• Journal of the Korean Wood Science and Technology
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• v.31 no.2
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• pp.84-91
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• 2003

In this study, the three species (Populus euramericana, Pinus densiflora and Quercus variabilis) were cut to difference (0, 0.15, 0.3, 0.45 mm) between the size of tip and that of root of the finger (DSTR) and jointed with poly vinyl acetate (PVA) and resorcinol-phenol resin (RPR). We described the relationship between the bending strength properties of finger DSTR and the acoustic emission (AE) generated during the bending test. The results were as follows: The AE generation time of finger-jointed specimens with RPR adhesive was earlier than that with PVA adhesive. The AE cumulative event count of finger-jointed specimens with RPR adhesive continuously increased with increasing load and the event count was much more than that with PVA adhesive. Also, the AE cumulative event count for resorcinol-phenol resin adhesive obtained from low load level was abundant. The AE wave in finger-jointed specimens with RPR adhesive could be detected in the below proportional limit load. Therefore, AE signals from bending test are useful for the estimation of strength in finger DSTR specimens.

• Korean Journal of Environment and Ecology
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• v.26 no.5
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• pp.707-718
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• 2012

This study was conducted to monitor 4 years of changes in the vegetation structure starting from 2007 when restoration began and propose vegetation management ideas for the riparian ecological restoration areas in the purchased land around Nakdonggang(River). The study was conducted in each of 15 locations ($208,342m^2$) in the riparian ecological restoration areas in November 2007, September 2008, October 2009 and September 2010. The analysis results of the changes in planting species and population showed that, in the case of trees, Acer pseudo-sieboldianum, Quercus acutissima, Acer ginnala, Quercus aliena, Quercus variabilis indicated relatively little changes in their numbers and Quercus dentata, Cornus walteri, Morus alba, Styrax obassia, Sorbus alnifolia var. macrophylla indicated a 100% withering rate. Most shrubs withered due to the oppressive pressure of herbs and climbing plants. The planting density decreased over 4 years on average 28 plants/$100m^2$ to 20 plants/$100m^2$ to 16 plants/$100m^2$. Shortly after the restoration, The the amount of growth was reduced by restoration stress. however as time goes on after the restoration tended to stabilize. The changes in the basal area showed a decrease from $507.1cm^2/100m^2$ in 2007 right after restoration to $301.8cm^2/100m^2$ in 2008 and afterwards showed an increasing trend by going to $324.9cm^2/100m^2$ in 2009 and $372.7cm^2/100m^2$ in 2010. To improve the planting structure of the riparian ecological restoration area, the selection of tree species that have been considered for soil moisture and the differentiation of suitable planting structures that have been considered for local conditions were needed.

• Journal of Korean Society of Forest Science
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• v.83 no.2
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• pp.164-174
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• 1994

Temporal changes in growth performances, chlorophyll contents, and tissue water relations for determining their physiological responses of five economic tree species subjected to chronic water and nutrition stresses were investigated with containerized seedlings grown in different soil moisture regimes and nutrition levels. Seedlings of Quercus acutissima, Q. variabilis, Q. mongolica, Q. serrata, and Fraxinus rhynchophylla were propagated in plastic pots(I.D. $16cm{\times}Depth$ 16cm) for the experiments. The seedlings were subjected to two soil moisture regimes of dry and wet soils and two nutrition levels of fertilization with N+P+K and no fertilization through the growing season from May to September in a green house. For the purpose of analyzing their responses to the environmental stresses, seedling heights and root collar diameters, chlorophyll contents, and P-V curve parameters of the seedlings were measured in May, July, and September. The environmental stresses coming from moisture and nutrient deficits affected the growth performances of seedlings variously among species and among different growing periods, as well as between height and basal diameter growth of seedlings. The growth performances of Q. acutissima were influenced sensitively on the stresses, but those of Q. mongolica less influenced in comparison with other species. Chlorophyll contents were generally higher in Quercus spp. than F. rhynchophylla through the growing season. The chlorophyll contents changed by species and by treatment through the season within ranges of 0.14~1.96 mg/g dry wt. of chlorophyll a and within 0.16~1.79mg/g dry wt. of chlorophyll b, respectively. But the contents seemed to be decreased gradually through the chronic environmental stresses and leaf senescence. The osmotic potential at full turgor(${\Psi}{{\pi}o}$) and turgor loss point(${\Psi}{\pi}p$) had temporarily declined up to 3 to 5bars from -7.0~-12.4bars in May to -10.2~-17.5bars in September and up to 5 to 6bars from -7.6~-14.2bars in May to -12.9~-20.4bars in September, respectively, with some exceptions. The values of ${\Psi}{\pi}p$ were generally high in F. rhynchophylla in May and July, but high in Q. serrata in September. Relative water contents at turgor loss point(RWCp) were generally high in F. rhynchophylla, but the temporal changes of RWCp were quite and frequently different among species and among treatment.

