• Journal of Wetlands Research
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• v.20 no.2
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• pp.124-130
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• 2018

This study was conducted to identify the characteristics of bird population dynamics using unmanned monitoring system in rice paddy. We compared the similarity of population dynamics of birds between unmanned monitoring system and field survey, and evaluated the spatial and temporal patterns of population dynamics of birds using the unmanned monitoring system. The monitoring using the system was conducted from January 1, 2014 to December 31, 2016 in Cheolwon, Dangjin, Buan, and Heanam. The images from the system were obtained at 10-min intervals from 6:00 to 20:00. The field survey was conducted once a month in Dangjin from January to December 2016. Total 91,980 images were obtained from the unmanned monitoring system. We extracted the number of individuals for herons, shorebirds, and waterfowl from the images. The population dynamics of waterbirds using the unmanned monitoring system were similar to that in field survey. Especially, population dynamics of herons was more similar than other waterbirds. It was identified that the population dynamics of herons using the unmanned monitoring system was different among the Cheolwon, Dangjin, Buan, and Heanam. Furthermore, the unmanned monitoring system was available on various time scale such as month, day, and minute. It is expected that long-term data storage using the unmanned monitoring system can be used to identify in detail and forecast the population dynamics of birds in rice paddy.

• Korean Journal of Ecology and Environment
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• v.47 no.spc
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• pp.57-65
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• 2014

Spatial and temporal distributions of zooplankton were measured in an oligotrophic pumped storage-type hydroelectric reservoir which was composed of two reservoirs exchanging water daily, with water going up at night and going down during the day. Repetitive diel disturbance of the water column can be a unique feature of this reservoir system. Chl-${\alpha}$ concentration was highest in the early winter season. Phytoplankton density was lower in summer monsoon due to high flushing rate on rainy days. The zooplankton density was higher in the smaller upper reservoir possibly due to lower fish density in the upper reservoir. In the seasonal variation a time gap was observed between the phytoplankton bloom and the zooplankton bloom (particularly a rotifer, Keratella cochlearis). It is likely to that Keratella production is partially supported by heterotrophic food sources than phytoplankton. The dominance of a mixotrophic dinoflagellate (Peridinium bipes f. ocultatum) might have complicated the trophic relationship between phytoplankton and zooplankton. Our results provide some ecological information of zooplankton community in a highly disturbed alpine reservoir ecosystem relying on mostly allochthonous organic matter.

• Korean Journal of Ecology and Environment
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• v.51 no.4
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• pp.354-364
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• 2018

In this study, we surveyed the fish community at the four sites(St. 1, 3, 5, 7) in Jungrang Stream from 2008 to 2016. We found 37 species grouped into nine families. There were three exotic species; Cyprinus carpio, Carassius cuvieri and Micropterus salmoides after rainfall. Dominant species was Zacco platypus (57.3%) and subdominant species was Carassius auratus(10.4%) in a community. The water quality, surveyed at the six sites(St. 1, 2, 3, 4, 5, 6), based on eight factors(Water temperature, pH, DO, BOD, SS, EC, TN and TP), largely varied depending on each site and period. Minimum values in four factors(BOD, EC, TN and TP) were observed in rainy season, indicating an ionic and nutrient dilution of stream water by precipitation. In contrast, a maximum value in SS was occurred in rainy season at St. 2 and St. 5. The precipitation, Maximum value observed in July ($497.5{\pm}297.2mm$), minimum value in January ($12.9{\pm}8.6mm$). In July and August, the precipitation was divided into before and after the rainfall season in Jungrang stream. Using cluster analysis three fish sites (St. 1, 3, 5) were identified as significantly influence 11 fish species; Hemiculter eigenmanni, Squalidus japonicus coreanus, Hemibarbus labeo, Gnathopogon strigatus, Pungtungia herzi, Rhynchocypris oxycephalus, Pseudogobio esocinus, Pseudorasbora parva, Cyprinus carpio, Carassius auratus and Zacco platypus by rainfall.

