• Journal of Environmental Science International
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• v.23 no.6
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• pp.1075-1083
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• 2014

The objective of this study was to evaluate the effect of cutting types on microclimate and growth characteristics of afforested tree in Quercus acutissima stand after different types of cutting. The difference in temperature reaching $5.2^{\circ}C$ was shown in between clear cutting and selective cutting treatments. On July and August days with temperatures more than $35^{\circ}C$ often appeared in clear cutting stand. The values of VPD in July and August were higher than those in other months. Maximum VPD of 3.99 kPa was shown in clear cutting stand on May 23 as a prolonged rainless days appeared. However, VPD in selective cutting stand always stayed under 3.0 kPa throughout growing season. A higher intensity was shown in clear cutting and strip clear cutting stands, reaching to more than $1,600{\mu}mol\;m^{-2}s^{-1}$ at midday on early August, while that in selective cutting stand stayed about 1,500. In relative growth rate selective cutting stand showed a significantly higher relative growth rate in plant height than those in other cutting stands (p<0.05). The number of leaf in current-year branches significantly increased in selective cutting stand, whereas no increase was shown in clear cutting and strip clear cutting stands (p<0.05). In addition, relative elongation rate of current year branch also showed higher values in selective cutting stand compared with that in strip clear cutting stand (p<0.05). However, leaf mass per unit area (LMA) was higher in order of strip clear cutting, clear cutting, and selective cutting stands. From these results it is concluded that environmental conditions in clear cutting and strip clear cutting stands during growing season are more stressful to afforested tree species, resulting in lower relative growth in plant height, elongation of current-year branches, and leaf number per branch compared with those in selective cutting stand. Consequently, more data must be accumulated in the field to find out best cutting type in plantation considering the adaptational characteristic of each tree species varies with species and life span of tree is long.

• Korean journal of applied entomology
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• v.53 no.4
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• pp.347-354
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• 2014

This study was carried out to clarify the change of butterfly community after clear cutting. Butterfly survey was conducted in clear cutting area, forest road, and forest using line transect method from May to November in 2011. A total of 32 species and 398 individuals of butterflies were observed. Abundance of food niche breadth and habitat type was significantly higher in clear cutting area than in forest. Estimated species richness and species diversity were significantly higher in clear cutting area than in forest. In clear cutting area, Leptidea amurensis and Argynnis niobe, vulnerable species, were abundant. This result suggests that grasslands formed by clear cutting play an important role to increase butterfly diversity in forest ecosystem.

• Journal of Korean Society of Forest Science
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• v.98 no.5
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• pp.609-617
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• 2009

This study was conducted to investigate ecological indicators of forest degradation after forest fire and clear-cutting in the Siberian larch (Larix sibirica Ledeb.) stand of Mongolia. The species abundance and biodiversity indices were higher in burned and clear-cut stands than those of reference stand, but boreal understory species, such as Vaccinium vitis-idaea, Pyrola incarnata, Linnea borealis and Maianthemum bifolium, completely disappeared and was replaced by sedge species, such as Carex duriuscula, C. lanceolata, C. pediformis, Poa attenuata and P. pratensis. During the research period, temperature increased by an average of $1.6^{\circ}C$ in burned stand and $1.7^{\circ}C$ in clear-cut stand compared to reference stand, but RH sharply decreased up to 15.7% in clear-cut stand. This result indicates that Larix sibirica stand became warmer and drier after forest fire and clear-cutting, and contributed to the abundance of sedge and grass species in the understory. Moreover, intense occupation of tall sedge grass after forest fire and clear-cutting had a vital role as obstacle on natural regeneration of Larix sibirica. The similarity of species composition between reference and burned stands was higher (73.6%) than between reference and clear-cut stands (63.8%). Soil moisture significantly decreased after forest fire and clear-cutting, and the extent of decrease was more severe in the clear-cut stand. The chemical properties at soil organic layer were significantly affected by forest fire and clear-cutting but not the mineral horizons. Inorganic nitrogen of the forest floor significantly decreased in the clear-cut stand ($1.1{\pm}0.4mg{\cdot}kg^{-1}$) than that of the burned ($4.5{\pm}2.3mg{\cdot}kg^{-1}$) and reference stands ($5.0{\pm}2.3mg{\cdot}kg^{-1}$). Available P of the forest floor significantly increased after fire, whereas it decreased after clear-cutting. These results indicate that existence of boreal understory vegetation, and changes in soil moisture and available P are distinct attributes applicable as ecological indicators for identifying forest degradation in Mongolia.

