• 한국산림과학회지
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• 제96권2호
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• pp.227-234
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• 2007

The forest canopy gap has been well known as a substantial process of forest cyclic regeneration and important role in stand structure, dynamics, and biodiversity of the forest ecosystem. Based on 3,600 $5m{\times}5m$ square grids in a 9ha permanent experimental plot, the study was conducted to evaluate the regeneration pattern of woody species by developmental stage {seedlings (<1 m of height), saplingI (>1 m of height, <2 cm of DBH), and saplingII (2 cm$<200m^2$), $201-400m^2$, $400-600m^2$, $601-800m^2$, and $>800m^2$) in the mixed broadleaved-Korean pine forest. The results indicated that the regenerating trees of Populus ussuriensis occurred only in the canopy gap area, considered to be a typical gap-dependent species. The regeneration of Ulmus japonica, Ulmus laciniata, and Maackia amurensis could be generally satisfied with the gap size of $201-600m^2$, Betula costata and Prunus padus with gap size of $401-800m^2$, Picea koraiensis with gap size of $201-800m^2$, Fraxinus mandshurica and Syringa reticulata var. mandshurica with smaller than $800m^2$, respectively. Acer ukurunduense and Acer tegmentosum were likely to have no problem with the gap size to make gap regeneration. Acer mono and Tilia amurensis looked more capable of regenerating in the closed canopy disregarding the upper crown condition. The regeneration of Pinus koraiensis and Abies nephrolepis had no trouble under the canopy condition in less than $800m^2$of gap size. The density of regenerating shrubs was rather high, especially under the closed canopy, considered to be associated with great amount of regeneration production in such shade tolerant species as Lonicera maackii, Corylus mandshurica, Euonymus pauciflorus, and Philadelphus schrenkii under the closed canopy. Pearson correlation coefficient was computed to compare the similarity among non-gap area and five gap size classes by developmental stages for trees and shrubs. The similarity coefficients among closed canopy and the gap size classes were mostly significantly correlated to each other with a few exceptions.

• The Korean Journal of Ecology
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• 제19권6호
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• pp.499-506
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• 1996

Forest stand development in Kwangnung Experimental Forest, Korea, was simulated with a forest succession gap model of the JABOWA/FORET type, in order to predict climax species and characterime the trend of community structure along the succession. The model runs for a period or 1, 000 yr and is based on the averaged successional characteristics of 50 forest plote with an individual size or 1/12 ha gap consisted of the 15 major tree species. The total bimass and leafarea index have arrived at a steady state since about 200 yr and these values are smaller than that or field survey. Carpinus cordata, C. laxiflora, Quercus mongolica and Q. serrata were epected to be climax species that represent about 86% or total biomass in later stage and these results coincided with the previous succession studies from field survey in the area.

• IEIE Transactions on Smart Processing and Computing
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• 제5권5호
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• pp.358-365
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• 2016

We propose a novel application of random forest, a machine learning-based general classification algorithm, to analyze the influence of design attributes on the silicon-to-SPICE (S2S) gap. To improve modeling accuracy, we introduce magnification of learning data as well as randomization for the counting of design attributes to be used for each tree in the forest. From the automatically generated decision trees, we can extract the so-called importance and impact indices, which identify the most significant design attributes determining the S2S gap. We apply the proposed method to actual silicon data, and observe that the identified design attributes show a clear trend in the S2S gap. We finally unveil 10nm key fin-shaped field effect transistor (FinFET) structures that result in a large S2S gap using the measurement data from 10nm test vehicles specialized for model-hardware correlation.

• Journal of Ecology and Environment
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• 제30권4호
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• pp.325-330
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• 2007

Recognizing the ecological importance of forest gap formation for forest community structure, we examined the differences in species diversity between forest gaps and closed canopy areas for trees and shrubs in three developmental stages (seedling, sapling I, and sapling II) in a typical mixed broadleaved-Korean pine forest. We randomly placed 100 sample plots ($2{\times}2m$ for seedling and sapling I, and $5{\times}5m$ for sapling II) in forest gap and closed canopy areas of a 9 ha permanent sample plot for vegetation surveys of plants of each developmental stage in each habitat type. Even though the formation of forest gaps encouraged the occurrence of gap-dependent species and increased overall species diversity, there were no significant differences in species richness among the three developmental stages for both tree and shrub species (p>0.05). Comparing the two types of sites, statistical tests revealed no difference in species richness for trees, but highly significant differences (p<0.01) between forest types for shrubs for seedlings and sapling I, but not sapling II. Analysis of variance test indicated that there were no significant differences in species diversity among the three developmental stages of tree species (p>0.05) for both Simpson and Shannon indices. The variance for shrub seedlings was significantly different between forest gaps and closed canopy areas, but not for sapling I and sapling II. The analysis showed that the species diversity in forest gaps was significantly different from that of closed canopy areas for seedling and sapling I (p<0.01), but not for sapling II (p>0.05).

• The Korean Journal of Ecology
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• 제18권1호
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• pp.189-201
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• 1995

In order to clarify regeneration processes and mechanisms of the disturbed Pinus densiflora forest, responses of Pinus densiflora to gap formed by disturbance were analysed by growth of saplings and mature and growth equations were obtained from branch growth of mature trees and height growth of saplings, and age distribution of saplings and young trees recruited within gap was analysed in relation to gap age. Height growth of saplings within gaps was accelerated after gap formation. Such abrupt increases of growth of saplings after the gap formation might be resulted in the difference of growth of saplings between gap and non-gap areas. In fact, height and diameter of saplings in the central part of gap were larger than those of saplings in marginal parts of gap and non-gap area. However, density of saplings was not different in both parts. In addition, growth of annual rings of mature trees bordering on gap also increased after gap formation. Branch growth of mature trees bodering on gap was 6.3 - 6.5 cm /year and the mean radius of gaps created by death of only one canopy tree was about 3 m. Therefore, for those gaps to be closed by branch growth it will take 46 years. Growth of saplings within gap showed exponential equation. Fifty years will be required for the saplings to enter the forest canopy by the exponential growth equation. Therefore, gap created by only one tree might be closed by branch growth of surrounding canopy trees in advance of being done by height growth of saplings. But gaps created by death of trees more than 2 will be closed by the growth of saplings. Among the regenerating saplings and young trees within gaps, individuals established in advance of gap formation were more than those established after the gap formation. From these results, it was assumed that the disturbed Pinus densiflora forests in these sites were regenerated by height growth of saplings recruited in advance of gap formation.

