• Korean Journal of Ecology and Environment
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• v.41 no.4
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• pp.541-546
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• 2008

The purpose of this study was to evaluate ecosystem health effect in the physiological levels, based on ethoxyresorufin-O-deethylase (EROD) and total oxyradical scavenging capacity (TOSC) assays using sentinel fish species. We collected fish samples of Zacco platypus in May 2008 from 3 sampling sites including upstream, midstream, and downstream of the Gap Stream. EROD activity was averaged 4.54 in the downstream, 2.7 fold higher than upstream and indicated that stream condition was degraded along with longitudinal gradient from up to downstream. Downstream, especially was significantly increased (p < 0.01) so that indicated various pollutants including nutrient enrichment and toxicant exposure from the point sources, wastewater treatment plant and industrial complex may impact to the stream condition. In the mean time, TOSC assays showed higher in the midstream than other sites, but the values were not significant, compared to the previous report on oxidative stress. Overall results indicated that our approaches applying two biomarkers can be effectively used for diagnosis of the physiological levels in an integrative stream health assessments and can be applied as useful pre-warning techniques as a biochemical alarm system of organic pollutions.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.6 no.6
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• pp.56-71
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• 2003

Waste landfills have been the center of environmental problems and they must be restored due to environmental pollution, disgusting landscape, and cost of management. It is suggested that they be recycled urban space as cities expand. Specially, nonsanitary waste landfills which have no pollution prevention facilities cause serious problems. Restoring the landfills as parks and golf courses, so on makes more benefits because of cheap use land, closeness to urban area, flat topography applicable to parks and golf courses, and high land values after restoration and the changes to local recreation sites. Restoration of waste landfills is a complex, costly, and interdisciplinary work. But, the waste landfill is a manmade ecosystem. Control, restoration and postmanagement of waste landfills are very important problems. The role of vegetation prevents soil erosion, reduces soil water storage, and obstructs leachate seepage. Early restoration makes derelict lands into man park artificially geared to soil, vegetation, landforms and hydrology. But, Ideal restoration is to make stable ecosystem nature-friendly and compatible with surrounding landscape without more management. Landscape is structured hierarchically with patches and stands as small components and forms forest as large components. Therefore, landscape formation of the waste landfills needs much restoration process. There are many ecological restoration techniques for the waste landfills. Those are divided into artificial and natural methods. The artificial method is anthropogenic plantings while the natural method is to trigger and use succession processes. The most important thing in the restoration of waste landfills is to consider the final restoration objectives of each waste landfill. According to these objectives, the depth of covering layer, planting degree, and structural design should be determined. The effective restoration methods should be selected of artificial and natural options.

• Journal of Ecology and Environment
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• v.33 no.1
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• pp.15-18
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• 2010

Mangroves are special plant communities that live along intertidal zones in tropical and subtropical areas. They are regarded as one of the most important types of natural ecosystem in the world because of the many ecosystem functions that they perform, of which water purification is the most complex. Mangrove ecosystems are conducive to the deposition and retention of heavy metals. So it is important to understand the impact of heavy metals on mangrove ecosystems, and especially on soil subsystems. We examined the levels of heavy metals in the soil of mangroves in the Dongzhaigang Mangrove National Nature Reserve. Dongzhaigang, the first mangrove nature reserve established in China, is located south of Haikou in Hainan Island and encompasses $33.37\;km^2$, of which mangroves comprise $20.56\;km^2$. To assess the impact of human activities, we collected a large number of soil samples in four sampling areas (the protection station, the harbor, a tour area, and Yeboluo island) in the study area. We measured the concentrations of Cu, Pb, Zn and Cd in the soil samples using the spectra of polyatomic molecules. The average concentrations of Cu, Pb, Zn and Cd were $5.04\;{\mu}g/g$, $10.36\;{\mu}g/g$, $20.06\;{\mu}g/g$ and $0.06\;{\mu}g/g$, respectively, and the heavy metal concentrations were lowest in the protected area, highest in the harbor, and intermediate in Yeboluo Island and the tour area. The heavy metal concentrations in the soil collected from different sample plots are related not only to the physical and chemical properties of the soil, but also to the heavy metal emitted by nearby pollution sources. Our analysis indicates that tourist boats are the main pollution sources in the study area.

