• Journal of Korean Society of Environmental Engineers
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• v.33 no.8
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• pp.564-571
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• 2011

In order to establish fundamental data for stream restoration and environmental flow, we investigated fish fauna, community and physical habitat conditions in the Dal Stream of Han River Basin. Field monitoring including fish sampling was conducted from September 2008 to October 2009. A total number of fish caught in the 5 sites was 2,080 representing 9 families 35 species, and 19 species (54.3%) including Acheilognathus koreensis and Iksookimia koreensis were Korean endemic species during the study period. The most frequently found species in number was pale chub (Zacco platypus, 25.7%, n = 632) followed by Coreoleuciscus splendidus (18.0%, n = 375) and Z. koreanus (13.0%, n = 272). The lower reach of Dal 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 0.63 level of similarity rate, sampling stations were divided into 2 groups. Most of upper streams in Korea consist of riffles and runs that are repeatedly followed by another one. However, stream channelization and leveling have caused reduction of habitat diversity. Therefore, it is necessary to make an effort on stream rehabilitation with evaluation of physical habitat condition by indicator species in order to maintain biodiversity and perform ecological restoration.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.6
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• pp.723-730
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• 2016

Domestic Manila clam production has been reduced due to coastline changes and environmental degradation, but aquaculture industry is facing difficulties caused by an increase in imports. It is important to recognize the integral habitat environment in order to do sustainable aquaculture. The habitat environment of Manila clams (Ruditapes philippinarum) is closely related to the productivity of aquaculture farms. This study investigated 3 indexes, survival (sediment type, hydrodynamic), growth (Chlorophyll a, DIN, DIP) and environment (water temperature, dissolved oxygen, sediment chemical oxygen demand, ignition loss) as indicators of habitat characteristics for a tidal flat farm in Geunso Bay (Pado and Beopsan) from June 2015 to May 2016. As a result, Pado (maximums.; sand 48.76 %, hydrodynamic 10.59 cm/s, Chlorophyll a 12.70 ug/L, exposure time 3 hours, DO 18.65 mg/L) had a higher sand content, faster current speed, more abundant nutrients and DO, providing more favorable conditions for Manila clams than Beopsan (maximums.; sand 37.40 %, hydrodynamic 6.02 cm/s, Chlorophyll a 6.41 ug/L, exposure time 7 hour, DO 14.81 mg/L). In fact, Pado showed a higher density than Beopsan. This study considered the habitat environments of Pado and Beopsan to provide a basis for optimal management practices and potential suitable sites in Geunso bay.

• Journal of the Korean Institute of Landscape Architecture
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• v.33 no.4 s.111
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• pp.108-118
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• 2005

While the recent lift of restrictions in greenbelt areas is expected to generate a number of development plans, there are efforts to create various development plans into spatial plans that consider the natural and ecological conditions of development sites. However, these development plans consider Degree of Green Naturality or Degree of Ecology only when designating areas for conservation within development sites. It is true that they don't fully reflect the value of green areas and wetlands as habitats and natural resources. Therefore, this study built an conservation value assessment model that is applicable to sites where development is planned in Korea by reviewing prior case examples md studies and applied the developed model to a case study area. The site where the conservation value assessment model was applied to is an area around Yongsan-ri and Suha-ri, Doam-myon, Pyeongchang-gun, Gangwon province where quality natural resources are located in and wend the site. This is a site for the development of Alpensia Resort where a resort including facilities for the Winter Olympics is planned to be introduced. In order to assess the conservation value of the site for Alpensia Resort, a total of eight items including area, distribution of communities, habitation of species with conservation value, functions of habitats, connectivity of habitats, vegetation layers of forests, age of forests, and ratio of non-native plants were studied through literature review and field surveys. The assessment was made by dividing the site into 95 habitats that are perceived by aerial photographs and each habitat unit was assessed on the eight items in a 3-point scale. Each unit habitat assessed in a 3-point scale was segmented into primary, secondary or tertiary areas based on the conservation value. Habitats assessed as primary were designated as priority (absolute) conservation areas and those assessed as secondary and tertiary were set as secondary conservation areas and tertiary conservation areas, respectively. As a result, each area represented 26.9%, 20% and 3% of total site area. Based on this result, habitat management plans were developed to conserve primary conservation areas, improve secondary conservation areas and restore tertiary conservation areas. In addition, a development plan was developed to create habitats in areas where new habitats are requested in order to build an eco-network in the site and a plan to create eco-corridors was proposed. In developing a land use plan for the site, a development plan that considers conservation areas first should be set up based on the outcome of conservation value assessment. This can be linked to the development of an environment-friendly land use plan as well as easing the establishment of a green area and eco-network. This study will facilitate the implementation of the 'conservation before development' principle, which can prevent reckless development, by assessing conservation value in setting up development plans.

