• Journal of the Korean Institute of Landscape Architecture
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• v.30 no.1
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• pp.75-86
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• 2002

This study was conducted to analyze the change of soil characteristics effect on the condition of urban forest in Sasang parti located near Sasang Industrial Complex. The results of this study are as follows; 1. Soil hardness is increasing from the area of forest, to the entrance, to facilities in that order. Soil acidity pH4.19∼4.23 in Sasang park indicated a high acidity condition. High levers of K, Na, Mg, Ca are shown in the areas composed of high soil hardness. 2. Pinus thunbergii in the overstory tree layer, Alnus japonica in the understory tree layer, and Rhus sylvestris in the shurb layer are shown respectively as dominant species based on the ground survey and the compution of important value. Pinus thunbergii is decreasing, while Alnus japonica and increasing. 3. Oplismenus undulatifolius which has a strong tolerance for air pollution, is shown as a dominant species of herbaceous plants in Sasang park. There are 10 species of Harbaceous in Sasang park compared to 20 species in Molundae park. This shows that deversity in herbaceous plants are imported by air pollution. 4. Species diversity indices of Sasang park is 0.8738∼0.9700 compared to 1.0817∼ 1.233 in Molundae park is due to the good condition of soil environment in addition to air pollution effects. 5. The vitality of Pinus thunbergii is 16.41∼20.42ER in Sasang park, and 12.42∼ 16.81ER, in Molundae park. This shows that tree vitality are impacted by soil characteristics. The regression analysis between tree vitality and soil environment shows the effects of is soil hardness, soil moisture, soil acidity, K, Na, Mg, Ca.

• Journal of Korean Society of Forest Science
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• v.81 no.4
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• pp.346-356
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• 1992

The extensive Snake River floodplain in Northwest United States has experienced major changes in water channels and vegetation types due to floodings. To detect the change of wetland cover-types for the period of 1985 and 1988, post-classification comparison and image differencing change detection techniques were evaluated using Landsat-5 TM digital data. Differenced infrared-band images indicated better accuracy indices than any visible-band images. A thresholding technique was applied to identify the change and no change categories from the transformed images produced by image differencing. The problems in using different accuracy indices, including the Kappa coefficient of agreement, overall accuracy, producer's accuracy, user's accuracy, and average accuracy(based on both the producer's and user's accuracy approaches) in determining an optimal threshold level, were examined.

• Journal of Korean Society on Water Environment
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• v.24 no.2
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• pp.206-213
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• 2008

Fish fauna and community structure were investigated at 2003, 2004 and 2006 in Lake Paldang and its inflows. In this survey, we collected 54 species belong to 14 families. Family Cyprinidae take 51.9% (28 species), Cobitidae and Gobiidae occupied 7.4% (each 4 species), respectively. E. erythropterus (11.8%) was dominant species and L. macrochirus (10.2%), designated as an ecosystem-invasive alien fish species by Ministry of Environment, M. yaluensis (9.1%), Z. platypus (7.7%) and R. brunneus (6.7%) were dominated in turn. H. molitrix, C. lutheri, P. altivelis, S. microdorsalis, L. costata. S. gracilis majimae, A. rivularis, P. koreanus. S. scherzeri and O. platycephala were rare species (less than 0.1% in relative abundance). In-lake area, 36 species of fishes belonging to 11 families were collected, and 48 species of 13 families were from inflows. The number of Korean endemic species were 19 species (35.2%), and 4 kinds of exotic species (7.4%), that is, C. cuvieri, H. molitrix, L. macrochirus and M. salmoides were found at this survey area. It was revealed by the analysis of fish community that diversity and richness indices were prominent at tributaries, and dominance index was high at the main body of Lake Paldang. Fish fauna showed rapid decline after dam construction which make the mid-Han river systems to lentic ecosystem, so many of meander-riffle fishes were disappeared dramatically. But after 1990s when installation of small scale wastewater treatment plants started in watershed, the water quality of small tributaries was improved. And also, expansion of the natural macrophytic vegetation of littoral zone should contribute to the development of diverse fish fauna in Lake Paldang.

