• Journal of the Korean Society of Environmental Restoration Technology
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• v.19 no.1
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• pp.73-83
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• 2016

Forest degradation reduces ecosystem services provided by forest and could lead to change in composition of species. In North Korea, there has been significant forest degradation due to conversion of forest into terrace fields for food production and cut-down of forest for fuel woods. This study analyzed the phenological changes in North Korea, in terms of vegetation and moisture in soil and vegetation, from March to Octorber 2013, using MODIS (MODerate resolution Imaging Spectroradiometer) images and indexes including NDVI (Normalized Difference Vegetation Index), NDSI (Normalized Difference Soil Index), and NDWI (Normalized Difference Water Index). In addition, marginal farmland was derived using elevation data. Lastly, degraded terrace fields of 16 degree was analyzed using NDVI, NDSI, and NDWI indexes, and marginal farmland characteristics with slope variable. The accuracy value of land cover classification, which shows the difference between the observation and analyzed value, was 84.9% and Kappa value was 0.82. The highest accuracy value was from agricultural (paddy, field) and forest area. Terrace fields were easily identified using slope data form agricultural field. Use of NDVI, NDSI, and NDWI is more effective in distinguishing deforested terrace field from agricultural area. NDVI only shows vegetation difference whereas NDSI classifies soil moisture values and NDWI classifies abandoned agricultural fields based on moisture values. The method used in this study allowed more effective identification of deforested terrace fields, which visually illustrates forest degradation problem in North Korea.

• Journal of Ecology and Environment
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• v.39 no.1
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• pp.1-10
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• 2016

Despite it has been mentioned that the successful restoration in landscape level was achieved in the Young-il soil erosion control project, quantitative evaluation of restored plant communities (Alnus firma as introduced species and Pinus thunbergii as native species) was hardly founded. Light availability, litter and woody debris cover, and forest structure and composition were determined for 500 m² band-quadrat in three forest types. Abiotic factors of Q. serrata stands, as reference forest, and A. firma stands were similar but not for P. thunbergii stands. There were no significant difference on mean stem density (stems ha^-1, H = 3.6, p = 0.162), and the mean basal area of each stand had marginal significance (m² ha^-1, H = 5.7, p = 0.058) among stands as total basal area was higher with the order of A. firma (21.4 m² ha^-1), P. thunbergii (19.8 m² ha^-1) and Q. serrata (16.2 m² ha^-1). Restoration of vegetation structure was more effective in fast-growing and N-fixing A. firma, as introduced species plantation. However, result of MRPP, NMS ordination and ISPAN for herbaceous layer, not for tree and shrub species composition, indicated that restoration of ground vegetation was likely influenced highly from local environment. Propagule availability from landscape context such as connectedness to natural vegetation and management practices in restored isolated stands are available explanations for restoration effects and gaps between restored plantations and secondary oak forest.

• Korean Journal of Agricultural Science
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• v.50 no.2
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• pp.165-180
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• 2023

This study investigated 62 nested quadrat plots of Jinaksan to identify community classification and changes of the vegetation by using the phytosocial method and analyzed importance values. Vegetation types were classified into 8 communities: Quercus mongolica community, Q. variableis community, Q. aliena community, Pinus densiflora, Q. acutissima, Zelkova serrata, Carpinis laxiflora, and C. tschonoskii. The significance value was highest in Q. mongolica (62.75) followed by P. densiflora (55.16), Q. variabilis community (25.03), Z. serrata (22.17), Q. aliena (18.30), Prunus serrulata var. pubescens (16.86), C. laxiflora (13.25), Q. acutissima (10.72), C. tschonoskii (10.08), Q. serrata (8.02), Fraxinus sieboldiana (6.93), Acer pseudosieboldianum (6.73), and Styrax obassis (5.73). Quercus mongolica displayed a stable distribution pattern, presenting a reverse J-shaped curve from the diameter at breast height (DBH) analysis, and it was judged that current state would be maintained for a certain period. In addition, P. densiflora is expected to dominate for the time being and Quercus species are expected to gradually decrease.