• Journal of Environmental Science International
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• v.9 no.2
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• pp.115-123
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• 2000

The dynamics of water quality and phytoplankton population had examined by monthly sampling from the upper to the lower part of watergate in an artificial Shihwa Reservoir in which situated near newly cities and incustrial complex on the west coast of Korea from January 1997 to December 1998. Among environmental factors, yearly average concentration of chl-a, TN and TP seemed to eutrophic or hypertrophic conditions that ranged 146.4~245.8 $\mu\textrm{g}$/$\ell$, 1.6~2.7 mg N/$\ell$, 258~448 $\mu\textrm{g}$ P/$\ell$, 26.9~80.7 $\mu\textrm{g}$/$\ell$, 1.0~2.4 mgN/$\ell$ and 74~239 $\mu\textrm{g}$P/$\ell$ respectively. Water quality was extremely deteriorated to consistently accumulation into inner reservoir by load of pollutants from autochthonous and allochthonous until early July 1997 after embankment. Water pollution of Shihwa Reservoir was remarkble on the biological condition with largely persistent bloom of phytoplankton and increase rate of standing crops was 2.4/yr. The development trend of phytoplankton in water ecosystem were closely related to increse and decrease of physico-chemical factors and those scale seemed to control by nutrient contents. Inflow of seawater into reservoir to object of repair of water quality. As to see dominant species, composition of those composed to mostly freshwater algae before inflow of seawater such as Selenastrum capricornutum of green algae, cyclotella atomus, C. meneghiniana of diatom and Microcystis spp. of blue-green algae and the other hand brackish algae were dominated after inflow of seawater such as Chaetoceros dicipiens, Skeletonema costatum of diatom, Dinophysis acuminata, Gymnodinium mikimotoi, G. sanguineum, Gyrodinium spirale, Prorocentrum minmum of dinoflagellate and Eutreptiella gymnastica of euglenoid. Moreover, small flagellates including Chroomonas spp. of cryptomonad were abundant throughout the year. The cause of water deterioration during fill of the freshwater were complexly supported with extra and intra parameters. The variation pattern of phytoplankton were related to water temperature and salinity by inflow of seawater based to plentiful nutrients. The dynamics of phytoplankton were assessed to ecosystem that clearly condition of dominant by unique or a few angel species seasonally.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.5
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• pp.638-648
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• 2013

To understand the geochemical characteristics of intertidal sediment in a semi-enclosed bay, we measured various geochemical parameters, including grain size, ignition loss (IL), chemical oxygen demand (COD), acid volatile sulfide (AVS), and trace metals (Al, Fe, Cu, Pb, Zn, Cd, Hg, and As), in intertidal sediment from three bays (Deukryang Bay, Yeoja Bay, and Gamak Bay) in the southern region of Jeollanam Province. The intertidal sediment in Deukryang Bay consisted of various sedimentary types, such as sand, gravelly muddy sand, mud, and silt, whereas the intertidal sediments in Yeoja and Gamak Bays were composed mainly of mud. The concentrations of IL, COD, AVS and trace metals in the intertidal sediments of the three study regions were relatively high near areas affected by input of stream waters and/or shellfish farming waste. The concentrations of organic matter and trace metals in Gamak Bay were much higher than those in Deukryang and Yeoja Bays, which appears to be due to the influence of anthropogenic pollutants, originating from the city and the industrial complex near Gamak Bay. The evaluation results of organic matter and metal pollution using the sediment quality guidelines showed that the intertidal sediments in the three study regions were not polluted in terms of organic matter and trace metals. In future, sustainable management for sources of organic matter and trace metal is necessary to conserve a healthy benthic ecosystem in intertidal sediments.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.2 no.2
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• pp.49-52
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• 1997

The man-made lake, Shihwa, was constructed in January, 1994 as a part of the 'development project of the Shihwa area'. The lake area was a typical coastal ocean environment before the construction, but after constructing the dikes to block the sea water inflow, the lake is in the process of becoming a freshwater lake, and faces various ecological changes. Due to the polluted water inflow from the neighboring industrial complex and Ansan city, many negative effects appear. In this group study we conducted integrated ecosystem investigations of the lake Shihwa and the adjacent coastal area in order to find out how the ecosystem is controlled by artificial changes of the lake environment. The results are compiled in the following several articles of this issue: Park et ai. (1997), Han et al. (1997). Choi et ai. (1997), Park and Huh (1997), Ryu et at. (1997), Lee et al. (1997).

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.11
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• pp.1659-1676
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• 2002

Ruminant animals develop a diverse and sophisticated microbial ecosystem for digesting fibrous feedstuffs. Plant cell walls are complex and their structures are not fully understood, but it is generally believed that the chemical properties of some plant cell wall compounds and the cross-linked three-dimensional matrix of polysaccharides, lignin and phenolic compounds limit digestion of cell wall polysaccharides by ruminal microbes. Three adaptive strategies have been identified in the ruminal ecosystem for degrading plant cell walls: production of the full slate of enzymes required to cleave the numerous bonds within cell walls; attachment and colonization of feed particles; and synergetic interactions among ruminal species. Nonetheless, digestion of fibrous feeds remains incomplete, and numerous research attempts have been made to increase this extent of digestion. Exogenous fibrolytic enzymes (EFE) have been used successfully in monogastric animal production for some time. The possibility of adapting EFE as feed additives for ruminants is under intensive study. To date, animal responses to EFE supplements have varied greatly due to differences in enzyme source, application method, and types of diets and livestock. Currently available information suggests delivery of EFE by applying them to feed offers the best chance to increase ruminal digestion. The general tendency of EFE to increase rate, but not extent, of fibre digestion indicates that the products currently on the market for ruminants may not be introducing novel enzyme activities into the rumen. Recent research suggests that cleavage of esterified linkages (e.g., acetylesterase, ferulic acid esterase) within the plant cell wall matrix may be the key to increasing the extent of cell wall digestion in the rumen. Thus, a crucial ingredient in an effective enzyme additive for ruminants may be an as yet undetermined esterase that may not be included, quantified or listed in the majority of available enzyme preparations. Identifying these pivotal enzyme(s) and using biotechnology to enhance their production is necessary for long term improvements in feed digestion using EFE. Pretreating fibrous feeds with alkali in addition to EFE also shows promise for improving the efficacy of enzyme supplements.