• 한국산림과학회지
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• 제89권5호
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• pp.543-551
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• 2000

소나무의 갱신 특성을 구명하기 위하여 강원도 평창군 중왕산 지역 소나무 천연림에서 교란에 의해 형성된 숲틈을 대상으로 line-transect 조사법에 의해 소나무의 수관 architecture 특성을 조사, 분석하였다. 갱신 초기단계에 소나무는 숲틈에서 생장환경에 적응능력을 나타내었고 소개된 임분에서 자라는 소나무에 비해 architecture 특성은 다르게 나타났다. 소나무 천연림내 숲틈에서 소나무의 주 가지의 분지각의 변이폭은 작았고 주 가지의 길이 생장량은 가지 연령이 4~5년생 일 때까지 비교적 크게 나다났고 그 이후에는 점차 작아졌다. 숲틈에서 소나무의 줄기로부터는 주 가지가 평균 5개씩 발생하였고 주가지에서는 잔가지가 평균 4개씩 발생하였다. 줄기에서 발생한 주 가지는 방위별로 균일한 분포양상을 나타내었지만 주가지에서 발생하는 잔가지의 수는 숲틈의 크기가 $100{\sim}120m^2$이하일 때 주로 $S44^{\circ}E{\sim}S90^{\circ}W$ 사이의 방위에 많이 분포하였다.

• 한국산림과학회지
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• 제89권3호
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• pp.452-460
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• 2000

본 연구에서는 Gap 갱신이 이루어지는 소나무를 대상으로 인위적으로 조성한 Gap처리구에서 소나무 묘목의 생장 및 광도의 변화에 따른 광합성속도, 중산속도 등 생리적 특성의 변화를 분석하고 Gap 생장환경에 대한 소나무 묘목의 적응과정에 대한 연구를 통해 갱신기작을 구명하고자 하였다. Open된 생장환경에 비해 광도가 낮고 광질이 다른 Gap처리구에서 소나무 묘목은 근원경보다는 상대적으로 묘고의 생장량이 더 많이 이루어졌고 건중량의 증가비율도 지하부보다는 지상부에서 상대적으로 크게 나타나 비교적 높은 T/R율을 보였다. 소나무 묘목의 지상부 C/F비율(지상부의 비동화기관과 동화기관 건중량의 비율)도 Gap처리구에서는 Open 생장환경에 비해 0.1~0.2정도 높았으며 광포화점은 $300{\mu}mol\;m^{-2}s^{-1}$정도 낮았고 광보상점도 40%정도 낮게 나타나 양수이지만 내음성을 나타내었다. 또한 광도가 $400{\sim}450{\mu}mol\;m^{-2}s^{-1}$보다 낮을 때 소나무 묘목은 비교적 높은 광합성속도와 수분이용효율을 나타내었으며 약한 광에너지를 효율적으로 이용하였다.

• The Korean Journal of Ecology
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• 제23권1호
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• pp.1-8
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• 2000

충북 제천시 소재 월악산 문수봉의 신갈나무림에서 gap연령이 다른 3개 지소와 성숙림인 1개 지소로 나누어 gap내 신갈나무의 재생과정을 밝혀 다음과 같은 결과를 얻었다. 식생조성은 gap형성 초기 에 관목층에서는 조록싸리, 물푸레나무, 미역줄나무, 신갈나무, 국수나무 등의 우점도가 높았다 특히, 관목층 전체를 볼때 gap형성 초기에는 개체수가 상당히 많으나 gap 연령이 증가할 수록 교목층을 형성 할 수 있는 신갈나무와 물푸레나무 등의 기저면적의 증가에 의한 피음으로 관목층의 개체수는 감소하였다. gap내에는 어린 개체가 많고 점차 감소하는 역 J자형의 분포를 나타내고 gap 연령이 증가하면서 gap내에서 급속한 성장으로 교목층을 형성하는 신갈나무의 피음에 의해 부분적으로 고사된 개체가 나타나는 것 을 볼 수 있.었다. 성숙림 에서는 어린 개체가 거의 없었으나 수령이 130년 이상인 개체가 주로 나타났고 이 들 중 한개 또는 그 이상의 개체가 어떤 교란요인에 의해서 Gap이 형성되면 이곳에 어린개체가 침입되어 재생이 이루어질 것으로 생각된다. 본 신갈나무림은 gap형성 후 gap 내에 침입한 신갈나무가 교목층을 형성하는 연령인 약 35∼40년 이후 부터 수령이 130∼330년 되는 성숙림까지 다른 신갈나무 유묘의 침입은 없지만 다른 수종으로 대치되는 것이 아니라 성숙림의 gap형성에 의해 불연속적인 재생으로 계속 유지되는 것으로 생각된다.

• 한국산림과학회지
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• 제11권1호
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• pp.43-55
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• 1970

• 한국농림기상학회:학술대회논문집
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• 한국농림기상학회 2011년도 학술발표회
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• pp.44-44
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• 2011