• Korean Journal of Environment and Ecology
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• v.34 no.1
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• pp.27-41
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• 2020

The purpose of this study was to survey vegetation characteristics of Jeopdo (island) for the construction of a database. We installed and analyzed 52 plots with 100㎡ quadrat to investigate the vegetation characteristics. The community classification based on TWINSPAN found seven categories of vegetation communities in the surveyed region: Pinus thunbergii-Pinus densiflora community, Pinus densiflora-Quercus serrata community, Carpinus turczaninowii-Quercus variabilis community, Carpinus turczaninowii-Quercus acutissima community, Quercus variabilis-Carpinus turczaninowii community, Castanopsis sieboldii community, and Actinodaphne lancifolia-Camellia japonica community. The vegetation in Jeopdo is largely composed of evergreen conifer trees community (communities I and II), Carpinus turczaninowii-deciduous broad-leaved trees such as Quercus spp. community (communities III, IV, and V), and evergreen broad-leaved trees community (communities VI and VII). The evergreen conifer tree (Quercus serrata) community is currently competing with Pinus densiflora and Pinus thunbergii. The current state is expected to continue due to the lack of forces, such as Castanopsis sieboldii and Actinodaphne lancifolia, in the succession middle stage and climax stage. The current state of Carpinus turczaninowii-deciduous broad-leaved trees such as Quercus spp. community is expected to last for a long time due to slow vegetation development because of soil conditions. The evergreen broad-leaved trees community is transforming from the initial stage of Pinus densiflora and Pinus thunbergii through the stage in Quercus serrata to Castanopsis sieboldii and Actinodaphne lancifolia. The overall ages of the specimens were similar, and the oldest tree was the 59-year old Castanopsis sieboldii. The correlation analysis of major species showed a high positive correlation between Pinus thunbergii and Eurya japonica, Pinus densiflora and Fraxinus sieboldiana, and Actinodaphne lancifolia and Camellia japonica and a high negative correlation between Pinus densiflora and Carpinus turczaninowii and Carpinus turczaninowii and Eurya japonica.

• Korean Journal of Medicinal Crop Science
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• v.11 no.3
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• pp.216-223
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• 2003

This experiment was carried out to investigation the growth differentiation between direct sowing and transplanting on P. ginseng cultivated on field and underwood. The results were as follows: In direct sowing treatment, emergence rate of P. ginseng cultivated on field and under conifer forest was above 80%, but it was only 40% at cultivated under broad-leaved forest. And survival rate was directly diminished about 10% every year. In transplanting treatment, survival rate was also diminished every year, it was slighter than that of direct sowing treatment. The growth amount of P. ginseng cultivated underwood was poor, compared to field culture, but there was no significant between conifer forest and broad-leaved forest. In transplanting treatment of 1 to 6 year-root seedling, survival rate of P. ginseng cultivated underwood was equal or slightly good compared to that of cultivated on field. Among seedling age, survival rate of elder seedling was lower than that of younger seedling. In P. ginseng cultivated underwood, the annual growth increment of 1 and 2 year-root seedling increased slowly and continually, whereas, that of 3 to 6 year-root seedling stopped or decreased slightly.

• The Korean Journal of Quaternary Research
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• v.24 no.1
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• pp.25-33
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• 2010

Holocene vegetation and climate changes were assumed on the basis of pollen records from Wonpyeong Trench II-3 of the Osong archaeological site, Cheongju, Chungbuk Province, Korea. An organic matter beared in coarse sediments appeared to be low throughout the succession. Although an occurrence of pollen grains is not high, some dominant and principal taxa may indicate vegetation changes response to climate changes in central inland area of the Korean Peninsula. The age determination can be estimated with indirect way by comparing with previous age-controlled pollen studies. It is assumed that the former last glacial conifer forests had been changed into open mixed conifers and deciduous broadleaved forest during the early Holocene period. Warmer and more humid climate conditions, during the mid-Holocene, might have allowed the hardwoods including deciduous- and evergreen-broadleaved trees, and warm-preferring pine tree to flourish. Subsequently, the former forests were replaced by mixed of conifer and deciduous broadleaved forest owing to deterioration of climate conditions during the late Holocene. Human activity is also detected by agricultural indicators, such as buckwheat and large pollen grains comparable to corn, in upper most pollen profile. During this time, the forests in studied area were primarily affected by human disturbance rather than natural environment.