• Korean Journal of Ecology and Environment
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• v.42 no.3
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• pp.280-289
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• 2009

The fish communities and physical habitat conditions of fifteen tributaries of Lake Paldang in spring and autumn, 2008 were surveyed to evaluate the ecological health of the streams. The total 2,746 individuals were collected belonging to 11 families 31 genera 40 species. Two new species (Cottus koreanus, Gnathopogon strigaus) that have never been reported as yet in Lake Paldang watershed were found for the first time. The most dominant species in the tributaries was Acheilognathus yamatsutae (19.9%) which is Korean endemic species. Ecological health evaluation of fifteen tributaries using index of biological integrity (IBI) model for fish community and qualitative habitat evaluation index (QHEI) was performed. According th the IBI analysis, four streams (Siwoo-Stream, Jojong-Stream, Moonho-Stream and Mugab-Stream) were evaluated as "good" condition (B grade), Woosan-Stream were "poor" condition (D grade) and others were "fair" condition (C grade). Qualitative habitat evaluation index values of the four streams were the grade "II" indicating "good" condition and those of eleven streams were the grade "III", indicating 'fair' condition. On the whole, dataset of IBI and QHEI showed that ecological health of Jojong-Stream has been well maintained compared to other tributaries of Lake Paldang.

• Journal of Environmental Impact Assessment
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• v.23 no.4
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• pp.271-284
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• 2014

The objectives of this research were to analyse the microhabitat of Cobitis choii which is designated as an endangered fish species (I) and national monument species in Korea (No. 454), and provide valuable information of suitable replacement habitat in the future for a conservation of the population with rapid decreases by environmental pollution. Sampling and microhabitat analysis in three streams such as Baekgok, Yugu and Gap Stream, known as one of the least habitats in Korea showed that the mean number of Cobitis choii observed was 2.6. This result indicated that the richness was too low, so the species conservation was very urgent. Optimal physical microhabitat of the population was determined as environmental conditions with > 60% sand with 1 mm particle size, optimal water depth of 20 - 60 cm in the habitats, and the optimal current velocity of < 0.4 m/s. Under the circumstances of the microhabitat, optimal water volume (discharge) was 0 - 2 m3/s in the each sectional analysis and this reach was mainly composed of the stream section with intermittant slow runs and pools. These microhabitats were largely disturbed by physical modifications of habitat and chemical pollutions due to direct influences of nutrient-rich water inputs from the urban area and intensive agricultural pollutants. For these reasons, optimal habitat replacement are required in the future for the conservation of the species.

• Korean Journal of Environment and Ecology
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• v.24 no.6
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• pp.744-750
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• 2010

This study examined the different polyphenism of larval salamander Hynobius ieechii according to two habitats, pond and stream. We collected salamander's eggs from three regions including Mountain Inwang, Surak and Gwangju. Eggs were treated by four different conditions according to predation level and habitat: high risk - which had a predation risk three times a day; low risk - which had no predation risk, pond and stream habitat. Predation risk was conducted by using chemical cue from Chinese minnows. The chemical cue treatment started from the day of collection and ended one week after the hatching. After the treatment phase, we measured the head width at the level of the eyes(HWE) and the largest head width(LHW) and snout-vent length of the each larva. We calculated the ratio of the head size by dividing HWE by LHW and made a comparison with each of the average ratio of head size according to the predation risk. The results showed that there was a significant difference in the ratio of the head size and snout-vent length according to the predation risk and habitat. From these results we found that predation risk and habitat condition can cause the different polyphenism to the larval salamander and these morphological changes could be affect their mortality.

