• Journal of the Korean Society of Environmental Restoration Technology
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• v.18 no.6
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• pp.97-110
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• 2015

This study aimed to classify damaged lands, to find what are the damage factors affecting the studied area, and to present a prescription in order to provide some benefit for the restoration of Regional Ecological Network at Chungnam province. Finally we classified damaged lands from 1st to 4th damaged lands according to relative intensity of damage. The main damage factors for the First Damage Lands were humus horizon, soil hardness and plant species richness. In the Second Damage Lands, those were soil hardness, plant species richness, number of plants and dominant plant species. In the Third Damage Lands, those were humus horizon, soil hardness, plant species richness, number of plants and dominant plant species. In the Fourth Damage Lands, those were humus horizon, organic matter, soil hardness, EC, T-N content, plant species richness, number of plants and dominant plant species. In every cases, the damage of soil and vegetation was originated due to development carried out by human being. The changes in soil condition were not big enough for it to affect plant growth, however, degradation of vegetation was still severe.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.88-88
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• 2022

Detection of stress responses in crops is important to diagnose crop growth and evaluate yield. Also, the multi-spectral sensor is effectively known to evaluate stress caused by nutrient and moisture in crops or biological agents such as weeds or diseases. Therefore, in this experiment, multispectral images were taken by an unmanned aerial vehicle(UAV) under field condition. The experiment was conducted in the long-term fertilizer field in the National Institute of Crop Science, and experiment area was divided into different status of NPK(Control, N-deficiency, P-deficiency, K-deficiency, Non-fertilizer). Total 11 vegetation indices were created with RGB and NIR reflectance values using python. Variations in nutrient content in plants affect the amount of light reflected or absorbed for each wavelength band. Therefore, the objective of this experiment was to evaluate vegetation indices derived from multispectral reflectance data as input into machine learning algorithm for the classification of nutritional deficiency in rice. RandomForest model was used as a representative ensemble model, and parameters were adjusted through hyperparameter tuning such as RandomSearchCV. As a result, training accuracy was 0.95 and test accuracy was 0.80, and IPCA, NDRE, and EVI were included in the top three indices for feature importance. Also, precision, recall, and f1-score, which are indicators for evaluating the performance of the classification model, showed a distribution of 0.7-0.9 for each class.

• Journal of the Korean Institute of Landscape Architecture
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• v.17 no.2
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• pp.41-46
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• 1989

Rhododendron micranthum grown over the area of Kyoung Puck, Kang Weon Province is showy and very attractive evergreen broad-leaned shrub of shade resistance. This shrub is considered very useful for exploiting as a garden plant. Environments, growth characteristics and vegetation association in the wild habitat and in the garden planted with this shrub, were investigated to find out some appropriate means of propagation and cultivation of this shrub. The results thus obtained were stated as follows ; 1. Light intensity for the native habitat ranged in the proximity of 9%. The most abundant stand of this shrub occurred in the northen side of mountains, while still some plants were found in the eastern sides also. 2. Soil of the native habitat was acidic (pH 4.4) and infertility. 3. Average elevation of the native habitat was shown to be 230m above the sea level. 4. The plant of the native habitat showed an average of 3.9 new shoots per branch, whereas that of the garden planted (light intensity 100%) showed 1.2, 5% of an average was for sun-burn leaves were noted, while garden Plants(light intensity 100%) showed 90% of them. 5. Other tree species associated with Rhododendron micrathum in the native habitat were primarily Pinus densiflora and secondarily Sorbus alnifolia, hemerocallis aurautiaca, Rubus crataegifolius, and Salix hulteni. 6. Vegetation rate of plant habitats in the Rhododendron growing area was observed to be 0 to 80% involving 27 to 50 species of associated trees in the vegetation for the 10${\times}$10m quadrat area.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.24 no.2
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• pp.71-84
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• 2021