• Korean Journal of Environment and Ecology
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• v.7 no.2
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• pp.252-269
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• 1994

This study was conducted to the early diagnosis of injuries on needles of conifer by acid rain and air pollutants in metropolitan area, Korea. It was executed to calculate of injured index, contact angle measurement, nutrient content analysis in needles, analysis of soil chemical properties from June 1990 to June 1991. The sensitive species (Picea abies, Abies holophylla) for acid rain and air pollutants were used as the study materials. And the results from this study were as follows : Degree of Injured index was divided into three groups in June 1990. The first group (not injured sites) was Kwangnung and Yangpyung. The Second group (slight injured sites) was Inchon, Boramae Park, Kwachun, Seoul Women's Univ., Anyng, and Yangsuri. The third group (serious injured sites) was Namsan, Seoul City Univ., Children's Park, and Kumgok Royal Tomb. But, Inchon, Kwachon area were changed from slight injured areas to serious injured areas in December 1990. As time goes on, the degree of injured gets worse. In contact angle analysis, value of December 1990 was lower than that of June 1990, especially, that of two-year-needle were lower than of one-year-needle. The correlation between injured Index and contact angle was significantly negative. In the result of needle nutrients analysis of Picea abies, Abies hozophylla, Ca, Mg, K contents was higher in December 1990 than that in June 1991 and that of one-year-needle were prominantly higher than that of two-year-needle. In case of wax quantity analysis in injured area, the older the leaf age is, the smaller the contented wax quantity is. In injured area, the higher a leaf age is, the much that of index is. As a result, the method of analysis referred in the former, is applied by a complementary cooperation. That of method is done sustainably in the future, the correct results will be expected.

• Journal of The Geomorphological Association of Korea
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• v.17 no.1
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• pp.39-48
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• 2010

This is a case study to research the environmental changes that occurred during the Latter Half of the postglacial age around the Basin of Onyang River in Asan, Korea. In line with this purpose, the author performed a pollen analysis and a radiocarbon dating on the deposits of alluvial fan around the upper Geumgok River, a tributary of Onyang River. Sampling point was at the altitude of about 67.5 meters, which belongs to the central zone of the cool temperate forest. The followings are the results of the study. The study area has passed through SC-I (the coniferous forest period in which Pinus was dominant), SC-II (the deciduous broad-leaved forest period in which Quercus and Castanea were dominant) and SC-III (the mixed conifer and deciduous broad-leaved forest period, in which Pinus, Quercus and Ulmus/Zelkova were dominant) respectively since about 3,000 yrB.P. SC-I period and SC-II period are presumed to be between about 3,000 and 2,000 yrB. P., and SC-III period to begin after 2,000 yrB.P. In comparison with the nationwide pollen zone during the postglacial age, SC-I and SC-II periods are contrasted with the R-IIIa zone and also the SC-III zone with the RIIIb zone. In addition, it is assumed that Pinus densiflora forest luxuriated there since 2,000 yrB.P. due to the destruction of forests, and that a lot of Fagopyrum pollen appeared; altogether, it was the so-called human interference period, from which forests began to be markedly destroyed. It is concluded that in those days inhabitants leaded agricultural life.

• Journal of The Geomorphological Association of Korea
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• v.17 no.2
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• pp.53-61
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• 2010

In this study, pollen analysis and a dating were performed on the alluvial deposits in the Tangjeong Plains in Asan-Si, Chungcheongnam-Do. Specimens were collected at the altitude of about 12m, which belongs to the mid-forest belt in the cool temperate zone. The followings show the results. In general, the target zone passed through TJ-I (the coniferous forest age in which the Pinus forest was dominant), TJ-II (the mixed conifer and deciduous broad-leaved forest age in which Pinus and Quercus were dominant) and TJ-III (the coniferous forest age in which the Pinus was dominant) respectively. TJ-II was subdivided into TJ-IIa and TJ-IIb. TJ-I is presumed to be between about 2,810 and 1,500yrB.P.; TJ-IIa to be between about 1,500 and 1,370yrB.P.; and TJ-IIb to be between about 1,370 and 770yrB.P. As for TJ-III, it is presumed to begin after about 770yrB.P. In comparison with the nationwide pollen zone during the Postglacial, TJ-I and TJ-II are contrasted with the R-IIIa period and also TJ-III is contrasted with RIIIb (so-called human interference age). It is also presumed that Pinus luxuriated there after about 770yrB.P. as forests began to be markedly destroyed in the Tangjeong Plains.

