• Journal of Wetlands Research
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• v.15 no.3
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• pp.397-406
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• 2013

Wetland conservation plan has been established to protect ecologically important wetlands based on vegetation integrity, spatial distribution of endangered species, but recently more demands are concentrated on the landscape ecological approaches such as topological relationship, neighboring area, spatial arrangements between wetlands at the broad scale. Landscape ecological analysis and graph theory are conducted to identify spatial characteristics related to core nodes and weak links of wetland networks in Nakdong basin. Regular planar model, which is selected for wetland networks, is applied in the Nakdong basin. The analysis indicates that 5 regional groups and 4 core wetlands are extracted with 15km threshold distance. The IIC and PC values based on the binary and probability models suggest that the wetland group C composed of main stream of Nakdong river and Geumho river is the most important area for wetland network. Wetland conservation plan, restoration projected of damaged and weak links between wetlands should be proposed through evaluating the node, links, and networks from wetlands at the local to the regional scale in Nakdong basin.

• Korean Journal of Agricultural and Forest Meteorology
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• v.12 no.1
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• pp.36-44
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• 2010

In order to rehabilitate forest sites damaged by wildfire via natural or artificial restoration, it is important to determine right tree species, which can acclimate to biogeoclimatic environment at the sites. The objectives of this study were to develop site index equation of different tree species for estimating forest productivity and to provide information on species selection for post-wildfire restoration. Site index equation was developed based on environmental information from wildfire damaged areas in Gangneung, Goseong, Donghae, and Samcheok, where were located in east coastal areas of South Korea. Despite the small numbers (4~5) of environmental variables used for the development of the site index equations, statistical analysis (e.g. mean difference, standard deviation of difference, and standard error of difference) showed relatively low bias and variation, suggesting that those equations can provide relatively high capability of estimation and practical applicability with high effectiveness. The small numbers of the variables enabled the model to be applied in a wide range of usages including determination of appropriate tree species for post-wildfire restoration. The estimation of forest site productivity showed the possibility of large distribution in east coastal region as the best site for Korean ash (Fraxinus rhynchophylla) and original oak (Quercus variabilis) that can be used for firebreak in the region. These results imply that damages by forest fire can be reduced significantly by replacing existing pure coniferous forests in the area with ones dominated by broad-leaved deciduous stands, which can play an important role as fire break and/or prevent a transition from surface fire to crown fire.

• The Journal of Fisheries Business Administration
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• v.29 no.2
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• pp.77-96
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• 1998

Fisheries products in Korea generally go through three markets, namely the wholesale market at production site (Market A), the wholesale market at consumption site (Market B), and the retail market (Market C), from producers to end consumers. As the products move from Market A through Market B to Market C, the marginal gap of prices asked in these markets demonstrates an apparent relationship. The producers, middlemen, consumers, and governmental departments concerned may influence the marketing prices of fisheries products. This study employing the cointegration theory tries to investigate whether causality of the price-setting among these markets exists and, if any, what it is. The authors have focused their attention on fisheries markets in Pusan, analyzing the long-run equilibrium relationship and causality between the prices of hairtail and squid among markets at different levels. Data used in this study cover the period f개m August 1984 to December 1997 fer hairtail, and the period from May 1989 to December 1997 for squid. The main findings of the study may be summarized as follows: First, regardless of the price time-series of hairtail and squid in individual market, the first difference is necessary fur satisfying the stationary conditions since each time-series is a first integration. This means homogeneous integration of time-series, which is a requirement of the long-run equilibrium of prices at different markets, is satisfied. Second, the study of the long-run equilibrium relationship between the prices at Market A and Market B shows that a long-run equilibrium relationship does exist for selling prices of the two species at Market A and Market B. Third, the ECM (error correction model ) used here to describe the long- and short-run dynamics of price change demonstrates that, in the case of squid, the price change in Market A will lead to a corresponding price change in Market B in the long-run period. In the short-run, however, the price at Market H is not only influenced by the price change in Market A but influence the price at Market A as well, that is, the Prices between Market A and Market B have a feedback effect. It should be stressed that the limitation in data collection, which cover only two species of hairtail and squid, is likely to cause a sampling bias. Nonetheless, we may conclude that a dynamic relation in the formation of prices does exist in view of the transaction amount of species at different markets. It is believed that the conclusion drawn from this study would not only contribute to a long-lasted debate on the direction of causality of price-setting among academic circle and fishing community, but would provide a useful standard for the policy makers in charge of the price-setting of fisheries products as well.

