• Korean Journal of Environment and Ecology
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• v.24 no.6
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• pp.638-647
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• 2010

This study was performed in order to analyze influences the actual vegetation between the communities of Pinus densiflora and Quercus mongolica in southern Korea to the species composition of the seed bank in the top soil. The soil samples were collected from the studied plots and transported to the Experimental Glasshouse at Department of Landscape Architecture, Yeungnam University and examined the germinated species individual numbers with species composition and germinated individual numbers by species. The overall germination status was the highest in the herbaceous layers than the layers of tree, sub-tree and shrub, respectively. There were no significantly different between numbers of species and individuals and between actual vegetation and seed bank in the two communities. The woody species marked in the seed bank as a pioneer or edge species than in the two communities which are in the stage of mid or late successional species. Although the plant species in the herbaceous layers was highly influenced to the species composition of the seed bank, but no significantly different was showed within the same forest zone and latitudes of Korean peninsula. As the pioneer or edge species of the actual vegetation possibly will be higher the buried in the top soil layer and this phenomenon will influence overall species composition in the seed bank population.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.4
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• pp.289-300
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• 2009

Flora distribution was surveyed in the newly reclaimed tidal flats in the west coastal area in Korea to understand changes in flora dynamics after reclamation. The surveyed reclaimed tidal flats were the newly reclaimed tidal flat in Hangdam, the mid Kyonggi Bay in 2002, and three reclaimed lands in Seukmun and Daeho, Chungnam, and Hangdam in Kyonggi Bay, of which reclamation years based on embankment were 7, 9 and 18 years, respectively. In the newly reclaimed tidal flat, the dominant flora was Suaeda japonica and other florae were rare, while various halophytes and glycophytes were distributed in the reclaimed lands. On the newly reclaimed tidal flat, four species of halophytic pioneer florae, Salicornia europaea, Suaeda glauca, Suaeda japonica, and Suaeda maritime occurred, and along with age facultative halophyte and glycophyte occurred sequently. On the reclaimed lands, the florae were more complex with various facultative halophyte and glycophyte, so these were predominated rather than pioneer halophyte, while one of pioneer halophyte that Suaeda japonica was not occurred. Increasing of various facultative halophyte and glycophyte, and decreasing of pioneer halophyte indicated that flora changed toward to increase of facultative halophyte and glycophyte by aged after reclamation. On the newly reclaimed tidal flat the ratio of flora species changed rapidly with the invasion of plant. This implied that the flora had begun to change in the early stage of reclamation. Facultative halophyte and glycophyte started to increase on the early stage of reclamation but relative density and frequency of pioneer halophyte was higher than facultative halophyte and glycophyte. According to the investigation up to 3 years after reclamation, pioneer halophyte predominated on it. Although flora changed, there were common representative halophytes among the reclaimed tidal flats: Salicornia europaea, Suaeda maritima, and Suaeda glauca as pioneer halophyte, Aster tripolium, Sonchus brachyotus, and Phragmites communis as facultative halophytes.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.4
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• pp.280-288
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• 2009

To identify controlling factors for spatial variation of vegetation in reclaimed tidal flats, plant stands were investigated in a newly reclaimed as well as three matured tidal flats, and a natural tidal flat in the midwest coast of Korea. Electrical conductivity of saturated soil extract (ECe) was measured to assess soil salinity. Soil salinity differed significantly among plant stands. Depending on soil salinity, plant species showed different niches: glycophyte predominated low saline spots, halophyte predominated high saline spots. Soil salinity for each plant habitats was in order of as follow: bare soil or plant wilted > mixed pioneer halophyte > pioneer halophyte > mixed with pioneer halophyte and facultative halophyte > mixed facultative halophyte > facultative halophyte > mixed with facultative halophyte and glycophyte > glycophyte > mixed glycophyte stands. These results suggested that plant distribution might have been influenced by spatial edaphic gradient (soil salinity), and thus it could be utilized as an indicator for field soil salinity gradient. Relationship between soil salinity and plant distribution was not different among the aged reclaimed tidal flats, suggesting that the vegetative population might have changed into a similar direction since the reclamation.

