• Journal of the Korean Society of Environmental Restoration Technology
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• v.20 no.1
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• pp.131-142
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• 2017

The function of urban parks as wildlife habitats is becoming increasingly important. The urban park serves as a key area for preserving urban biodiversity. The purpose of this study is to estimate the bird species diversity in 30 parks in Cheonan city and quantitatively analyze the influence of vegetation, park structure and landscape connectivity index. As the results, a total of 27 birds species and 1,509 individuals were found at the sites and the largest number of birds were found in the Cheongsa park with 17 species. The optimal regression model was selected as the explanatory variables for the logged park area (LPA), the tree cover ratio (Co_T) and the patch betweenness centrality (PB). LPA and Co_T mean the internal characteristics of the park, and PB was the external environmental variable meaning landscape connectivity. LPA was the most important factor (73.3%) as bird habitat, and the PB could be interpreted as a factor that should be considered as important (26.7%). It will be possible to consider these environmental variables in the park and green area construction and management.

• Journal of the Korean Institute of Landscape Architecture
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• v.31 no.5
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• pp.43-57
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• 2003

This paper presents the air corridor planning strategy based on simulation with MUKLMO_3 (Micro-scale Urban Climate Model) to investigate the wind field and air corridor caused by the land-use change of the New Town Development Area in Pan-Gyo. In the first part, the most frequently observed wind field in the New Town Development Area was measured and used as an initial value to simulate a more realistic wind field and air corridor. Several experiments with different initial values of wind fields were carried out to investigate the wind field change affected by the New Town Development. The results show the features of the wind field of the neutral stability condition in the urban canopy layer with a high resolution near the ground. The wind speed is weakened at this level due to the New Town Development. It was found that the wind field and air corridor are influenced by the land-use change. After the development of the New Town, the speed of the wind field decreased and the main wind directions and air corridor changed. In this study, this model is found to be a useful tool for evaluating air corridor and change of wind field in speed and direction.

• Journal of the Korean Institute of Landscape Architecture
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• v.43 no.4
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• pp.37-49
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• 2015

The goal of this research is to examine air temperature changes according to tree type, plantation type, roadside green area structure, and green volume of street green area within a city. The plantation type that could be analyzed for comparison by tree type with over 3 species was 1 rows of tree+shrubs. The results of analysis of average air temperature difference between pedestrian and car streets vis-a-vis 1 row of tree+shrub in high air temperature areas were: Pinus densiflora, $1.35^{\circ}C$; Zelkova serrata, $1.84^{\circ}C$; Ginkgo biloba, $2.00^{\circ}C$; Platanus occidentalis, $2.57^{\circ}C$. This standard large wide canopy species was analyzed by the roadside to provide shade to have a significant impact on air temperature reduction. In terms of analysis of the relationship between plantation type of roadside trees and air temperature, the average air temperature difference for 1 row of tree type was $1.80^{\circ}C$; for 2 rows of trees it was $2.15^{\circ}C$. In terms of analysis of the relationship between the roadside green area structure and air temperature, for tree type, average air temperature $1.94^{\circ}C$: for tree+shrub type, average air temperature $2.49^{\circ}C$; for tree+mid-size tree+shrub type, average air temperature $2.57^{\circ}C$. That is, air temperature reduction was more effective in a multi-layer structure than a single layer structure. In the relationship analysis of green volume and air temperature reduction, the air temperature reduction effect was enlarged as there was a large amount of green volume. There was a relationship with the green volume of the road, the size of the tree and number of tree layers and a multi-layer structured form of planting. The canopy volume was large and there were a great number of rows of the tree layer and the plantation type of multi-layer structure, which is what is meant through a relationship with the green volume along the roadside. Green composition standards for air temperature reduction effects and functional improvement were proposed based on the result. For a pedestrian street width of 3m or less in the field being ideal, deciduous broadleaf trees in which the canopy volume is small and the structure of the tree+shrub type through the greatest 1m green bend were proposed. For a pedestrian street width of over 3m, deciduous broadleaf trees in which the canopy volume is large and is multi-layer planted with green bend over 1m, tree+mid-size tree+shrub type was proposed.