• Journal of Environmental Impact Assessment
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• v.19 no.3
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• pp.347-356
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• 2010

Forests are being seriously fragmented as a result of land development. Land development with disregard to its subsequent environmental impacts is a primary threat to biodiversity by incurring massive habitat losses and changes in structure and composition of forests. The purpose of this study was to develop the impact assessment model for quantitative distance or degree of disturbance by land developments. This study conducted a survey about structure and composition of forest species to determine degree of impact from land development. The edge effect of forest fragmentation on the number of bird species, population size, and bird diversity was obvious. In particular, the bird diversity sharply declines around the forest edge where intensive land development projects take place. To assess the disturbance of forest species, the factors selected were the bird diversity and the rate of edge species. The impact assessment model about bird diversity was explained by type of forest fragmentation and type of vegetation ($R^2$=0.23, p<0.005). The other model about edge species explained by a distance, type of forest fragmentation, type of vegetation, and width of road ($R^2$=0.34, p<0.001). In order to test the applicability of the model developed in this study, the models was applied to the Samsong housing development in Goyang-si, Gyunggi-do. The impacts of land development on the bird species were reasonably quantified to suggest effective mitigation measure. The impact assessment model developed in this study is useful to assess the magnitude of disturbance of bird species. Particularly, the model could be applied to the current Environmental Impact Assessment practices to predict and quantify the impacts of land developments projects on forest bird species.

• Korean Journal of Environment and Ecology
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• v.16 no.2
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• pp.131-140
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• 2002

The bryophyte communities on the forest floor of the mixed coniferous and deciduous broad-leaved forest of cool temperate zone on Deongnyusan(1,616m) south-eastern part of the Korean Penninsula were investigated from the phytosociological viewpoint. As a result, a bryophyte community was recognized, considering the phytosociological unit of the forest: Sasamorpha borealis-Abies koreana / Hylocomiopsis ovicarpa-Thamnoblyum alopecurum community. This community was interpreted as a counterpart one of the Sasamorpha borealis-Abies koreana / Dicranum scoparium-Plagiothecium silvaticum community in the Jiri Mountains, but between the two communities, the species composition was somewhat different. The bryophyte community on the forest floor on Deongnyusan was confirmed as a synusie belonging to the Fraxino-Abietetum koreanae Song 1988. Up to date many investigators have described the coniferous forest distributed above 1,400m on Deongnysan as the forest vegetation of subarctic(=subalpine) zone. However, from the results of the present study, the forest vegetation, a mixed forest, was elucidated to be one of cool temperate zone. Species diversity of the terri-colous bryophyte community on Deongnyusan was very close to that of the communities of the similar type in the Jiri Mountains. The taxa of the bryophyte community was composed of 19 families,25 genera and 38 species.

• Korean Journal of Environment and Ecology
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• v.25 no.4
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• pp.540-561
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• 2011

We carried out a study for ecological management and ideal vegetation structure selection on the shrine forest of 'Miwhang-sa' considering the species diversity and the vegetation structure analysis associated with global warming. We carried out the analyses of phytosociological vegetation structure, correlation between vegetation units and environmental variables, life form, species diversity, and species evenness. This study identified the vegetation units as 3 communities. The identified vegetation units are as follows: Quercus acuta community(DQ), Quercus serrata-Quercus variabilis community(QQ) and Celtis sinensis community(CS). According to the basis on the environmental variables; Ca, Mg and P, Celtis sinensis community and other communities were classified. Quecus serrata-Quercus variabilis comm. and Quercus acuta comm. were classified, according to the basis on the environmental variables; organic matter(OM), Ni and Zn. Sasa borealis as life form R1-2, dominated the herb layer and will dominate the herb and shrub layers. Species simplification is formed on herb layer and will be formed on shrub layer. The species diversity of Quercus serrata-Quercus variabilis community is higher than the one of Quercus acuta community, and the species diversity of shrine forest around Miwhang-sa was higher than the shrine forest around Nameun-sa where evergreen broad-leaved forests dominate. It is essential that the long-term vegetation management considering the vegetation units by phytosociological analysis, the species simplification problem of low layers by S. borealis and the species diversity and evenness in the shrine forest, Miwhang-sa.