• Journal of Korean Society of Forest Science
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• v.104 no.3
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• pp.368-374
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• 2015

On the basis of vegetation data by point quarter sampling method, the natural forest of Jirisan(Mt.) was classified into eight forest types by cluster analysis. They were Quercus mogolica forest type, Fraxinus mandshurica - Betula costata forest type, Mixed mesophytic forest type, Abies koreana forest type, Carpinus laxiflora forest type, Quercus serrata forest type, Pinus densiflora forest type, and Quercus variabilis forest type. Then, succession index was estimated for each forest type so as to evaluate succession process comparatively among forest types. The results showed that Carpinus laxiflora forest type had highest succession index of 219.7, followed by Mixed mesophytic forest type with little difference of the index of 218.3. Pinus densiflora forest type had lowest index. Succession indices were hardly correlated with species diversity indices of forest types. We presumed that the higher value of succession index a forest type had, the closer toward the climax forest. However, the estimated index was not supposed to be absolute level of successional stage, but it could play a role of comparative assessment in the position of the seral stage among forest types.

• Asian Journal of Atmospheric Environment
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• v.12 no.1
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• pp.1-16
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• 2018

Ground-level ozone ($O_3$) can be a menace for vegetation, especially in Asia where $O_3$ levels have been dramatically increased over the past decades. To ensure food security and maintain forest ecosystem services, such as nutrient cycling, carbon sequestration and functional diversity of soil biota, in the over-populated Asia, environmental standards are needed. To set proper standards, dose-response relationships should be established from which critical levels are derived. The predictor of the response in the dose-response relationship is an $O_3$ metric that indicates the dose level to which the plant has been exposed. This study aimed to review the relevant scientific literature and summarize the $O_3$ metrics used worldwide to provide insights for Asia. A variety of $O_3$ metrics have been used, for which we discuss their strengths and weaknesses. The most widely used metrics are based only on $O_3$ levels. Such metrics have been adopted by several regulatory agencies in the global. However, they are biologically irrelevant because they ignore the plant physiological capacity. Adopting AOT40 ($O_3$ mixing ratios Accumulated Over the Threshold of $40nmol\;mol^{-1}$) as the default index for setting critical levels in Asia would be a poor policy with severe consequences at national and Pan-Asian level. Asian studies should focus on flux-based $O_3$ metrics to provide relevant bases for developing proper standards. However, given the technical requirements in calculating flux-based $O_3$ metrics, which can be an important limitation in developing countries, no-threshold cumulative exposure indices like AOT0 should always accompany flux-based indices.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.2
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• pp.159-164
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• 2019

Weed control is a crucial practice not only in organic farming, but also in modern agriculture because it can lead to loss in crop yield. In general, weed is distributed in patches heterogeneously in the field. These patches vary in size, shape, and density. Thus, it would be efficient if chemicals are sprayed on these patches rather than spraying uniformly in the field, which can pollute the environment and be cost prohibitive. In this sense, weed detection could be beneficial for sustainable agriculture. Studies have been conducted to detect weed patches in the field using remote sensing technologies, which can be classified into a method using image segmentation based on morphology and a method with vegetative indices based on the wavelength of light. In this study, the latter methodology has been used to detect the weed patches. As a result, it was found that the vegetative indices were easier to operate as it did not need any sophisticated algorithm for differentiating weeds from crop and soil as compared to the former method. Consequently, we demonstrated that the current method of using vegetative index is accurate enough to detect weed patches, and will be useful for farmers to control weeds with minimal use of chemicals and in a more precise manner.

• Journal of Korean Society of Forest Science
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• v.109 no.2
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• pp.124-135
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• 2020

Alder (Alnus japonica) forests are representative of the wetland in East Asia, including Korea. In the past, alder forests were relatively common in various habitats such as mountains, riversides, back marshes, and alluvial plains. However, this plant community has recently become rare due to increasingly arid habitats and the influence of various land uses. In this study, we identify the synecological characteristics of alder (A. japonica) forests distributed naturally in the mountainous wetlands of Korea and provide basic data for their systematic conservation and management in the future. Based on vegetation survey data collected from 66 alder forests, community types were classified using the methods of the Zürich-Montpellier School of Phytosociology and two-way indicator species analysis. There were eight community types: Styrax obassia, Weigela subsessilis-Fraxinus mandschurica, Spiraea fritschiana, Viola verecunda, Impatiens textori-Spiraea salicifolia, Glyceria leptolepis, Molinia japonica, and Lindera obtusiloba-Quercus acutissima. These community types constituted a vegetation unit hierarchy of two communities, four subcommunities, and eight variants. In addition, the ecological characteristics of each community type were compared (including total coverage per 100 square meter, importance value index, constancy class, life-form composition, diversity indices, community similarity coefficient, and indicator species).