• Korean Journal of Plant Resources
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• v.13 no.3
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• pp.188-194
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• 2000

This study was carried out to obtain the optimum cultivation conditions of wild ornamental plant resources, Dicentra spectabilis L. The altitude of the habitat was ranged from 630m to 690m in Mt. Gujeol. Most of the habitat faced toward the northeast aspect and the gradient was ranged from 25 to 33 degrees. The light intensity of Dicentra community was 14,000lux on the average, and it was tendency to decrease by foliation of other woody plants. The appearance number of Dicentra per quadrat was 30 individuals on the average, and total appearance species in all quadrat surveyed was 52 taxa. Among them, Quercus mongolica, Lindera obtusiloba, Corylus heterophylla, Cornus controversa, woody plants, Corydalis speciosa, Pseudostellaria heterophylla, Artemisia keiskeana, Dryopteris crassirhizoma, Arisaema amurense var. serratum, Carex siroumensis, and Chloranthus japonicus, herbaceous plants, were showed as dominant species. Soil acidity in the habitat was 5.15 to 5.96, and average content of soil moisture was 32.6%. The contents of average organic matter, $P_2O_5$, K, Ca, and Mg were 1.99%, 14mg/kg, 0.55me/100g, 15.2me/100g, and 3.3me/100g, respectively. Electron conductivity was ranged from 0.50 to 0.76dS/m. Also, the average air temperature of May and June was 14.2$^{\circ}C$ and 19.4$^{\circ}C$, respectively.

• Korean Journal of Environmental Biology
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• v.36 no.4
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• pp.638-646
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• 2018

The purpose of this study was to investigate the long-term habitat morphological alteration resulting from a large dam and weirs in the Tamjin River. To achieve this, we carried out a hydrograph analysis and a substrate size distribution analysis. We also estimated the channel width, bar area and vegetation encroachment using aerial photographs taken before and after the construction of the dam and weirs. The result of the hydrological analysis showed that flooding downstream was greatly reduced with small peaks occurrence after the dam construction. Interestingly, normal hydrographs in the main channel appeared just after tributary conjunction. There was a similar pattern in the substrate size analysis. Despite coarsened substrate just downstream of the dam site, more sand appeared again after introduction of the tributary. However, there was an increase in the bar area downstream of the dam's channels with most bars covered with vegetation. The channel width increased at the upper area of weirs through impoundment, but decreased downstream because of vegetation encroachment. This study indicate that unregulated tributary plays an important role in restoring hydro-physical habitat conditions in mainstream channels below a large dam. However, numerous weirs could be a causal factor to accelerate habitat deterioration in the dam downstream channels.

• Journal of Microbiology and Biotechnology
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• v.29 no.9
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• pp.1453-1459
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• 2019

Zeaxanthin is an important pigment in the photo-protection mechanism of microalgae. However, zeaxanthin epoxidase, an enzyme involved in the accumulation and conversion of zeaxanthin, has not been extensively studied in microalgae. In this work, we report the expression pattern of zeaxanthin epoxidase in Dunaliella tertiolecta (DtZEP) at different light and diverse salinity conditions. To confirm the responsiveness to light conditions, the ZEP expression pattern was investigated in photoperiodic (16 h of light and 8 h of dark) and continuous (24 h of light and 0 h of dark) light conditions. mRNA expression levels in photoperiodic conditions fluctuated along with the light/dark cycle, whereas those in continuous light remained unchanged. In varying salinity conditions, the highest mRNA and protein levels were detected in cells cultured in 1.5 M NaCl, and ZEP expression levels in cells shifted from 0.6 M NaCl to 1.5 M NaCl increased gradually. These results show that mRNA expression of DtZEP responds rapidly to the light/dark cycle or increased salinity, whereas changes in protein synthesis do not occur within a short period. Taken together, we show that DtZEP gene expression responds rapidly to light irradiation and hyperosmotic stress. In addition, ZEP expression patterns in light or salinity conditions are similar to those of higher plants, even though the habitat of D. tertiolecta is different.

• Journal of Species Research
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• v.1 no.2
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• pp.257-261
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• 2012

In Irkutsk region the plants of spring wheat (Tr. aestivum) grow in three agro-ecological zones: steppe, forest-steppe and subtaiga. Due to this reason, the paper determines the coefficients of correlation between the indicators field germination of seeds, plant safety, productivity, temperature and moisture content of the plant habitat for each zone. The zonal moisture saving features of soil treatment for growing wheat plants (Tr. aestivum) are discussed on the basis of these data.