• Korean Journal of Environment and Ecology
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• v.31 no.2
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• pp.202-219
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• 2017

The purpose of this study was to analyze the community structure of forest vegetation in Mt. Geumsusan belong to Woraksan National Park for providing basic information of ecological management. Data were collected by 41 plots from June to November in 2016 using Z-M phytosociology method, which was analyzed with vegetation types, mean importance value and coincidence method. As the results, the forest vegetation was classified into Quercus mongolica community group including Cornus controversa community, Castanea crenata community(Vegetation unit 3), Quercus variabilis community(Vegetation unit 4) and Q. mongolica community(Vegetation unit 5). C. controversa community was divided into two groups such as Ulmus davidiana var. japonica group(Vegetation unit 1) and Parthenocissus tricuspidata group(Vegetation unit 2). Mean importance percentage of vegetation unit 1 was showing Fraxinus rhynchophylla 14.9%, Morus bombycis 8.7% and Acer pictum subsp. mono 8.3%, that of unit 2 was Larix kaempferi 23.2%, C. controversa 20.1% and P. tricuspidata 6.5%, that of unit 3 was Q. mongolica 15.8%, C. crenata 13.4% and F. rhynchophylla 9.8%, that of unit 4 was Q. mongolica 26.6%, Q. variabilis 20.8% and Pinus densiflora 16.7%, that of unit 5 was Q. mongolica 48.3%, Styrax obassia 7.5%, F. rhynchophylla 5.3% in the order, respectively. Each vegetation unit was classified with dependance on environmental factors as 700m of altitude, $20^{\circ}$ of slope degree, middle slope of topography, 20% of bare rock, 30 taxa of present species, 80% of tree layer coverage rate and 20m of tree layer height. In conclusion, it was preferentially considered that development of peculiar and specific management methods with vegetation unit classified above should be needed for ecological and sustainable forest vegetation management.

• Journal of Korean Society of Forest Science
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• v.110 no.4
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• pp.648-657
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• 2021

This study was conducted to estimate the volume growth by forest type and major species using the national forest resource inventory and to predict the final age of maturity by deriving the mean annual increment (MAI) and the current annual increment (CAI). We estimated the volume growth using the Chapman-Richards model. In the volume estimation equations by forest type, coniferous forests exhibited the highest growth. According to the estimation formula for each major species, Larix kaempferi will grow the highest among coniferous tree species and Quercus mongolica among broad-leaved tree species. And these estimation formulas showed that the fitness index was generally low, such as 0.32 for L. kaempferi and 0.21 for Quercus variabilis. In the analysis of residual amount, which indicates the applicability of the volume estimation formula, the estimates of the estimation formula tended to be underestimated in about 30 years or more, but most of the residuals were evenly distributed around zero. Therefore, these estimation formulas have no difficulty estimating the volume of actual forest species in Korea. The maximum age attained by calculating MAI was 34 years for P. densiflora, 35 years for L. kaempferi, and 31 years for P. rigida among coniferous tree species. In broad-leaved tree species, we discovered that the maximum age was 32 years for Q. variabilis, 30 years for Q. acutissima, and 29 years for Q. mongolica. We calculated MAI and CAI to detect the point at which these two curves intersected. This point was defined by the maximum volume harvesting age. These results revealed no significant difference between the current standard cutting age in public and private forests recommended by the Korea Forest Service, supporting the reliability of forestry policy data.

