• The Korean Journal of Mycology
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• v.51 no.4
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• pp.419-428
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• 2023

Several endophytic fungal strains were isolated from Taxus cuspidata and identified by molecular analysis of the internal transcribed spacer and RNA polymerase II second largest subunit. This study aimed to determine the relative abundance and compare the species diversity of endophytic fungal communities within needle leaves and twigs. We identified a total of 49 endophytic fungal species. Notably, two species, Trichoderma dingleyae and Xylaria cubensis, were discovered to be previously unrecorded in Korea. The fungal communities in both plant tissues demonstrated distinct species composition. Differences were observed in the relative abundance and species diversity index between needle leaves and twigs. Our findings suggest that the host plant tissues influence the species diversity of endophytic fungal communities.

• Korean Journal of Environment and Ecology
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• v.28 no.5
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• pp.550-558
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• 2014

This study was conducted to investigate the distribution and the population dynamics of Hipparchia autonoe by using a line transect and Mark-Release-Recapture (MRR) at the Mt. Halla in Jeju Island. The results showed that H. autonoe was found from 1,500 m above the sea level. Total 1,493 H. autonoe with 978 males and 515 females were captured and released in the MRR study site. Among them, 518 individuals including 284 males and 234 females were recaptured. The average survival time was 2.31 days with 2.14 days for males and 3.47 days for females, indicating longer survival time in case of females than males. The daily population size of males estimated in the MRR study site was maintained about 1,000 individuals in July and gradually decreased less than 200 in August. The number of females showed peak at 335 individuals on July 24, and gradually decreased less than 120 in August. Thus, female population was 1/3 of males. The average travel distance of male and female H. autonoe were $116.8{\pm}191.9m$ and $118.4{\pm}161.5m$, respectively, indicating almost same between sexes. H. autonoe in the Mt. Halla formed single population group in the wide meadow around the Baekrokdam Lake. The highest population density of H. autonoe was occurred in the restored area from damages, where host plants such as the sheep's fescue or the food plant are abundant by artificial restoration efforts.

• Journal of Ecology and Environment
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• v.43 no.2
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• pp.226-245
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• 2019

To understand the dynamics of radial growth of trees and micro-climate at a site of Korean fir (Abies koreana Wilson) forest on high-altitude area of Mt. Hallasan National Park, Jeju Island, Korea, high precision dendrometers were installed on the stems of Korean fir trees, and the sensors for measuring micro-climate of the forest at 10 minutes interval were also installed at the forest. Data from the sensors were sent to nodes, collected to a gateway wireless, and transmitted to a data server using mobile phone communication system. By analyzing the radial growth data for the trees during the growing season in 2016, we can estimate that the radial growth of Korean fir trees initiated in late April to early May and ceased in late August to early September, which indicates that period for the radial growth was about 4 months in 2016. It is interesting to observe that the daily ambient temperature and the daily soil temperature at the depth of 20 cm coincided with the values of about 10 ℃ when the radial growth of the trees initiated in 2016. When the radial growth ceased, the values of the ambient temperature went down below about 15 ℃ and 16 ℃, respectively. While the ambient temperature and the soil temperature are evaluated to be the good indicators for the initiation and the cessation of radial growth, it becomes clear that radii of tree stems showed diurnal growth patterns affected by diurnal change of ambient temperature. In addition, the wetting and drying of the surface of the tree stems affected by precipitation became the additional factors that affect the expansion and shrinkage of the tree stems at the forest site. While it is interesting to note that the interrelationships among the micro-climatic factors at the forest site were well explained through this study, it should be recognized that the precision monitoring made possible with the application of high resolution sensors in the measurement of the radial increment combined with the observation of 10 minutes interval with aids of information and communication technology in the ecosystem observation.

