• Journal of the Korean Institute of Traditional Landscape Architecture
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• 제33권4호
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• pp.87-98
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• 2015

The natural monument forests (no.374) located at Pyeongdae-ri in Jeju island are described and classified by using phytosociological methods and numerical analysis. The purpose of this paper is to identify the ecological character of Torreya nucifera forests between natural habitat and artificial habitat, as well as their spatial and phytogeographical distribution in the Korea. The comparison of forests between Pyeongdae-ri and other regions was analyzed by using a non-metric multidimensional scaling analysis (NMDS) and hierarchical clustering. On the basis of the 12 phytosociological $relev{\acute{e}}s$, the vegetation of T. nucifera dominant forest in Jeju island was arranged in one syntaxon (Alangium platanifolium-Torreya nucifera community included typicum and one subcommunity) within Camellietea. The community of T. nucifera dominant forests were characterized floristically and ecologically. We discussed diagnostic species with references, and proposed a few important diagnostic species (Ilex crenata for. microphylla, Acer palmatum, Zingiber mioga, Mercurialis leiocarpa, Osmorhiza aristata, Mecodium wrightii etc.) to explain condition of the habitat and synecological character. The communities were described by concerning their edaphical and syndynamical niche; we discussed their total distribution in Korea. In most forests they are widespread in Korean peninsular and their distribution is primarily determined by artificial plantation and periodical management. The forests consisted of T. nucifera have developed from natural environment element and artificial management. As a result they have very unique characters with the floristic, structural characterization and distribution. Furthermore, we identified that they need to apposite management for sustainability.

• Journal of Aquaculture
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• 제19권1호
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• pp.7-13
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• 2006

In this study, environmental parameters of natural habitat were measured to find out suitable place for release and improve the productivity of Protothaca jedoensis in Gamak Bay. Water temperature, salinity of the habitat ranged from 5.4 to 27.6 and from 26.5 to $34.5\%_{\circ}$, respectively. Range of pH, DO, COD, Chl-a, T-N and T-P were $7.82{\sim}8.39,\;5.31{\sim}11.28mg/L,\;0.13{\sim}1.38mg/L,\;3.05{\sim}11.55mg/L,\;0.005{\sim}0.180mg/L\;and\;0.007{\sim}0.028mg/L$ respectively. Dominant grain size was fine silt and the IL of sediment was ranged from $0.75{\sim}7.26%$. The water content was $20.16{\sim}53.65%$ and highest value was observed in Baegyado. The COD and AVS in the sediments ranged from $0.53{\sim}8.67mg/g-dry$ and $0.002{\sim}0.113mg/g-dry$ respectively. The bottom condition of Baegyado was higher than other area.

• Journal of the Korean association of regional geographers
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• 제18권4호
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• pp.473-493
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• 2012

Malaria infection is sensitively influenced by regional meteorological conditions along with global climate change. Remote sensing techniques have become an important tool for extraction of climatic and environmental factors, including rainfall, temperature, surface water, soil moisture, and land use, which are directly linked to the habitat qualities of malaria mosquitoes. Improvement of sensor fidelity with higher spatial and spectral resolution, new multinational sensor development, and decreased data cost have nurtured diverse remote sensing applications in malaria research. In 1984, eradication of endemic malaria was declared in Korea, but reemergence of malaria was reported in mid-1990s. Considering constant changes in malaria cases since 2000, the epidemiological management of the disease needs careful monitoring. Geographically, northmost counties neighboring North Korea have been ranked high in the number of malaria cases. High infection rates in these areas drew special attention and led to a hypothesis that malaria dispersion in these border counties might be caused by north-origin, malaria-bearing adult mosquitoes. Habitat conditions of malaria mosquitoes are important parameters for prediction of the vector abundance. However, it should be realized that malaria infection and transmission is a complex mechanism, where non-environmental factors, including human behavior, demographic structure, landscape structure, and spatial relationships between human residence and the vector habitats, are also significant considerations in the framework of medical geography.

• Journal of Wetlands Research
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• 제20권2호
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• pp.181-189
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• 2018

This study was performed to analyze the dynamics and distributional condition of biological community and to support the basic information about the estuarine ecosystem management by using the intensively surveyed results by each taxon experts around Tamjin river. We analyzed the biological diversity, abundance, correlation among species, and ecological characteristics about 11 taxa groups including vegetation, fish, birds, mammals, etc. in the Tamjin river estuarine ecosystem. We classified vegetation types into 7 physiognomic types and 18 communities according to habitat conditions with the physical environments and salinity. In total, 1125 species including 9 species of endangered species were identified in research area. The species composition and distributional characteristics of each taxon were corresponded to the environmental characteristics of the estuarine ecosystem. Especially, the species diversity and distribution were clearly distinguished in the river according to the difference of the environmental factors such as flow rate, salinity, and soil. Despite the disturbance factors such as barrage and levees, the biodiversity and its distribution were evaluated to be high level under the current environmental conditions. However, loss or reduction of wildlife habitat due to reclamation, embankment, barrage installation and expansion of farmland has been identified as a major threat to the diversity and health of the local ecosystem. The results of this study can be used as a basic data to cope with various development pressure and damage crisis of the whole estuaries including Tamjin river.

