• Korean Journal of Plant Resources
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• v.11 no.1
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• pp.9-14
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• 1998

Two types of somatic embryos were directly induced from the immature zygotic embryos of the wild prunus yedoensis in Mt. Halla after 16 weeks of culture on MS medium supplemented with 0.1mg/L $GA_3$ and 0.1mg/L BAPor 0.5mg/L $GA_3$ and 0.1mg/L BAP. One was normal single embryo with a single basal part. Normal somatic embryos germinated successfully on 1/2 MS medium. However, abnormal nulticotyledonary somatic embryos, formed shoots only on hormone free MS medium and about 80% of shoots rooted on MS medium with 0.5mg/L IBA. The mximum frequency (62.5%) of normal somatic embryos was directly obtained from the zygotic embryo 30 days after full blooming but it was decreased with further maturation.

• Korean Journal of Plant Resources
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• v.25 no.1
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• pp.89-95
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• 2012

This study was conducted to provide basic information for conservation and restoration through investigation of vegetation structure on the Euchresta japonica Hook. f. ex Regel (Korean endangered species) in Mt. Halla in Jeju Island. Very few individuals were discontinuously distributed and restricted at 220 m above sea level, very steep slope ($40-50^{\circ}$), rocky area of north face of Donneko Valley. For investigation of environmental condition, we established $10{\times}20\;m$ quadrat and one control $20{\times}20\;m$ quadrat in the habitats. Thirty three species were found at habitat under 10-16 m Castanopsis sieboldii tree layer (70-80%). The principal causes of threat which were investigated in this study are competition among companies, very steep slopes, artificial management of valley. For restoration and conservation of habitats, it is needed to suitable plans.

• The Korean Journal of Mycology
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• v.47 no.3
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• pp.199-208
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• 2019

In this study, the community structures of the ectomycorrhizal (ECM) fungi in the roots of Abies koreana and Taxus cuspidata were investigated at different altitudes of Mt. Halla. We identified the collected ECM root tips based on morphological characteristics and phylogenetic analysis through sequencing of the rDNA ITS regions. From the roots of A. koreana and T. cuspidata, 11 species and 12 species were identified, respectively. The Shannon's index and species evenness and abundance of the ECM fungi were higher in the higher than lower regions, regardless of host plant species, however, the number of ECM root tips showed the opposite pattern. The community similarity among the ECM fungi in A. koreana was significantly higher than that among the ECM fungi in T. cuspidata or than that between A. koreana and T. cuspidata (p < 0.05). These results could be useful for the conservation and management of the habitat of A. koreana, which is threatened with extinction due to increasing ambient air temperature.

• The Journal of the Convergence on Culture Technology
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• v.8 no.3
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• pp.493-499
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• 2022

This paper reports the results of the eruption of a volcano on Jeju Island at a certain rate, and the tumulus formed after the eruption and the basalt that erupted from the middle of Mt. Halla washed up to the sea. We analyzed the speed when basalt underground magma breaks through the neutral zone on the ground with an absolute temperature of about 1000K and explodes at an absolute temperature of 1200K at an altitude of 1950m. The density of combustion gas becomes smaller than the surrounding air due to the plume volcanic eruption, which is the heat flow of the flame column due to buoyancy, and buoyancy is generated and an updraft is formed. Flame pillars are classified as continuous, intermittent, and buoyant flame zones. As the speed of the flame pillar of Mt. Halla (1950m) falls from the highest point it has risen, potential energy is converted into kinetic energy and is caused by the flow of fluid, solving these two equations equal, the volcanic eruption velocity is 87.5 m/s. At this time, the density of magma is inversely proportional to the temperature. Geomunoreum (456m) had an explosion speed of 42.6m/s.

• Journal of The Geomorphological Association of Korea
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• v.20 no.3
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• pp.95-107
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• 2013

