• 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).

• Journal of Korean Society of Forest Science
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• v.88 no.4
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• pp.541-554
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• 1999

The objectives of this study were to examine the amount of nutrient input by throughfall and stemflow, and the nutrient dynamics by throughfall, stemflow and soil solution among Piuns koraiensis, Larix leptolepis and hardwood forests including oaks at Kwangju-Gun, Kyonggi-Do. A total amount of rainfall during the study period was 1410.1mm. Of the total rainfall, 85% was from throughfall at the L. leptolepis stand, 84.5% at the thinned P. koraiensis stand, 83.2% at the unthinned P. koraiensu stand and 81.2% at the hardwood stand, showing greater throughfall at the conifer stand than at the hardwood stand. Stemflow showed 2.7% of rainfall at the hardwood stand, 1.3% at the unthinned P. koraiensis stand, 1.2% at the thinned P. koraiensis stand and 0.8% at the L. leptolepis stand, showing greater stemflow at the hardwood stand than at the conifer stand. Ion concentration of stemflow was greater than those of rainfall and throughfall. The conifer stand showed higher ion concentration than the hardwood stand both for cation and anion. The ion concentrations of throughfall and stemflow were higher in the descending order : $NH{_4}^+$-N > $K^+$ > $K^+$ > $Na^+$ > $Mg^{2+}$ for cations and $SO{_4}^{2-}$ > $NO{_3}^-$-N > $Cl^-$-N for anions. After the precipitation passed through the canopy, $K^+$ increased most at the hardwood stand, whereas $NH{_4}^+$-N did most at the P. koraiensis and L. leptolepis stands. The ion concentration of soil solution was higher in the descending order : $Ca^{2+}$ > $Mg^{2+}$ > $Na^+$ for cations and $NO{_3}^-$-N > $Cl^-$ > $SO{_4}^{2-}$ for anions. $NH{_4}^+$-N and $K^+$ seemed to be supplied primarily from atmospheric deposition while $Ca^{2+}$, $Mg^{2+}$ and $Na^+$ from weathering.

• Journal of Korean Society of Forest Science
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• v.111 no.1
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• pp.150-164
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• 2022

This study was conducted to provide basic information for the development of silvicultural guidelines and manuals. This was achieved through analysis of tree and stand characteristics according to the first and second thinning in Korean white pine plantations. Data were collected from permanent plots installed at Korean white pine plantations according to thinning intensity, and residual tree and stand variables, including diameter at breast height (DBH), volume, and mortality at age 19-43, were analyzed using data repeatedly collected in 4-5 measurements by experiments. According to one-way variance of analysis, tree DBH and volume were significantly different according to thinning intensity (p<0.05). DBH distribution was skewed to the left side over time as thinning intensity was heavier. Thus, tree DBH values were larger in heavy thinning plots with increased age. The periodic annual increment (PAI) of DBH was higher with heavier thinning intensity and fewer years after thinning. The PAI range by thinning intensity was 0.48-0.95 cm/year at age 19-24. In addition, the PAI increased in heavy thinning plots after the second thinning; The PAI range by thinning intensity was 0.29-0.67 cm/year after the second thinning at age 37-42. The PAI of tree volume differed according to thinning intensity, and the PAI value did not decrease obviously, in contrast to the pattern of the DBH PAI. Stand volume was generally higher in high-density stands, and the PAI of stand volume was high in unthinned and light thinning plots. Mortality was highest in unthinned plots, and the differences in mortality according to thinning intensity increased over time. Consequently, the growth of DBH and tree volume was lower as stand density increased, but this growth was facilitated with appropriate first and second thinning operations.

• Korean journal of applied entomology
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• v.49 no.3
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• pp.187-198
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• 2010

Thinning treatment has a huge effect on understory and litter structures in forest ecosystem, and the resulting changes may impact some arthropod groups such as plant-feeders and detritivores. This study was carried out to find a change in arthropod abundance and their structures in relation to the thinning activity in a Pinus koraiensis plantation in Chuncheon, Korea, where thinning was conducted twice: in 1998-2000 (old-thinning) and 2007 (new-thinning). Arthropods were collected using pitfall traps in 2006 and 2008. Effects of old-thinning on change of abundance and community structure of arthropod were significant, but the effects of new-thinning were not significant. The most significant thinning effect was found in detritivores, followed by plant feeders, but the effect was hardly significant in predators. Among detritivores the changes in abundance was diverse. The abundance of orthopteran plant-feeder increased, but Curculionidae declined after thinning. There was not different in abundance of total arthropods between thinned and unthinned areas because the difference may have cancelled each other out by increased or decreased abundance of taxa. Community structures of arthropods were most greatly affected by years, followed by the old-thinning, but the new-thinning did not affect community structures.

• Journal of Korean Society of Forest Science
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• v.107 no.2
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• pp.174-183
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• 2018

This study aims to make the stand density management diagram which is useful for establishing stand density management system in Chamaecyparis obtusa forest. By using 216 sample plots to estimate Yield-Density relationship ($R^2=0.743$), the stand density management diagram was modeled by the estimated parameters. As a result of this diagram, after planting 3,000 trees per hectare the mortality rate of this unthinned C. obtusa stands over 80 years was estimated to be equal to $12.0{\sim}18.1trees{\cdot}ha^{-1}{\cdot}year^{-1}$, and stand volume was $463.1{\sim}695.4m^3{\cdot}ha^{-1}$, and stand density was $1,555{\sim}2,038trees{\cdot}ha^{-1}$. Developed stand density management diagram for C. obtusa is effective to establish the management criteria and production objective. Therefore, this study allowed us to make the optimal forest working plan.

• 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.

• Journal of Korean Society of Forest Science
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• v.71 no.1
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• pp.40-44
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• 1985

This study was carried out to know the difference in growth and degree of competition between individuals of thinned and unthinned larch stands. Annual increment and total growth were obtained from the cores sampled at breast height. The correlation between adjacent individual trees was investigated. 1) The correlation between radius growth and basal area was used to estimated the degree of competition among individual trees. 2) In estimating the degree of competition the correlation between two individual trees was better method than others. 3) Up to 9 years after planting no competition between individual trees occurred and the Night positive correlation was shown. 4) High degree of competition was observed at age of 10 years after the planting, as the correlation coefficient was getting smaller. 5) The degree of competition among individual trees increased with increase of the growth of total stand.