• Korean Journal of Environment and Ecology
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• v.38 no.4
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• pp.388-404
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• 2024

The focus of conserving plant diversity at the national level includes endemic species restricted to specific regions. This study thus aimed to investigate and evaluate the current distribution status of the Pulsatilla tongkangensis Y.N. Lee & T.C. Lee, one of Korea's endemic plants. The study also examined the vegetation environment of its habitat and assessed the structure of each population. Furthermore, the performance variable of each population was comparatively evaluated, and its annual growth characteristics were also observed. The distribution area of the P. tongkangensis is largely divided into limestone cliffs, ridge rocks, mountain peaks in limestone regions, and sandy soil areas resulting from weathering. Plants in the same distribution area were categorized based on their geographical location, which reflected their respective habitats. According to the population structure evaluated using the number of measured leaves numbers, the plants were categorized into stable and relatively unstable populations. A relatively young population was observed at the top of mountains and rocky ridges of limestone areas and sandy soil areas resulting from weathering. The number of mature individuals was the highest in the population observed around limestone cliffs. In contrast, the population near the top of the limestone mountain range had more leaves , but the plants were of short stature and had the fewest inflorescences. The individuals distributed in limestone cliffs grew, produced, and dispersed seeds for an extended period following establishment. The growth of individuals was limited due to environmental factors in the habitat of distribution areas, including ridges, mountain tops in limestone regions, and sandy soil areas resulting from weathering. It was assessed to have a comparatively brief life cycle compared to that of the plants found on limestone cliffs. P. tongkangensis began flowering in early spring, and both fruit maturation and seed dispersal were completed before the onset of summer. The habitats were determined to receive around seven hours of sunlight per day during the summer, which was considered suitable for establishing a life cycle for the P. tongkangensis, a species requiring strong sunlight for growth to establish and success in a dry environment. Considering the status data gathered from this study, the P. tongkangensis was classified as an endangered species (EN). In addition, the collected data are expected to provide important information for the IUCN Red List of Threatened Species. Therefore, we proposed that the P. tongkangensis holds significant value as a core distribution site, given the observation of species with diverse characteristics on limestone cliffs in Pyeongchang-gun and Jeongseon-gun, Gangwon-do.

• Korean Journal of Environmental Biology
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• v.36 no.2
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• pp.107-116
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• 2018

In this study, the distribution of sedimentary environment and benthic macro-fauna in habitats and non-habitats of Zostera marina were investigated. The purpose of this study was to obtain basic data about the sedimentary environment and benthic macro-fauna in the habitats and non-habitats of Z. marina. Sand was dominant within habitat environments, whereas the non-habitats were predominantly composed of silt. As a result, the habitats of Z. marina have a different grain size and organic matter content compared to the non-habitats. These differences in the sedimentary environment were expected to influence the species composition of benthic animals. Benthic communities in the habitats of Z. marina showed a higher density and a greater number of species than in the non-habitats. As a result of an ecological index evaluation, the species diversity index (H') was $3.44{\pm}0.10$ for the habitat; the non-habitat was analyzed as $2.34{\pm}0.35$. It was also found that the stability of community in the habitats was higher than that in the non-habitats. The cluster analysis also clearly showed that habitats and non-habitats of Z. marina have distinct characteristics.

• Ecology and Resilient Infrastructure
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• v.6 no.4
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• pp.179-190
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• 2019

In this study, a fish survey was conducted to investigate the habitat status of black shinner (Pseudopungtungia nigra) designated as endangered species level from the lower part of Yongdam Dam to the upper part of Daecheong Dam. Biodiversity analysis was performed on the basis of the number of fish emerged, and biological health and physical habitat environment were quantitatively analyzed using collected P. nigra. According to the survey, the habitat range of P. nigra was found from Banguri-myeon, Buri-myeon, Geumsan-gun, downstream of Yongdam Dam. The biodiversity analysis results of all species appeared to be low in overall dominance index and relatively high in species diversity and uniformity index. In addition, P. nigra collected in this study was confirmed to have normal growth and nutritional status by the full-length-weighted relativities and condition factor. The physical habitat environment of P. nigra was 0.3 - 0.6 m in depth, 0.3 - 0.7 m/s in flow rate, and bed materials showed high frequency of occurrence in the range of cobbles (64.0 - 256.0 mm) to boulders (>256.0 mm). These results are expected to be used as data for habitat restoration and management in the future as basic data on the spatial range and preferred physical habitat environment of P. nigra in Geumgang.

