• Korean Journal of Environment and Ecology
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• v.30 no.4
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• pp.658-675
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• 2016

The environmental characteristics of the habitats, the population structures, ecological niche, life traits and the population demography are used as an essential informations to the effective conservation plans about the target species. We first confirmed a total of 37 populations through 12 years of investigation on the extents, and investigated the environmental factors of habitats and the population structures of the 25 cohorts in 12 regions among them. And, we investigated the population dynamics targeting at 8 cohorts in the population of Daegwanryeong-myeon, Pyeongchang-gun, Gangwon-do. Along with this, we conducted 4 years of cultivation experiments and how pollinators affect the success of reproduction. The results shows that the Paeonia obovata Maxim. was found in a relatively wide range of habitats. For the population structures of the 25 cohorts, there were considerable differences among cohorts, including a case which showed relative stable structure and an extreme case in which only adults were found. The factor that affected the population dynamics during the investigation was thought as a forest gap created in the tree layer. In the cultivation experiment, seedlings grew well in a less soil organic matter. The seed setting rate and the number of seeds generated by visiting pollinators were higher trends. In conclusion, to understand the distribution of the Paeonia obovata Maxim., there needs to be investigated on the other factors that are involved in dispersal factors other than environmental factors, and thus we suggest the necessity of the research on the dispersal vectors. The current Paeonia obovata Maxim. population was thought as a process of expansion after the rapid reduction of the extents in the past. For the effective conservation of the Paeonia obovata Maxim., an endangered plant, we recommend to understand the species through the spatio-temporal expansion, and maintain the health of the ecosystem based on it.

• Ecology and Resilient Infrastructure
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• v.7 no.3
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• pp.189-198
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• 2020

Wetlands, which provide various ecological services, have been regarded as an important nature-based solution for, for example, sustainable water quality improvement and buffering of impacts from climate change. Although the importance of conserving wetlands to reduce the impacts of various perturbations (e.g., changes of land use, climate, and hydrology) has been acknowledged, the possibility of applying these efforts as a nature-based solution in a macro-scale (e.g., landscape) has been insufficient. In this study, we examine the possibility of ecological network analysis that provides an engineering solution as a nature-based solution. Specifically, we analyzed how land use change affects the structural and functional characteristics (connectivity, network efficiency, and clustering coefficient) of the ecological networks by using the ecological networks generated by multiple dispersal models of the hypothetical inhabiting species in wetlandscape. Changes in ecological network characteristics were analyzed through simultaneously removing wetlands, with two initial conditions for surface area, in the zones where land use change occurs. We set a total number of four zones of land use change with different wetland densities. All analyses showed that mean degree and network efficiency were significantly reduced when wetlands in the zones with high wetland density were removed, and this phenomenon was intensified especially when zones contained hubs (nodes with high degree). On the other hand, we observed the clustering coefficient to increase. We suggest our approach for assessing the impacts of land use change on ecological networks, and with additional analysis on betweenness centrality, we expect it can provide a nature-based engineering solution for creating alternative wetlands.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.18 no.1
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• pp.53-69
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• 2015

Plants and birds have symbiotic relationship as the birds eat the fruits and disperse its seeds from the different places. Because Brown-eared Bulbul eats various fruits, We investigated the fruits consumed by Brown-eared Bulbul and the distribution of these seeds. Surveys were conducted at several area throughout Jeju Island at least twice a month from 2013 to 2014. We identified the fruits consumed by Brown-eared Bulbul through observation, pictures and interviews from the local residents. Results showed that this species consumed fruits from 82 plant species, belonging to 38 plant families. Thirty nine percent(39%) of these plant species belong to the Rosaceae, Lauraceae, Moraceae, Aquifoliaceae and Vitaceae and 33 species were classified as warm-temperate and subtropical plant which is 40% of the total plant species consumed. Two feeding types, which were gulper type and pecking type were observed for the Brown-eared Bulbul. It was also observed that this species preferred eating fruits of gulping type compared to that of pecking type. The average size of the fruits consumed through gulping was $8.92{\pm}3.41mm$ while it was $45.25{\pm}26.67mm$ for the pecker type. This bird species also consumed more fruits with globular shape compared to those of fruits with ellipse shape. For the fruit color, red and black-colored fruits were more preferred than yellow-colored fruits by Brown-eared Bulbul. Eaten frequency varied from 0.04 to 0.58 and the 10 fruits species were eaten frequently by Brown-eared Bulbul. This study would provide information for the role of Brown-eared Bulbul in the ecosystem as a seed dispersal agent.

