• Title, Summary, Keyword: light thinning

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Thinning Intensity for Large Diameter Trees in Korean White Pine Plantation of South Korea

  • Lee, Daesung;Seo, Yeongwan;Park, Jiyoung;Choi, Jungkee
    • Journal of Forest and Environmental Science
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    • v.33 no.1
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    • pp.74-77
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    • 2017
  • The purpose of this study is to analyze the effect of thinning intensity on the growth of large diameter trees in Korean white pine (Pinus koraiensis S. et Z.) plantation. Eight thinning plots were analyzed by categorizing into heavy thinning, light thinning, no thinning (control) according to thinning intensity. As a result, average DBH increased more in heavy thinning plots than in light thinning or unthinned plots. The number of large trees (DBH>25 cm) were obviously shown the most in heavy thinning plots. It is considered that heavy thinning is needed for the production of the large diameter trees.

The Three-year Effect of Thinning Intensity on Biomass in Larix kaempferi and Pinus koraiensis Plantation

  • Chhorn, Vireak;Seo, Yeongwan;Lee, Daesung;Choi, Jungkee
    • Journal of Forest and Environmental Science
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    • v.36 no.1
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    • pp.17-24
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    • 2020
  • This study aimed to figure out and compare the increment of biomass by thinning intensity focused on the plantation of the two major coniferous species (Larix kaempferi and Pinus koraiensis) of South Korea. The inventory interval was three years under the effects of three types of thinning treatments; control (no thinning), light (20% thinning) and heavy (40% thinning). The results showed standing biomass increment of both species decreased as thinning intensity increased (heavylight>control). Meanwhile, the lowest of on-site biomass changes occurred in the control plot, and the greatest was in the heavy thinning plot because thinning was involved with leaving the felling residual biomass (leaves, branches and roots) on the site. According to the results from this short-term study, unthinned stands is preferable for maximizing standing biomass as well as carbon sequestration. However long-term investigation should be considered in order to see more clear results.

Effect of Fruit Thinning and Foliar Fertilization under the Low Light Intensity in Oriental Melon(Cucumis melo L. var. makuwa MAKINO) (저광도 조건시 참외의 적과와 엽면시비 효과)

  • 서태철;강용구;윤형권;김영철;서효덕;이상규
    • Journal of Bio-Environment Control
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    • v.12 no.1
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    • pp.17-21
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    • 2003
  • This experiment was conducted to find out the method of preventing decrease in the marketable yield of oriental melon (Cucumis melo L. var. makuwa MAKINO) under low light intensity. By maintaining low light of 400 $\mu$mol$.$m$^{[-10]}$ 2$.$S$^{-1}$ from 10 days after fruit set to fruit enlargement period, the photosynthetic rate and chlorophyll contents of leaf were reduced. Leaves which had no urea application showed largely decreased photosynthetic rate The content of soluble solids was lower$.$ in the low light than natural light treatment. Regardless of foliar application of urea, % fermentation fruits was under 4% in the natural light treatment and over 10% in the low light treatment. The less the fruit thinning, the greater was % fermentation fruits under low light condition. The % fermentation fruits were 39% and 40% in no fruit thinning treatment. The harvest was delayed under low light condition regardless of foliar fertilization. As the number of thinned fruits was decreased, the harvest time was delayed more. Marketable yield per plant sharply decreased under low light intensity. Compared with natural light, the yield under low light treatment was 16∼34%. The treatment fertilized with 0.5% urea on leaf had 34% greater harvest index of marketable yield than other treatments. In conclusion, when the long low light condition from 10th day after fruiting was forecasted, thinning two fruits out of six fruits and two times foliar fertilization with 0.5% urea should be applied.

Ecological responses of natural and planted forests to thinning in southeastern Korea: a chronosequence study

  • Cho, Yong-Chan;Pee, Jung-Hun;Kim, Gyeong-Soon;Koo, Bon-Yoel;Cho, Hyun-Je;Lee, Chang-Seok
    • Journal of Ecology and Environment
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    • v.34 no.4
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    • pp.347-355
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    • 2011
  • Effects of forest thinning on community level properties have not been understood yet in Korea. We investigated regeneration patterns and trajectories after a disturbance by applying a chronosequence approach. Light availability, litter and woody debris cover, and species composition were determined for twenty 50 m line-transect samples representing a disturbance duration gradient (within 11 years). Environmental factors such as light availability and coverage of woody debris and litter changed abruptly after thinning and then returned to the pre-disturbance state. Although species richness was gained at shrub and ground layer in a limited way in both forests, cover of various functional types revealed diversity in their responses. Notably, Alnus firma stands exhibited a larger increment of cover in woody plants. Ordination analysis revealed different regeneration trajectories between natural and planted stands. Based on ordination analysis, rehabilitated stands showed movement to alternative states compared with natural ones, reflecting lower resilience to perturbation (i.e., lower stability). Our results suggest that community resilience to artificial thinning depends on properties of the dominant species. But to get more explanatory ecological information, longer-term static observations are required.