• Asian Journal of Turfgrass Science
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• v.20 no.2
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• pp.175-190
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• 2006

The term mycoherbicide started in 1970, but its interest heightened due to increase costs of chemical herbicides. A classical biocontrol agent is expected to become a permanent part of its new environment and do no harm to it. Contemporary biological control agent(BCA) must be produced by artificial culture and could be applied like chemical herbicides over weeds. BCA is different from the classical approach in that it released through natural spread. To date 26 species of fungi are used as classical BCA against 26 species of weeds in seven countries. There are a number of examples of pathogens attacking non-target plants. But through risk assessments which include understanding the taxonomy, biology and ecology, the target and non-target species, it will be safe to introduce of exotic pathogens to control weeds. But pathogens have not been successfully used in practice. Many mycoherbicides show potential in laboratories, but are ineffective in the field and not consistent from year to year or field to field. There is also a lack of understanding humidity, dew formation and temperature and their effects on suppression of weeds by plant pathogens. Potential pathogen must be selected as a BCA. Previous studies suggest that these pathogens must (1) produce abundant and durable inoculum in artifical culture, (2) be genetically stable and weed specific and (3) kill weeds in control. A granular preparation of mycoherbicide into sodium alginate is lighter than liquids and less bulky than organic matter. Gel forms have also been used.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.25 no.1
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• pp.25-38
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• 2022

Urban problems are constantly occurring around the world due to rapid industrialization and population decline. In particular, as the number of vacant houses is gradually increasing as the population decreases, it is necessary to prepare countermeasures. A plan to utilize vacant houses has emerged to restore the natural environment of the urban ecosystem where forest destruction, damage to habitats of wild animals and plants, and disconnection have occurred due to large-scale development. Through connectivity analysis, it is possible to understand the overall ecosystem flow based on the movement of species and predict the effect when vacant houses are converted into green spaces. Therefore, this study analyzed the green area network to confirm the possibility of greening of vacant houses neglected in Jeonju based on circuit theory. Using Circuitscape and Least-cost path, we tried to identify the connectivity of green areas and propose an ecological axis based on the analysis. In order to apply the resistance values required for analysis based on previous studies, the 2020 subdivision land cover data were integrated into the major classification evaluation items. When the eight forests in the target site were analyzed as the standard, the overall connectivity and connectivity between forests in the area were high, so it is judged that the existing green areas can perform various functions, such as species movement and provision of habitats. Based on the results of the connectivity analysis, the importance of vacant houses was calculated and the top 20 vacant houses were identified, and it was confirmed that the higher the ranking, the more positive the degree of landscape connectivity was when converted to green areas. In addition, it was confirmed that the results of analyzing the least-cost path based on the resistance values such as connectivity analysis and the existing conceptual map showed some differences when comparing the ecological axes in the form. As a result of checking the vacant houses corresponding to the relevant axis based on the width standards of the main and sub-green areas, a total of 30 vacant houses were included in the 200m width and 6 vacant houses in the 80m width. It is judged that the conversion of vacant houses to green space can contribute to biodiversity conservation as well as connectivity between habitats of species as it is coupled with improved green space connectivity. In addition, it is expected to help solve the problem of vacant houses in the future by showing the possibility of using vacant houses.

