• Journal of the Korean Society of Environmental Restoration Technology
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• v.22 no.5
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• pp.1-12
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• 2019

It is important to measure the height of trees as an essential element for assessing the forest health in urban areas. Therefore, an automated method that can measure the height of individual tree as a three-dimensional forest information is needed in an extensive and dense forest. Since airborne LiDAR dataset is easy to analyze the tree height(z-coordinate) of forests, studies on individual tree height measurement could be performed as an assessment forest health. Especially in urban forests, that adversely affected by habitat fragmentation and isolation. So this study was analyzed to measure the height of individual trees for assessing the urban forests health, Furthermore to identify environmental factors that affect forest growth. The survey was conducted in the Mt. Bongseo located in Seobuk-gu. Cheonan-si(Middle Chungcheong Province). We segment the individual trees on coniferous by automatic method using the airborne LiDAR dataset of the two periods (year of 2016 and 2017) and to find out individual tree growth. Segmentation of individual trees was performed by using the watershed algorithm and the local maximum, and the tree growth was determined by the difference of the tree height according to the two periods. After we clarify the relationship between the environmental factors affecting the tree growth. The tree growth of Mt. Bongseo was about 20cm for a year, and it was analyzed to be lower than 23.9cm/year of the growth of the dominant species, Pinus rigida. This may have an adverse effect on the growth of isolated urban forests. It also determined different trees growth according to age, diameter and density class in the stock map, effective soil depth and drainage grade in the soil map. There was a statistically significant positive correlation between the distance to the road and the solar radiation as an environmental factor affecting the tree growth. Since there is less correlation, it is necessary to determine other influencing factors affecting tree growth in urban forests besides anthropogenic influences. This study is the first data for the analysis of segmentation and the growth of the individual tree, and it can be used as a scientific data of the urban forest health assessment and management.

• The Korean Journal of Mycology
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• v.48 no.4
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• pp.475-484
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• 2020

Various indigenous yeasts were isolated and obtained from flowers in the Republic of Korea, and their distribution and species diversity were studied. Seventy-seven flowers were collected from 25 areas in Korea, and 502 yeast strains were isolated from these flowers. A total of 50 species were identified by comparing large subunit rDNA gene sequence homology with the type strains of yeasts. The analysis of yeast distribution showed that the dominant yeast species were Aureobasidium pullulans, A. leucospermi, and Filobasidium magnum in each region and flower samples. Except for the above three yeast species, no species of yeasts showed any meaningful distribution among the habitat regions and sources. In conclusion, 50 species of indigenous yeasts were obtained from flowers that can be used as industrial resources, and the data could be used for further research on yeast diversity and interactions between yeast and its host.

• Korean Journal of Environment and Ecology
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• v.35 no.3
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• pp.265-276
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• 2021

This study investigated the characteristics of fish communities and river health in the Sincheon stream of Imgin River between April and October 2019. The survey collected 3,677 objects in 30 species belonging to 12 families from 23 survey stations. The dominant and subdominant species were Zacco platypus (28.4%) and Oryzias sinensis (13.6%), respectively, followed by Z. koreanus (11.8%), Rhynchocypris oxycephalus (11.7%), Carassius auratus (9.6%), and Pseudorasbora parva (7.9%) in that order. Among the fish species collected, 10 (33.3%) were endemic species in Korea. The exotic species were 5 (16.7%), including Micropterus salmoides, Lepomis macrochirus, Cyprinus carpio (Israeli type), Poecilia reticulata, and Xiphophorus maculatus. The land-locked species included Cottus koreanus and Rhinogobius brunneus, while C. koreanus was a climate change-sensitive species. The dominance of the fish community was low, and the diversity was high in the Sincheon mainstream, Sudongcheon and Cheongdamcheon, whereas Dongducheon and Sangpaecheon showed higher dominance and low diversity. The river health was very good and good in the uppermost and Sudongcheon areas, whereas the upper stream was normal, and the middle and lower streams were poor and very poor, respectively. The water quality was also mostly poor or very poor from the midstream to the downstream, and only Sudongcheon was very good. Therefore, the water quality had a great impact on fish habitat and eventually affected river health significantly. Although the water quality of Shincheon has improved each year, the introduction of several foreign species had a very negative effect. Improvement of river health in Shincheon requires water quality improvement and management of exotic fish species.

