• Korean journal of applied entomology
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• v.42 no.4
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• pp.367-381
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• 2003

Dispersal polymorphism in insects Is a kind of adaptive strategy of the life history together with the diapause, consisting of the “long-winged or alate forms” of migratory phase and the “short-winged or apterous forms” of stationary phase. Dispersal polymorphism is a polymorphism related with the flight capability, and has three categories ; the wing polymorphisms, flight muscle polymorphisms, and flight behavior variations. Phase variation is another type of dispersal polymorphism varying in morphology, physiology and wing forms in response to the density of the population. The dispersal migration is a very adaptive trait that enables a species to keep pace with the changing mosaic of its habitat, but requires some costs. In general, wing reduction has a positive effect on the reproductive potential such as earlier reproduction and larger fecundity The dispersal polymorphism is a kind of optimization in the evolutionary strategies of the life history in insects; a trade-off between the advantages and disadvantages of migration. Wing polymorphism is a phenotypically plastic trait. Wing form changes with the environmental conditions even though the species is the same. Various environmental factors have an effect on the dispersal polymorphisms. Density dependent dispersal polymorphism plays an important role In population dynamics, but it is not a simple function of the density; the individuals of a population may be different in response to the density resulting different outcomes in the population biology, and the detailed information on the genotypic variation of the individuals in the population is the fundamental importance in the prediction of the population performances in a given environment. In conclusion, the studies on the dispersal polymorphisms are a complicated field in relation with both physiology and ecology, and studies on the ecological and quantitative genetics have indeed contributed to understanding of its important nature. But the final factors of evolution; the mechanisms of natural selections, might be revealed through the studies on the population biology.

• Journal of Korean Society of Forest Science
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• v.97 no.3
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• pp.291-295
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• 2008

We investigated the differences in characteristics of rodent populations among unburned and two burned forest areas which were fire damaged in 2000 and 1980, Samcheok and Yangyang, Gangwon province, Korea. Apodemus peninsulae, Myodes regulus and Tamias sibiricus were captured in three study areas. Total density of rodents was the least at burned area which was damaged in 2000. Trappabilities of Apodemus peninsulae and Myodes regulus were higher in burned areas than in unburned area. However, trappability of Tamias sibiricus was the highest in unburned area. Changes in forest type and habitat structure due to time elapsed after forest fire might affect density and species composition of rodents. Mean body weight of rodents were the highest in burned area which was damaged in 2000 while the lowest in unburned area. Differences in body weight of rodents would be related with the coverage of understory. Detailed long-term ecological monitoring is needed to elucidate changes in characteristics of rodent populations after forest fire.

• Journal of the Korean Institute of Landscape Architecture
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• v.40 no.6
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• pp.35-46
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• 2012

This study attempts to specifically analyze green volume and scenery characteristics by classifying the streets in Seoul and suggest improvements accordingly. The subject streets for research were limited to those that have high occupancy ratio and are wide enough to have a big potential in improving green volume. In terms of green volume and scenery according to the types of streets, Platanus occidentalis and Ginkgo biloba were most common regardless of the street type, and the green ratio was 51.6% in residential areas, 50.4% in commercial areas, and 43.7% in business areas. Apart from the residential area, there was almost no green areas, and the ratio of green coverage was 71.0% in business areas, 64.0% in green areas, 37.3% in residential areas, and 36.2% in commercial areas, while the green volume coefficient was $1.9m^3/m^2$ on average. Based on the study results, it was set as a goal to provide the residential areas with a green community space and flowering trees throughout the year for scenery, and commercial areas with flowering trees and maples to emphasize the stores' image while not interfering with service and walking. For business areas, the goals were to improve green ratio and create streets that suit the urban image, and to set up spaces to provide habitat for wild animals with multi-layer planting and link to surrounding forests.

• Parasites, Hosts and Diseases
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• v.35 no.1
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• pp.9-17
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• 1997