• Korean Journal of Weed Science
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• v.30 no.1
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• pp.17-24
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• 2010

Field study to find appropriate species for phytoremediation and phytomonitoring with higher plants was carried out at four abandoned metalliferous mines. In order to know the tolerant degree of plant resources collected at heavy metal polluted sites, soil and plants were sampled at same sites and metal concentrations were determined. Most serious heavy metal polluted in the sites was As that showed range from 29.1 to 1372.2 mg $kg^{-1}$ in investigated area. The dominant species were Oenothera biennis, Commelina communis, Persicaria senticosa, Conyza annuus, Artemisia princeps, and Erigeron canadensis. These species were predominant species that were proliferated in any survey area. Compared with other sites, vegetational characteristics of Dal-Seong, a mine site abandoned early in 1973, showed higher diversity index and lower dominance index. Distributions of weed species according to life cycle indicated that the proportions of perennial plants were lowered in every investigated site. Although the polluted areas were distant from each other, similarity indices among these vegetation were relatively similar. These results means the vegetations of abandoned mine areas were beginning stage of vegetational succession, and the vegetations were adversely affected by disturbance with heavy-metals and lack of water in soil.

• Korean Journal of Environment and Ecology
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• v.29 no.4
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• pp.599-604
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• 2015

This study was conducted the vegetation clustering analysis for the 3 mountains of Mt. Bulam, Mt. Daemo, Mt. Bonghwa which were the urban forests of Seoul. Based on the results of the analysis related to the vegetation clustering, it was found that the clustering of Mt. Bulam consisted of pine trees(Pinus densiflora)-Mongolian oak(Quercus mongolica), Hornb eam(Carpinus laxiflora)-Pitch pine(P. rigida), oriental oak(Q. variabilis) - a wild pear tree(Sorbus alnifolia) while the clustering of Mt. Daemo consisted of Pitch pine-Japanese larch(Larix leptolepis), Poplar(Populus tomentig landulosa)- black birch(Betula davurica pall). Meanwhile, the clustering of Mt. Bonghwa consisted of pine trees-a wild pear tree Community and Sawtooth oak(Q. acutissima)-Cherry Blossoms(Prunus serrulata). In relation to the similarity index by region in Mt. Bulam, Mt. Daemo, and Mt. Bonghwa, the similarity index of Mt. Bulam and Mt. Daemo stood at as high as 0.634, suggesting the distribution of similar vegetation, and the dominance index of the Mt. Daemo region was found to be 0.166 which suggests the dominance of many species compared to other regions. In addition, the results of species diversity showed that Mt. Daemo had the highest stability, and the species diversity, maximum species diversity, evenness indices were highest in Mt. Bulam, followed by Mt. Bonghwa and Mt. Daemo. The dominance index was the lowest in Mt. Bulam, followed by Mt. Bonghwa and Mt. Daemo.

• Journal of Korean Society of Forest Science
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• v.79 no.3
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• pp.245-254
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• 1990

This study was carried out to analysis the structure of forest vegetation at the southern and northern slopes of Mt. Kum in Namhae. The results obtained were summarized as follows : The upper layer of south slope at the altitude of 100m was only distributed at Pinus thunbergii and Pinus densiflora. According to increase of altitude, the importance value of Pinus thunbergii was more decreased. In the upper layer of north slope, importance value of Pinus thunbergii was very high in the altitude of 100m, and was very low in the 200m. And also, importance value of Quercus variabilis and Steuortia koreana was high from 200m to 600m. The number of individuals of Pinus thunbergii and Pinus densiflora in the south slope were more increased than those of the north slope. The distributional class of D.B.H, showed an equal tendency in south and north slope, especially-Quercus variabilis and Quercus serrata had a good growth in north slope. The stand density in the upper lacer was high in south slope but mean acreage and mean distance of individual trees showed low. The species diversity indices were relatively lower in south slope than in north slope, and the maximum of species diversity showed slightly high in south slope. The evenness showed lower in south slope than in north slope relatively. By the cluster analysis used the similarity.