• Journal of Radiation Protection and Research
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• v.37 no.4
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• pp.167-172
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• 2012

Jeju Island is a significant area as a reference site of in situ gamma spectrometry because there are a number of open spaces which includes $^{137}Cs$ above a certain level. In this paper, the pasture within the Hallasan National Park was selected as one of the open spaces of Jeju Island. The homogeneity of $^{137}Cs$ at the site was assessed by analysis of variance on count and by radioactivity concentration obtained through in situ gamma spectrometry. For this purpose, the count of a total of 79 points at 3 sites were measured with less than count uncertainty of 5% for 2000 seconds. In the results of the analysis of variance, the 2 sites were homogeneous, and the remaining 1 site can be specified to be homogeneous through the adjustment of measuring range. The distribution of radioactivity concentration calculated by in situ gamma spectrometry were $53.7{\sim}93.2Bq\;kg^{-1}$, $30.5{\sim}61.0Bq\;kg^{-1}$ and $48.8{\sim}102Bq\;kg^{-1}$ at each site.

• Korean Journal of Environment and Ecology
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• v.21 no.2
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• pp.149-160
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• 2007

This study was performed to clarify general characteristics of the bird community structure within the boundaries of Hallasan National Park. The surveys were made during April 2006 to February 2007, and the birds were identified and the individual number of those birds was counted up to 38 species and 2,323 individuals in total. Among the total 38 species, 27 residents, 6 summer visitors, 2 winter visitors and 8 passage birds were identified by migratory pattern categories. The most dominant species was Corvus macrorhynchos (14.81%), followed by the Hypsipetes amaurotis(12.66%), and the third was Carduelis sinica(10.33%), and next, Corvus corone (8.44%). About 31 species and 1,639 individuals of birds were sighted around Sallok road 1 (A), and 27 species and 693 individuals of birds were spotted around mountain trails (B), Consequently, it was found that [A] area abounds in more birds than [B] area. Species diversity (H') was distributed over the range of $1.34{\sim}2.56$ degrees in view of the surveyed areas by season. The maximum species diversity (2.56) was found in (A) area in the spring, and the minimum species diversity (1.34) was seen in [B] area in the winter. There are different distributional patterns of birds in terms of the altitude. It was also observed that there were differences in weather factors and food resources by the altitude.

• Korean Journal of Environment and Ecology
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• v.6 no.1
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• pp.72-85
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• 1992

The analysis of visitor's behavior in Hallasan National Park was executed for a month in september, 1990. In the characteristics of trip purpose, the nature-oriented motive was 68.9% of the total. And in the characteristics of the accompanied, the ratio of such items as company, friends,2-3 persons and above 12 persons was generally high. The ratio of lunch box was 62.7％ and the item of bring back waste treatment was 69.6% in the characteristic of activity. The degree of landscape satisfaction was 3.98 and comparatively high on considering the maximum degree of 5.0, but in the degree of facility, the degree of dissatisfaction was high. Therefore the degree of total satisfaction was 3.43. In the opinion of users, the entrance by order of arrival, the adoption of reserved system and the limitation of the entrance of a group were gen- orally objected but the adoptation of nature rest-rotation system was comparatively assented Specially, visitor center was rarely used but many visitor who has attended there positively think about it. In factor analysis, 4 factors were extracted. Facilitate, social. user behavior and natural property were the most affecting factor to psychological satisfaction test. Multiple regression results showed that cleanness, land-scape, safety, no. of wastebasket and crowdness items affected the total satisfaction variable in total and local area.

