The admixture of evergreen coniferous plants and deciduous breadleaved plants, however, indicates a probable temperate climate for much of the Middle Pleistocene. There are couple of evidences which are indicative of an early-stage anthropogenic disturbance of natural vegetation during the Middle Pleistocene of Korea. The presence of cold-episodes during the Upper Pleistocene caused a general expansion of deciduous plants and cryophilous evergreen coniferous, plants. It is likely that the maximum southward expansion of cryophilous arctic-alpine and alpine floras in Korea occured during the penultimate glacial period. The disappearance of some cryophilous genera from 10,000 years B.P. marks the continued climatic amelioration since then, along with minor climatic fluctuations during the Holocene period.

• Korean Journal of Environment and Ecology
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• v.35 no.2
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• pp.193-203
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• 2021

As endangered species are gradually increasing due to land development by humans, it is essential to secure sufficient protected areas (PAs) proactively. Therefore, this study checked priority conservation areas to select candidate PAs when considering the impact of land development. We determined the conservation priorities by analyzing four scenarios based on existing conservation areas and reflecting the development impact using MARXAN, the decision-making support software for the conservation plan. The development impact was derived using the developed area ratio, population density, road network system, and traffic volume. The conservation areas of endangered species were derived using the data of the appearance points of birds, mammals, and herptiles from the 3rd National Ecosystem Survey. These two factors were used as input data to map conservation priority areas with the machine learning-based optimization methodology. The result identified many non-PAs areas that were expected to play an important role conserving endangered species. When considering the land development impact, it was found that the areas with priority for conservation were fragmented. Even when both the development impact and existing PAs were considered, the priority was higher in areas from the current PAs because many road developments had already been completed around the current PAs. Therefore, it is necessary to consider areas other than the current PAs to protect endangered species and seek alternative measures to fragmented conservation priority areas.

• Journal of The Geomorphological Association of Korea
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• v.17 no.2
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• pp.63-76
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• 2010

The Jangdo wetland is located on a very gentle slope of the mountain area in Daejangdo island, Shinan-gun, Korea, in which the area of the watershed is estimated at 147,000 m². The wetland has been regarded as a peat bog without any sedimentological evidence. This study was conducted to analyze the geomorphological and sedimentological characteristics of the wetland. The geographic information system (GIS) was used to analyze the drainage system, and field surveys were conducted to measure the range and depth of wetland deposits. The grain size analysis, organic matter determination, elements analysis and radiocarbon dating were performed on samples from the wetland. As a result, the wetland deposits were about 30 cm deep on average, the mean grain sizes ranged from 50 to 500 μm, and the average C/N ratio was 11.5. The portion of organic matter it contained was only 5~26%, which did not satisfy the peat standards. The radiocarbon ages from the wetland deposits range 180±50 ¹⁴C yr BP to modern, which indicated that natural and anthropogenic interferences including agricultural activities have continuously happened. We conclude that the Jangdo wetland is still in its infancy, not a steady state, so that it could be very sensitive to a small disturbance.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.26 no.4
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• pp.17-34
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• 2023

Camera trapping has been used as a non-invasive survey method that minimizes anthropogenic disturbance to ecosystems. Nevertheless, it is labor-intensive and time-consuming, requiring researchers to quantify species and populations. In this study, we aimed to improve the preprocessing of camera trapping data by utilizing an object detection algorithm. Wildlife monitoring using unmanned sensor cameras was conducted in a forested urban forest and a green space on a university campus in Cheonan City, Chungcheongnam-do, Korea. The collected camera trapping data were classified by a researcher to identify the occurrence of species. The data was then used to test the performance of the YOLO-X object detection algorithm for wildlife detection. The camera trapping resulted in 10,500 images of the urban forest and 51,974 images of green spaces on campus. Out of the total 62,474 images, 52,993 images (84.82%) were found to be false positives, while 9,481 images (15.18%) were found to contain wildlife. As a result of wildlife monitoring, 19 species of birds, 5 species of mammals, and 1 species of reptile were observed within the study area. In addition, there were statistically significant differences in the frequency of occurrence of the following species according to the type of urban greenery: Parus varius(t = -3.035, p < 0.01), Parus major(t = 2.112, p < 0.05), Passer montanus(t = 2.112, p < 0.05), Paradoxornis webbianus(t = 2.112, p < 0.05), Turdus hortulorum(t = -4.026, p < 0.001), and Sitta europaea(t = -2.189, p < 0.05). The detection performance of the YOLO-X model for wildlife occurrence was analyzed, and it successfully classified 94.2% of the camera trapping data. In particular, the number of true positive predictions was 7,809 images and the number of false negative predictions was 51,044 images. In this study, the object detection algorithm YOLO-X model was used to detect the presence of wildlife in the camera trapping data. In this study, the YOLO-X model was used with a filter activated to detect 10 specific animal taxa out of the 80 classes trained on the COCO dataset, without any additional training. In future studies, it is necessary to create and apply training data for key occurrence species to make the model suitable for wildlife monitoring.