Photo Epilation with Intense Pulsed Light for Thinning of Anterior Hairline after Hairline Correction Surgery in East Asians

  • Park, Jae Hyun;Lee, Seung Yong;You, Seung Hyun;Kim, Na Rae
    • Archives of Plastic Surgery
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    • v.44 no.2
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    • pp.157-161
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    • 2017
  • Background Thin hairs are critical to achieve natural result in female hairline correction surgery. However, there are few studies on the usefulness of hair thinning by intense pulsed light (IPL) after hairline correction surgery in East Asian females. Methods Hair thinning using IPL was performed in 54 women who had complained about thick hairs along the frontal hairline after hairline correction surgery. Patient mean age was 31.2 years old and patients were an average of 2.1 years post-hairline correction surgery. Initial treatment used 10 J, while second and third sessions were conducted with 10 to 15 J according to responsiveness to treatment. Results Mean thickness of individual hairs assessed before the procedure was $78.86{\mu}m$. The mean number of procedures was 1.6 per patient. Forty of 54 subjects (74%) achieved satisfactory hair thinning with only one procedure from 78.01 to $66.14{\mu}m$ after treatment. The measured thickness was $66.43{\mu}m$ at the end of the first year in patients who were satisfied after one procedure. Thirteen cases achieved satisfactory hair thinning after two sessions. Mean thickness was $74.44{\mu}m$ and $67.51{\mu}m$, before and after the second session. One case required a third session with 15J, thinning from 89.00 to $66.50{\mu}m$. Conclusions Hair thinning by IPL is a very useful method to provide a natural look after hairline correction surgery in East Asians, who have naturally thick hair.

Changes in Understory Vegetation of a Thinned Japanese Larch (Larix leptolepis) Plantation in Yangpyeong, Korea

  • Son, Yo-Whan;Lee, Yoon-Young;Kim, Rae-Hyun;Seo, Kyung-Won;Ban, Ji-Yeon;Seo, Kum-Young;Koo, Jin-Woo;Kyung, Ji-Hyun;Noh, Nam-Jin
    • The Korean Journal of Ecology
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    • v.27 no.6
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    • pp.363-367
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    • 2004
  • Photosynthetically active radiation (PAR) beneath the forest canopy, understory species richness and diversity, and biomass were measured in a Larix leptolepis plantation seven years after thinning in Yangpyeong. Four different thinning intensities (control, $10\%,\;20\%\;and\;40\%$ stocking reduction) were applied in 1997. The current PAR values were lower than those measured four years after thinning, and PAR at the heavy thinning plots was significantly higher than that of other thinning intensities. A total of 23 species including 9 tall-trees and 14 shrubs were found for the high layer while a total of 82 species including 10 tall-trees, 29 shrubs, and 43 herbs for the low layer. Species richness and diversity generally increased with thinning intensities, and the trends were more evident for the low layer. Aboveground biomass significantly differed among thinning intensities for both shrubs and herbs. Also there was a negative correlation between biomass and the current number of stems per hectare. The current study suggested that the effects of thinning on light conditions at the forest floor, species richness and diversity and production of understory vegetation continued seven years after the treatment.

Changes in Soil Temperature, Moisture Content, Light Availability and Diameter Growth After Thinning in Korean Pine (Pinus koraiensis) Plantation (잣나무 임분 내 간벌 후 토양 온도, 수분, 광 유효도 및 직경생장 변화)

  • Bae, Sang-Won;Hwang, Jae-Hong;Lee, Sang-Tae;Kim, Hyun-Seop;Jeong, Jun-Mo
    • Journal of Korean Society of Forest Science
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    • v.99 no.3
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    • pp.397-403
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    • 2010
  • This study was conducted to investigate the changes in soil temperature, soil moisture content, light availability (photosynthetically active radiation, PAR) and diameter growth in 46-year-old Korean pine (Pinus koraiensis Siebold et Zuccarini) plantation located in Gwangneung experimental forest after 4 years from thinning. Three different thinning intensities [control, 45%(T45), and 60%(T60) basal area reduction] were applied in 2004. Mean soil temperature and soil water content were $8.9^{\circ}C$ and 14.3% for control, $10^{\circ}C$ and 16.1% for T45 and $10.2^{\circ}C$ and 16.1% for T60, respectively. Mean soil temperature and moisture content were significantly different among the treatment plots (p<0.05). Mean PAR in control, T45 and T60 was 44, 143 and178 ${\mu}mol/m^2$/sec, respectively and the differences were also statistically significant among the treatment plots (p<0.05). Mean annual diameter growth in control, T45 and T60 was 0.4, 1.5 and 1.2 mm, respectively. Diameter growth of Pinus koraiensis was steadily increased after thinning in comparison to control. Consequently, the results suggested that soil temperature, soil moisture content and light availability were likely to last beyond the 4 years after thinning in this Korean pine plantation.

