• Journal of Korean Society of Forest Science
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• v.109 no.3
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• pp.249-258
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• 2020

The purpose of this study examined the succession by vegetation type after forest ecosystem restoration in the Baramjae area. Vegetation of the Baramjae area was classified using a survey of 81 sites from May to October 2019. The vegetation type was classified as Pinus densiflora community group with both Quercus mongolica community and P. densiflora typical community. The group unit was further classified as the Quercus dentata typical subgroup, Salix koreensis subgroup, and Q. mongolica typical subgroup. Such as Q. mongolica, Quercus variavilis in vegetation unit 1, Q. mongolica, Q. dentata in vegetation unit 2, P. densiflora in vegetation unit 3 and S. koreensis in vegetation unit 4 were shown a high importance value. The difference in species by vertical layer is explained by sere. Based on the vegetation type classification system, Detrended Correspondence Analysis was conducted to observe the trend of succession. Since restoration, vegetation unit 1 and vegetation unit 2 were considered to have developed the most extensive vegetation. In vegetation unit 2 and vegetation unit 4, many of the species found were in the early vegetation development in S. koreensis subgroup. Accordingly, vegetation in the Baramjae area can be categorized as a stepwise succession.

• Journal of Korean Society of Forest Science
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• v.105 no.2
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• pp.157-166
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• 2016

This study was carried out to classify the current forest cover types and to propose the successional trends in the natural forest of Mt. Deogyu. The vegetation data were collected by the point-centered quarter method. The forest cover types were classified by various multivariate statistical analysis methods such as cluster analysis, indicator species analysis and multiple discriminant analysis. This forests were classified into five forest types by the species composition of upper layer and topographic positions: Quercus mongolica forest in the ridge, Fraxinus mandushurica-F. rhynchophylla-Cornus controversa forest and F. mandushurica forest in the valley, the Q. serrata - Pinus densiflora - Q. mongolica forest and P. densiflora forest in the low-slope. As a result of the forest successional trends depending on ecological and environmental characteristics in each forest type, the current forest types were expected that the forest succession would be proceeded toward Q. mongolica forest, F. mandshurica forest, mixed mesophytic forest, and oak-Carpinus laxiflora forest.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05b
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• pp.231-236
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• 1998

원자력 발전소의 핵연료 피복관 재료로 사용되고 있는 Zr합금의 부식특성에 미치는 Sn의 영향을 조사하기 위해 Sn 함량을 0.5, 0.8, 1.5, 2.0wt.%로 조절한 Zr-xSn 2원계 합금과 Zr-0.4Nb-xSn 3원계 합금을 제조하여 36$0^{\circ}C$ 물 분위기의 mini-autoclave에서 부식실험을 수행하였다. 2원계 합금에서 Sn이 0.5, 0.8, 1.5wt.% 첨가된 합금에서는 15일에서 속도천이가 발생한 후 급격한 부식 가속 현상이 나타났으나, 2.0wt.%가 첨가된 합금에서는 100일까지 부식 실험에서도 천이 현상을 보이지 않는 매우 높은 부식 저항성을 보였다. 그러나 3원계 합금에서는 2원계 합금과는 달리 40일 시험에서도 모든 합금들이 속도 천이 현상을 보이지 않고 천이전 영역에서의 부식 거동을 보이며, Sn 함량 변화에 따른 부식 속도의 차이를 감지할 수 없었다. 이러한 경향은 2원계 합금과 3원계 합금에서 Sn의 고용도 차, 미량 첨가된 Nb의 영향 및 석출물의 특성과 관련이 있는 것으로 사료된다. 또한 수소 흡수율면에서도 Sn 함량 변화에 따라 부식 거동과 비슷한 경향을 보이면서 2.0wt.%에서 가장 낮은 수소흡수율을 보였다 천이전 영역에서 산화막 구조 관찰 결과 천이전 영역의 모든 산화막에서 보호적 성질을 나타내는 tetragonal-ZrO$_2$가 관찰되었는데, tetragonal-ZrO$_2$의 분율은 Sn 함량에 따라 거의 같게 나타났다.

• Proceedings of the Korean Society of Environment and Ecology Conference
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• 2004.04a
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• pp.121-125
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• 2004

• Korean Journal of Environment and Ecology
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• v.10 no.1
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• pp.113-127
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• 1996

To investigate the plant community structure and to establish restoration counterplan of forest area in Seoul, fifty six plots(each size was 400m$^{2}$) were set up and surveyed. According to analysis DCA ordination techniques, the communities were divided into six community, P. rigida community, Populus * albagladulosa community, Quercus acutissima community and Q. monholica community. The successional trend of forest area in Seoul was seem to Pinus densiflora, Robinia pseudoacacia, P. rigida, Populus * albagladulosa, Wuercus acutissima$\longrightarrow $Q. mongolixa, Q. serrata by analysis of plant community structure. Shanon's diversity was 1.1381~1.2694 and Soil pH was 3.18~4.76 in survey sites.