• Korean Journal of Agricultural and Forest Meteorology
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• v.16 no.2
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• pp.93-102
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• 2014

This quantitative research aims to examine the connectivity of forest networks in seven metropolitan cities of South Korea using a graph-theoretical approach. We first estimated an overall network connectivity at multi-scales (i.e., dispersal distances), ranging from 100 m to 20 km, and quantified the contribution of small forest patches (less than 10 ha) to the overall network connectivity by comparing networks according to the presence and absence of small ones. As a result, the cities were divided into two groups depending on the network connectivity; one group of cities with high connectivity such as Daegu, Daejeon, and Ulsan and the other group of cities with low connectivity including Gwangju, Busan, Seoul, and Incheon. The result showed that small forest patches, especially in the cities with low connectivity, played a key role as stepping stones that connect large forested patches, thereby contributing to maintaining connectivity. This study also suggests that large and well-connected forest areas may be the key factor to preserve the connectivity in the cities with high connectivity, while the cites with low connectivity are in need of some complementary strategies. Through the study, we suggest that the creation of new forest patches in the areas where a gap in connectivity presents is needed in order to improve connectivity; and that the conservation of the existing small forest patches is essential in order to maintain the current connectivity level.

• Proceedings of the Microbiological Society of Korea Conference
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• 2008.05a
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• pp.42-44
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• 2008

Bacterial biofilms are analogous to multi-cellular organisms or to clonal communities of higher organisms. In this respect, it can be demonstrated that biofilms display the type of genetic variation associated with macroorganisms. The formation of genetic variants from biofilms is the result of internally produced and regulated signals and the appearance of these variants coincides with dispersal from the biofilm. Moreover, the generation of such variation, has similar outcomes for the bacterial community, where diversification of phenotypic traits ensures that the bacterial community optimizes its chances of success when dispersing or surviving when challenged with environmental stress. These observations increase the complexity with which we view bacteria and also suggest that microbial systems can serve as models for the testing of eukaryotic ecological theories.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.11 no.3
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• pp.94-106
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• 2008

As populations inhabiting in natural ecosystem are fragmented by artificial barriers and habitats are destructed by development, extinction possibility of species is getting higher. It is necessary to design and to manage conservation areas and corridors considering animals' movement and migration for sustainable species diversity in present circumstances. 'Least-cost modeling' is one commonly employed approach in which dispersal costs are assigned to distinct habitat types and the last-costly dispersal paths among habitat patches are calculated using a geographical information system (GIS). This study aims to design ecological corridor using least-cost path method and to apply it to a regional ecological network considering movability of medium-large size mammals. This study was carried out over the metropolitan area, which has been deforested by rapid urbanization. Nevertheless there is connected with Gangwon province, Baekdudaegan mountain range and DMZ, considered where many forest species can migrate to this region. This study employs such an approach to develop least-cost path models for medium-large size mammals, have inhabited for this entire region. Considering those species, two forest areas as a source of species supply and forest areas more than 1,000ha are selected as focal forest areas. Movement and migration paths from species supply sources to focal forest areas are calculated by applying landscape permeability theory using land cover map, road density map and land slope map. Results showed least-cost paths from species supply sources to focal forest areas on two species. Wildcat and roe deer are different in some least-cost paths caused by their landscape permeability but paths show generally same specifics. The result of considering regional distribution of expected movement and migration paths to regional ecological network, low altitude mountains of western metropolitan area are evaluated important area for species connectivity. In national or regional levels ecological connectivity is essential to promote species diversity and to preserve integrated ecosystem. This study concludes that developing least-cost models from similar empirical data could significantly improve the utility of these tools.