• Korean Journal of Ecology and Environment
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• v.51 no.1
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• pp.16-28
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• 2018

Although physiological and ecological characteristics of cyanobacteria have been studied extensively for decades, unknown areas still remain greater than the already known. Recently, the development of omics techniques based on molecular biology has made it possible to view the ecosystem from a new and holistic perspective. The molecular mechanism of toxin production is being widely investigated, by comparative genomics and the transcriptomic studies. Biological interaction between bacteria and cyanobacteria is also explored: how their interactions and genetic biodiversity change depending on seasons and environmental factors, and how these interactions finally affect each component of ecosystem. Bioinformatics techniques have combined with ecoinformatics and omics data, enabling us to understand the underlying complex mechanisms of ecosystems. Particularly omics started to provide a whole picture of biological responses, occurring from all layers of hierarchical processes from DNA to metabolites. The expectation is growing further that algal blooms could be controlled more effectively in the near future. And an important insight for the successful bloom control would come from a novel blueprint drawn by omics studies.

• Journal of Ecology and Environment
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• v.43 no.4
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• pp.364-375
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• 2019

Background: Ecologists continue to investigate the factors that potentially affect the pattern and magnitude of tree damage during catastrophic windstorms in forests. However, there still is a paucity of research on which trees are more vulnerable to direct damage by winds rather than being knocked down by the fall of another tree. We evaluated this question in a mixed hardwood-softwood forest within the Big Thicket National Preserve (BTNP) of southeast Texas, USA, which was substantially impacted by Hurricane Rita in September 2005. Results: We showed that multiple factors, including tree height, shade-tolerance, height-to-diameter ratio, and neighborhood density (i.e., pre-Rita stem distribution) significantly explained the susceptibility of trees to direct storm damage. We also found that no single factor had pervasive importance over the others and, instead, that all factors were tightly intertwined in a complex way, such that they often complemented each other, and that they contributed simultaneously to the overall susceptibility to and patterns of windstorm damage in the BTNP. Conclusions: Directly damaged trees greatly influence the forest by causing secondary damage to other trees. We propose that directly and indirectly damaged (or susceptible) trees should be considered separately when assessing or predicting the impact of windstorms on a forest ecosystem; to better predict the pathways of community structure reorganization and guide forest management and conservation practices. Forest managers are recommended to adopt a holistic view that considers and combines various components of the forest ecosystem when establishing strategies for mitigating the impact of catastrophic winds.

• Journal of Family Resource Management and Policy Review
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• v.8 no.2
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• pp.61-84
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• 2004

This thesis attempted to generate ideal tea culture space that connects environment and culture. Therefore, this examines: First, history of tea and the characteristics of tea culture space from Gochosun to modern times was reviewed Second, psychological factors (spirit of tea) of Korea tea culture space were reviewed. Third, the connection between the concept of tea culture space and Human Ecosystem Model by was analyzed. Also, this thesis examined how the culture of ecosystem and why tea culture space is needed. because tea includes varieties of ingredients for protecting environmental pollution. Finally, tea culture spaces were reviewed each region during Chosun dynasty, and tea culture space of recent tea users. In order to study tea culture space, complex residential area and single residential areas were compared. The useful of tea culture space as a ecological space was also examined. To achieve the purpose of this study, related literatures were reviewed, and investigations of museums and a survey on modern living space were also conducted. The results show that the space of our tea culture were affected by nature worshipping of Gochosun, Buddhism of Koryo, and Confusianism of Chosun with 'Pungryu', the idea that enjoys nature, thereby applying environment-friendly ecological beauty to their living space and life. The cultyral space in Korea is composed of natural environment such as mountain, sea, rock, or trees and artificial environment such as pond or pavilion. In the future, oriental culture with metaphysical value will lead the world culture, and especially, tea culture would play an important role regardless of nationality, race, religion, and ideology. Therefore, establishing a tea culture space in a living space would be the fundamental methods that would be able to settle down such tea life into our daily life. Our attempts to create ecological tea culture space as a integrated cultural space of natural, artificial, and human behavioral environment will contribute to enhance our quality of life.