• Journal of Forest and Environmental Science
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• v.17 no.1
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• pp.1-17
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• 2001

Forming a part of "Cooperative Practical Study for the Modernization of the Management of National Forest", this study was conducted to provide overall ecological information for the natural regeneration of major tree species on the basis of community structural attributes in the deciduous forest ecosystem. Followings are summarized characteristics of the natural regeneration for the selected tree species. Betula costata : Although large number of seeds are dispersed by wind, they require mineral soils to germinate. Thick litter layer could be an obstacle to germinate. After germination, the seedling requires large amount of light for successful establishment. Acer mono : Characterized by high shade tolerance and weak drought resistance, the seedling should be overcasted with more than 50% of canopy coverage. High stand density should be maintained to produce good quality of timber. The potential of coppice may be high. Ulmus laciniata : Since this species needs high rate of troll moisture and light, around 60% of canopy coverage should be maintained to retain moisture and incoming light. The competition with other vegetation should be removed for the favor of successful seedling establishment. Fraxinus mandshurica : This species requires moist mineral soils to germinate. After germination, the seedling needs large amount of light and moisture for successful establishment. Site preparation should be applied to reduce competition with weedy vegetation. Fraxinus rhynchophylla : Interval of large seed crops may be highly varied. Thick litter layer could be an obstacle to germinate. Site preparation should be applied to reduce competition with weedy vegetation so as to achieve successful seedling establishment. Quercus mongolica : Including the difficulty of seed supply by the consumption, thick litter layer and mountain bamboo cover could be the obstacle to germinate. More than 50% of relative light intensity is necessary to achieve successful seedling establishment. Kalopanax pictus : Thick litter layer could be an obstacle to germinate. The seedling needs large amount of light and moisture for successful establishment. Abies holophylla : In spite of high shade tolerance, the growth rate in sapling stage may be extremely slow. Cornus controversa : Seeds (drups) are consumed and dispersed by animals, tending to be not sufficient in seed supply. This species requires large amount of light for successful germination and seedling establishment. Tilia amurensis : The difficulty of seed supply might be expected with low seed purity and double dormancy. Since thick litter layer could be an obstacle to germinate, the species requires moist mineral soils for successful germination. The potential of coppice may be extremely high.

• Korean Journal of Environment and Ecology
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• v.22 no.6
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• pp.648-657
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• 2008

This research was conducted to investigate the breeding density and seasonal food items of the magpies in Jeju Island and the near-manned islets. The examination of nest distribution to determine breeding density was performed during breeding season from February 2006 to April 2008, and that of food items from May 2006 to February 2008. A total of 2,113 nests were found across Jeju Island, the average density was $1.33\;nest/km^2$, and the magpies were distributed up to 600 meters above the sea level. The nest density was the highest in the central areas of Jeju Island, with 688 nests at $3.61\;nest/km^2$, while that in the eastern areas was the lowest, with 214 nests at $0.66\;nest/km^2$. In terms of the number of nests depending on the height above the sea level, 1,172 nests, which was equivalent to the density of $1.85\;nest/km^2$, was observed below 100m and highest among the intervals of height, but 16 nests found at 500-600m were the lowest, corresponding to $0.20\;nest/km^2$. The number of nests found in the manned islets near Jeju Island was eight in Biyang-do with the density of $15.38\;nest/km^2$, nine in U-do with $1.49\;nest/km^2$, and one in Gapa-do with $1.15\;nest/km^2$, whereas none of nests were observed in Mara-do. The contents of stomach consisted of 17 types of prey sources including countless bones, eggshells, plants, and seed, most of which were the individuals of the order Coleoptera. In spring and summer, the foraging frequency for invertebrate animals such as insects was high, but less than 30% in winter. In contrast, the magpies preyed upon plants and seeds at the frequency of 10% and 30%, respectively, in spring, while the foraging frequencies for both of them were 100% in winter and higher than any of other seasons. Eggshells and bones of birds were also detected infrequently. If the density of the magpies, which may play role as the upper predator within the ecosystem, increases, it would be expected to affect directly the reduction of the number of the species and population of endemic animals such as small birds and reptiles, etc. Therefore, it is considered that long-term monitoring for the density of the magpies and precaution is prerequisite to minimize adverse effects on ecosystem.