• Journal of Korean Society of Forest Science
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• v.81 no.4
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• pp.325-336
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• 1992

The successional status and potential natural vegetation were examined in a mixed broadleaved-Abies forest located at Mt, Odae National Park. The examination was based on the subsequent process of generation replacement by understory saplings for the dominant canopy trees within 88 $5m{\times}50m$ belt transects. The transition matrix model, which was modified from mathematical theory of Markov chain, was employed to analyze the successional status of the study forest. The model suggests that the study forest is still seral, and it is considered to be more than 700 years away from the steady state or climax in terms of species composition. The simulations predict a remarkable decrease in the proportion of species composition of the present dominant Quercus mongolica and Tilia amurensi.s from current 28% and 13% to less than 3% and 5%, respectively, at the steady state. On the contrary, the proportions of Abies holophylla, Acer pseudo-sieboldianum, Carpinus cordata, and Pinus koraiensis will increase at the steady state. The ratio of mixture between deciduous and coniferous trees will be gradually changed from current 6.5 : 3.5 to 5.0 : 5.0 at equilibrium. Discussion for the problems of Quercus mongolica in successional status noted that the species behaved as a mid-successional dominant, not a climax species in the study forest. The hypothesis and sensitivity of the transition matrix model were also discussed to evaluate the applicability to the real situation. The overall results indicated that the present dynamics of the forest must reflect the seral state due to previous disturbance mainly by hyman related interference.

• Korean Journal of Environment and Ecology
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• v.27 no.6
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• pp.733-744
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• 2013

This study was launched in order to collect basic data such as emergent species, a succession trend based on the actual vegetation at the ridge from Haneoryoung to Daetjae, thereby designating 46 quadrats($10m{\times}10m:100m^2$). As a result of classification by TWINSPAN, the plant community was categorized into eight different communities, such as Pinus densiflora-Quercus mongolica-Fraxinus rhynchophylla, P. densiflora-Q. mongolica, Ulmus davidiana var. japonica, Q. mongolica-Deciduous Broad-leaved, Q. mongolica, Q. mongolica-Betula davurica, Q. mongolica-F. sieboldiana, and Larix kaempferi. An analyzation of each communities indicated that P. densiflora dominant community will change into a Q. mongolica dominant community if there are no outside artificial disturbances. U. davidiana var. japonica community maintains its present condition, because it doesn't appear to be a competitive species. In the case of Q. mongolica dominant community, if nothing comes in a competitive species against Q. monglica, it is possible to succeed to a muture stand. These communities with competitive species such as F. rhynchophylla, B. davurica that do not emerge at a canopy layer will gradually progress to the Deciduous Broad-leaved community. With regard to the species diversity index per unit ($400m^2$), succession processing communities (P. densiflora: 1.0477~1.1283) tend to be higher than succession-processed communities (Q. mongolica dominant: 0.6446~0.9424).

• Journal of the Korean Society for Nondestructive Testing
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• v.22 no.3
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• pp.284-291
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• 2002

An attempt was made to evaluate the degree of aging degradation in thermally aged 2.25Cr-1Mo steel by electrical resistivity measurement. Artificial aging was performed to simulate the microstructural degradation in 2.25Cr-1Mo steel arising from long time exposure at $540^{\circ}C$. Microstructural parameter (amount of solid solution element), mechanical property (ductile-brittle transition temperature) and electrical resistivity were measured to investigate the mutual relationship among these parameters. Depletion of solid solution element(Mo and Cr) in matrix was detected after aging. The ductile-brittle transition temperature(DBTT) increased rapidly in the initial stage of aging and then saturated afterward. On the other hand, the electrical resistivity decreased rapidly in the beginning and then saturated in the later stage of aging.

• Journal of Korean Society of Forest Science
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• v.94 no.6
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• pp.453-461
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• 2005

Structural characteristics and successional trends of actual forest vegetation in Youngil soil erosion control district, South Korea, were studied and described by the phytosociological investigations and diameter measurement. And also the incremental growth pattern of the major trees for erosion control analyzed using increment core. Sixty-eight releves were sampled with $100m^2$ plots. Two main vegetation types (Lespedeza bicolor-Miscanthus sinensis-type and Alnus firma-Styrax japonica-type) have been distinguished and typified nine vegetation units. Constancy classes diagram showed that the higher species (${\geq}IV$) have only 2.6% and that most species occurred were rare and had low abundances. The successional trends of the actual forest vegetation would be mostly changed as Quercus serrata forest. Annual diameter growth was 3.0~3.4 mm in case of conifer (Pinus rigida and Pinus thunbergii), and the broad-leaved trees (Alnus firma, Robinia pseudo-acacia, and Alnus hirsuta) showed 4.3~4.9 mm. The incremental growth patterns showed to be decreased rapidly since twenty to twenty-five years regardless of the species of trees.

• Journal of Korean Society of Forest Science
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• v.76 no.4
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• pp.418-424
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• 1987

Considering the seral stage of succession, phytosocialogical analysis was carried out to investigate the structure and property of community of Pinus densiflora, Pinus densiflora-Quercus spp.-Carpinus laxiflora, and Quercus spp.-Carpinus laxiflora. The study area included a section of 200m high at the sea level in Mt. Jokye, Seungju-gun, Chunlanam-do. The results show that density of forest trees tended to be decreased, Shannon species diversity index increased, and dominance decreased as seral stage progressed. Patterns of DBH class distribution showed nearly S types. In the study area succession of forest community might progressed toward climax, leading from Pinus densiflora community to Quercus spp.-Carpinus laxiflora community with intermediary Pinus densiflora-Quercus spp.-Carpinus laxiflora community. The fact that there was no pure community of Quercus spp. might be due to the rapid development of forest community investigated.