• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.23 no.4
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• pp.192-203
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• 2018

The surfgrass Phyllospadix iwatensis is native in the exposed rocky shores of the Northwestern Pacific Ocean. In Korea, P. iwatensis is mainly found on the rocky subtidal zone in the central eastern coast. In this study, to examine the ecological characteristics of P. iwatensis, we investigated changes in morphological characteristics, density, biomass, and leaf productivity as well as changes in the underwater irradiance and water temperature of its habitat monthly from August 2017 to July 2018. Underwater irradiance and water temperature showed clear seasonal changes; increases in spring and summer and decreases in fall and winter. Morphological characteristics, shoot density, biomass, and leaf productivities of P. iwatensis exhibited significant seasonal variations, increasing in winter and spring and decreasing in summer and fall months. P. iwatensis leaf productivities both per shoot and per unit area showed significant positive correlations with underwater irradiance. The average leaf productivity of P. iwatensis per area was $6.3{\pm}1.3g\;m^{-2}d^{-1}$, while minimum and maximum values were $2.4{\pm}0.3g\;m^{-2}d^{-1}$ in February 2018 and $16.4{\pm}4.4g\;m^{-2}d^{-1}$ in May 2018, respectively. The optimum water temperature for the growth of P. iwatensis in this study was between $12-13^{\circ}C$.

• Korean journal of applied entomology
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• v.59 no.4
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• pp.417-420
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• 2020

In this study, to grasp the current status of cone insects occurrence on Korean fir (Abies koreana) in Mt. Halla, 117 cones damaged by cone insects in three areas in Mt. Halla were collected and placed in growth chamber until adults emerged from the cones from August to October on 2019. And species and numbers of adults emerged from the cones were identified. Also proportion of cones damaged by cone insects was examined at four study plots in Mt. Halla. As a result, total 233, 101, and 4 adults of Dioryctria abietella (Denis & Schiffermüller), Cydia kamijoi Oku, and Scathophaga stercoraria (L.) were identified from 117 collected cones, respectively. The average number of emerged adults per cone was 1.99 for D. abietella and 0.86 for C. kamijoi. And the average damage rate of cone insects in four study plots of Mt. Halla ranged from 49.7-80.1 percent, with differences between regions. Also, our results show that positive correlation between the damage rate per tree and the number of cones per tree, and between number of emerged cone insects and the size of cones were found. It suggests that the cone insects prefer host trees with lots of cones per tree and with larger size of cones.

• Journal of Life Science
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• v.32 no.8
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• pp.641-646
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• 2022

There are concerns about the environmental release of living modified organism (LMO) maize created to increase yields. In fact, there are cases in which LMO crops for feed have been leaked in Korea to form autoite colonies, and concerns about LMO spill are intensifying. In this study, the possibility of environmental outflow and occurrence of native organisms was analyzed using maize feed and seeds distributed in Korea. In the evaluation of the possibility of spontaneous occurrence of maize in the event of an unintentional release of maize feed made by crushing maize, the incidence rate of maize was 0.01%, which was extremely low compared to the germination rate of maize seeds. A survey of the dormant rate of maize showed that all maize seeds collected every month were dead. In the germination rate test by temperature using Daehak wax corn and Kwangpyeongok, high germination rates were found at 20℃ and 30℃, and relatively low germination rates were found at 10℃ and 40℃. In addition, all germination tests showed a higher germination rate Daehak wax corn than Kwangpyeongok. The difference between domestic and overseas cultivation maize was confirmed through a survey on the agricultural properties of three varieties of maize. The data obtained through this experiment could be the basis for the evaluation of the weediness potential of environmental risk assessment and technology to suppress the occurrence of autoite in preparation for future LMO spills.

• Journal of Korean Society of Forest Science
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• v.112 no.1
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• pp.11-22
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• 2023

This study was established to provide basic information necessary for ecological management to restore the naturalness of black locust (Robinia pseudoacacia L.) plantations located in the mountains of Gyeongbuk, Korea. Using vegetation data collected from 200 black locust stands, vegetation types were classified using the TWINSPAN method, the spatial arrangement status according to the environmental gradient was identified through DCA analysis, and a synoptic table of communities was prepared based on the diagnostic species determined by determining community fidelity (Φ) for each vegetation type. The vegetation types were classified into seven types, namely, Quercus mongolica-Polygonatum odoratum var. pluriflorum type, Castanea crenata-Smilax china type, Clematis apiifolia-Lonicera japonica type, Rosa multiflora-Artemisia indica type, Quercus variabilis-Lindera glauca type, Ulmus parvifolia-Celtis sinensis type, and Prunus padus-Celastrus flagellaris type. These types usually reflected differences in complex factors such as altitude, moisture regime, successional stage, and disturbance regime. The mean relative importance value of the constituent species was highest for black locust(39.7), but oaks such as Quercus variabilis, Q. serrata, Q. mongolica, Q. acutissima, and Q. aliena were also identified as important constituent species with high relative importance values, indicating their potential for successional trends. In addition, the total percent cover of constituent species by vegetation type, life form composition, species diversity index, and indicator species were compared.