• Korean Journal of Ecology and Environment
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• v.49 no.4
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• pp.271-278
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• 2016

Forest clear-cutting operations influence biodiversity through habitat changes and food resource availability for inhabitant species. This study examined the effects of clear-cutting on forest arthropod communities. Arthropods were collected from two different forest treatment areas (clear-cut and control) in summer and autumn. In each treatment area, arthropods were sampled from both crown and ground surfaces using sweeping and pitfall trap methods, respectively. Then, the taxonomic order of the collected arthropod specimens was easily identified. Results indicate that arthropod abundance and number of taxa present were higher at ground surface than at crown levels in both clear-cut and control areas. At crown level, more homopteran species were present in clear-cut areas than in control areas in summer. At ground surface, populations of Isopoda and Opiliones were higher in control areas than in clear-cut areas, whereas numbers of Araneae, Orthoptera, and Hymenoptera were greater in clear-cut areas. Cluster analysis and principal component analysis showed distinct differences between clear-cut and control communities at crown level in summer and at ground surface in autumn. Thus, our results indicate that clear-cutting significantly influences arthropod communities, and higher taxa are valuable for conducting rapid biological assessments of ecosystem disturbances.

• Journal of Korean Society of Forest Science
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• v.112 no.3
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• pp.331-339
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• 2023

This study was conducted to identify seed inflow characteristics according to harvest typeand to provide basic data for developing a regeneration technology for secondary growth forests in Korean red pine (Pinus densiflora) succession forest formation by natural regeneration. Experimental sites were established by applying seed tree (single and group) and clear-cutting methods (10- 20- 30-m strip and 20- 30- 40-m patch). The seed inflow characteristics of the natural regeneration site were analyzed for 6 years from 2014. Most seeds were flowed to the regeneration stand from October to November. In years with good seed fructification, more than 80% were flowed in October. The average annual seed inflow by harvest type was highest in the seed tree area (296,000 seeds/ha/yr), followed by the 20-m patch clear-cutting area (291,000 seeds/ha/yr) and 10-m strip clear-cutting area (281,000 seeds/ha/yr). The distribution uniformity of seed inflow according to treatment was analyzed in the order of the 20-m strip clear-cutting area (52.2), 20-m patch clear-cutting area (52.9), and 10-m strip clear-cutting area (56.1). As a result, the 10-m strip and 20-m patch clear-cutting areas with relatively small harvest areas showed high seed inflow and distribution uniformity.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.12 no.3
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• pp.89-95
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• 2003

This research analyzes the cutting mechanism of A1100-H18 of commercially pure aluminum by image processing in SEM(Scanning Electron Microscope) for the measurement of strain rate distribution near a cutting edge in orthogonal micro-cutting. The distribution is measured using various methods in order. The methods are in-situ observations of cutting process in SEM, inputting image data, a computer image processing, calculating displacements by SSDA(Sequential Similarity Detection Algorithm) and calculating strain rates by FEM. The min results obtained are as follows: (1)It enables to measure a microscopic displacement near a cutting edge. (2) An application of this system to cutting process of various materials will help to make cutting mechanism clear.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.604-607
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• 2003

This study investigates the micro-cutting of cemented carbides using PCD(polycrystalline diamond) and PCBN(polycrystalline cubic boron nitride) cutting tools are performed with SEM direct observation method. The purpose of this study is to make clear the cutting mechanism of cemented carbides and the fracture of WC particles at the plastic deformation zone in orthogonal micro-cutting. And also to achieve systematic understanding, the effect of machining parameter on chip formation and machined surface was investigated, including cutting speed. depth of cut and various tool rake angle.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.9
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• pp.55-62
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• 2003

