• Journal of Korea Foresty Energy
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• v.19 no.1
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• pp.1-6
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• 2000

This study was carried out to investigate the growth responses of Pinus densiflora seedlings to enhanced UV-B environment for 16 weeks in the field condition. The seedlings were treated with one of three levels of UV-B dosages - ambient UV-B, ambient + 3.2, and ambient + 5.2 KJ m$^{-2}$day$^{-1}$ and the irradiation was performed at the stage before the germination, the fully expanded cotyledon, and the primary needles grown more than 0.8cm in length of the seedlings, respectively. Enhanced UV-B irradiation reduced the height and the root collar diameter growth, and dry mass production of the seedling, and T/R ratio was increased by the UV-B treatment. Difference in seedling growth was observed by difference in time of the UV-B treatment. Among the seedlings which were treated with ambient - 3.2 KJ m$^{-2}$day$^{-1}$, height and root collar diameter growth was relatively high in the seedling received the UV-B treatment at the stage before the germination. The lowest dry mass production was observed in the seedlings received the UV-B at stage of cotyledon both in two levels of enhanced UV-B treatment. Chlorophyll concentration was reduced by enhanced UV-B irradiation, and chlorophyll a/b ratio was increased by the UV-B treatment.

• Korean Journal of Environment and Ecology
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• v.10 no.1
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• pp.76-86
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• 1996

We studied the degree of damage of trees which have been chronically damaged by environmental pollutants and the area of damaged stands in each region of the middle part of Korea with three tree species - Picea abies, Abies holophylla and Pinus densiflora. So as to diagnose the degree of tree damage in an early stage, We investigated injury index and measured contact angle and finally got the following results; 1) Visible and physiological damage such as the increase of injury index and the decrease of contact angle was serious centering around metropolitan cities live Seoul and Inchon; 2) The trees of all of 14 sites surveyed were damaged by environmental pollutants although there was difference to some extent among sites. Especially, the degree of damage appeared to be increased gradually in the western parts along including Inchon, the seacoasts. In fact, more systematic studies for this issue should be continued in other regions and countermeasures should be devised.

• Korean Journal of Environment and Ecology
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• v.16 no.3
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• pp.309-320
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• 2002

In order to understand the condition of mostly-degraded evergreen broad-leaved forests(EBLF) and to make a restoration plan of EBLF in the Korean warm temperate, the distribution of EBLF and forest vegetation types have been investigated and the categories of degraded levels have been set. The coverage of the EBLF in the Korean peninsula was approximately 10,285ha based on the existing literature review and the actual vegetation map. Forest vegetation types have been investigated at thirty-two area of the south coast and inland in the warm temperate region. As a result, The forest vegetation was classified as 52 types; 26 types of EBLF, 13 types of semi-evergreen broad-leaved forests, 9 types of deciduous broad-leaved forests, 4 types of evergreen coniferous forests. The categories of degraded levels were divided into 8 levels and 14 sub-levels according to the importance percentage(I.P.) and the number of warm temperate species.

• Korean Journal of Medicinal Crop Science
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• v.8 no.4
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• pp.327-333
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• 2000

This study was carried out to obtain the basic information for effective conservation and cultivation of Atractylodes japonica Koidz. The soil texture was sandy loam with low pH and high organic matter content compared to general cultivative land. Aerial part growth such as plant height, number of leaf, leaf length and leaf width was the highest in Tongyong indigenous species, but fresh rhizome weight was the highest in Pyongchang. Frequency of light penetration rate was high at $60{\sim}80%$ of full sun-light, but growth was better in high light penetration rate. The correlation between growth characteristics and habitat environment were investigated in 59 districts. Correation among growth characteristics in habitat, fresh rhizome weight was significant with plant height, number of leaf and stem diameter.

• The Korean Journal of Ecology
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• v.28 no.6
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• pp.417-431
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• 2005

Soils of Korea experienced with long-term acidic deposition have been exhaustively leached exchangeable base cation (BC) for plant nutrient comparable with soils of forest decline areas in Europe and N. America. Ratios of $BC/Al^{3+}$ of most soils are below than 1, which value is critical load for plant growth. Acid soil applied with dolomitic liming is increased as much as 20% and 244% in concentrations of $Ca^{2+}$ and $Mg^{2+}$, respectively, as well as shrub leaves increase much cation uptake by 1 year later. Ions of $NO_3^-$ and $NH_4^+$ in acid rain are absorbed by the canopy acted as the sink but f is leached out from the canopy to throughfall as the source at Gwangneung forest with a little of acidic deposition, however, such sink and source functions are not found at Kwanaksan forest because of so much deposition. In coniferous and deciduous forested watershed ecosystems ions of $K^+$, $Cl^-$, $NO_3^-$ and $SO_4^{2-}$ from throughfall are retained in forest floor but ions of $Na^+, $Mg^{2+}$ and $Ca^{2+}$ are leached from the floor to streamwater.