• The Journal of Engineering Geology
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• v.25 no.4
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• pp.473-484
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• 2015

Geophysical exploration using electric resistivity, ground penetrating radar (GPR), and impedance high-frequency (ZHF) surveys was conducted in Gujwa-eup, Jeju City, Jeju Island, an island in the Korea Strait, to confirm the existence of new caves near known caves. The exploration revealed a number of anomaly zones, presumed to be caves; 27 sites at suitable locations and depth ranges were selected for drilling and further surveys. However, contrary to predictions, most of the anomaly zones were clinker layers or paleosols intercalated with lavas. Only five boreholes intersected caves. The clinker layers and paleosols were possibly detected as anomalies owing to their different physical properties from the other rocks. Two of the five cave-finding boreholes penetrated Yongcheon Cave; a new cave was found at the other. The two boreholes that penetrated Yongcheon Cave were drilled in areas where the cave has not been previously reported, and thus helped correct an error in the cave distribution map. The cave newly discovered in this boring exploration is 180 m long, and it is connected to the upstream part of Dangcheomul Cave (110 m). The cave contains well-developed lava helictites, lava levees, and ropy structures; carbonate speleothems such as soda straws, stalagmites, columns, and curtain shawls are also well preserved. Notably, the unique shape of the carbonate speleothems is attributed to their growth in relation to the cavern water that flowed into the cave along plant roots.

• Korean Journal of Environmental Biology
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• v.35 no.4
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• pp.437-445
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• 2017

An analysis of recent studies and a field survey were conducted to investigate the distribution of the exotic species Ophraella communa LeSage (Coleoptera, Chrysomelidae) and the results' applicability for biological control against ragweed, which disturbs the island's ecosystem. The ragweed beetle (O. communa) can be found anywhere on the host plant Ambrosia artemisiifolia L., which grows in Jeju Island. Moreover, ragweed beetles possess the following characteristics: a high host plant specificity, a high-temperature resistance, an excellent mobility, and multivoltinism. Ragweed is extensively distributed and gradually expands its habitat further on Jeju Island. For this reason, it is recommended to take advantage of O. communa for the biological control of ragweed instead of pesticides or direct removal, considering that Jeju is endowed with many natural reserves and unique insular traits.

• Journal of agriculture & life science
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• v.52 no.6
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• pp.163-173
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• 2018

This study was carried out to propose the baseline data for in situ conservation by analyzing environmental and growth characteristics in Pedicularis hallaisanenesis habitats. P. hallaisanensis habitats, according to investigations, were located on the slope of southwest at an elevation of 1,400 m in Mt. Gayasan and on the slope of southeast at an elevation of 1,500 m in Mt. Hallasan. Pedicularishallaisanensis habitats. Also, habitats were found at the grassland with no upper vegetation. In the study sites, soil pH and soil organic matter were 4.9-6.5 and 4.4-8.1%, respectively. A total of 55 vascular plants taxa were identified in ten quadrats in two habitats, of which 25 were inhabited in Mt. Gayasan and 37 in Mt. Hallasan. Current status of P. hallaisanensis habitats were very vulnerable with the pressure of the vegetation constantly threatening the species' survival. Thus, concrete conservation plans including diverse factors as light intensity, temperature and genetic analysis to protect natural habitats should be set up as soon as possible.

• Journal of Korean Society of Forest Science
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• v.110 no.2
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• pp.141-154
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• 2021

The change in vegetation structure along elevational gradients on the southeastern part of Mt. Hallasan was studied. Vegetation data were collected with 59 quadrates located from 16 to 1,565 m with 100 m intervals. Community types were classified using cluster analysis, and species composition and diversity were analyzed along elevational gradients. The vegetation was classified into seven, namely, type 1 Quercus serrata community, type 2 Carpinus tschonoskii community, type 3 Carpinus laxiflora community, type 4 Pinus densiflora community, type 5 Abies koreana community, type 6 Castanopsis sieboldii community, and type 7 Quercus acuta community. The species with a high importance value in tree layer in each elevational zone were C. sieboldii and Q. acuta at 100-600 m; C. laxiflora, Q. serrata, and C. tschonoskii at 700-800 m; P. densiflora at 1,100-1,200 m; and Abies koreana at 1,500-1,600 m. The species diversity indicated higher value at 700-800 m, 1,200-1,300 m and 1,400-1,500 m than at the other elevation.