• Journal of Environmental Science International
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• v.21 no.8
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• pp.1009-1013
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• 2012

Leptoglossus occidentalis Heidemann, 1910 was newly recorded in Korea as a invasive species at Gyeongsangnam-do, Korea in 2010 and 2011. Leptoglossus Guerin-Meneville, 1831 is also newly recorded Coreid genus in Korea. The diagnostic shape is expanded leaf-like hind tibiae. The origin of this species is North America and it has been rapidly propagated around the world as a pest. This bug recognized as a pest on almost of Pinaceae plants and they suck on developing cones, so the monitoring on the present invasion of this species in Korea is urgent. It was presumed that the invasion of Leptoglossus occidentalis into Korea was before 2010 with present study.

• Journal of the Korean Wood Science and Technology
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• v.40 no.2
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• pp.61-70
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• 2012

In this study the effect of heartwood-coating (HCO), vapor-dam (VD), bark-remaing (BR) and bark-remaining- coating (BRC) treatments were evaluated during air circulating oven-drying of hollowed round-post of Korean red pine. Hollowed round-post could be dried from the green condition to approximately 6% MC within 84 to 156 hours for the UC, HCO and VD specimens and it took 72 to 240 hours to about 8% MC, which is recommended as the indoor in-use MC. The temperatures in the hole of the Control (UC) and HCO specimens constantly showed a higher-leveled distribution pattern than those inside wood. The vapor pressure in the hole of the UC, HCO and BR specimens was higher than that inside wood and showed difference as highest value of about 20 mbar. The surface checks of all specimens were mild and were observed in increasing order of BRC, BR, UC, VD and HCO specimens.

• The Korean Journal of Ecology
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• v.17 no.3
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• pp.415-424
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• 1994

Community structure, size and age distribution of tree species of the subalpine Korean fir (Abies koreana) forest at the elevation of 1, 400~1, 700m were strudied in the north-west side of Chonwangbong Peak (1915m) in Mt. Chiri for the purpose of better understanding of the population dynamics of Abies koreana. Eight 20m X 20m permanent quadrats were established in 1991, and trees $\geq$ 2.5cm DBH for all species were marked with numbered aluminum tag, and saplings of Korean fir and Korean pine (Pinus koraiensis) were also tagged with aluminum sheet. These two conifer species comprised more than 60% of the total density and total basal area of the community. Quercus mongolica and Acer pseudo-sieboldianum were subdominats. Oridination study showed that cool temperate species such as Sorbus commixta, Betula costata, Acer tschonoskii and Acer ukurunduense occurred in close association with Abies koreana and Pinus koraiensis. Major tree species, especially Abies koreana and Pinus koraiensis, were well represented in samller size classes, indicating that they were regenerating well. Age distributuion of the Abies koreana and Pinus koraiensis showed that the former has longer physiological longevity than the latter, and that establishment were episodic and varied with sites, which implies the importance of the role of natural and artificial disturbances in this Abies kireana forest.

• Proceedings of the KSME Conference
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• 2001.06e
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• pp.748-753
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• 2001

The objective of the present study is to visualize the pulsatile flow fields by using three-dimensional computer simulation and the PIV system. A closed flow loop system was built for the steady and unsteady experiments. The Harvard pulsatile pump was used to generate the pulsatile pressure and velocity waveforms. Conifer powder as the tracing particles was added to water to visualize the flow field. Two consecutive particle images were captured by a CCO camera for the image processing at several cross section. The range validation and the area interpolation methods were used to obtain the final velocity vectors with high accuracy. The finite volume predictions were used to analyze three-dimensional flow patterns in the bifurcation model. The results of the PIV experiment and the computer simulation are in good agreement and the results show the recirculation zones and formation of the paired secondary flow distal to the apex of the bifurcated model. The results also show that the branch flow is pushed strongly to the inner wall due to the inertial force effect and helical motions are generated as the flow proceeds toward the outer wall.