Restoration of DMZ has come up with the discussion on the peaceful use of the DMZ and the conservation plan of the army. In this study, we aim to identify soil characteristics of 108 sites to figure out environmental conditions around the iron fence of DMZ where vegetation has been removed repeatedly. Based on the soil characteristics and climate variables, hierarchy clustering was performed to categorize sites. As a result, we categorized 108 sites into 4 types: middle elevation region, lowland, East coast lowland, other areas. Group of 'other area' is only high in nutrient and clay proportion. Others are in igneous rock and metamorphic rocks with a high proportion of sand and lower nutrients than the optimum range of growth in Korean forest soil. The middle elevation region has a high altitude, low temperature. The east coast lowland has a high temperature in January and low precipitation. The lowland has a low altitude and high temperature. This category provides the environmental condition around the DMZ fence and can be used to select plants for restoration. The restoration project around the DMZ iron fence should satisfy the security of military plans, which means that functional restoration is prior to ecological restoration such as vegetation management under a power line. Additionally, improvement of soil quality and surface stability through restoration projects is required to enhance the resilience of the ecosystem in DMZ.

• Journal of Korea Water Resources Association
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• v.53 no.3
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• pp.167-179
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• 2020

Recently, new levee material has been developed to enhance natural soil strength and vegetation growth using biopolymer. In the study, critical tractive force of vegetated mats mixed with biopolymer mixed soil has been evaluated to apply the mixed soil to levee construction material. The mixed soil has been produced by mixing beta-glucan, clay, and sand. Full scale test bodies have been constructed with 3 cm thick of the mixed soil. Total 4 test bodies have been constructed and experimented. Critical tractive forces have been evaluated by observation and measurement of failure conditions and soil loss. Although performance of the vegetated revetments are affected by vegetation coverage conditions, the critical tractive forces are shown about 40 N/㎡ and the critical velocities are shown about 4 m/sec by full scale experiment. Erosion resistance is also enhanced by combination of root and net with mat materials.

• Korean Journal of Environment and Ecology
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• v.35 no.4
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• pp.408-423
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• 2021

We established and monitored survey sites in seven regions of Mt. Jiri to investigate population decline and change of the Korean fir (Abies koreana) over a ten-year period from 2009 to 2018. With the exception of one site (Seseok), the six remaining ones all showed a four-layer stratification structure. The importance value of Korean firs in all of the survey areas decreased significantly by 28.5%, from 55.7% in 2009 to 39.8% in 2018. The average population of objects with a diameter at breast height (DBH) of 5cm or more in all survey sites was 711 objects/ha in 2018, and the cumulative death rate from 2009 to 2018 was 10.8%. Among the death types, DS (dead standing) was the most dominant, comprising 82.4% of the total survey area. However, in Banyabong 1, which had a high gradient of 35°, the death types other than DS accounted for 44.2%. We estimate that A. koreana can maintain a stable population as its distribution type for each diameter class in the Saeseokpyeongjeon site showed a reverse-J shape. The average annual ring growth in all survey sites was 1.09 mm/year, with the most abundant growth observed in the Seseokpyeongjeon site, which was formed mainly by a subtree layer. The growth ring survey showed the estimated average age of A. koreana population in the Byeoksoryeong and Banyabong 1 sites to be 102 and 91 years, respectively, a general downward trend of vitality since 2013.

• Journal of Korean Society of Forest Science
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• v.98 no.4
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• pp.472-478
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• 2009

Pine (Pinus densiflora) forests of 58 sites on the ridge of the Baekdudaegan, South Korea were classified by applying the phytosociological method and TWINSPAN. The floristic composition and life-form characteristics of the vegetation types analyzed and documented. The vegetation types were classified into five groups including four groups of Carex humilis var nana type and one group of Abies koreana-Sasa borealis type. Compositae was the most diverse family (26 species), Liliaceae (21 species), Rosaceae (18 species) and Betulaceae (11 species) whereas 27 families were represented by only one species. Taxonomically, Compositae was the most diverse (17 genera), Liliaceae and Rosaceae(12 genera) whereas 41 families were represented by only one genus. The Fagaceae was the most important family in total coverage (19.0) and followed Pinaceae (16.7) and Ericaceae (15.1). Five families such as Compositae, Liliaceae, Rosaceae, Betulaceae, and Umbelliferae contributed little to total coverage, although represented by numerous species. In the correlation between species richness and life forms, the species richness was highly correlated with growth and disseminule forms. In general, the correlation coefficients between life forms represented lower values than those between species richness and life-forms.