• Journal of Ecology and Environment
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• v.45 no.4
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• pp.277-286
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• 2021

Background: As trade increases, the influx of various alien species and their spread to new regions are prevalent and no longer a special problem. Anthropogenic activities and climate changes have made the distribution of alien species out of their native range common. As a result, alien species can be easily found anywhere, and they have nothing but only a few differences in intensity. The prevalent distribution of alien species adversely affects the ecosystem, and a strategic management plan must be established to control them effectively. To this end, hot spots and cold spots were analyzed according to the degree of distribution of invasive alien plants, and major environmental factors related to hot spots were found. We analyzed the 10,287 distribution points of 126 species of alien plants collected through the national survey of alien species by the hierarchical model of species communities (HMSC) framework. Results: The explanatory and fourfold cross-validation predictive power of the model were 0.91 and 0.75 as AUC values, respectively. The hot spots of invasive plants were found in the Seoul metropolitan area, Daegu metropolitan city, Chungcheongbuk-do Province, southwest shore, and Jeju island. Generally, the hot spots were found where the higher maximum temperature of summer, precipitation of winter, and road density are observed, but temperature seasonality, annual temperature range, precipitation of the summer, and distance to river and sea were negatively related to the hot spots. According to the model, the functional traits accounted for 55% of the variance explained by the environmental factors. The species with higher specific leaf areas were more found where temperature seasonality was low. Taller species preferred the bigger annual temperature range. The heavier seed mass was only preferred when the max temperature of summer exceeded 29 ℃. Conclusions: In this study, hot spots were places where 2.1 times more alien plants were distributed on average than non-hot spots (33.5 vs 15.7 species). The hot spots of invasive plants were expected to appear in less stressful climate conditions, such as low fluctuation of temperature and precipitation. Also, the disturbance by anthropogenic factors or water flow had positive influences on the hot spots. These results were consistent with the previous reports about the ruderal or competitive strategies of invasive plants instead of the stress-tolerant strategy. The functional traits are closely related to the ecological strategies of plants by shaping the response of species to various environmental filters, and our result confirmed this. Therefore, in order to effectively control alien plants, it is judged that the occurrence of disturbed sites in which alien plants can grow in large quantities is minimized, and the river management of waterfronts is required.

• Korean Journal of Environment and Ecology
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• v.36 no.6
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• pp.662-675
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• 2022

This study was intended to investigate and analyze the current status of the plant community structure in order to provide basic data for the systematic conservation and management of the Buxus sinica area appearing on the ridgeline connecting the Gyeokjabong(Mt.) and Keungiljae, on Bogildo Island. In consideration of location characteristics such as density, topography, and direction of B. sinica appearing in the shrub layers, a total of 26 sites were set as the survey area for representative vegetation communities or areas with changes in topography. According to DCA and TWINSPAN, it was classified into 6 communities, namely Carpinus turczaninovii-Deciduous broad-leaved, C. turczaninovii, C. turczaninovii-B. sinica, C. turczaninovii-Evergreen broad-leaved, Q. acuta, and D. trifidus-Q. acuta. The community dominated by C. turczaninovii maintains the status quo for the present moment, however, Q. acuta will dominate the surrounding area in the long term, so Q. acuta has high succesion potential. In the case of the Q. acuta and D. trifidus-Q. acuta communities, Q. acuta, known as the climax species of warm-temperate forests, will maintain dominant status. In a case of B. sinica, the community dominated by C. turczaninovii will remain in good status due to the topographical conditions, but the community dominated by Q. acuta growth difficulties are expected due to the high coverage. In the relationship between environmental factors and vegetation distribution, analysis showed that only soil pH affect vegetation distribution. Furthermore, the soil acidity (pH) was 3.78-5.30, the electrical conductivity was 0.186-0.543 dS/m, and the organic matter content was 2.25-2.89%.

• Korean Journal of Environmental Biology
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• v.40 no.1
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• pp.99-111
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• 2022

Vegetation is the basis for biodiversity conservation and sustainable development. In the Environmental Impact Assessment (EIA), which is the most direct and efficient policy measure to prevent degradation of nature, vegetation-related assessment has limitations as it is not based on quantitative and scientific methods. In addition, it focuses on the presence of protected species; hence, it does not take into account the role of vegetation as a habitat on a wide-area scale. As a way to overcome these limitations, this study aims to contribute to the quantification and advancement of future EIA on vegetation. Through the review of previous studies, core areas, connectivity, and vegetation condition were derived as the items to be dealt within the macroscopic aspect of vegetation impact assessment. Each item was spatially constructed using land cover maps and satellite imageries, and time series change analysis was performed. As a result, it was found that vegetation has been continuously deteriorating due to development in all aspects, and in particular, development adversely affects not only the inside of the project site but also the surrounding area. Although this study suggested the direction for improvement of the EIA in the vegetation sector based on data analysis, a more specific methodology needs to be established in order to apply it to the actual EIA process. By actively utilizing various environmental spatial data, the impact of the development on the natural ecosystem can be minimized.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.2
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• pp.73-80
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• 2007