• Journal of Korean Society of Forest Science
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• v.107 no.4
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• pp.344-350
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• 2018

This study was carried out to improve the forest management method considering the use of high value added timber in the natural broadleaf forests. For this purpose, the criteria for evaluating the quality grade of standing trees were established and applied to the oak stand in the central region of Korea. The evaluation factors of the grade were bending of stem, branch, stem damage, and other defects. If the logs are divided into 2.1 m units and three logs up to 6.3 m are available, they are classified as Grade I (G-I). If two logs are available, they are classified as Grade II (G-II), If only one log is available, it is classified as Grade III (G-III). When any log is not available as timber, it is classified as Grade IV (G-IV). As a result of applying the grade to the oak stand, G-I was 6.7 %, G-II was 28.0 %, G-III was 38.3 %, and G-IV was 27.0 %. The ratio of standing trees by oak species of higher than G-III was 88.2 % for Quercus acutissima, 88.1 % for Q. variabilis, 83.5 % for Q. serrata, 56.3 % for Q. aliena, and 50.3 % for Q. mongolica, respectively. The G-IV ratio for Q. variabilis and Q. mongolica tended to decrease with increasing diameter at breast height. The order of major defect affecting the grading level was bending of stem > branch > stem damage > other defects. Considering the grade level and oak species distribution, it was concluded possible to produce high quality hardwood timber when we concentrate forest tending techniques on Q. acutissima and Q. variabilis stand. In order to improve the accuracy of grading, it is necessary to continuous complement through the monitoring research for evaluation factors.

• Journal of Korean Society of Forest Science
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• v.14 no.1
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• pp.33-38
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• 1972

This study was carried out to investigate on the variation of wood fiber dimensions of some oakwoods. Every 2 annual ring was selected for specimens from pith toward bark up to 28th annual ring on 3 species of Oak SINGALNAMOO(Quercus mongorica Fisch.), JOLCHAMNAMOO(Quercus serrata Thunb.) and KULCHAMNAMOO(Quercus variabilis Blume) which grew in Mt. Jiri. The investgated results are as follows: 1. Values of wood fiber lengths increase rapidly up to 16th annual ring, however, considerably stable at the rear part. Range of wood fiber length variations: Species Range of length(mean) CV SINGALNAMOO, $640{\sim}1,544{\mu}$($1,142.3{\mu}$), 8~16% JOLCHAMNAMOO, $592{\sim}1,600{\mu}$($1,179.6{\mu}$), 6~21% KULCHAMNAMOO, $679{\sim}1,592{\mu}$($1,298.9{\mu}$), 2~15% 2. The increment of wood fiber width and thickness by annual rings shows quite inactive contrary to the length. Range of wood fiber width: $7.6{\sim}10.0{\mu}$(mean $9.3{\mu}$) Range of wood fiber thickness: $2.0{\sim}3.2{\mu}$(mean $2.6{\mu}$) 3. There was no significance between species through their wood fiber lengths. 4. And these wood fibers believed to be valuable for pulp-wood through their fiber bonding ratio, Runkel ratio and flexibility coefficient.

• Journal of Wetlands Research
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• v.17 no.1
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• pp.45-52
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• 2015

We obtained the following results from investigation on vegetation damage from 5 to 6 August, 2013, about one year after an accident that hydrofluoric acid leaked from a chemical maker, Hube Globe in Gumi. Pinus densiflora and Pinus strobus showed very severe damage. Ginko biloba, Quercus acutissima, Pinus rigida, Salix glandulosa, Hibiscus syriacus, and Lagerstroemia indica showed severe damage. Quercus variabilis, Lespedeza cyrtobotrya, and Miscanthus sinensis showed moderate damage. Quercus aliena, Smilax china, Arundidinella hirta, Ailanthus altissima, Robinia pseudoacacia, and Paulowinia coreana showed slight damage. We did not find any plants without leaf damage around there. This result means that fluoride damage still persists in this area as was known that fluoride remains for a long time in air, soil and water and exerts negative effects at all levels of an ecosystem. In addition, fluoride content contained in plant leaf depended on the distance from a fertilizer producing factory and vegetation damage tended to proportionate to the concentration in the Yeocheon industrial complex. In these respects, a measure for removal or detoxification of the remaining fluoride is urgently required around the hydrofluoric acid leak spot. Fertilizing of dolomite containing Ca and Mg, which can trap fluoride, was prepared as one of the restoration plans. In addition, phosphate fertilizing was added in order to enhance soil ameliorating effects. Furthermore, we recommend the introduction of tolerant plants as the second measure to mitigate fluoride damage. As the tolerant plants to make a new forest by replacing trees died due to hydrofluoric acid gas damage, we recommended Q. aliena and S. china, A. hirta, etc. were recommended as plant species to add mantle vegetation to the forest margin to ensure stable interior environment of the forest.