• Ecology and Resilient Infrastructure
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• 제1권1호
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• pp.39-48
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• 2014

In order to establish fundamental data for stream restoration and environmental flow, we investigated optimal ecological flowrate (OEF) and riverine health condition in the Chogang Stream, a tributary to Geum River, Korea. The number of fish individuals sampled in this period were 4,669 in 36 species of 9 families. The most abundant species was Korean chub (Zacco koreanus, 34.0%) followed by pale chub (Z. platypus, 22.6%) and Korean shinner (Coreoleuciscus splendidus, 13.3%). Index of biological integrity (IBI) and qualitative habitat evaluation index (QHEI) values decreased from upstream to downstream along the stream. The estimated IBI value ranged from 27.9 to 38.6 with average 32.2 out of 50, rendering the site ecologically fair to good health conditions. OEF was estimated by the physical habitat simulation system (PHABSIM) using the habitat suitability indexes (HSI) of three fish species Z. koreanus, C. splendidus and Pseudopungtungia nigra selected as indicator species. In Z. koreanus, HSI for flow velocity and water depth were estimated at 0.1 to 0.4 m/s and 0.2 to 0.4 m, respectively. In P. nigra, HSI for flow velocity, water depth and substrate size were estimated at 0.2 to 0.5 m/s and 0.4 to 0.6 m and fine gravel to cobbles, respectively. OEF values increasing from up to downstream was found to increase, weighted usable area (WUA) values increased accordingly.

• Korean Journal of Environment and Ecology
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• 제19권2호
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• pp.150-161
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• 2005

Soraksan National Park and Odaesan National Park, that are 20.7 km apart, should play an important role as habitats and corridors for wildlife because they are located in the center of Baekdudaegan. However, landscape features such as small area, fragmentation, and geographic isolation seem to impede the proper ecological functions of these two national parks. Using GIS technique, we examined the pattern of fragmentation in these two national parks and adjacent regions (Sokcho-si, Goseong-gun, Inje-gun, Yangyang-gun, and Hongcheon-gun) encompassing a total of $4573.5km^2$ in area. We then selected the patches suitable for an endangered carnivorous species, leopard cat, based on habitat conditions, and identified the network and stepping stone among patches to enable leopard cats to migrate. Diverse roads and artificial facilities in the study area generated a total of 24,701 patches: 39 patches among these were selected as potential habitats upon considering the habitat condition such as vegetation types and minimum area for leopard cat. Three patches nearby Gyebangsan and Bangtaesan were identified as a potential network center to relieve the effects of fragmentation and isolation of the two national parks. Our results also showed that patches containing Jombongsan and Bangtaesan would act as a source patch from there leopard cats can disperse to both national parks. It is an urgent task to identify the pattern of fragmentation and the connectivity between patches in national parks and adjacent areas for wildlife conservation because almost all national parks confront land- scape problems similar to the two national parks examined in this study.

• Ecology and Resilient Infrastructure
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• 제2권3호
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• pp.216-223
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• 2015

The conservation project to protect an endangered fish, Gobiobotia naktongensis was executed against declining the gene diversity of the fish after the construction of Youngju Dam in a sand-bed stream (Naeseongcheon Stream). We tried to move the populations of G. naktongensis from submerged planned sites to alternative habitats, bred artificially and augmented the juveniles to optimal habitat, and monitored the results of the restoration implementation. No entity of G. naktongensis was confirmed at the planned submerged sites despite attempting to capture more than 8 times and eventually the movement to alternative habitat could not be implemented. About 40 individuals of G. naktongensis were captured in the Naeseongcheon Stream and a total of 5,000 individuals were artificially spawned up. The population of juvenile inherited the genetic diversity from the brood stock. The bred juveniles were discharged at the selected optimal site that had a habit condition what was similar to their natural habitat. The micro-dispersion around the discharging area was found at the early stages of the augmentation. The re-capturing rate of discharged juveniles was reduced as time passed. The discharged juveniles seemed to adapt to the natural environment of Naeseongcheon Stream. The observation of their high abdominal distension and excrement demonstrated that the juveniles fed successfully in the discharging area. Therefore, securement of genetic homogeneity and enhancement of restoration population of G. naktongensis in upstream and downstream of Youngju Dam site from the artificial seed producing seemed to be primarily successful and long-term monitoring and analysis of the effect was expected to be necessary.