Thinning Intensity and Growth Response in a Quercus acuta Stand (붉가시나무림의 솎아베기 강도에 따른 생장 반응 효과)

  • Jung, Su Young;Ju, Nam Gyu;Lee, Kwang Soo;Yoo, Byung Oh;Park, Yong Bae;Yoo, Seok Bong;Park, Joon Hyung
    • Journal of Korean Society of Forest Science
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    • v.104 no.4
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    • pp.536-542
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    • 2015
  • This study was examined for the growth response of tree diameter and volume to thinning treatments from different thinning intensities using three long-term thinning trials for Japanese Evergreen Oak (Quercus acuta Thunb.) stands in Wando island, Korea. After thinning in 1999, annual tree growth of diameter and volume was highest in heavy thinned stands for individual tree and this growth pattern of thinning response showed similar tendency to the individual tree growth response in light thinned stands. By increasing diameter growth, the value of H/D ratio (HDR) as an indicator of stem form was properly decreased and improved up to 80%. Although there is significant growth response of basal area in both heavily and lightly thinned stands, the growth potential both of heavily and lightly thinned stands in total stand volume is not likely to reach at the level of unthinned stands because of basal area growth loss associated with both light and heavy thinnings.

The Adequacy Assessment and Growth Effects by Methods of 1st Thinning in Chamaecyparis obtusa Forest (편백림의 1차 솎아베기 방법에 따른 생장효과와 적절성 연구)

  • Park, Joon Hyung;Son, Yeong-Mo;Lee, Kwang Soo;Park, Eun Jung;Jung, Su Young
    • Journal of Korean Society of Forest Science
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    • v.108 no.3
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    • pp.349-356
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    • 2019
  • This study examines the effect of thinning in terms of changes in the growth characteristics of Chamaecyparis obtusa stands after they were thinned with varying intensity in Gochang, North Jeolla Province, Korea. Thinning was carried out in 2000 on Chamaecyparis obtusa stands (22 years old), and the stands were categorized in terms of the thinning intensity in the experiment: very heavy, heavy, medium, light, and control. The results of monitoring up to 2018 revealed that the diameter at breast height and the growth rate of individual trees after thinning had a positive correlation with the thinning intensity, whereas the stand volume showed a negative correlation. The height to diameter (H/D) ratio decreased by up to 70-80 due to the increased diameter at breast height after thinning and thereby resulted in better quality. The relative yield index right after the first thinning was between 0.75 and 0.95, which suggests the best timing for the first thinning had been missed. This study's findings are expected to serve as a basic reference in establishing the thinning system for Chamaecyparis obtusa forests.

Changes of Ground-dwelling Arthropod Communities for 10 Years after Thinning in a Pinus koraiensis Plantation (잣나무림에서 간벌 이후 지표 절지동물 군집의 변화 특성 분석)

  • Lee, Dae-Seong;Kwon, Tae-Sung;Kim, Sung-Soo;Park, Young Kyu;Yang, Hee Moon;Choi, Won Il;Park, Young-Seuk
    • Korean Journal of Ecology and Environment
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    • v.53 no.2
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    • pp.208-219
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    • 2020
  • Forest thinning brought the large variation to forest ecosystem including environment and animal. Our study was result of long-term monitoring for ground-dwelling arthropod communities after thinning in forest ecosystem. In this study, we conducted field study on plantation forest in Chuncheon, Korea in 2018, and compared with previous study data (2006 and 2008). We found that the effect of thinning was still existent 10 years later from thinning with difference of habitat environment(depth of ground organic matter, coverage rate of ground vegetation and canopy). And ground-dwelling arthropod communities showed changes of abundance and taxa at the study area and thinning conditions. Ground-dwelling arthropod communities in 2018 were dominant in the order of Diptera, Hymenoptera, Coleoptera (Insecta), Araneae (Arachnida) and Collembola (Collembola). Among the conditions of thinning, Araneae (Arachnida), Coleoptera and Hymenoptera (Insecta) showed amount of abundance in heavy thinning. And Collembola (Collembola) and Diptera (Insecta) were most common in area of light thinning. In 2018 ground-dwelling arthropod communities, abundance of Diptera and Coleoptera (Insecta) and Isopoda (Crustacea) were decreased although Hemiptera and Orthoptera (Insecta) were increased than 2008 arthropod communities. Arthropod communities in 2018 were more similar with those in 2008 (after thinning) than with those in 2006 (before thinning).