• The Korean Journal of Ecology
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• v.22 no.3
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• pp.145-153
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• 1999

Authors report the changes of the community structure and secondary succession after fire in Mt. Samma (333 m). Approximately six ha of the red pine (Pinus densiflora) forest and its floor vegetation were burned and cutted down. The vegetation and soil properties were investigated in the burned and unburned sites from April to October, 1998. The dominant species based on SDR₃ in the burned site were Lespedeza cyrtobotrya (96.87), Quercus serrata (77.90), Cyperus amuricus (46.22) and Miscanthus sinensis var. purpurascens (38.33), whereas the dominant species in the unburned site were Pinus densiflora (100.00) and Q. variabilis (66.10) at the tree layer, Q. serrata (100.00) and Zanthoxylum schinifolium (29.64) at the shrub layer., and Q. serrata (76.30) and M. sinensis var. purpurascens (72.84) at the herb layer. The biological spectra based on SDR₃ were Th-D₁-R/sub 5/-e for the burned and H (M)-D₁-R/sub 5/-e type for the unburned site, respectively. The index of similarity (CCs) between the burned and unburned sites was 0.41. The degree of succession (DS) were 609 for the burned and 1168 for the unburned site, respectively. The species diversity (H) and evenness indices (e) of the burned site were lower than those of the unburned site, but the dominance indices (C) was higher in the burned site. In the analysis of soil properties, pH, the content of NO₃/sup -/-N, available phosphrous, and exchangeable cations (K/sup +/, Ca/sup 2+/, Na/sup +/, Mg/sup 2+/) in the burned site were higher than those in the unburned site, whereas the contents of organic matter, total carbon, total nitrogen and NH₄/sup +/-N were lower in the burned site. The results show that dominant species in the burned site change from Miscanthus-Lespedeza→Lespedeza→Quercus and finally to Quercus forest, and the changes of soil properties also affect the early vegetational succession after fire.

• Korean Journal of Environment and Ecology
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• v.28 no.2
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• pp.215-234
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• 2014

The purpose of this study is to identify the type and characteristics of the domestic natural streams in order to establish a basis for stream restoration and evaluation. To this end, 95 domestic natural stream areas, which have various natural environments, were selected except for the province of island and then the characteristics of natural environment, hydromorpholoy, plant and vegetation were investigated and analyzed in each stream area. As a result, 95 stream areas were classified into total 24 types according to 3 criteria such as stream size (4 types), altitude (3 types), bed material (5 types). Depending on altitude class that is the environmental factor showing the highest correlation with each stream types, the emergence of vegetation and plant, 24 stream types were reclassified into 3 types such as lowland (altitude less than 200m), mountain (altitude from 200m to 500m), highland (altitude more than 500m), and hydromorpholoy, plant and vegetation characteristics of each stream type were compared. First, when compared to the mountain and highland streams, the typical features of lowland streams were as follows: Stream size was large but bed material size was small and there were many valley forms where flood plane were developed well. In addition, the more large stream size was, the more cross-section width variability, bars and sinuosity were in good conditions. In lowland stream, representative vegetation community was Salix koreensis community. On the other hand, when compared to the lowland streams, the typical features of mountain and highland streams were as follows: Stream size was small but bed material was coarse-grained and its size was large. Mountain and highland streams valley form where flood plane was not developed well was narrow, and sinuosity and bars development were weak. Representative vegetation communities of mountain streams were Quercus serrata -, Quercus variabilis -, Styrax japonica community and representative vegetation communities of highland streams were Pinus densiflora -, Quercus mongolica -, Fraxinus rhynchophylla community.