• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.627-633
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• 2019

Rapid and accurate identification of marine microalgae causing harmful algal blooms (HABs) is a crucial tool for predicting and managing HABs. We previously developed a nuclease protection assay sandwich hybridization (NPA-SH) method for the in situ detection of blooming microalgae Cochlodinium polykrikoides. In this study, we improved the applicability of the NPA-SH method for the detection of C. polykrikoides by simplifying the reaction step. For this purpose, invertase (INV) was conjugated to the signal probe instead of using fluorescence, and sucrose was used as a reactant to induce a color reaction. The INV-signal probe conjugation was confirmed by SDS-PAGE and epifluoromicroscopy. The treatment time and appropriate amounts of the probe and sucrose that optimized the reaction were determined. As a result, the developed INV-SH reduced the treatment time in the field compared with NPA-SH, and also enabled the use of a relatively small volume and low-priced personal glucose meter, as well as an absorbance meter. INV-SH is the first C. polykrikoides species identification technology to which INV has been applied and could be an improved field technique.

• Korean Journal of Environment and Ecology
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• v.32 no.6
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• pp.582-590
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• 2018

Although there are many studies of the effect of climate change on the breeding phenology and community diversity of amphibians, the studies of variations in reproductive population size of individual species according to climate change are still lacking. We examined the effect of climate change on the reproductive population size of Rana huanrenensis and Hynobius leechii, which bred in mountain valleys, by surveying the reproductive population of the two species between 2005 and 2012 and analyzing the correlation between the variation of the outdoor population and the surrounding climate change factors, obtained from a meteorological observatory located at 5.6 km from the study site. The size of the reproductive population of the two species commonly fluctuated with aan pproximately 3.5-year cycle. That of H. leechii, in particular, decreased significantly over eight years. The air temperature tended to more closely relate with the reproductive population size of R. huanrenensis as was the case of the precipitation with that of H. leechii. The yearly mean highest temperature and spring mean temperature variation consistently decreased over the eight years, and the latter was related with the significantly decreased size of H. leechii reproductive population. These results showed that recent climate change directly could affect the reproductive population size of amphibians, particularly H. leechii, which breeds in mountain valleys.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.7
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• pp.878-884
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• 2017

It is important to understand interactions in the sediment-water environment because nitrate (N) and phosphorus (P) nutrient fluxes released into overlying water can represent a significant fraction of the total nutrient requirement for primary productivity. In this study, we analyzed and estimated benthic nutrient fluxes at the sediment-water interface, investigating environmental conditions in Gomso and Geunso Bays. Also, we compared previously reported nutrient flux data to identify regional differences. As a result, benthic nutrient fluxes in Beopsan were DIN: $6.14mmol\;m^{-2}d^{-1}$ and DIP: $0.32mmol\;m^{-2}d^{-1}$ higher than other survey sites. Sediment COD were $4.0-10.8mg/g{\cdot}dry$, and environmental deterioration was observed due to organic pollution. If no solution is found for tidal flat farm management, problems such as a decrease in aquaculture production will follow. Therefore, long-term monitoring of tidal flat environments should be pursued to enable the sustainable use of biological resources.

• Korean Journal of Heritage: History & Science
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• v.52 no.1
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• pp.82-89
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• 2019

In this study observation records of the National Natural Environment Survey (2008-2012, 2014-2017) and the Korean Natural History Research Information System (KNHRIS) for the common kestrel (2013-2016) were consulted to determine the correlation of the distribution of kestrels in an area and the area's land use type. Distribution characteristics were studied based on data collected over the last 10 years (2008-2017). Findings show that the common kestrel is widely distributed between 4,407 sites registered in KNHRIS in the period of 2008-2012, 3,899 sites in 2014-2017, and 508 sites in 2013-2016. Relationship analysis was conducted for the altitude and urban planning factors of statistics based on a 2017 GIS check to determine the distribution characteristics. The birds' altitude was confirmed to range from 0 to 1,200 metersck but was most commonly observed at less than 100 meters. Above 200 meters, the rate of occurrence decreased rapidly. The rate of occurrence of the common kestrel was highest in Chungcheongnam-do province, followed by Gyeongsangbuk-do, Kyonggi-do, Jeollanam-do and Jeollabuk-do. As urban areas, green areas, commercial areas, and industrial areas the presence of swere positively correlated with the presence of kestrels, the rate of occurrence of the kestrel was higher in those regions. However, there was no significant relationship between the incidence of kestrels and housing construction or residential areas.