• Korean Journal of Environmental Biology
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• v.39 no.2
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• pp.207-217
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• 2021

Using the data from the national survey of fish, we determined the population size and the distribution of Micropterus salmoides, which is a translocated species into the aquatic ecosystem of Korea. . The spatial concentration of this species was determined by performing an optimized hot spot analysis. After determining potential invasiveness and risk assessment, we measured the disturbance of biodiversity in the aquatic ecosystem. The result of distribution analysis indicates that the population of M. salmoides was concentrated in the major basins of Han river, Geum river, Nakdong river, and Yeongsan-Seomjin river, including the Jeju island. In particular, Nakdong river basin showed the highest appearance rate. On the contrary, Yeongsan-Seomjin river basin showed the lowest appearance rate. The Nakdong river and the Nakdong river basin were the areas with the high spatial concentration of M. salmoides. On the other hand, only Han river basin and Geum river basin had the lowest spatial concentration. The fish invasiveness screening kit(FISK) was used to assess M. salmoides, which inhabited a broad region of aquatic ecosystem: the assessment score was 31.0, indicating its 'highly invasive' nature. Our study aims to encourage research that improves the biodiversity and the conservation of M. salmoides in a priority area.

• Journal of Digital Convergence
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• v.20 no.3
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• pp.41-52
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• 2022

Although domestic public libraries achieved quantitative growth based on the 1st and 2nd comprehensive library development plans, there were some qualitative shortcomings, and various studies have been conducted to improve them. Most of the preceding studies have limitations in that they are limited to social and economic factors and statistical analysis. Therefore, in this study, by applying the spatiotemporal concept to quantitatively calculate the decrease in public library loan demand due to rainfall and heatwave, by clustering areas with high demand for book loan due to weather changes and areas where it is not, factors inside and outside public libraries and After the combination, changes in public library loan demand according to weather changes were analyzed. As a result of the analysis, there was a difference in the decrease due to the weather for each public library, and it was found that there were some differences depending on the characteristics and spatial location of the public library. Also, when the temperature was over 35℃, the decrease in book loan demand increased significantly. As internal factors, the number of seats, the number of books, and area were derived. As external factors, the public library access ramp, cafe, reading room, floating population in their teens, and floating population of women in their 30s/40s were analyzed as important variables. The results of this analysis are judged to contribute to the establishment of policies to promote the use of public libraries in consideration of the weather in a specific season, and also suggested limitations of the study.

• Korean Journal of Ecology and Environment
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• v.54 no.3
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• pp.247-256
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• 2021

Understanding the selective feeding behavior of zooplankton on phytoplankton is essential for evaluating the nutrient cycle and energy flow in the food web. Although many studies have been conducted regarding the feeding behaviors of zooplankton through gut content analyses, there are limitations in the visual identification of digested contents using a microscope. DNA techniques have been applied to overcome these limitations since they can detect and amplify small amounts of prey DNA remaining in the gut contents. We designed a method to extract prey DNA from the gut contents of the whole body of the copepod specimen and tested the resolution of DNA identification for the prey phytoplankton. The common brackish species, Sinocalanus tenellus, were collected from Saemangeum Reservoir in different sites and seasons, and gut content DNA was extracted using 2.5% bleach treatment for 2 min for removal of potential contamination sources existing in preserved specimens without dissolution of the body. The sequences of the extracted gut contents were confirmed using BLASTn suite based on the NCBI database. The phytoplankton species detected in the gut showed temporal and spatial differences. Although DNA analysis of small copepod gut contents has been suggested as an effective method to examine the dynamics of primary prey sources at the genus or species level, uncertainties such as misidentification and limitations in the detailed information of the composition still exist.

• Journal of Environmental Impact Assessment
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• v.27 no.5
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• pp.489-508
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• 2018

As climate changes, it is necessary to predict changes in the habitat environment in order to establish more aggressive adaptation strategies. The bioclimatic classification which clusters of areas with similar habitats can provide a useful ecosystem management framework. Therefore, in this study, biological habitat environment of Northeast Asia was identified through the establishment of the bioclimatic zones, and the impac of climate change on the biological habitat was analyzed. An ISODATA clustering was used to classify Northeast Asia (NEA)into 15 bioclimatic zones, and climate change impacts were predicted by projecting the future spatial distribution of bioclimatic zones based upon an ensemble of 17 GCMs across RCP4.5 and 8.5 scenarios for 2050s, and 2070s. Results demonstrated that significant changes in bioclimatic conditions can be expected throughout the NEA by 2050s and 2070s. The overall zones moved upward, and some zones were predicted to be greatly expanded or shrunk where we suggested as regions requiring intensive management. This analysis provides the basis for understanding potential impacts of climate change on biodiversity and ecosystem. Also, this could be used more effectively to support decision making on climate change adaptation.