• 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 Ecology and Environment
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• v.47 no.spc
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• pp.66-73
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• 2014

In order to determine whether vegetation would be one of the factors for the selection of otter home range, vegetation structure and other potential factors were studied in Hwacheon, Korea. Thirteen sites, otter's activity found and not found, were investigated in North Han River and connected tributary streams of Hwacheon-gun. Three types of vegetation were classified by cluster analysis, which is short grass, tall grass and shrub type. Vegetation zone of each channel is composed of either one type, or mosaic of tall grass and shrub type. Short grass type is common in Lake Paro and upper North Han-river where water level is highly variable throughout a year. Therefore, annual species such as Persicaria nodosa, Fimbristylis dichotomam and Chenopodium ficifolium are the most dominant. Shrub type is common at the downstream sites of Jichon stream and along mainstream of North Han River down Lake Paro. A shrub species, Salix koreensis, is the most common. Tall grass type is dominant occupying the most vegetation zone of the tributary channels. Phragmites japonica is absolutely dominant. Due to its dense cover, a few plant species are co-existed. Otter activity was found in all three vegetation types and no marked activity was found at some sites of tall grass type. There is no difference in species composition and physiognomy between tall grass sites with and without otter activity, while it shows significant difference in fish availability between two groups. Overall we found that home range of otters in the region is along the mainstream and downstream of tributary streams with high fish availability in all vegetation types and in various human activity levels.

• Korean Journal of Environment and Ecology
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• v.6 no.2
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• pp.154-161
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• 1993

To investigate the structure and the conservation strategy of Taxus cuspidata forest and at Birobong area in Sobeaksan. 24 plots(400$m^2$) set up with random sampling method. Four groups were classified by cluster analysis. High positive correlations was proved between Quercus mongolica and Symplocos chinensis, Rhododendron schlippenbachii and Pinus densiflora, Taxus cuspidata and Acer pseudo-sieboldianum, Prunus padus and Eunonymus macroptera, Acer mono and Styrax obassia, and high negative correlations was proved between Quercus mongolica and Taxus cuspidata, Prunus padus and Eunonymus macroptera, Rhododendron schlippenbachii and Taxus cuspidata, Acer pseudo-sieboldianum, Prunus padus and Eunonymus macroptera. Species diversity(H') of investigated area was calculated 1.3702-2.9119. To conserve Taxus cuspidata forest at Birobong area in Sobeaksan, research and rescription on the declining of Taxus cuspidata. forest was needed and Quercus mongolica, Styrax obassia, Tripterygium regelii and Weigela subsessilis in the Taxus cuspidata forest should be cleared out.

• Korean Journal of Plant Resources
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• v.33 no.2
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• pp.93-105
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• 2020

The study was investigated in vegetation and environmental factors of Thuja koraiensis habitats where provided for ecological evidence data for conservation and management. Study plots were located at altitudes of 1,000~1,588 m with inclinations of 10~30°. A total of 150 taxa was identified 22 quadrates in 6 study sites. The highest basal area was analyzed in Mt. Gariwangsan 49.98 ㎡/㏊ with the lowest Mt. Hwaaksan 3.46 ㎡/㏊. Thuja koraiensis forest was classified into two communities; Abeis nephrolepis-Taxus cuspidata community, Betula ermanii-Thuja koraiensis community. As a result of Multi-Response Permutation Procedures test, there was significant difference among the communities.

• Korean Journal of Soil Science and Fertilizer
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• v.30 no.1
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• pp.72-83
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• 1997

Forty six natural habitats of Korean lespedeza(Leapedeza stipulacea Maxim.) were investigated for the growth characteristics, mineral contents of plant and the physico-chemical properties of natural habitat's soil compared with the upland soil nearby the habitat. The results obtained were summarized as follows. Plant height and dry matter yield were higher in the samples taken in late than early August showing large variation within the sampling date and location. Korean lespedeza showed higher contents of Fe and Mn, but lower contents of K, Ca, Mg and Cu than Alfalfa. The contents of P and Zn were about the same. The natural habitat showed higher soil pH and Ca content but lower contents of $P_2O_5$, K, and organic matter than the vicinity of natural habitats and the average soil of Korea. The contents of Mg were about the same. The soil texture of natural habitats showed much higher portion of sand and extremely low portions of silt and clay than both area. Korean lespedeza is so well adapted to the soil with low fertilizer and organic matter that other crops and most weeds fail. It also appears to thrive on the sandy loams, loamy sands of the piedmont region such as waste land and on the similar soils with variously physico-chemical properties.

• Journal of Life Science
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• v.33 no.3
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• pp.227-233
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• 2023

The purpose of this paper was to describe a statistical analysis for the spatial distribution of geographical distances of Erythronium japonicum at Mt. Geumjeong in Korea. The spatial pattern of E. japonicum was analyzed according to the nearest neighbor rule, population aggregation under different plot sizes by dispersion indices, and spatial autocorrelation. Most natural plots of E. japonicum were uniformly distributed in the forest community. Disturbed plots were aggregately distributed within 5 m × 5 m of one another. Neighboring patches of E. japonicum were predominantly 7.5~10 m apart on average. If the natural populations of E. japonicum were disturbed by human activities, then the aggregation occurred in a shorter distance than the 7.5~10 m distance scale. The Morisita index (IM) is related to the patchiness index (PAI) that showed the 2.5 m × 5 m plot had an overly steep slope at the west and south areas when the area was smaller than 5 m × 5 m. When the patch size was one 2.5 m × 5 m quadrat at the west distributed area of Mt. Geumjeong, the cluster was determined by both species characteristics and environmental factors. The comparison of Moran's I values to a logistic regression indicated that individuals in E. japonicum populations at Mt. Geumjeong could be explained by isolation by distance.