• Korean Journal of Environmental Biology
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• v.40 no.1
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• pp.1-10
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• 2022

Global warming has a major impact on the Earth's precipitation and temperature fluctuations, and significantly affects the habitats and biodiversity of many species. Although the number of alien plants newly introduced in South Korea has recently increased due to the increasing frequency of international exchanges and climate change, studies on how climate change affects the distribution of these alien plants are lacking. This study predicts changes in the distribution of suitable habitats according to RCPs climate change scenarios using the current distribution of the invasive alien plant Conyza sumatrensis and bioclimatic variables. C. sumatrensis has a limited distribution in the southern part of South Korea. Isothermality (bio03), the max temperature of the warmest month (bio05), and the mean temperature of the driest quarter (bio09) were found to influence the distribution of C. sumatrensis. In the future, the suitable habitat for C. sumatrensis is projected to increase under RCP 4.5 and RCP 8.5 climate change scenarios. Changes in the distribution of alien plants can have a significant impact on the survival of native plants and cause ecosystem disturbance. Therefore, studies on changing distribution of invasive species according to climate change scenarios can provide useful information required to plan conservation strategies and restoration plans for various ecosystems.

• Journal of Environmental Impact Assessment
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• v.31 no.4
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• pp.241-249
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• 2022

Humans and wild birds coexist in cities, where habitat fragmentation due to urbanization threatens the habitat and movement of birds. In this study, in order to identify landscape features associated with wild bird collide, we characterized landscape composition within a 500 m radius and points of wild bird carcasses in Suwon-city, South Korea. Dead birds were identified as having a Normalized Difference Vegetation Index (NDVI) of 0.3, Normalized Difference Built-up Index (NDBI) of -0.05, and Normalized Difference Water Index (NDWI) of -0.16 at the points of collide. And there were NDVI of 0.34, NDBI of -0.01, NDWI of -0.18, building height of 13.8 m, and soundproof wall length of 227.3 m within a radius of 500 m. Land cover type was dominated by grassland, used area, and bare land. In particular, the edges of urbanized areas, where apartments bordered forests, reservoirs, and golf courses, were identified as high-risk spaces. In order to minimize bird mortality risk in urban environments, the impact of changes to a vertical landscape should be reviewed from an environmental impact assessment approach. In addition, a preventive management plan that considers the temporal and spatial features that wild animals can safely avoid and adapt to in urbanized spaces should be prepared.

• Korean Journal of Ecology and Environment
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• v.52 no.4
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• pp.306-315
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• 2019

The estuary of the Han River constantly suffers from pollutants and pathogenic microorganisms which could cause serious damage to aquatic organisms living there. Despite of this potential risk, it is hard to find any reliable scientific reports on the status of reportable disease infection to the organisms living in this area. In this study, cyprinid fish and crustaceans in Jeonryu-ri, a region of the Han River estuary, were investigated for the infection by representative reportable communicable diseases(SVC, spring viraemia of carp; KHVD, koi herpesvirus disease; EUS, epizootic ulcerative syndrome; WSD, white spot disease) and parasites. Peripheral fish and primary freshwater fish were observed in Jeonryu-ri with cyprinid caught most frequently. Crustaceans were mostly marine species. No positive bands to any of the reportable diseases were produced in any of the fish and crustacean examined in this study by PCR. No trace of Clonorchis sinensis, a liver fluke potential threat to human health, was detected in any of fish samples. However, many fish were infected by metacecaria of other flukes, and other various parasites such as nematode, cestode, copepod, monosite and acanthocephalan. These results suggest that important aquatic organisms in the Han River estuary is not seriously polluted yet. However, it is important to keep monitoring the diseases since the water quality in this region is constantly changing, and devastating influence of infectious diseases is unpredictable. Further, it is required to expand monitoring area toward upstream and increase the number of fish for examination.

• Journal of Life Science
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• v.30 no.10
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• pp.919-929
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• 2020

Aromatic compounds are widely used in the chemical, food, polymer, cosmetic, and pharmaceutical industries and are produced by mainly chemical synthesis using benzene, toluene, and xylene or by plant extraction methods. Due to many rising threats, including the depletion of fossil fuels, global warming, the strengthening of international environmental regulations, and the excessive harvesting of plant resources, the microbial production of aromatic compounds using renewable biomass is regarded as a promising alternative. By integrating metabolic engineering with synthetic and systems biology, artificial biosynthetic pathways have been reconstituted from L-tryptophan biosynthetic pathway in relevant microorganisms, such as Escherichia coli and Corynebacterium glutamicum, enabling the production of a variety of value-added aromatic compounds, such as 5-hydroxytryptophan, serotonin, melatonin, 7-chloro-L-tryptophan, 7-bromo-L-tryptophan, indigo, indirubin, indole-3-acetic acid, violacein, and dexoyviolacein. In this review, we summarize the characteristics, usage, and biosynthetic pathways of these aromatic compounds and highlight the latest metabolic engineering strategies for the microbial production of aromatic compounds and suitable solution strategies to overcome problems in increasing production titers. It is expected that strain development based on systems metabolic engineering and the optimization of media and bioprocesses using renewable biomass will enable the development of commercially viable technologies for the microbial production of many aromatic compounds.