• Journal of Ecology and Environment
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• v.40 no.1
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• pp.55-65
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• 2016

Background: In this article, it was analyzed how snow melting affects the assembly of lichen and moss communities in a small area of the coastal region of Barton Peninsula, which is in maritime Antarctic. In the small area, even though there is a huge gap of difference of the environment between the snow-filled area and snow-melt one, the latter did not have distinctive environmental gradients. Results: Depending on the snow melting time, coverage and species diversity of lichens and mosses tend to increase remarkably. For species with significant changes depending on the snow-covered period, there are Andreaea regularis, crustose lichens, Placopsis contortuplicata, Usnea aurantiaco-atra, and snow algae. In this area, the process of vegetation assembly process has shown the directional development in the order of snow algae${\rightarrow}$crustose, lichen sub-formation${\rightarrow}$fruticose lichen, moss cushion sub-formation (Andreaea sociation)${\rightarrow}$fruticose lichen, and moss cushion sub-formation (Usnea sociation), according to the order of snow melting. These directional development stages are shown in gradual change in small area with the snow melting phenomena. However, in the snow-free area, where water is sufficiently supplied, it is expected that moss carpet sub-formation (Sanionia sociation) will be developed. Vegetation development in the small area with the snow melting phenomena, depending on differences of resistance on snow kill and moisture settled by species in according to the time of snow melting, tolerance model to form community is followed. Conclusions: The research results explain the development of vegetation in the Antarctic tundra and its spatial distribution according to the period for growth of lichens and mosses in the summer time by differences of snow melting in the small area. In the future, if research for the community development process in a large scale will be done, it will be helpful to figure out temporal and spatial dynamic of vegetation in the Antarctic tundra where snow and glaciers melt rapidly due to climatic warming.

• Korean Journal of Plant Taxonomy
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• v.45 no.3
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• pp.213-220
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• 2015

To elucidate the origin and patterns of establishment of insular plants on Ulleungdo Island, maternally inherited chloroplast DNA, which is useful for tracing seed movements, was used. Fagus multinervis, an endemic species that dominated broadleaf deciduous forests on Ulleungdo Island, is an excellent model for such a study. To understand the diversity and spatial distribution of the chloroplast haplotypes of F. multinervis, nucleotide sequences of the psbA-trnH region were determined from 144 individuals sampled throughout the island. Results of a phylogenetic analysis of the region with close relatives of F. multinervis suggest that F. multinervis is sister to a clade of F. japonica and F. engleriana. No haplotype variation was found within F. multinervis. This remarkably low cpDNA haplotype diversity is in contrast to the findings of previous allozyme studies of F. multinervis populations that showed high genetic diversity on Ulleungdo Island. Repeated colonization during the early stage of establishment via birds that migrated from a source area where the F. multinervis cpDNA haplotype was geographically structured may have resulted in the observed pattern of haplotype diversity. Alternatively, long-distance dispersal of seeds of the progenitor of F. multinervis via birds or typhoons to Ulleungdo may have been a single event, whereas the immigration of pollen from the mainland likely occurred frequently. Comparative phylogeographic studies of other species endemic to Ulleungdo Island and their close relatives on the neighboring mainland are necessary for a more complete understanding of the evolution of the island's native species.