In order to examine the temperature regime responsible for periglacial processes, air and ground temperatures were monitored from October 2010 to May 2011 at a subalpine bare patch (1,710m asl) of Mt. Halla. Four thermistor sensor probes were installed at 55 cm above a ground surface and depths of 2 cm, 10 cm, and 20 cm, respectively. A mean air temperature is $-0.1^{\circ}C$, while mean ground temperatures are $1.8^{\circ}C$ at 2 cm, $2.6^{\circ}C$ at 10 cm and $3.2^{\circ}C$ at 20 cm deep. A mean monthly ground temperature at 2 cm deep demonstrates below $0^{\circ}C$ successively from January to March, while those at 10 cm and 20 cm deep show no sub-zero temperature. A total of 72 freeze-thaw cycle was observed in air temperature. However, the numbers in ground temperature reduced into 17 at 2 cm, 8 at 10 cm, and 3 at 20 cm deep. The cycles of air temperature and ground temperature at 2 cm deep mostly fluctuated diurnally, while those of ground temperature at 10 cm and 20 cm deep exhibited a several-daily oscillation. Snow cover over 55 cm high remained from January to early April, and it seemed to disappear completely on April 16. A seasonal frost of at least 2 cm thick was formed on late December and the isotherm of $0^{\circ}C$ descended slowly into 10 cm deep on late March to early April due to the insulating snow cover. It showed the maximum freezing depth of 20 cm on April 7 to 14 and then thawed rapidly so that the frozen ground did not longer after April 17. Periglacial processes are predominant during a freezing period than a thawing period when the ground surface is still covered with snow. The periglacial mass movement in the subalpine zone of Mt. Halla is mainly generated by frost creep in terms of the occurrence depth of diurnal freeze-thaw cycle and the maximum freezing depth of ground.

• Journal of Environmental Science International
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• v.19 no.4
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• pp.491-507
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• 2010

This study focuses on the fauna, seasonal prevalence and altitudinal distribution of the flies from March to November, 2008 in Mt. Hallasan, Jejudo Island, Korea. The fauna of flies was 39 species belonging to 5 Families which consist of 12 Calliphoridae, 19 Muscidae, 5 Sarcophagidae, 1 Dryomyzidae 1, Scathophagidae and 1 Anthomyiidae. The total number of flies collected was 21,605 with sex ratio of 57.98% in Mt. Halla. The ratio is higher than that of the residential area and other mountain survey sites. The average number of per trap individuals collected on the trapping day is 267, which is similar with the average of Mts. Jiryong, Juwang, Palgong and Gumo. The five dominant species showed a distinctive seasonal prevalence of 92.6% of the total flies: Chrysomyia pinguis (34.2%), Calliphora lata (25.3%), Hydrotaea dentipes(23.1%), Fannia scalaris (5.1%), and Lucilia caesar (4.9%). The seasonal prevalence of the flies was from the beginning of March to the end of November, and the highest peak time of the whole flies, males and females were different respectively. In the similarity index of the flies collected in different altitude, that of between 1,000 meters and 1,500 meters was the highest among the indices of 500 meters and above 1,000 meters. The index at each altitude was above 80% because of the same area. The diversity index of fly species was between 0.00 and 0.88 through altitudinal traps monthly. The highest index in Trap 1 was 0.88 in October, in Trap 2, 0.82 in July and in Trap 3, 0.63 in July. The diversity above 1,000 meters was most various in July. The five dominant species of C. pinguis, C. lata, H dentipes, F. scalaris, and L. caesar showed distinctive seasonal prevalence, relative abundance and altitudinal distribution respectively.

• Journal of the Korean earth science society
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• v.26 no.2
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• pp.109-113
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• 2005

In this study, the estimation of the temperature distribution of Jeju Island with coastal ocean derived from the thermal band of Landsat 7/ETM+ of January 6, 2003 was carried out. For the computation of the temperature of the island and the coastal ocean based on the thermal band, we used NASA method wiich is the 8 bit Digital Number(DN) converted into spectral radiance. The computed results showed that the land temperature variations were from 0 to 12 Celsius degrees, and a good agreement with the observation ones based on the method. However, the ocean surface temperature was not much changed ground 15 degree since the water was well mixed between the coastal and the offshore ocean. The interesting results were that the temperature distributions of the southern part(Seogwipo City) of Jeju Island were higher than those of the north one(Jeju City) by more than 2 Celsius degree at the same height although the distance between the Jeju and the Seogwipo is only about 35km in winter season. The reason was found that the solar irradiance intensity of the south part was stronger than the north one by Halla mountain in winter season only. From the results, we found that the seasonal variations of solar irradiation and the height of Mt. Halla were an important role of temperature distribution of Jeju Island.

• Journal of Plant Biology
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• v.35 no.4
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• pp.307-316
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• 1992

A key to the species which have been isolated from the Korean forest soils was provided, and three unrecorded species found in the forest soils of Mt. Halla were described and illustrated. Twenty dictyostelid cellular slime molds had been found in Korean forest soils. Among these, nine species were PG positive, and eleven species were PG negative. Three species described in this study were all PG positive. These were Dictyastelium aurea-stipes Cavender, Raper et Norberg vaL aurea-stipes (new strain HL-5), Dictyastelium monachasiaides Hagiwara, PalysPhandylium tenuissimum Hagiwara. Morphological features and growth habits of these species were examined and compared, and their distribution patterns were illustrated.trated.