This paper investigates the micro-cutting of cemented carbides using PCD (polycrystalline diamond) and PCBN (polycrystalline cubic boron nitride) cutting tools are performed with SEM direct observation method. The purpose of this study is to make clear the cutting mechanism of cemented carbides and the fracture of WC particles at the plastic deformation zone in orthogonal micro-cutting. And also to achieve systematic understanding, the effect of machining parameter on chip formation and machined surface was studied, including cutting speed, depth of cut and various tool rake angle. Summary of the results are shown below. (1) Three type of chip formation process have been proposed by the results of the direct observation in orthogonal micro-cutting of cemented carbide materials. (2) From the whole observation of chip formation, primary WC particles are crushed and/or fine grained in the shearing deformation zone. A part of them are observed to collide directly with a cutting edge of tool by following the micro-cutting. (3) Surface finish, surface morphology and surface integrity is good to obtain by cutting with PCD cutting tool compared with PCBN. (4) The machined surface has the best quality near the low cutting speed of 10${\mu}m$/sec with a cutting depth of 10 ${\mu}m$ using 0$^\circ$ rake angle and 3$^\circ$ flank angle in this condition, but it was found that excessively low speed, for example the extent of 1 ${\mu}m$/sec, is not good enough to select for various reason.

• Korean Journal of Environment and Ecology
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• v.29 no.5
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• pp.785-790
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• 2015

As an alternative to large-scale clear cutting silviculture, strip clear cutting (SC) is being considered as a system compatible with ecological conservation and forest regeneration. In South Korea, application and effectiveness of SCC in varying forest types were rarely found. In this study, under the subject of strip clear cutting lands of pinus densiflora forest at Samcheok, Gangwon-do Province, the developmental aspect of low vegetation prior to and after deforestation and the correlation between environmental factor and pine regeneration were analyzed. The cover rate of understory vegetation was appeared to be increased after deforestation and rapidly increased two years after deforestation, and it was evaluated to be affected by vigorous tree species and photophilic species. From the perspective of relative importance value, Quercus mongolica, Artemisia keiskeana, and Rubus crataegifolius that influence the cover rate showed the inclination of continuous growth. The diversity of species showed increment inclination as well due to introduction and settlement of early transient species. As a result of analyzing the correlation between vegetation and environmental factor and generation of pine tree size, the soil exposure rate, intensity of light, and canopy openness showed positive relationship, and the understory vegetation cover and woody debris cover rate showed negative relationship.

• Journal of Korean Society of Forest Science
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• v.95 no.4
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• pp.501-506
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• 2006

To study the regeneration process of tree species after clear cutting, we investigated the density of seedling occurred after 1 year in the coniferous forest of Sikotuko Hokkaido, northern Japan that was clearcut after windthrow damage due to typhoon. As the results, 25 species of tree seedlings were growing and the density of seedlings and sprouts was $9.8trees/m^2$ ($1.25tres/m^2{\sim}54.44trees/m^2$) in the area of clear cutting. The 87% ($8.6/m^2$) of all seedlings was current seedlings and non-animal dispersal seedlings (average density $7.2tree/m^2$) were about 5 times more than animal-dispersal seedlings ($1.4tree/m^2$). The seedling density was beyond $6tree/m^2$ within 10m and $2{\sim}9tree/m^2$ in 150~250m from a natural forest. Number of non-animal dispersal seedlings were decreased along the distance from a natural forest but there was not such a tendency in animal dispersal seedlings. The variation in seedling density was higher in non-animal dispersal seedling than in animal dispersal seedling. In natural regeneration of tree species after clear-cutting, the possibility that pioneer species like Betula spp. etc. will be composed of the major species is high. Therefore, in order to maintain the species diversity, the nurture work for reducing competition among the individuals is necessary.