• Korean Journal of Environment and Ecology
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• v.21 no.3
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• pp.290-298
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• 2007

The results of this research on the diversity, zonation of vegetation and micro-topography by TWINSPAN classification and DECORANA ordination, executed with Sinduri coastal dunes of Korea, are as follows: The vegetation and micro-topography of coastal dunes formed a noticeably clear zonation structure. The beach in the direction of the coastline saw a lot of appearance of Salsola komarovi and the primary dune was dominated by Elymus mollis. Imperata cylindrica var. koenigii and Carex pumila formed a colony at flat area of the sand hills and Calamagrostis epigeios was widely distributed at the wet slack. The secondary dune was dominated mostly by Ischaemum anthephoroides and Imperata cylindrica var. koenigii, and it showed an aspect of the distribution of Vitex rotundifolia and Rosa rugosa. while the hinterland hillside in the direction of inland was dominated by Robinia pseudo-acacia and Pinus thunbergii. However, Carex kobomugi, known as the pioneer species of the coastline-bound areas at the coastal dune, dominantly occupied the secondary dune of the rear side and continentally-inclined Miscanthus sinensi and Oenothera biennis of naturalized plant were irregularly spread over the whole of the coastal dune, so the stabilization of micro-topography seemed to be uncertain. Particularly, Miscanthus sinensis was predicted to be changed into dominant species of the primary dune, and secondary dune and slack having a commonly high species gathering inclination with the more progress of stabilization of the coastal dune. The expansion of sand hill wetlands and roads located between the primary dune and secondary dune was judged to have an effect on the zonation structure of plant distribution.

• The Korean Journal of Soil Zoology
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• v.7 no.1_2
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• pp.51-57
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• 2002

Two new and two known species of mononchid nematodes from Korea are described and illustrated. lotonchus cucumis sp. n. is characterized by 2.9-3.2 ㎜ long body, presence of 3 each pre- and post-vulval papillae, vagina with cuticularized pieces, a long tail with terminal spinneret. Mylonchulus unicus sp. n. has 1.1-1.2 ㎜ long body, and is characterized by having 2 pairs of teeth on subventral walls of buccal cavity; submedian denticles arranged in 2-3 rows, very short post-vulval sac and terminal spinneret. Mononchus sinensis Soni and Nama (1983) and Mononchus aquaticus Coetzee (1968) are reported for the first time from Korea.

• Korean Journal of Plant Resources
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• v.33 no.1
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• pp.1-14
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• 2020

This study was conducted to analyze community structure and species composition of Pinus densiflora for. erecta Stand in Mt. Cheonchuk (653 m). Field survey was carried out from June to September in 2013. 74 plots (20×20 m) were set up, 5 herb layer plots (3×3 m) were constructed for each plot, and there, Diameter at Breast Heigh t(DBH), height, environmental factor, annual growth were measured. Vascular plants were surveyed as following; 66 family, 165 genus, 211 species, 2 sub species, 29 variety, 6 form 248 taxa. Results of cluster analysis for P. densiflora for. erecta forest, 3 communities were divided into; Quercus mongolica (P-1), Quercus variabilis (P-2) and Quercus aliena-Stephanandra incisa (P-3). There were significant environmental factors that organic layer, annual growth, CEC, total total nitrogen, organic matter and pH for each community. As a result of DCA, P-1 and P-2 were distributed large range of environmental factors but relatively limited in P-3. Distributions of herb layer were affected by sand, cation exchange capacity, silt and total nitrogen. Results of MRPP test for herb layer communities, it was significantly analyzed (A=0.003, P<0.008). Species diversity index was highly recorded in P-3 and influenced by cation exchange capacity, total nitrogen, annual growth in consequence of NMS analysis.

• Proceedings of the KSR Conference
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• 2003.05a
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• pp.309-314
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• 2003

A vertical curve should be installed in straight section. In case, it be installed on horizontal curved section, safety factor go down. In this study, it is calculated that the deficiency of cant about vertical curve radius on horizontal curved section. The result of this study will be used on planning the tack layout of railroad and design the track construction.

• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.153-153
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• 2000