• Korean journal of applied entomology
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• v.49 no.2
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• pp.105-113
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• 2010

Moths were collected using a 22W UV black light trap in June through September in 2005 and May, June, August and September in 2006. The study sites were Namsan (Mt. Nam), Jirisan (Mt. Jiri), Woraksan (Mt. Worak) which are part of the Korean National Long Term Ecological Research (KNLTER). There were two common forest communities, Quercus mongolica and Pinus densiflora. The purpose of this study was to compare species diversity of the major plant feeding Lepidoptera in the two forest types at the regional KNLTER sites. We collected a total of 435 species from the KLTER sites in 2005 and 2006. Abundance of moths was highest at Woraksan (Mt. Worak) followed by Jirisan (Mt. Jiri). The Namsan (Mt. Nam) site had the lowest, with five families (Arctiidae, Geometridae, Noctuidae, Notodontidae, and Pyralidae). Analysis of variance (ANOVA) showed statistically significant differences at sampling date in species abundance as a response variable and at site in species richness as another response variable. Although we expected a distinct cluster with the forest type at each study site, one of ordination analyses, nonmetric multidimensional scaling (NMS), showed distinct clusters with the moth assemblages at each site only but NMS did not show any distinct cluster with the different forest types at each site as we expected.

• Korean Journal of Ecology and Environment
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• v.51 no.2
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• pp.192-203
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• 2018

Headwater streams provide various microhabitats, resulting in high diversity of macroinvertebrate community. In this study, we compared the differences of communities between two adjacent headwater streams (Jangjeon stream (GRJ; GRJ1-GRJ5) and Haanmi stream (GRH; GRH1-GRH3)) in Jungwang and Gariwang mountains, Gangwon-do and evaluated the effects of habitat condition to the macroinvertebrates community composition. In order to characterize the macroinvertebrate communities and extract influential environmental factors, we applied to Cluster analysis (CA), Indicator species analysis and Non-metric multidimensional scaling (NMDS). Total 33,613 individuals in 3 phyla, 5 classes, 13 orders, 51 families, and 114 taxa (genera or species) were collected. Gammarus sp. was dominant at the upper stream of GRJ, whereas Chironomidae spp. was abundant at GRH and the downstream of GRJ. The CA classified samples into six clusters (1-6) reflecting spatial and temporal variation of benthic macroinvertebrate communities. Benthic macroinvertebrate community composition was significantly different between two adjacent streams. Sweltsa sp. 1, Psilotreta kisoensis, Rhyacophila shikotsuensis and Serratella setigera were identified as representative indicator species for clusters 1, 2, 3 and 5, respectively. Similar to CA results, NMDS revealed the spatial and temporal differences of benthic macroinvertebrate communities, indicating the difference of community composition as well as microhabitat condition. Forest composition, proportion of boulders (>256 mm), and water velocity were main factors affecting the macroinvertebrate community composition.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.4
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• pp.251-264
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• 1992

Distribution of indicator species of copepods and chaetognaths were studied as an indicator species of water mass in the southeastern area of the Yellow Sea. Undinula darwini, Lucicutia flavicornis, Pleuromamma gracilis, Euchaeta resselli, Euchaeta plane and Sagitta enflata were found to be reliable indicator species for determining warm water mass. Of these species, E. plana and E. rusrelli have a weak tolerance on the low temperature. Sagitta crassa was indicator species of neritic waters; Sagitta bedoti was that of mixing waters. Centropages abdominalis represented neritic cold waters. In February, U darwini, L. flavicornis, P. gracilis, E. russelli, E. plana and S. enflata occurred in the western waters of Cheju-Do where warm waters over $14^{\circ}C$ occupied. Centropages abdominalis occurred in the northern area beyond Chindo with water temperature less than $10^{\circ}C$. E. plana, E. russelli and S. bedoti were found at the regions between Cheju-Do and Chindo where the water temperature was $12- 14^{\circ}C$ corresponding to the mixing waters. Based on cluster analysis and T-S diagram in February three different water masses were identified from the south to the north. In August, water masses were analyzed at two different layers, 0-20m and 20m- bottom layers, separated by bhermocline depth. In 0-20m layer, E. plana and E. russelli were found from the western waters of Cheju-Do to Daehuksando. In 20m- bottom layer, E. russelli and E plena occurred at the northwestern waters of Cheju-Do with the water temperature warmer than $12^{\circ}C.\;C.$ abdominalis was found at the northern area beyond Chindo. Based on the cluster analysis and T-S diagram in August three different water masses at 0-20m and 20m-bottom layers were identified from the coast to the offshore. C. abdominalis was found at the adjacent water of Chindo at 0-20m layer and the northern area beyond Chindo at 20m~bottom layer. This fact suggested that the cold water mass existed at tile adjacent waters of Chindo in summer.