• Journal of Bio-Environment Control
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• v.32 no.4
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• pp.366-376
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• 2023

This study was conducted to develop a model for predicting the growth of kimchi cabbage using image data and environmental data. Kimchi cabbages of the 'Cheongmyeong Gaual' variety were planted three times on July 11th, July 19th, and July 27th at a test field located at Pyeongchang-gun, Gangwon-do (37°37' N 128°32' E, 510 elevation), and data on growth, images, and environmental conditions were collected until September 12th. To select key factors for the kimchi cabbage growth prediction model, a correlation analysis was conducted using the collected growth data and meteorological data. The correlation coefficient between fresh weight and growth degree days (GDD) and between fresh weight and integrated solar radiation showed a high correlation coefficient of 0.88. Additionally, fresh weight had significant correlations with height and leaf area of kimchi cabbages, with correlation coefficients of 0.78 and 0.79, respectively. Canopy coverage was selected from the image data and GDD was selected from the environmental data based on references from previous researches. A prediction model for kimchi cabbage of biomass, leaf count, and leaf area was developed by combining GDD, canopy coverage and growth data. Single-factor models, including quadratic, sigmoid, and logistic models, were created and the sigmoid prediction model showed the best explanatory power according to the evaluation results. Developing a multi-factor growth prediction model by combining GDD and canopy coverage resulted in improved determination coefficients of 0.9, 0.95, and 0.89 for biomass, leaf count, and leaf area, respectively, compared to single-factor prediction models. To validate the developed model, validation was conducted and the determination coefficient between measured and predicted fresh weight was 0.91, with an RMSE of 134.2 g, indicating high prediction accuracy. In the past, kimchi cabbage growth prediction was often based on meteorological or image data, which resulted in low predictive accuracy due to the inability to reflect on-site conditions or the heading up of kimchi cabbage. Combining these two prediction methods is expected to enhance the accuracy of crop yield predictions by compensating for the weaknesses of each observation method.

• Journal of the Korean earth science society
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• v.41 no.2
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• pp.111-128
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• 2020

This study presents a possibility of intensification of fine dust mass concentration due to the complex urban structure using data mining technique and clustering analysis. The data mining technique showed no significant correlation between fine dust concentration and regional-use public urban data over Seoul. However, clustering analysis based on nationwide-use public data showed that building heights (floors) have a strong correlation particularly with PM₁₀. The modeling analyses using the single canopy model and the micro-atmospheric modeling program (ENVI-Met. 4) conducted that the controlled atmospheric convection in urban area leaded to the congested flow pattern depending on the building along the distribution and height. The complex structure of urban building controls convective activity resulted in stagnation condition and fine dust increase near the surface. Consequently, the residual effect through the changes in the thermal environment caused by the shape and structure of the urban buildings must be considered in the fine dust distribution. It is notable that the atmospheric congestion may be misidentified as an important implications for providing information about the residual probability of fine dust mass concentration in the complex urban area.

• Journal of Korean Society of Forest Science
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• v.103 no.3
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• pp.321-338
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• 2014

In the Natural Monument (No. 432) Jeju Sanghyo-dong Cymbidium kanran Habitat (39 ha), flora, vegetation diversity, stand structure, mirco-climate, canopy openness, light environment and soil temperature and moisture were quantified from Oct. 2013 to Feb. 2014. Compare to Seogwipo-si, daily mean temperature ($5.7^{\circ}C$) and moisture (75.8%) in study area were lower at $3.3^{\circ}C$ and 15%, respectively. Mean soil temperature and moisture were $16.5^{\circ}C$ and 37.3%, respectively, and mean litter layer depth (n = 81) was 4.3 cm. Mean canopy openness and light availability at forest floor were 15.5% and $8.5mol{\cdot}m^{-2}{\cdot}day^{-1}$, respectively. Total of 22 species including vascular and bryophyte plants and 6 vegetation group were observed. Castanopsis siebildii was dominant species in study area, and density and basal area were 1,777 stem/ha and $90.3m^2/ha$.

