• Ocean and Polar Research
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• v.34 no.1
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• pp.65-71
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• 2012

Gambierdiscus toxicus, Adachi et. Fukuyo, is a benthic ciguatoxin-producing armored dinoflagellate, often attached to macroalgae. This organism is the primary causative agent of ciguatera fish poisoning which occurs in tropical and subtropical regions. However, regardless of the fact that the population of Gambierdiscus spp. has expanded to such temperate areas from sub-trophic and trophic areas, monitoring of G. toxicus has been lacking in the Korean coastal waters of temperate areas. This study was performed at the uninhabited Baekdo Islands off the southern coast of Korea and at Seopsom Island in the vicinity of Seogwipo, Jeju Province during April and May, 2011. Cell densities of Gambierdiscus spp. on macroalgae at Baekdo and Jeju Island ranged from zero to 56.4 cells $g^{-1}$. Maximum density was recorded on the brown alga Cladophora japonica at St. 3 of Jeju Island. In particular, the cell densities of Gambierdiscus spp. were influenced by the substrate characteristics of macroalgae. In the future, the continuous monitoring of toxic benthic dinoflagellate is necessary to predict and prevent ciguatera poisoning in Korean coastal waters.

• Current Research on Agriculture and Life Sciences
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• v.13
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• pp.31-44
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• 1995

Mt. Kumjeong is located in south-eastern part of the Korean Peninsular($129^{\circ}$01' to $129^{\circ}$05' E, $35^{\circ}$03' to $35^{\circ}$17' N) and the altitude of the summit is 802 meter. In order to find out the vegetation units which made it possible to classify subtropical forest and south-temperate forest, Mt. Kumjeong (which is located in a border of between subtropical forest and south-temperate forest) was selected as a study area. The primary result of actual vegetation analysis in Mt. Kumjeong based upon the vegetation community analysis methods by the ZM-school, and the relationships between vegetation community and two parameters(altitude, topography) analyzed by using coincidence analysis method were summarized as followings. 1. Based upon analytic methods of the vegetation community by the ZM-schools, the primary analytic result of the analysis of vegetation community in Mt. Kumjeong was divided into 10 communities, 9 groups, 2 subgroups. 2. Eurya japonica group of Pinus densiflora community out of 16 vegetation units was thought as a indicator vegetation group which made it possible to border subtropical forest and south-temperate forest. 3. Natural regeneration of Stewartia koreana group was thought to be difficult because seedling and sapling was rarely showed, 4. In relationship between vegetation units and altitude, Carpinus tschonoskii community, Quercus variabilis community, Quercus serrata community, Wisteria floribunda community,. Eurya japonica group of Pinus densiflora community, Pinus thunbergii community mainly distributed below altitude 500 meter, and Quercus mongolica community, Typical group of Pinus densiflora community, Quercus dentata community, Carpinus coreana community, Quercus acutissima community mainly distributed above altitude 500 meter. 5. In relationship between vegetation units and topography, Carpinus tschonoskii community, Quercus variabilis community, Quercus serrata community, Wisteria floribunda community,. Eurya japonica group of Pinus densiflora community distributed below middle slope, Quercus mongolica community, Typical group of Pinus densifiora community, Quercus dentata community, Carpinus coreana community, Pinus thunbergii community Quercus acutissima communily clistributed above midclle slope.

• Korean Journal of Agricultural and Forest Meteorology
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• v.7 no.3
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• pp.201-210
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• 2005

This study was conducted to prepare efficient and systematic measures for nature conservation and management in Beomseom Islet, and to provide for basic data to investigate the process of vegetation change in the future. The vegetation of Beomseom Islet was classified to six vegetation type; i.e., Miscanthus sinensis community, Pinus thunbergii community, Iythophyte vegetation, evergreen broad leaf community, shrub community, and Pseudosasa japonica community. The size of each vegetation type was 40,230 $m^2$ ($23.3\%$) for shrub community, 39,366 $m^2$($22.8\%$) for Iythophyte vegetation, 30,012 $m^2$ ($17.4\%$) fur Pinus thunbergii community, 29,853 $m^2$ ($17.3\%$) for Miscanthus sinensis community, 5,564 $m^2$ ($3.2\%$) for evergreen broad leaf community, and 3,325 $m^2$ ($1.9\%$) for Pseudosasa japonica community. The area of non-vegetated sea cliff Bone that composed of bare rocks is 24,246 $m^2$($14.1\%$). We estimated that these distribution patterns of vegetation were the result of various environmental factors such as the steepness of slope and shallowness of soil as well as the cultivation of exotic plants causing disruption of native vegetation.