• Journal of Plant Biotechnology
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• v.45 no.4
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• pp.400-408
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• 2018

Biodiversity has continued to degrade in the $21^{st}$ century due to global warming occasioned by destruction of the environment around the world.. The Nagoya protocol places Korea in a unique position to effectively develop and protect its domestic genetic resources. Microalgae under study in this research contains large amount of antioxidant substances such as beta carotene and astaxanthin, that can be used as biological resource owing to the large amounts of biomass that can be secured through photosynthesis. However, it is difficult to preserve it since cryopreservation method used for long-term preservation is yet to be developed. A basic study for long term cryopreservation was carried out on Nizschia frustulum and Nitzschia amabilis which belong to marine diatoms. As cryoprotectants (CPAs), glycerol, DMSO, and methanol which penetrate into cells were prepared at 5%, 10%, and 15% concentrations each, in case of methanol, it was tested at concentrations of 5%, 10% and 12% by its nature. Two kinds of microalgae, N. frustulum and N. amabilis, were diluted with $10^2$, $10^3$ and $10^4cells\;ml^{-1}$, respectively. The highest survival rate was shown at12% concentration of methanol, and the figures were $6.94{\pm}0.31%$ in N. frustulum and $8.85{\pm}0.16%$ in N. amabilis. As a result of 3 weeks cultivation of thawed microalgae after freezing, the result is shows that N. frustulum increased about 10 times faster and N. amabilis increased about 12 times the original concentration.

• Korean Journal of Environmental Biology
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• v.33 no.1
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• pp.7-18
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• 2015

In this study, we studied the effect of dissolved cement powder on Carassius auratus by analysis of the morphophysiological changes. The gill exposed to dissolved cement powder showed the thickened primary lamellae and the activity of chloride cells and mucous cells was also significantly increased and the proliferation, separation and clubbing of gill filament was observed in the secondary lamellae. In the kidney tissue, the space in Bowman's capsule was widen and the arrangement of dermis was irregular due to the thinned epidermis in the integument tissue. The activities of antioxidant enzymes and LDH tended to increase with the duration of cement exposure. It was confirmed that the up-regulated proteins were identified as involved in glycolysis and energy metabolism and down-regulated proteins were myofibrillar proteins which were involved in muscle contraction by the cement exposure to the integument. With these results, dissolved cement powder was thought to be a big threat to the survival of the fish because it causes the morphological changes and weakens the physiological activity in C. auratus tissues.

• Korean Journal of Environmental Biology
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• v.29 no.4
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• pp.241-250
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• 2011

The safety of human exposure to an ever-increasing number and diversity of electromagnetic field (EMF) sources both at work and at home has clearly become a public health issue. To date many $in$ $vivo$ and $in$ $vitro$ studies revealed that EMF exposure can alter cellular metabolism, endocrine function, immune activity, reproductive function, and fetal development in animal system. The major parameters found to be altered in cells or individuals following EMF exposure include an increase of free radicals, DNA damage, cancer risk, developmental defect, and reproductive dysfunctions. Epidemiological studies reported EMF can increase life-threatening illnesses such as leukemia, brain cancer, amyotrophic lateral sclerosis, clinical depression, suicide, and Alzheimer's disease has been identified. These effects of EMF exposure differ according to duration of exposure, frequency of waves, and strength (energy) of EMF. In the present review, we briefly introduced the physical properties of EMF and summarized the effect of EMF on human and wildlife animals according to types of EMF, duration of exposure at cellular and organism levels.

• Korean Journal of Environmental Biology
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• v.28 no.2
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• pp.49-55
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• 2010

There are only 10,000 Saunders' Gull's (Larus saundersi Swinhoe) surviving in the world today. But they are being threatened by coastal habitat, degradation, development pressure and disturbance by humans. Their first breeding record in Korea was in 1998 and the breeding status has been studied, however, the breeding status is not sufficient for this species. This study was performed from May 1999 to June 2009 to clarify breeding populations and trend of the Saunders' Gull population in Korea. The results indicate that the breeding population has been increasing gradually from 300 to 1,300 individuals, though disturbance increased. As threats to the breeding birds, physical environmental factors such as development and human disturbance were identified as a major threatening factors. Also, as a secondary factor, eggs and chicks are falling pray to predators. Incheon bay breeding places have been created by a landfill projects for the purpose of urban and industrial development, thus, these places will no longer be available for this species. In addition, the breeding habitat has been reduced and changed by expansions of development on the ground. Therefore, well planed management schemes should be provided for the species' breeding population to be continually breed and survive.

• Korean Journal of Environmental Biology
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• v.21 no.2
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• pp.203-207
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• 2003

Amphibian biodiversity, community structure and habitats were surveyed in the Mt. Myungji area from April 2002 to March 2003. During the survey period 2orders, 4 families, 7 species of amphibians were observed. Bombina orientalis (DI =45.1%) was dominant and Bufo stejnegeri (DI = 12.8%), Rana rugosa and Rana dybowskii (DI = 9.9% each) Rana nigromaculata and Rana huanrenensis (DI 1.4% each), and Onycodactylus fisheri (DI = 7.0%) followed. Frequency of occurrence of O. fisheri and B. stejnegeri was largely different according to the altitude and human residence in their habitats.R. nigromaculata and R. huanrenensis showed low frequency of occurrence (<10%) suggesting the decrease in habitation density in this area. The species richness (R'), general diversity (H'), and evenness (E') of amphibians in this area were 0.98, 2.12, and 0.76, respectively, suggesting relatively healthy condition of amphibian community in this area.

• Ecology and Resilient Infrastructure
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• v.10 no.4
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• pp.184-192
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• 2023

Influx of exotic fishes is the reason of destruction of the ecosystem and Eco-Diversity Recently, River project was conducted to consider environmental function. Therefore, farmlands structure along the river was removed such as vinyl greenhouse. In order to supply water eco-diversity, ecological park was built. In spite of nature river improvement, the ecological system in river will be break down by exotic fishes. This study was conducted to investigate analyze the fish faun and prevailing species occupancy in Nakdong river. This data will be used to make the management plan of exotic fishes in ecological park around Nakdong river.