The chum salmon enhancement program in Korea started at Gowon in Hamgyeong nam-do in 1913 and the program has been more active since Yeongdong Inland Fisheries Research Institute was established at Yangyang in 1984. The major activities were the release of chum salmon fingerlings and the catch of adult chum salmon for artificial fertilization. The range of return rate to Korean waters was in $0.72{\sim}1.57%$ during 1990s, but it has declined seriously since 2000. To overcome the low return rate and enhance chum salmon resources in Korean waters, we must understand the mechanisms of mass mortality of chum salmon during their early life in rivers and coastal areas in conjuction with the fluctuation of return rates and climate. In addition, comprehensive and effective habitat protection and restoration policies will be needed.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.27 no.2
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• pp.55-65
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• 2024

This study aimed to figure out diel activity patterns of water deer and wild boar, whose habitat is disturbed by human activity in a suburban area. Photographic data of water deer and wild boar collected by 18 camera traps from January 2021 to November 2022 was categorized into four diel periods (dawn, day, dusk, and night), and converted into frequencies per 100 CTD (Camera Trap-Days) for seasonal and spatial diel activity pattern analysis. Water deer exhibited intense nocturnality in fall, and wild boar did in fall and winter. During the fall, water deer's night-time capture rate was the highest (61.9%), and day-time photographic rate was the lowest (13.9%) among other seasons. During the fall and winter, wild boar's night-time photographic rate was relatively high (77.6%, 78.0%, respectively), and day-time photographic rate was relatively low (0.7%, 1.8%) in comparison with other seasons. In spatial diel activity analysis, both water deer and wild boar showed a tendency to avoid humans, especially near trails during day-time hours. The day-time photographic rate of water deer in trail-near group was 12.1% and trail-far group was 24.6%. The day-time photographic rate of wild boar was 3.4%, 5.7%, respectively. Because the diel activity patterns of wildlife reflect human disturbance, this study provides useful ecological information for developing appropriate management plans for the coexistence of water deer and wild boar in suburban areas.

• Korean Journal of Environment and Ecology
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• v.38 no.2
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• pp.156-168
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• 2024

This study was carried out to provide fundamental data for forest land and the environment by investigating the vegetation structure and soil properties of forest land where Sarcodon impricatus are present. The study area was divided into the Quercus mongolica community, dominated by Q. mongolica and the Quercus variabilis community, a mixed forest with Q. variabilis, Q. mongolica and Pinus densiflora. Also, Calamagrostis arundinacea in the former community and Disporum smilacinum and Carex siderosticta in the latter community showed significant levels as indicator species. Both communities showed a strong correlation between available phosphate and pH, sand, and clay, and the high organic matter content and slightly acidic pH of the soil are believed to be related to the development of S. impricatus. The species appearing at the lower layer continue to dominate because the species appearing at the upper layer have secured realized niches. The site was distributed in a relatively humid place in a north-east direction, and soil was developed with a thin litter layer and low rock exposure. In the selected S. impricatus growing areas, vegetation centered on highly adaptable species to disturbance or external interference was developed. Therefore, it is expected to be used as fundamental data to promote the occurrence of S. impricatus during artificial cultivation, as it is possible to identify the stand where S. impricatus occurs indirectly.

• Journal of Korea Water Resources Association
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• v.57 no.8
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• pp.519-532
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• 2024

This study aims to investigate stream drying phenomena and determine ecological flow in upper Jungnangcheon basin(118.2 km²) of Han River basin. Satellite imagery was used to compare historical and current land cover, and field surveys, including fish surveys, were conducted to assess stream drying conditions. Satellite image analysis revealed a significant increase in impervious surface area due to the expansion of residential and commercial areas. Streamflow and water quality measurements at Hannae Bridge in study area during the dry season showed and average minimum flow of 1.39 m³/sec and elevated SS levels, indicating poor water quality for T-P and TOC. The representative fish species in the study area was P.herzi. Optimal habitat suitability index for depth, velocity, and substrate were 0.3~0.5 m, 0.1~0.3 m/sec, and sand, respectively. Using PHABSIM, the ecological flow for the study area was estimated as 1.00 m³/sec. The derived ecological flow can be used as a reference flow for stream drying mitigation strategies.