• Journal of Korean Society of Forest Science
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• v.101 no.1
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• pp.1-6
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• 2012

To achieve the forest fire management goals such as early detection and quick suppression, fire resources should be allocated at high probability area where forest fires occur. The objective of this study was to develop and validate models to estimate spatially distributed probabilities of occurrence of forest fire. The models were builded by exploring relationships between fire ignition location and forest, terrain and anthropogenic factors using logistic regression. Distance to forest, cemetery, fire history, forest type, elevation, slope were chosen as the significant factors to the model. The model constructed had a good fit and classification accuracy of the model was 63%. This model and map can support the allocation optimization of forest fire resources and increase effectiveness in fire prevention and planning.

• Journal of the Korean Wood Science and Technology
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• v.26 no.4
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• pp.6-12
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• 1998

Test results of domestic softwood lumber were presented to examine the notch effect of beams and compare to present AIJ(Architecture Institute of Japan) formula in notched wood member especially positioned in bottom side (tension side) of a beam. Notched lumber was tested under following condition : each specimen supported simply, and subjected to third-point loading at points of 1/3 of the span length. Notch was located opposite side to loading direction and notch depth were 1/6, 1/4, 1/3 of beam depth. Deflection and load were measured by digital dial guage each in 25kgf increment. Bending test results were as follows; Mpro/Mmax range (proportional and maxium bending moment ratio in notched beam) was 0.5 - 0.65. It was considered that maxium bending moment was about 1.5 times to proportional bending moment in notched beam and showed same tendency in the test result of ordinary wood specimens. AU standard formula for the tension side notch, Mmat = 0.6 ${\times}$ (Zo $\sigma$), the constant 0.6 was suitble for notch ratio(notch depth to beam depth) 1/6, but this ratio for 1/4, and 1/3 was not. So it is preferable to accept smaller value than 0.6 for notch ratio more than 1/3. These experiment results showed critical effect in tension side notched wood beam especially in greater than notch ratio 1.3 of wood beam. From the above results, it is recommened to revise design formula adoptable to domestic wood constructon member with tension side notched member.

• Fire Science and Engineering
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• v.24 no.1
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• pp.1-7
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• 2010

This paper shows combustion characteristics of fallen leaves of Quercus variabilis and Pinus densiflora according to variation of mass densities. Combustion temperature, mass loss rate, flame height, duration of combustion and velocity of hot gas are measured and analyzed. For the experiment 10cm heighted baskets with varying diameters of 20, 30, 40 and 50cm are used for the combustion and the pilot ignition is carried on the top of the fuel. In case of Pinus densiflora mass loss rate, duration of flame, flame height and combustion time become larger as the mass density and diameter of basket increase, on the other hand Quercus variabilis shows saturation characteristics in mass loss rate and flame height. Velocity of hot gas is proportional to flame height.

• Journal of Korean Society of Forest Science
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• v.79 no.4
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• pp.431-434
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• 1990

The growth pattern of bud-shoot-needle of isolated 15-year-old trees, and seansonal changes in litter-falls and fine root dry weights in the unthinned 28-year-old plantation were investigated to understand the growth phenology of Pinus koraiensis. Shoot growth was continued by 7th June when buds appeared, while current needle growth was by 19th July when the bud growth started. Most of the litter-falls occurred in October but many of them were fallen in July and August due to storms, Fine roots were produced mostly in autumn(1,004 kg/ha), and were dead during winter (583 kg/ha) and spring(1,331 kg/ha).

• Korean Journal of Remote Sensing
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• v.19 no.6
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• pp.411-419
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• 2003

An area corresponding to the spatial resolution of optical remote sensor imagery often includes more than one pure surface material. In such case, a pixel value represents a mixture of spectral reflectance of several materials within it. This study attempts to apply the spectral mixture analysis on forest and to evaluate the information content of endmember fractions resulted from the spectral unmixing. Landsat-7 ETM+ image obtained over the study area in the Kwangneung Experimental Forest was initially geo-referenced and radiometrically corrected to reduce the atmospheric and topographic attenuations. Linear mixture model was applied to separate each pixel by the fraction of six endmember: deciduous, coniferous, soil, built-up, shadow, and rice/grass. The fractional values of six endmember could be used to separate forest cover in more detailed spatial scale. In addition, the soil fraction can be further used to extract the information related to the canopy closure. We also found that the shadow effect is more distinctive at coniferous stands.