• Korean Journal of Ecology and Environment
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• v.47 no.4
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• pp.282-291
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• 2014

This study was conducted to make distribution model of the Red-crowned Crane and the White-naped Crane according to the anthropogenic and natural factors affecting distribution of crane in Cheorwon, Korea. It was investigated that the impact power and its range of the indirect anthropogenic influence to feeding flock density in cranes from the road, residential area, military facilities, civilian control zone (CCZ), greenhouse and natural influence such as roosting site and available feeding area. Available feeding area is the most important factor for the crane's feeding site selection. The feeding flock density of the cranes near the residential area was lower than that of area far from the area, and tended to increase within 2.5 km distance. The increasing tendencies of feeding flock density from military facilities and high traffic volume road were similar, but the density in military facilities increased within 800 m, and the density from high traffic volume road increased within 2 km. These results suggested that residential area, military facilities and the road with high traffic volume had significant effect on foraging densities to the certain range. As the distance from the road with low traffic volume and roosting site increased, feeding flock density tended to decrease. The density of Red-crowned crane and White-naped crane inside the CCZ were respectively higher than those of outside the CCZ, especially for the Red-crowned crane. As a result, density of Red crowned cranes inside the CCZ was 5.2 times higher than that of outside, while that of white-naped cranes was 2.2 times bigger. If the density of greenhouse is lower than $40km^{-2}$, crane's feeding flock density in the low greenhouses density area was higher than that of high greenhouses density area. However, there was no difference in the feeding flock density if the density of the green houses is higher than $40km^{-2}$. The model for the Red-crowned Crane was related with available feeding area, distance from residential area, civilian control zone and distance from high traffic road. The model of the White-naped Crane was related with available feeding area, distance from roosting site and distance from lake. Finally, the estimated feeding flock density of cranes significantly correlated with density model according to the natural and anthropogenic factors.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.4
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• pp.2461-2476
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• 2013

To assess environmental contamination with carcinogens, carbonaceous compounds, water-soluble ionic species and trace gaseous species were identified and quantified every three hours for three days st three different atmospheric layer at the heart of chiang-Mai, bangkok and hat-Yai from December 2006 to February 2007. A DRI model 2001 Themal/Optical Carbon Analyzer with the IMPROVE thermal/optical reflectance (TOR) protocol was used to quantify the organic carbon(OC) and elemental carbon content in $PM_{10}$. Diurnal and vertical variability was also carefully investigated. In general, OC and EC contenttration shoeed the highest values at the monitoring period o 21.00-00.00 as consequences of human activities at night bazaar coupled with reduction of mixing layer, decreased wind speed and termination of photolysis nighttime. Morning peaks of carboaceous compounds were observed during the sampling period of 06:00 -09:00, emphasizing the main contribution of traffic emission in the three cities. The estimation of incremental lifetime partculate matter exposure (ILPE) raises concern of high risk of carbonaceous accumulation over workers and residents living close to the observatory sites. The average values of incremental lifrtime particulate matter exposure (ILPE) of total carbon at Baiyoke Suit Hotel and Baiyoke Sky Hotel are approsimately ten time shigher then those air sample collected at prince of songkla University Hat-Yai campus corpse incinerator and fish-can maufacturing factory but only slightly higher than those of rice straw burnig in Songkla province. This indicates a high risk of developing lung cancer and other respiratory diseases across workers and residents living in high buildings located in Pratunam area. Using knowledge of carbonaceous fractions in $PM_{10}$, one can estimate the gas-particle partitioning of polycyclic aromatic hydrocarbons (PAHs). Dachs-Eisenreich model highlights the crucial role of adsorption in gas-particle partitioning of low molecular weight PAHs, whereas both absorption and adsorption tend to account for gas-particle partitioning of high molecular weight PAHs in urban residential zones of Thailand. Interestingly, the absorption mode alone plays a minor role in gas-partcle partitiining of PAHs in Chiang-Mai, Bangkok and hat-Yai.