• Korean Journal of Ichthyology
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• v.31 no.1
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• pp.16-22
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• 2019

Investigations on the study of the distribution aspects and extinction threat evaluation of the Korean endemic species, Iksookimia pacifica were done from 2017 to 2018 in Korea. During the study period, the samples of I. pacifica were collected in 17 streams, 46 sites (from Baebongcheon Stream of Goseong-gun to Gunsuncheon Stream of Gangneung-si) among the noted 33 streams and 104 sampling sites investigated. The population size of I. pacifica was relatively large in streams such as Bukcheon, Baebongcheon, Hwasangcheon, Cheonjincheon, Ohhocheon Stream etc., but the population size was small in streams such as Sacheoncheon, Namcheon, Gangneung Namdaecheon Stream etc. The main habitat of I. pacifica was the downstream pool of clean water with slow velocity and sand bottoms, and their sensibility was estimated to be due to river work and water pollution. Comparing the previous records of the appearance of I. pacifica, they were first seen in Sampocheon Stream, but they did not appear in Jusucheon, Jeoncheon, Samcheok Osipcheon Stream. Given this evidence as noted for the 19.5% reduction in occupancy within 3 generations, in small appearance range ($1,343km^2$) and small occupancy area ($184km^2$), the number of locations were many (18) and the population was relatively large within the range of habitat. Therefore, I. pacifica is now considered a Near Threatened (NT) based on the IUCN Red List categories and criteria.

• Journal of Korean Society of Forest Science
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• v.109 no.4
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• pp.361-370
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• 2020

Long-term observation of the life cycle of plants allows the identification of critical signals of the effects of climate change on plants. Indeed, plant phenology is the simplest approach to detect climate change. Observation of seasonal changes in plants using digital repeat imaging helps in overcoming the limitations of both traditional methods and satellite remote sensing. In this study, we demonstrate the utility of camera-based repeat digital imaging in this context. We observed the biological events of plants and quantified their phenophases in the northern temperate type deciduous broadleaf forest of Jeombong Mountain. This study aimed to identify trends in seasonal characteristics of Quercus mongolica (deciduous broadleaf forest) and Pinus densiflora (evergreen coniferous forest). The vegetation index, green chromatic coordinate (GCC), was calculated from the RGB channel image data. The magnitude of the GCC amplitude was smaller in the evergreen coniferous forest than in the deciduous forest. The slope of the GCC (increased in spring and decreased in autumn) was moderate in the evergreen coniferous forest compared with that in the deciduous forest. In the pine forest, the beginning of growth occurred earlier than that in the red oak forest, whereas the end of growth was later. Verification of the accuracy of the phenophases showed high accuracy with root-mean-square error (RMSE) values of 0.008 (region of interest [ROI]1) and 0.006 (ROI3). These results reflect the tendency of the GCC trajectory in a northern temperate type deciduous broadleaf forest. Based on the results, we propose that repeat imaging using digital cameras will be useful for the observation of phenophases.

• The Korean Journal of Mycology
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• v.48 no.4
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• pp.407-414
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• 2020

To replace the sawdust in the growth medium of oyster mushroom to utilize its by-product spent mushroom substrates (SMS) as feed for ruminant, we performed cultivation test using cotton seed hull pellet (CSHP), corn stalk pellet (CSP), corncob (CC), and analyzed the feed chemical properties of those SMS. As a result of cultivation test, CC and CSHP treatment took 27 days for spawn run, 4 days for primordium formation, and 3 days for development fruiting bodies, resulting in a total cultivation period of 34 days. The yield per bottle was 134 g for CC treatment, similar to 130 g for control, while CSHP treatment (112 g) and CSP treatment (68 g) were lower than that of control. The highest biological efficiency (BE) was shown in CC treatment as 80.1%, which was 11.4% higher than 68.7% of control. The SMS of CC treatment had a relatively low content of neutral detergent fiber and acid detergent fiber, and in particular, lignin content was the lowest and crude protein content was the highest among other treatments. Therefore, CC as a substitute material for sawdust was capable of stable mushroom production and excellent nutritional value as a feed for its by-products.