During the period of 1933-1994, house dusts were collected from 65 homes at 10 different localities by operating electric vacuum cleaners. House dust mites were isolated from 10 g dust by applying the modified wet sieving method. Total 7,257 mites were collected and 23 species were identified. Among them, Demctophqgoines loyinaf (DF) was predominant (65. Soy) of the total) , followed by D. pteronvssinus (DP) (20.6%) and Tyrophagus nutrescentios (TP) (6.5%) . Rhizoglvphur robini, Sancqsscnin phvIlophogiann, Cheyletus trcussarti and Scheloribates latipes were the first findings from Korea. DF was predominant in Seoul (66.8%), Kwangju (63.6%), inland of Pusan (79.6%1, Inchon (96.5%), Taejon (83.9%), Chouju (87.15) and Chongiu (95.2%), whereas DP was predominant in Yongkwang-ub (72.5%) and Yongdo (island) of Pusan (64.9%), and TP in Chunchon (38.2%) The localities where DP and TP were predominant showed higher relative humidity in air (> 73% RH) . Among 62 study homes, DF, DP and TP were found in 24.6% of the homes, co-habitat of two species in 48.1% and one species in 27.3%. DF was predominant in 63.5% of the homes studied, DP in 29.6% and TP in 6.9%. In 10 g of the house dust, less than 99 mites were found in 49 homes (70.0%), 100-499 mites in 11 homes (15.7%), 500-999 mites in 3 homes (4.3%) and more than 1,000 mites in 2 homes (2.9%). No mite was found in 5 homes (7.1%). In order to evaluate environmental factors affecting the population density of house dust mites, house type, age of house construction, size of the house, number of the family and frequency of the cleaning were compared with the number of mites, and none of the above factors were statistically correlated with the mite density.

• Korean Journal of Environment and Ecology
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• v.32 no.1
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• pp.118-131
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• 2018

The forest vegetation of Juwangsan National Park, which is famous for its towering scenic valleys, was syntaxonomically described. The study adopted the $Z{\ddot{u}}rich$-Montpellier School's method emphasizing a matching between species composition and habitat conditions. A combined cover degree and the r-NCD (relative net contribution degree) were used to determine a performance of 265 plant species listed-up in a total of 52 phytosociological $relev{\acute{e}}s$. Nine plant communities were classified through a series of table manipulations, and their distribution and actual homotoneity($H_{act}$) were analyzed. Syntaxa described were Carex gifuensis-Quercus mongolica community, Athyrium yokoscense-Quercus mongolica communiy, Arisaema amurense-Quercus serrata community, Lespedeza maximowiczii var. tomentella-Quercus variabilis community, Tilia rufa-Quercus dentata community, Carex ciliatomarginata-Carpinus laxiflora community, Aristolochia manshuriensis-Zelkova serrata community, Onoclea orientalis-Fraxinus mandshurica community, and Carex humilis var. nana-Pinus densiflora community. A zonal distribution was reviewed and the altitude of about 700 m was the transition zone between the cool-temperate central montane zone (Lindero-Quercenion mongolicae region) and southern submontane zone (Callicarpo-Quercenion serratae region). Only 19 taxa were associated with r-NCD 10% or more, most of which were tree species occurring in the Lindero-Quercenion and some of which was a member of open forests. Species composition of forest vegetation was much less homogeneous, showing the lowest $H_{act}$. Nearly natural forests and/or secondary forests in the Juwangsan National Park were defined as a regional vegetation type, which reflects much stronger continental climate in the Daegu regional bioclimatic subdistrict, rhyolitic tuff predominant, and wildfire interference.

• Korean Journal of Environment and Ecology
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• v.30 no.5
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• pp.896-907
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• 2016

The habitat characteristics of Aconitum austrokoreense Koidz. were investigated to provide basic data for conservation and restoration. The altitude ranged from 260m to 728m with inclinations of $4-39^{\circ}$. As a result of vegetation survey within natural populations, a total of 147 taxa were identified inside 20 quadrates in 7 natural habitats. The importance value of Aconitum austrokoreense was 23.0% based on the coverage and frequency of the herbaceous layer and sat is more dominant. Species diversity was 1.23, and dominace and evenness were found to be 0.22 and 0.77, respectively. The soil type were silty loam (four sites), sandy loam (two sites) and loam (one site). The average field organic matter was 7.83% and the total nitrogen and pH were 0.35, and 5.69. Correlation analysis between environmental factors and population characteristic showed the correlations between chlorophyll content and slope, flowering rate and soil humidity. Conservation on habitats conditions is important for stable maintenance the flora and the surrounding area including habitats has to be designated a protection area for habitats conservation.