• Korean Journal of Agricultural and Forest Meteorology
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• v.7 no.3
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• pp.211-219
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• 2005

Vegetation composition and structure of Sorbus commixta - native forests of South Korea were studied using phytosociological procedures and its ecological characteristics analyzed with special respect to species correlations, importance values, and constancy classes. Vegetation types were divided (great division) into Tripterygium regelii - Quercus mongolica (Inland high mountain type) and Acer takesimense - Fague crenata var. multinervis (Ulleung Island type) and ten accompanying vegetation units. In between S. commixta and life-farms, 120 correlations were positive with 23 of these having a p-value < 0.01 for trees, 21 for shrubs, 10 for woody vines, and 25 for herbs. In trees, there was a positive correlation between S. commixta and A. takesimense and T. insularis on the $1\%$ level. In shrubs, there was a positive correlation between S. commixta and Sasa kurilensis, Callicarpa japonica, Ligustrum foliosum on the $5\%$ level. In woody vines, there was a negative correlation between S. commixta and Tripterygium regelii and Actinidia rufa on the $1\%$ level. In herbs, there was a positive correlation between S. commixta and Majanthemim dilatatum and Solidago virga-aurea var. gigantea on the $1\%$ level.

• Korean Journal of Environment and Ecology
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• v.32 no.2
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• pp.176-184
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• 2018

This study was intended to provide basic data for more ecological and systematic preservation and management planning of forest vegetations in the Baekdudaegan sector between Danmoknyeong and Guryongnyeong where biodiversity is considered to be very important. A vegetation survey using the Zurich-Montpellier (Z.-M.) method of phytosociology was carried out in a total 142 sites to examine the environmental characteristics. The survey showed the forest vegetation types of one community group, two communities, four groups, and four subgroups. Quercus mongolica and Acer pseudosieboldianum, which fall under Constancy Class V, were dominant species and deemed to be the key species of the forest ecosystem management plan for the investigated areas. Regarding species diversity, it was found that the dominant species of the VT3 type were evenly distributed in the area while the species of the VT4 type showed not only a diverse composition but also the most abundant number of species. Moreover, there were 24 of rare plants found in the Danmoknyeong-Guryongnyeong section: the critically endangered species include Dracocephalum rupestre; the endangered species include Saxifraga octopetala; the vulnerable species include Paeonia japonica, Euphorbia fauriei, Hanabusaya asiatica, and Parasenecio pseudotaimingasa; the least concern species include Aristolochia manshuriensis, Rodgersia podophylla, Salvia chanryoenica, Scopolia japonica, and Parasenecio firmus.

• Journal of agriculture & life science
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• v.43 no.6
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• pp.19-27
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• 2009

This study was carried out to obtain the basic model to estimate damage degree from the correlation analysis between forest fire and site environment factors and to clarify the restoration trends thorough multi-temporal survey by observing species diversity followed by various treatments at damaged forest area over time. From the derived model, the damage degree of forest fire was higher in the area of dense coniferous stands composed of simple story at the elevation of about 100m and 200m, and on steeper slope area over 30 degree. As results of this study, fire damaged trees are needed to cut down and a mixed stand with deciduous and coniferous species from the same area is desirable for the future species composition on fire damaged forest. Thus, site characteristics, local species, and mixed stands are the main consideration to enhance the vegetation recovery.

• Journal of Forest and Environmental Science
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• v.38 no.2
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• pp.90-101
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• 2022

The study aims to assess composition, diversity and population indices of natural regeneration of woody species in Jebel El Gerrie forest reserve, Blue Nile State, Sudan. We conducted field work between December 2018 and January 2019. We used random sampling to collect vegetation data in the forest where we made a total of 90 circular sample plots (radius 17.84 m) and distributed them proportionally to the area of each of the four density-based vegetation classes of the forest i.e. high density (C1), medium density (C2), low density (C3) and crop land (C4). In each sample plot we identified all regenerating tree species and counted their regeneration frequencies. We calculated ecological metrics of regeneration frequency, density, abundance, richness, evenness, diversity and importance value index (IVI) and drew abundance rank curve. Results revealed that out of fifteen mature tree species present, natural regeneration of 8 species, which belong to 6 families, was observed. The relatively most frequently naturally regenerating and abundant species were Anogeissus leiocarpa and Combretum hartmannianum. Richness, evenness and diversity of regenerating species were 1.33, 0.82 and 1.7, respectively. One-way ANOVA (α=0.05) of mean regeneration densities disclosed that there were significant differences (F_3,86=16.77, p=0.000) between C2 & C3 (p=0.000) and C2 & C4 (p=0.000). While regeneration of seven tree species were absent, two, two and four species were of good, poor and fair regeneration status, respectively. A comparison of mean density of natural regeneration with that of parent trees reflects a poor regeneration status of the forest. The study provides empirical results on the regeneration status of species and signifies the need for management interventions for species conservation and restoration, maintenance of biodiversity and sustainable production.