• Korean Journal of Ecology and Environment
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• v.53 no.4
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• pp.427-435
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• 2020

The most important thing to successfully restore an oak forest is finding suitable climatic conditions and topographic factors for the oak species to be introduced. In this study, in order to find suitable environmental conditions for the five dominant oak trees on the Korean Peninsula, we carried out analysing the information on the location of forest vegetation on the Korean Peninsula. The range of annual mean temperature of the five oak trees was narrow in the order of Q. mongolica (7.7~14.3℃), Q. variabilis (9.2~13.8℃), Q. acutissima (10.5~14.3℃), Q. serrata (11.4~13.7℃), Q. aliena (11.0~12.9℃). The range of annual precipitation of oaks was narrow in order of Q. mongolica (1072.7~1780.9 mm), Q. variablis (1066.6~1554.9 mm), Q. acustissima (1036.5~1504.8 mm), Q. serrata (1062.6~1504.7 mm). The range of altitude was in order of Q. mongolica (147~1388m), Q. serrata (93~950m), Q. variabilis(90~913m), Q. acustissima (60~516m), Q. aliena (55~465 m). The range of slope was in the order of Q. mongolica (8~56°), Q. variabilis(5~52°), Q. serrata (11~45°), Q. aliena (15~38°), Q. acustissima (16~37°). These results are considered to be very useful in the case of ecological restoration using deciduous oak trees on the Korean Peninsula.

• Korean Journal of Ecology and Environment
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• v.54 no.2
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• pp.108-119
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• 2021

We aimed to develop a naturalness index for forest-dwelling birds in four national parks in Korea and to simulate the effect of species loss on this naturalness index. Five bird specialists were asked to give 112 bird species a disturbance susceptibility score (DSS), and the naturalness index was calculated based on this. The 112 bird species represented 8 orders (Cuculiformes, Piciformes, Accipitriformes, Falconiformes, Columbiformes, Caprimulgiformes, Strigiformes, and Passeriformes). DSS was the highest for Terpsiphone atrocaudata and Pitta nympha, and lowest for Pica pica, Hypsipetes amaurotis, and Streptopelia orientalis. There was a significant negative relationship between a species' population number and its DSS. Among the four national parks, Mt. Songni had the highest naturalness index, followed by Mt. Wolak, Mt. Juwang, and Mt. Wolchul. We investigated the change in biodiversity indices under four scenarios, which assumed the extinction of species with less than 5 (Scenario 1), 10 (Scenario 2), 50 (Scenario 3), and 100 individuals (Scenario 4). The results showed that although all biodiversity indices decreased as the species loss increased, they all behaved differently. Fisher's alpha diversity decreased as the number of species proportionally decreased. There was almost no change in Shannon-Wiener H' index in Scenarios 1 and 2. The naturalness index showed increased sensitivity in Scenarios 1 and 4. Our future aims are to obtain the DSS for all forest-dwelling bird species, and to adopt the naturalness index to evaluate temporal and spatial changes in biodiversity.

• Microbiology and Biotechnology Letters
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• v.48 no.4
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• pp.547-555
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• 2020

Microalgae are a promising resource in energy and food production as they are cost-effective for biomass production and accumulate valuable biological resources. In this study, CO2 assimilation, biomass, and lipid production of 4 microalgal species (Chlorella vulgaris, Mychonastes homosphaera, Coelastrella sp., and Coelastrella vacuolata) were characterized at different CO2 concentrations ranging from 1% to 9%. Microscopic observation indicated that C. vulgaris was the smallest, followed by M. homosphaera, C. vacuolata, and Coelastrella sp. in order of size. C. vulgaris grew and consumed CO2 more rapidly than any other species. C. vulgaris exhibited a linear increase in CO2 assimilation (up to 9.62 mmol·day-1·l-1) as initial biomass increased, while the others did not (up to about 3 mmol·day-1·l-1). C. vulgaris, Coelastrella sp., and C. vacuolata showed a linear increase in the specific CO2 assimilation rate with CO2 concentration, whereas M. homosphaera did not. Moreover, C. vulgaris had a greater CO2 assimilation rate compared to those of the other species (14.6 vs. ≤ 11.9 mmol·day-1·l-1). Nile-red lipid analysis showed that lipid production per volume increased linearly with CO2 concentration in all species. However, C. vulgaris increased lipid production to 18 mg·l-1, compared to the 12 mg·l-1 produced by the other species. Thus, C. vulgaris exhibited higher biomass and lipid production rates with greater CO2 assimilation capacity than any other species.