• Journal of Wetlands Research
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• v.17 no.4
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• pp.359-369
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• 2015

Stream ecosystems are highly valued natural resources, however, stream environments are currently under threat in several respects. We evaluated vegetation and ecological characteristics according to different revetment types. The distribution of vegetation differed with revetment type, with a 42~45 taxa found in natural revetments, and 23~38 taxa in vertical revetments. Thus, natural revetments host more diverse vegetation than vertical revetments. We also found more plants belonging to the families Labiatae and Cyperaceae growing in natural revetments than in vertical revetments. We proposed that habitat space be apportioned to introduce annual plants as part of stream restoration projects. And, we identified 7 families and 18 taxa of naturalized plants, majority taxa were either biennial or perennial. Moreover, naturalized ratio was higher in vertical(14.3%) than natural(12.1%), we proposed a plan to promote and improve natural streams and revetments. Furthermore, we applied a waterfront evaluation method developed by the Natural Resources Conservation Service of the USDA-NRCS, which confirmed that stream health can be improved in most regions by controlling naturalized plants and ensuring shrub and tree growth. We adopted a new method to remove naturalized plants and establish natural revetments to ensure shrub and tree growth to aid in small-stream restoration and improvement. In future studies, we hope to develop methods for small-stream restoration projects in rural areas.

• Journal of the Korean association of regional geographers
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• v.19 no.1
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• pp.1-13
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• 2013

Damyang Wetland Reserve with $980,575m^2$ area is located in Damyang-gun, Jeonlanam-do and Buk-gu, Gwangju Metropolitan City. The purpose of this paper is to divide Damyang riverine wetland into several geomorphic units, to analyze their sediments, and to categorize small ecosystem units composing riverine wetland. Riverine wetlands are classified into three types such as riverbed-, floodplain-, and abandoned-channel-wetland, and Damyang riverine wetland belongs to riverbed-wetland type. In this paper to categorize small geomorphic units of riverine wetland, we divide small geomorphic units from aircraft images analysis, and modify and supplement them following field survey results. Damyang Wetland Reserve is categorized into 22 ecosystem units. That physical and chemical properties of their sediments are different spatially, implicate that inorganic environment of Damyang riverine wetland ecosystem is very extensive. On the basis of the results of this study, policymakers will be able to design a strategy which manage Damyang Riverine Wetland Reserve more effectively, and for them interdisciplinary researches on relationships between various fluvial landforms and various lifeforms inhabiting them in Damyang Riverine Wetland Reserve are required.

• The Korean Journal of Mycology
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• v.38 no.2
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• pp.95-98
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• 2010

One interesting parasitic forming fungus, being grown on the eggs of Phallus impudicus was collected from Mulchajoreum and on woods of Saryeoni in Jeju island. This taxon identified as a Podostroma solmsii (E. Fisch.) S. Imai f. octospora Yoshim. Doi (Hyporeaceae) based on morphological characteristics. According to the interpretation of Doi(1978), this taxon hsving the stipitate, genus Podostroma, family Hypocreaceae, Hypocreales, Ascomycota was identified as Podostroma solmsi f. octospora and its korean common name designated by authors. This species is characterized in having the fusiforme to ellipsoidal, unicellular and warted ascospores without septate and with blunt apiculus at each end and mycoparasitic habitat. Although there is some mycologists suggest that this taxon having above characters needs to be derived from Hypomyces. But authors are primarily going to record this species as a named "Podostroma solmsii (E. Fisch.) S. Imai f. octospora Yoshim. Doi" for the fungus flora of Korea. In a future, it is need in detail to compare their DNA sequencing data on the type species and some related species. All collections cited here are deposited in the Herbarium Conservation Center of National Academy of Agricultural Sciences.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.2 no.4
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• pp.229-234
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• 2021

Iris dichotoma Pall. found on Daechung Island in Korea has been designated as an endangered species. To aid in conservation efforts of this species, this study investigated its germination characteristics and seed dormancy type. Four sets of seeds were incubated at different temperatures (4/1℃, 15/6℃, 20/10℃, and 25/15℃). One set of seeds was cold stratified (4 weeks at 4/1℃). The final germination rate and mean germination time showed that the optimal germination temperature was 25/15℃. Final germination rates were ~70%, showing no significant difference among temperature treatments. However, mean germination time were significantly different among all temperature treatments except for 4/1℃. Mean germination time for seeds with temperature treatments of 15/6℃, 20/10℃, and 25/15℃ were 3.2, 2.1, and 1.5 weeks, respectively. At 25/15℃, the mean germination time was half of that at 15/6℃. Seeds of I. dichotoma had fully developed embryos at the time of dispersal. No additional growth of the embryo was observed. Cold stratification did not affect the final germination rate or the mean germination time. This study shows that seeds of I. dichotoma have no physiological or morphological dormancy, unlike other members of the Iris genus known to have seed dormancy that needs a relatively high incubation temperature (≥25/15℃) for mass propagation to occur. These results will be useful for understanding ecophysiological mechanisms related to the species' habitat. They are also useful for mass propagation of I. dichotoma for the purpose of conserving this endangered species.