• Korean journal of applied entomology
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• v.62 no.4
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• pp.227-243
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• 2023

The Asiatic pink stem borer, Sesamia inferens (Walker, 1856) (Lepidoptera: Noctuidae) is a pest that attacks rice stems. In this study, we estimated the annual generation of insect in several regions of the Republic of Korea. Adult trapping using a sex pheromone trap detected the occurrence of S. inferens adults in the three northernmost areas around 38° latitude and showed that the insect inhabits all of Korea. In most areas investigated, the seasons of the adult generations estimated using the single-sine degree-day model did not deviate from the corresponding observed seasons of adult occurrence. We estimated that the overwintering larvae hypothetically-estimated using the model could be originated from the last generation of adults. When larvae collected in paddy fields during the autumn season in a few middle and southern areas were reared at 25℃, ca. 70% of pupae did not show additional larval molting before their pupation. All larvae collected in early March in a southern area (Goseong, Gyeongsangnam-do) pupated without additional larval molting when reared at 25℃. Based on these results, we presumed that S. inferens could overwinter as mainly the last instar larval stage in the area. Taken together, we conclude that S. inferens primarily has two generations per year in areas around 38° latitude, and three generations in the areas between 35.3° and 37.3° latitude. In addition, approximately 35% of insects captured by the sex pheromone trap were species other than S. inferens, as determined by analyzing the nucleotide sequences of the cytochrome c oxidase 1 gene. These species were not morphologically misidentified as S. inferens.

• Korean Journal of Environment and Ecology
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• v.35 no.1
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• pp.24-36
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• 2021

Countries around the world, including the Republic of Korea, are participating in efforts to preserve biodiversity. Concerning species, in particular, studies that aim to find potential habitats and establish conservation plans by conducting habitat suitability analysis for specific species are actively ongoing. However, few studies on mid- to long-term changes in suitable habitat areas are based on accumulated information. Therefore, this study aimed to analyze the time-series changes in the habitat suitable area and examine the otters' changing pattern (Lutra lutra) designated as Level 1 endangered wildlife in Gangwon-do. The time-series change analysis used the data on otter species' presence points from the 2nd, 3rd, and 4th national natural environment surveys conducted for about 20 years. Moreover, it utilized the land cover map consistent with the survey period to create environmental variables to reflect each survey period's habitat environment. The suitable habitat area analysis used the MaxEnt model that can run based only on the species presence information, and it has been proven to be reliable by previous studies. The study derived the habitat suitability map for otters in each survey period, and it showed a tendency that habitats were distributed around rivers. Comparing the response curves of the environmental variables derived from the modeling identified the characteristics of the habitat favored by otters. The examination of habitats' change by survey period showed that the habitats based on the 2nd National Natural Environment Survey had the widest distribution. The habitats of the 3rd and 4th surveys showed a tendency of decrease in area. Moreover, the study aggregated the analysis results of the three survey periods and analyzed and categorized the habitat's changing pattern. The type of change proposed different conservation plans, such as field surveys, monitoring, protected area establishment, and restoration plan. This study is significant because it produced a comprehensive analysis map that showed the time-series changes of the location and area of the otter habitat and proposed a conservation plan that is necessary according to the type of habitat change by region. We believe that the method proposed in this study and its results can be used as reference data for establishing a habitat conservation and management plan in the future.

• Ecology and Resilient Infrastructure
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• v.3 no.4
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• pp.307-314
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• 2016

River restoration has recently been performed not only for the improvement of the artificial parts in the past but also for the restoration of abandoned river reaches which were blocked and isolated. For the restoration of abandoned river reaches, it is important to recover the hydraulic and ecological connectivity in the isolated space by longitudinal structures like levees. But because the assessment tools to determine whether the river restoration is performed properly are so rare at present, we aim to provide a tool for assessing ecological connectivity in a target river in this study. In the first step, one-dimensional numerical model for rainfall-runoff and channel routing was developed and then applied to the watershed of the Cheongmi Stream. In this step, a numerical model was developed to assess the restoration of connectivity. The model consists of two parts: one part is to convert the results of one-dimensional channel routing into two-dimensional spatial distribution. The other is to calculate the habitat suitability index according to time steps by using two-dimensional hydraulic features. The model was applied to a restoration area of the Cheongmi Stream. The advantage of this study is that two-dimensional hydraulic analysis can be easily obtained from one-dimensional hydraulic analysis without a complex and time-consuming two-dimensional analysis. HHS (Hydraulic Habitat Suitablility) by sections of target reaches and target species can be easily obtained using the results of this study.