• Korean journal of applied entomology
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• v.59 no.3
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• pp.233-241
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• 2020

Several hard tick species in Ixodidae are medically important pests that transmit infectious disease including severe fever with thrombocytopenia syndrome (SFTS). In Korea, the number of SFTS patients continues to steadily increase since its first report in 2013, and Gyeongsangbuk-do (province) is the second most frequent area of SFTS patient occurrence. In order to investigate the distribution of ticks in Sangju city, we collected ticks using the flagging method from 26 sites comprising urban green area, vulnerable area of management, and rural area, and examined SFTS virus from the collected ticks in 2019. Based on Collection Index (CI = tick number / 1 h / 2 people), CI 143 ticks, including Haemaphysalis longicornis, Haemaphysalis flava, and Ixodes nipponensis, were collected; the most abundant species among the three tick species was H. longicornis (CI 138, 96.5%). Ninety two percent (CI 131) of ticks were collected in vulnerable area of management, where people cannot easily enter and are not managed by city hall, whereas only 8.4% (CI 12) were collected in the urban green area and rural area. Regarding SFTS virus detection, virus was not investigated from 26 pools containing CI 143 ticks. The results of this study are expected to be used as a recommendation for ensuring the safety of local residents from tick-borne diseases.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.8 no.3
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• pp.285-294
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• 2003

To select an appropriate sampler for the environmental monitoring survey in coastal waters of Saemangeum, Jeollabuk-do, a macrobenthic sampling was conducted in April 2002. Employed samplers were dredge (type Charcot), a semi-quantitative sampler and Smith-McIntyre (SM) and van Veen grab (VV) as quantitative ones. One haul was tried for dredge and 3 replicates (0.1 ㎡${\times}$3) for SM and W at each of 11 stations. Comparisons of sediment volume in sampler bucket and of precision of biological parameters (i.e., density, biomass, species number and diversity index, H') were made between SM and VV. Sediment volume was significantly different (SM > VV) at p-value of 0.0050 (paired t-test) and, in average, 3 replicate samples of SM and VV satisfied a precision level of 0.2 by applying 4th root transformation. Patterns of observed and expected species numbers and H' were compared. Dredge-VV samples showed higher affinity than any other pair. Several dominant species in the area were underestimated in dredge samples (e.g., polychaete Heteromastus filiformis. Aricidea assimilis etc.). Quantifying the agreement pattern of multi-species responses was accomplished by estimating correlations between similarity matrices. Correlation between dredge and VV was slightly higher, but near-per-fect matches were found in general. Different ranks and composition among principal species lists were presumably linked to the effect of penetration depth that differs among samplers. Lower level of some species' abundance in VV samples (ca. 50％ compared with those of SM) was explained in this context. It seem appropriate to regard the effect as a probable cause of relatively higher correlations in dredge-VV, Overall bio-logica1 features indicated that a better choice could be SM in situations of requiring high data quality. The others work well, however, on observing and defining faunal characteristics and their capability cannot be questionted if we do not expect a first-order quality.

• Korean journal of applied entomology
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• v.59 no.2
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• pp.93-107
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• 2020

Adults of seven noctuid potential pests (Spodoptera frugiperda, S. litura, S. exigua, Ctenoplusia agnata, Mythimna loreyi, Athetis dissimilis, and A. lepigone) of soybean and maize in Suwon, Korea were identified by their morphological characteristics in the wing pattern and male genitalia and partial mitochondrial DNA sequences of cytochrome c oxidase subunit 1 gene. The generation number of adults that emerge annually in six species (except A. lepigone) was estimated from the data on density fluctuations of adults caught in sex pheromone traps in 2019 and the forecasted data using temperature-associated development and reproduction models for those species. S. frugiperda adults were caught from July 27th to October 31st in 2019, and hence were initially estimated to emerge three times per year. But, it was finally expected that S. frugiperda adults could possibly emerge a total of four times per year in Suwon, considering larval emergence observed during mid- and late June in other areas. Adult emergence of S. litura, S. exigua, C. agnata, and M. loreyi in 2019 was observed from May 29th to November 6th, from May 14th to November 6th, from May 26th to October 25th, and from May 31st to November 23rd, respectively. Annual adult emergence of these four species was estimated as at least four times. Adults of A. dissimilis were caught from May 26th to September 11th in 2019, and adult emergence was estimated at only twice per annum. It was postulated that the first adult populations of five species except the two Athetis species were probably migrated from other areas.