• Korean Journal of Environment and Ecology
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• v.37 no.2
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• pp.163-178
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• 2023

This study was conducted to understand the vegetation characteristics of Cheongwansan Provincial Park through the analysis of the plant community structure and to build data necessary for the continuous management and protection of Cheongwansan Provincial Park. The TWINSPAN and DCS analyses of the plant community structure of 63 survey districts in Cheongwansan Provincial Park identified eight colonies, including Cryptomeria japonica Community (I), Chamaecyparis obtusa-Pinus densiflora Commuity (II), P. rigida-P. densiflora Community (III), mixed coniferous and broad-leaved Community (IV), P. densiflora Community (V), deciduous broad-leaved such as Quercus spp. Community (VI), Q. mongolica-P. densiflora Community (VII) and P. thunbergii Community (VIII). The colonies can be grouped into afforestation communities (I, II, and III) dominated by C. obtusa, C. japonica, and P. rigida and natural forest communities (IV, V, VI, VII, and VIII) dominated by native species. Although Cheongwansan Provincial Park is a provincial park area that can represent natural ecosystems and landscapes, the rate of artificial forests is higher than that of other provincial parks. Most of the artificial forest communities are expected to maintain their current state, but since native species such as Machilus thunbergii, Neolitsea sericea, and deciduous broad-leaved, which are warm-temperate trees introduced through surrounding natural forests, appear in the lower layer, it is determined that it is possible to induce succession to natural forests suitable for climatic characteristics through management, and monitoring for continuous management is also necessary. Deciduous broad-leaved such as Quercus spp. Copete with P. densiflora in most natural forest communities. The vegetation series in the warm-temperate region of Korea appears to be in the early stages, and it is believed that the succession to Q. serrata or Q. mongolica, which appears next to coniferous in the series, is in progress. However, M. thunbergii and N. sericea, which appear in the middle stage of the succession in the warm-temperate region, have started to appear, and since Jangheung-gun belongs to the warm-temperate region considering the climate characteristics, the eventual succession to the warm-temperate forests dominated by evergreen broad-leaved is also expected. In this study, we built vegetation data from Cheongwansan Provincial Park, which lacks research on vegetation. However, since vegetation research in Cheongwansan Provincial Park is still insufficient, it is believed that further research should be continuously conducted to establish forest vegetation data and observe vegetation changes.

• Journal of Crop Science and Biotechnology
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• v.11 no.4
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• pp.269-276
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• 2008

Field resistance is defined as the resistance that allows effective control of a parasite under natural field condition and is durable when exposed to new races of that parasite. To identify the genes for field resistance to rice blast, quantitative trait loci (QTLs) conferring the resistance for races and blast nursery screening in japonica rice cultivars were detected and mapped using SSR markers. QTL analysis was carried out in 190 RILs population from the cross between Suweon365 (moderately resistant) and Chucheong (highly susceptible). Twelve QTLs against nine blast races inoculated were detected on chromosomes 1, 2, 4, 6, 7, 11 and 12. They explained from 5.1% to 34.9% of total phenotypic variation. Eight QTLs against blast nursery screening in four regions for three years were detected on chromosomes 1, 2, 4, 11 and 12. The phenotypic variation explained by each QTL ranged from 4.3% to 37.7%. Three chromosome segment substitution lines (CSSLs) of $BC_2F_6$ by backcross method were developed to transfer the QTLs into the susceptible cultivar Chucheong as a recurrent parent. A CSSL4-1 containing two QTLs qLB6.2 and qLB7 against blast races showed to the reaction of 6 to 7 at blast nursery in two regions for two years. The CSSL4-2 and CSSL93 containing QTLs, qLB11.2 and qLB12.1 of the resistance against leaf blast in blast nursery screening, respectively, had enhanced the resistance for blast nursery screening across two regions and in two years.

• Journal of Korean Society of Forest Science
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• v.89 no.1
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• pp.93-104
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• 2000

The ecological characteristics of 10 natural stands of Dendropanax morbifera(Haenam, Wando 1, Wando 2, Bogildo, Kemundo and Hongdo and Sendol, Suoak, Hannam, and Kidowon populations in Cheju island) were studied. In most of the Dendropanax morbifera natural stands, the following tree species appeared predominantly : Camellia japonica, Castanopsis cuspidate var. sieboldii, Castanopsis cuspidate var. thunbergii, Carpinus laxiflora, Quercus acute and Eurya japonica. Especially, Camellia japonica and Eurya japonica appeared in all the stands. Dendropanax morbifera occupied 17.2% of the upper story, 12.9% of the middle story, and 10.3% of the lower story, respectively. The distribution patterns by Morisita's Index showed that Dendropanax morbifera was distributed randomly in all of the three stories, i.e. the upper, the middle and the lower stories. Dendropanax morbifera was positively associated with Camellia japonica, Eurya japonica, Carpinus laxiflora, Cinnamomum japonicum, Ligustrum japonicum, Callicarpa Japonica, Castanopsis cuspidate var. thunbergii, Castanopsis cuspidata var. sieboldii, Daphniphyllum macropodum, Acer palmatum and Euonymus oxyphyllus. This might suggest that the ecological niche is similar to each other. The cluster analysis using percent dissimilarity(PD) based on species composition divided into two groups. One group consisted of the populations located along the south-western coasts. The other group consisted of the populations of Cheju island. This result was agree with that of ordination analysis. From these results, We could find out that the species composition of the populations of Dendrapanax morbifera in Cheju island was quite different from those of other regions.