• 한국균학회소식:학술대회논문집
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• 2018.05a
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• pp.33-33
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• 2018

Air-borne plant pathogenic fungus Fusarium graminearum and seed-borne plant pathogenic bacterium Burkholderia glumae are cause similar disease symptoms in rice heads. Here we showed that two pathogens frequently co-isolated in rice heads and F. graminearum is resistant to toxoflavin produced by B. glumae while other fungal genera are sensitive to the toxin. We have tried to clarify the resistant mechanism of F. graminearum against toxoflavin and the ecological reason of co-existence of the two pathogens in rice. We found that F. graminearum carries resistance to toxoflavin as accumulating lipid in fungal cells. Co-cultivation of two pathogens resulted in increased conidia and enhanced chemical attraction and attachment of the bacterial cells to the fungal conidia. Bacteria physically attached to fungal conidia, which protected bacterium cells from UV light and allowed disease dispersal. Chemotaxis analysis showed that bacterial cells moved toward the fungal exudation compared to a control. Even enhanced the production of phytotoxic trichothecene by the fungal under presence of toxoflavin and disease severity on rice heads was significantly increased by co-inoculation rather than single inoculation. This study suggested that the undisclosed potentiality of air-born infection of bacteria using the fungal spores for survival and dispersal.

• Korean Journal of Ichthyology
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• v.31 no.4
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• pp.187-194
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• 2019

This study was conducted to know the genetic diversity and population structure of Japanese halfbeak (Hyporhamphus sajori) in the Northeast Asia, using mitochondrial DNA control region. In the present study, a total of 70 individuals were collected from three locations of China (Liaoning), Korea (Tongyeong) and Japan (Wakasa Bay), and 47 individuals sequences from three locations of Japan (Wakasa Bay, Toyama Bay and Mikawa Bay) were downloaded from genbank. A total of 7 haplotypes were identified with 7 polymorphic sites from 358 bp length sequences. Haplotype and nucleotide diversity were very low and ranged from 0 to 0.295±0.156 and 0 to 0.0009±0.0011, respectively. Ancestral haplotype was shared by 94% individuals. An extremely low haplotype and nucleotide diversity, and starlike minimum spanning tree indicated that the species have undergone a recent population expansion after bottleneck. Pairwise F_ST values were low and there was no significant differences among populations suggesting a gene flow among the populations. Dispersal of the eggs with the aid of drifting seaweed and currents might be the major responsible factor for the genetic homogeneity.

• Korean journal of applied entomology
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• v.39 no.1
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• pp.43-52
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• 2000

A portion of mitochondria1 COI gene (438 bp) was sequenced from the sampls of Plutella xylostella from four localities in Korea to investigate the population genetic structure and characteristics by measuring the magnitude of genetic diversity and the degree of gene flow among populations. Thirteen haplotypes ranging in nucleotide divergence 0.3% to 1.4%, were obtained from 21 individuals. The nucleotide divergence was similar to the other related studies, but haplotype diversity was substantially higher (mean h = 0.81). The genetic distance among geographically remote Cheju Island population and the two Kimhae populations, distant 1 lkm to each other, was not statistically significant (p<0.05). Instead, a substantial or high female gene flow was detected (Nm = 2-30). One Hawaiian haplotype of the diamondback moth obtained through GenBank search also was genetically similar to the ones obtained from this study. Collectively, the genetic population structure of the diamondback moth in Korea can be characterized into two aspects. First, the diamondback moths in Korea possesses overall moderate genetic divergence based on a high number of haplotypes. Second, a high haplotype diversity within each population due to the long distance dispersal with a substantial dispersal power and the resultant genetic similarity among geographic populations is characteristic.

• Journal of Korean Society of Transportation
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• v.34 no.4
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• pp.318-329
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• 2016

There has been a growing interest on the effect of volcanic eruption on the aviation safety, air travel and economy especially after the eruption of Eyjafjallajokull in Iceland. Since volcanic eruption is influential on a large geographic region, the effect usually extends to other neighboring countries. Korea also has an active volcano named Mountain Baekdu. Hence, the need to estimate in advance the quantitative impact of the potential eruption of Mt. Baekdu on South Korean air transportation system. However, previous studies with quantitative estimation were confined to the calculation of the direct economic loss from shut down of the airports, grounding of airlines, and trade deficits caused by the eruption. Therefore, this paper introduces a new approach to assess more accurate impact simultaneously considering volcanic ash dispersal and aviation routes. This approach is then applied to a virtual scenario to predict the damage to air traffic. With further development, this method can help estimate the damage in the air transportation industry in more accurate and faster ways. Prediction outcomes can also be utilized in setting up the emergency response plan for the air transportation industry and contribute to the creation of more proactive and predictive measures in the future.