• Plant Resources
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• v.5 no.3
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• pp.214-223
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• 2002

The objective of this study was to understand the conservation of gene resources and provide information for mass selection' of winter bud characters among the selected populations of Kalopanax septemlobus Koidz using analysis of variance(ANOVA) tests. The obtained results are shown below; 1. Ten populations of K. septemlobus were selected for the study of the variation of winter bud characters in Korea. The results of the analysis of variance(ANOVA) tests shows that there were statistically significant differences in all of the winter bud characters among those populations. 2. Correlation analysis shows that width between Height and DBH(Diameter at breast height) characters have negative relationship with all of the characters, as ABL(Apical branch length), ABW(Apical branch width), AWBL(Apical branch winter bud length), AWBW(Apical branch winter bud width), ABT(Apical branch No. of thorns), ABLB(Apical branch No. of lateral bud) and LBL(Lateral branch length), LBW(Lateral branch width), LBT(Lateral branch No. of thorns), LBLB(Lateral branch No. of lateral bud). 3. The result of principal component analysis(PCA) for winter buds showed that the first principal components(PC' s) to the fourth principal component explains about 78% of the total variation. The first principal component(PC) was correlated with AWBW, LWBW, and LBL and the ratio of ABL/ABW and LBL/LBW out of 16 winter bud characters. The second principal component correlated with ABL, ABW, ABLB, LWBL(Lateral branch winter bud length), and LBW and the ratio of AWBL/AWBW. The third principal component correlated with ABL, ABW, LWBL, LBL, and the ratio of LBL/LBW. The fourth principal component correlated with LBL and the ratio of LWBL/LWBW(Lateral branch winter bud width), LBL/LBW. Therefore, these characters were important to analysis of the variation for winter bud characters among selected populations of K. septemlobus in Korea. 4. Cluster analysis using the average linkage method based on 10 selected populations for the 16 winter bud characters of K. septemlobus in Korea showed a clustering into two groups by level of distance 1.1(Fig. 3). As can be seen in Fig. 3, Group I consisted of three areas(Mt. Sori, Mt. Balwang and Mt. Worak) and Group Ⅱ contisted of seven areas(Suwon, Mt. Chuwang, Mt. Kyeryong, Mt. Kaji, Mt. Jiri, Muan, and Mt. Halla). The result of cluster analysis for winter bud characters corresponded well with principal component analysis, as is shown in Fig. 2.

• Economic and Environmental Geology
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• v.28 no.4
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• pp.395-404
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• 1995

The geologic structure of the Cheju volcanic island has been investigated by analyzing the gravity and magnetic data. Bouguer gravity map shows apparent circular low anomalies at the central volacanic edifice, and the maximum difference of the anomaly values on the island appears to be 30 mgal. The subsurface structure of the island is modeled by three-dimensional depth inversion of gravity data by assuming the model consists of a stacked grid of rectangular prisms of volcanic rocks bounded below by basement rocks. The gravity modeling reveals that the interface between upper volvanic rocks and underlying basement warps downward under Mt. Halla with the maximum depth of 5 km. Magnetic data involve aeromagnetic and surface magnetic survey data. Both magnetic anomaly maps show characteristic features which resemble the typical pattern of total magnetic anomalies caused by a magnetic body magnetized in the direction of the geomagnetic field in the middle latitude region, though details of two maps are somewhat different. The reduced-to-pole magnetic anomaly maps reveal that main magnetic sources in the island are rift zones and the Halla volcanic edifice. The apparent magnetic boundaries inferred by the method of Cordell and Grauch (1985) are relatively well matched with known geologic boundaries such as that of Pyosunri basalt and Sihungri basalt which form the latest erupted masses. Inversion of aeromagnetic data was conducted with two variables: depth and susceptibility. The inversion results show high susceptibility bodies in rift zones along the long axis of the island, and at the central volcano. Depths to the basement are 1.5~3 km under the major axis, 1~1.5 km under the lava plateau and culminates at about 5 km under Mt. Halla. The prominent anomalies showing N-S trending appear in the eastern part of both gravity and magnetic maps. It is speculated that this trend may be associated with an undefined fault developed across the rift zones.