• Journal of Ecology and Environment
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• v.29 no.6
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• pp.495-501
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• 2006

This study was conducted to investigate the effects of thinning on soil properties and seed productivity in the 25-year-old Cryptomeria japonica and 30-year-old Chamaecyparis obtusa seed orchards in which thinning had been performed 4 years prior to the study. To this end, soil properties, cone and seed characteristics, seed production (kg/ha), and nutrient contents in seeds and cones were studied by 4 different thinning intensities (0, 20, 40, and 60%). Soil properties were not significantly different between the two orchards. Meanwhile, electric conductivity, total nitrogen, and $K^+$ concentration in the soil of C. obtusa seed orchard were significantly different among 4 different thinning intensities (p<0.05), while only $Ca^{2+}$ concentration in the C. japonica seed orchard was different (p<0.05). In the C. obtusa seed orchard, cone productivity increased with the increase of thinning intensities (p<0.05), whereas that in the C. japonica seed orchard did not show any significant differences. Both of the two seed orchards showed a tendency that seeds become bigger and heavier with the increase of thinning intensities, but any significant differences were not found. Seed production (kg/ha) in the C. obtusa seed orchard significantly increased with the increase of thinning intensities, while that of the C. japonica seed orchard decreased. Nutrient contents in seeds and cones did not show any significant differences among different thinning intensities in both of the two seed orchards.

• Korean Journal of Environment and Ecology
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• v.27 no.4
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• pp.473-486
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• 2013

Vegetational structure and successional sere were investigated for Paryeongsan Zone in the Dadohaehaesang National Park incorporated in National Park in 2011. To do so, seventy-five plots($100m^2$) were set up and surveyed. The surveyed plots were divided into six groups according to the analysis of classification by TWINSPAN; (I) Quercus acutissima community, (II) Q. serrata-Carpinus tschonoskii var. tschonoskii community, (III) Pinus densiflora-Q. mongolica community, (IV) Q. variabilis community, (V) P. rigida-Q. variabilis-P. densiflora community, (VI) Chamaecyparis obtusa community. The results of vegetation structure analysis were. I, IICommunity, were expected that the deciduous oak trees with deciduous oak trees or Carpinus tschonoskii var. tschonoskii competing with oak trees would flourish in a deciduous broad-leaved forest. III, VCommunity, were expected that the P. densiflora and P. rigida competing with oak trees would flourish in a deciduous broad-leaved forest. IVCommunity, have expanded the influence of Q. variabilis, but understory will be developed next ecological succession by a high percentage of Machilus thunbergii in frequency of warm-temperate trees. VI Community, Chamaecyparis obtusa community were expected continue. This Chamaecyparis obtusa community is picked thinning Chamaecyparis obtusa as moving purpose of National Park, it will be inducement a plant vegetation succession to the natural forest. Frequency of warm-temperate trees in the Paryeongsan Zone of warm temperate climate zone was a total 9 species, Machilus thunbergii, Eurya japonica, Elaeagnus macrophylla, etc.

• The Korean Journal of Mycology
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• v.51 no.3
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• pp.229-237
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• 2023

In the present study, we isolated endophytic fungi from different tissues of two plants, Pseudosasa japonica and Quercus serrata from Taean-gun, Korea. Morphological characteristics of the isolated fungal strains were observed. We identified the fungi based on the phylogenetic analysis using DNA sequences from the region of internal transcribed spacer, large subunit rDNA, β-tubulin, and translation elongation factor 1-α DNA. Three endophytic fungi that were not previously recorded in Korea, namely Geomyces asperulatus, Leptoxyphium fumago, and Tubakia oblongispora were identified. Here, we describe the morphological characteristics of these unrecorded fungi and present the results of the phylogenetic analysis.

• Journal of agriculture & life science
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• v.44 no.6
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• pp.27-37
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• 2010

This study was carried out to offer the basic information on ecological succession of evergreen broad-leaved forest through understanding of ecological characteristics of forest community by distance from Camellia japonica stand. Importance value of C. japonica at tree layer was highest in site I and those of Pinus densiflora and P. thunbergii were highest in site II, III and IV. At subtree layer, the importance value of C. japonica was highest in site I while Neolitsea sericea and Styrax japonica had the highest importance value in site II, III, and IV. In all sites, species diversity ranged from 0.121 to 0.515 and 1.112 to 1.589 at tree layer and subtree layer respectively. Evenness ranged from 0.811 to 0.930 at subtree layer, 0.796 to 0.913 at shrub layer and 0.155 to 0.727 at tree layer, this indicates that distribution pattern by species is more uniform at subtree and shrub layer than at tree layer. Soil pH was highest as 5.72 at site I. Contents of total N, organic matter and available P were higher at site I than other sites.