Si 산화는 반도체 공정상 필요한 과정으로 산업적으로나 학문적으로 중요하고 많이 연구되었다. 이중에서 Si(1110-7x7표면에서 초기 흡착된 산소는 준안정적 상태로 존재하며 표면온도, 산소의 노출량 그리고 진공도에 따라 그 수명이 제한된다. 이러한 준안정적 상태의 산소의 화학적 성질은 여러 표면분석장비가 동원되어 연구되었으나 아직까지 논쟁이 되고 있다. 이 경우 산소가 어떤 상태로 존재하는가는 표면화학종을 검출함으로서 해결될 수 있다. 저에너지 Cs+ 이온 반응성 산란은 이러한 요구를 충족시킬수 있는 가장 적합한 실험 방법중의 하나이다. 저에너지 Cs+ 이온 산란의 특징 중의 하나는 입사된 Cs+ 이온이 표면에 흡착된 화학종과 충돌후 탈착되면서 반응을 하여 송이 이온을 형성한다는 것이다. 이 송이 이온을 관측함으로서 표면에 존재하는 화학종을 알아 낼 수 있다. 이에 산소가 흡착된 Si(111)-7x7 표면에서의 산소의 준안정적 상태가 저에너지 Cs+ 이온 산란 실험을 통하여 연구되었다. 실험은 0.2-2L(1Langmuir = 10-6 Torr x 1 sec) 산소 노출량과 -15$0^{\circ}C$ - $25^{\circ}C$의 표면온도 그리고 5eV - 20eV의 Cs+ 이온 충돌에너지에서 CsSiO+ 이온이 유일한 생산물로서 검출되었다. CsSiO+ 이온은 입사된 Cs+ 이온과 표면에 존재하는 SiO 분자가 충돌 후 반응하여 탈착된 것으로 생각된다. 이것은 낮은 산소 노출량 즉, 초기 산화 단계에서 SiO가 표면에 존재한다는 것을 의미한다. 즉, 산소 분자는 산화단계의 초기에 해리되어 표면에 흡착되고 선구물질인 SiO를 형성함을 제시한다. 최근의 이론적 계산인 density functional calculation에서도 산소분자가 Si(111)-7$\times$7 표면의 준안정적 산화상태의 선구물질일 가능성을 배제한다. 이는 본 저에너지 Cs+ 이온 반응성 산란실험을 뒷받침하는 계산 결과이다. 높은 Cs+ 이온 충돌에너지에서 CsSi+, Si+, SiO+, Si2+, Si2O+ 등이 추가로 검출되었다. 이는 CsSi 이온을 제외하고 수 keV의 충돌에너지를 사용하는 이차 이온 질량 분석법과 비슷한 결과이다.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.2
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• pp.83-93
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• 2008

Assessing for flora distribution is necessary for land management and environmental research in reclaimed lands. This study was conducted to find out the relationship between vegetation distribution and soil salinity on three reclaimed tidal flats of Kyonggi-bay in the mid-west coast of Korea. We investigated the soil salinity and identified the vegetation at the continuum distribution spots, and describe the characteristics of continuum distribution. On the reclaimed tidal flats, spatial variation of vegetation formed partially, however as the result for connection of each spatial variation along with the soil salinity, continuum distribution formed and it was overlapped edaphic gradient with vegetation distribution, it means that the continuum distribution correspond with soil salinity gradient, as the evidence high salt tolerance species occurred at high saline spots, non salt tolerance species occurred at low saline spots. On the aged reclaimed tidal flats, continuum type was various and also clearly distinguished but it was not clear on the early stage of reclamation. The continuum distribution distinguished sequential and non-sequential type. Sequential type started from high saline zone and connected to low saline zone gradually, on this type, vegetation changed from pioneer halophyte to facultative halophyte and glycophyte along with the salinity gradient. Non-sequential type formed by non-sequential change of soil salinity, on this type, vegetation distribution was non-regular form because it has not changed gradually. In the aged reclaimed land, vegetation wilted zone existed with high salinity, and continuum distribution started from this zone with bare patch.

• Animal Systematics, Evolution and Diversity
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• v.18 no.1
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• pp.165-179
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• 2002

In spite of dramatic change of environmental condition since Cambrian big-bang (explosion occurred ca.540 mya, the phylum Arthropoda retains a great diversity, and it is estimated approximately that 1-10 million arthropod species are extant on the earth. Except for an extinct arthopod subphylum Trilobita, extant arthropods could be divided into five subphyla: Hexapoda, Crustacea, Myriapoda, Chelicerata, and Pycnosonida. During the last century, systematists have disputed about interrealtionships among Arthropoda and its relatives (Onychophora, Tardigrada, and Pentastomida), arthropod phylogenetic position within protostome animals, monophyly or polyphyly of the phylum Arthropods, and interrelationships among five arthropod subgroups (subphyla) etc. Recently, new animal phylogeny was reported that protostomes could be clustered into two groups, Lophotrochozoa and Ecdysozoa, and molting animals such as Nematoda and Arthropoda were included within the Ecdysozoa. On the basis of the new animal phylogeny, first of all, I would mention phylogenetic positions and relationships of Arthropods and its relatives to introduce controversies of arthropod phylogeny in phylum level of animals. After that, I focused mainly on the controveries related to arthropod monophyly and phylogenetic relationships among four major arthropod groups except Pycnogonida. In this work, Pycnogonida which is a relatively small group and one of the five arthropod subphyla was not handled significantly although there are some controversies if it is a sister taxon of chelicerates or the most primitive arthropod group (namely, a sister of four remains arthropod groups).