• Korean Journal of Environment and Ecology
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• 제27권3호
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• pp.316-326
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• 2013

This study has researched the national expansion, dispersion of nutria and investigated its inhabitation status for the past 3 years. The report has shown that the number of nutria habitat, reported to be distributed in 9 cities or districts in 2010, has been increased to 13 in 2012. In the research of 629 nutria habitats, 95.9% of habitat traces were found in Busan-Kyungnam area. From the research of relative density by location type for the 6 survey areas in these 5 areas above, it was shown 3.98(${\pm}2.56$)ind./100m in 2010, 2.90(${\pm}2.69$)ind./100m in 2011 and 1.39(${\pm}0.66$)ind./100m in 2012. From the research of relative density by habitat types, it was shown 3.48(${\pm}2.15$)ind./100m in palustrine wetland area, $1.01{\pm}(0.25)ind.$/100m in river area and $3.69{\pm}(2.83)ind.$/100m in riverine wetland area. It was shown that the annual average density in the areas has slightly been decreased for the past 3 years between 2010 and 2012. It also reported that the habitat density in the river area is a bit lower than that in the wetland area. Currently it can be determined that the nutria has fully adapted themselves to the various local environments of wetland, river, stream, and so on in Korea and the Relative density could be remarkably increased especially in the favorable condition like a wetland. As the ones living in the area with over-density could be spread out to other areas, the efficient management plan to control should be prepared considering ecological conditions.

• Korean Journal of Ecology and Environment
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• 제41권2호
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• pp.188-197
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• 2008

This research was a preliminary case study to determine the levels of total mercury in the tissues of sentinel species (Zacco platypus) and ecological health in relation to habitat characteristics and chemical conditions. We collected fishes in Gap Stream during June$\sim$October 2007 and analyzed the total mercury from five types of tissues such as liver, kidney, gill, vertebrae and muscle of Zaceo platypus using Direct Mercury Analyzer (DMA-80, US EPA Method 7473). Mean concentrations of total [Hg], based on all tissues, was 67.2 and $20.7\;{\mu}g\;kg^{-1}$, in the upstream and downstream site, respectively, indicating 3 times greater level in the upstream. In other words, the levels were higher in the pristine upstream than the downstream influenced by the wastewater disposal plant. Chemical water quality, based on BOD, COD and nutrients (TN, TP) showed that severe degradation occurred in the downstreams than the upstreams. Index of Biological Integrity (IBI) using fish multi-metric model averaged 32, indicating a "good$\sim$fair" condition and varied from 42 (excellent$\sim$good) at S2 to 22 (fair$\sim$poor) at S5 depending on the sites sampled. Qualitative Habitat Evaluation Index (QHEI) in the all sites averaged 142, which was judged as "good" habitat health, but showed a high variation (181 in Site 2 vs. 67 in Site 5). Overall data suggest that health conditions, based on IBI and QHEI, was better in the upstream sites but the mercury bioaccumulation levels in the fish tissues were opposite. We believe that measurements of various parameters are required for a diagnosis of integrative ecosystem health.

• Korean Journal of Ecology and Environment
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• 제43권2호
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• pp.279-287
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• 2010

This study was to evaluate ecological conditions of Hyeongsan River watershed from April to September 2009. The ecological health assessments was based on Qualitative Habitat Evaluation Index (QHEI), water chemistry during 2000~2009, and the fish multi-metric model, Index of Biological Integrity (IBI). For the study, the models of IBI and QHEI were modified as 8 and 11 metric attributes, respectively. Values of IBI averaged 25.4 (n=6), which is judged as a "fair" condition (C) after the criteria of Barbour et al. (1999). The distinct spatial variation was found in the IBI. Physical habitat health, based on the values of QHEI, varied from 76 in the downriver (H6) to 150.5 in the headwater (H1) and was evidently more disturbed in the downriver reach. Values of BOD and COD averaged 2.4 $mgL^{-1}$ (range: 0.3~13.8 $mgL^{-1}$) and 4.3 $mgL^{-1}$ (scope: 0.6~12.8 $mgL^{-1}$), respectively during the study period. Total nitrogen (TN) and total phosphorus (TP) averaged 3.0 $mgL^{-1}$ and 103.5 ${\mu}gL^{-1}$, respectively, indicating a severe eutrophication, and the nutrients increased more in the downriver than the headwater. Overall, physical, chemical and IBI parameters showed a typical downriver degradation along main axis of the river from the headwater-to-the downriver. This was mainly attributed to livestock waste and residential influences along with industrial discharge from the urban region.