• Korean Journal of Environmental Agriculture
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• v.30 no.1
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• pp.9-15
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• 2011

BACKGROUND: This study was conducted to evaluate the effects of the fertilizer sources and ground cover mulches on nutrient release, growth, and photosynthesis in small one-year-old apple (Malus ${\times}$ domestica Borkh.) trees in controlled conditions. METHODS AND RESULTS: Treatments included no fertilizer (NF), commercial organic fertilizer (CF), and poultry litter (PL) for fertilizer treatments, and wood chips (WC), shredded paper (SP), green compost (GC), and grass clippings (GR) for cover mulch treatments. All treatments were applied proportionally based on the volume ratio equivalent to the soil. CF, PL, and GR treatments that had optimum carbon (C) and nitrogen (N) ratios (less than 30:1) for N mineralization through the microbes released the greatest $NH_4^+$ concentrations in the pot media at 90 days after the treatments, but GC mulch with the optimum C:N ratio did not. CF-, PL- and GR-treated plants had the largest leaf area, thickest stem diameter, longest shoot extension, and greater dry matter production. CONCLUSION(s): CF and PL showed an suitable organic nutrient source for improving plant growth in an orchard. Interestingly, GR also could be a nutrient source for tree growth, if vegetation competition is controlled by maintaining vegetation height and recycling enough grass clippings to the soil in an orchard.

• Korean Journal of Agricultural Science
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• v.43 no.4
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• pp.522-536
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• 2016

Fluorine is unique chemical element which occurs naturally, but is not an essential nutrient for plants. Fluoride toxicity can arise due to excessive fluoride intake from a variety of natural or manmade sources. Fluoride is phytotoxic to most plants. Plants which are sensitive for fluorine exposure even low concentrations of fluorine can cause leave damage and a decline in growth. All vegetation contains some fluoride absorbed from soil and water. The highest levels of F in field-grown vegetables are found up to $40mg\;kg^{-1}$ fresh weight although fluoride is relatively immobile and is not easily leached in soil because most of the fluoride was not readily soluble or exchangeable. Also, high concentrations of fluoride primarily associated with the soil colloid or clay fraction can increase fluoride levels in soil solution, increasing uptake via the plant root. In soils more than 90 percent of the natural fluoride ranging from 20 to $1,000{\mu}g\;g^{-1}$ is insoluble, or tightly bound to soil particles. The excess accumulation of fluorides in vegetation leads to visible leaf injury, damage to fruits, changes in the yield. The amount of fluoride taken up by plants depending on the type of plant, the nature of the soil, and the amount and form of fluoride in the soil should be controlled. Conclusively, fluoride is possible and long-term pollution effects on plant growth through accumulation of the fluoride retained in the soil.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.7 no.3
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• pp.35-47
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• 2004

In order to study changes in vegetation pursuant to rooftop revegetation plantation methods, plantation methods for rooftop revegetation were divided into two types through an analysis of recent trends. Then, Planted plants and invasive plants on sites where the planting methods were introduced were monitored. Planting methods were divided into mono-layer meadow cover type and multi-layer planting cover type. They showed some differences in terms of the availability of wetland, the structure of vegetation layers, the planted species, and the material of mulching. According to the results of monitoring the two sample sites for different plantation methods, the number of invasive plants was higher in multi-layer planting cover type and the ratio of naturalized plants was higher by 30% in average in mono-layer meadow cover type. The main reason for such a result is that the natural soil used in the multi-layer planting cover type likely contained some seeds. Moreover, it's harder for invasive plant seeds to germinate in volcanic rocks than in natural soil. Also, it is attributable to wetlands available in multi-layer planting cover type and diverse living environments created by multi-layer planting. The reason of the ratio of naturalized plants being higher by at least 10% in mono-layer meadow cover type is the character of naturalized plants being stronger in unfavorable conditions than nature plants are. Accordingly, the germination rate in the volcanic rock mulching has likely contributed in raising the introduction and germination of naturalized plants. The results showed that multi-layer planting cover type using wetland creation and nature soil can increase the number of invasive plants and lower the ratio of naturalized plants. However, since seeds contained in the natural soil can affect the growth of planted plants, this needs to be clarified, It was judged that mono-layer meadow cover type may affect more greatly on the germination and growth of invasive plants than on those of planted plants, Its potential adoption in highly urbanized areas was examined. By complementing with the mutual benefits of each plantation method, it appeared possible to shift to a rooftop revegetation system suitable to the site.