• Korean Journal of Soil Science and Fertilizer
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• v.5 no.1
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• pp.33-39
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• 1972

For the increase of productivity, canopy structure and nutritional status in various productivity grades (high>700, medium>600 and low>500kg/l0a as head rice) were investigated in a study using Jinheung(Oryza sativa L.) for the increase of producticity with following results: 1. High yield plot showed greater leaf area and slow decrease of it after heading stage. While low yield plot had rapidly decrease of leaf area. 2. High yield plot showed higher light transmission ratio (LTR) durnig early grow stage, low LTR. during late grow stage, and higher leaf area per LTR. 3. Net assimilation ratio was decrease with the increase of leaf area index (LAI) and it was always higher in high yield plot. 4. High yield plant had greater amount of total nitrogen uptake, slow uptake rate, and considerable uptake after heading while low yield plant showed higher uptake of nitrogen in early stage of growth and no uptake after heading. 5. The percent ratio starch at heading to total at harvesting was 40% for low yield plant and 10% for highyield plant inderting that high yield depends much on past-heading starch synthesis. 6. Main factor determining secondary yield was ripened grain ratio.

• Journal of Korean Society of Forest Science
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• v.99 no.1
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• pp.153-162
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• 2010

Abies holophylla Maxim. is a shade tolerant species that has potential to be used for continuous cover forestry system. Stand structure and natural regeneration of A. holophylla stands in Yong-In area located in the central part of Korea was investigated to estimate the self sustainability of A. holophylla plantation. Species composition, diameter at breast height (DBH) and height distribution of trees larger than 2 cm DBH were measured in ten stands in three study sites of Jeongsu-ri, Daedae-ri, and Hodong. Species and coverage of shrub layer, and A. holophylla seedlings were also investigated. While A. holophylla in non-managed stands (Jengsuri and Daedae-ri study sites) had the importance value of 40% and showed continuous diameter and age distribution, A. holophylla in Hodong site had narrow bell-shaped DBH distribution mostly concentrating between 25-35 cm DBH classes, and single canopy structure. Abies holophylla stands in Hodong have experienced occasional thinning and selective cutting. The correlation coefficient between age-DBH was significant but low ($R^2$=0.2, P=0.03), and similar aged A. holophylla had diverse DBH values. Continuos DBH distribution and multi-canopy structure of A. holophylla stands in Jeongsu-ri site show that natural regeneration of A. holophylla has been continuously occurred in this area. Seedling density of A. holophylla was between 2000 and 33000/ha, however, the number of trees in 2-5 cm DBH class was only 40-150 trees/ha, implying that the survival rate of seedlings is not high. Continuous natural regeneration and 0.6 cm/year of diameter growth rate of A. holophylla indicate that this area could be an appropriate habitat for this species, and A. holophylla plantation in this region seem to persist suggesting the possibility of managing the stands for continuous cover forestry system as well as selective harvesting practices.

• Korean Journal of Environment and Ecology
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• v.18 no.4
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• pp.351-358
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• 2004

This study was achieved to investigate the distribution state and the characteristic of Ageratina altissima community in five districts(90.15$\textrm{km}^2$), north of Seoul, Korea. Total distribution area of Ageratina altissima community was 1,860,805$m^2$ and the distribution rate of Ageratina altissima community was 23.7% in Yongsan-gu, Seoul and it was 13.7% in Joong-gu, Seoul including the Namsan-mountain. As a result of correlation between Ageratina altissima community and the actual vegetation, in case of the whole sites Ageratina altissima community was distributed mainly in the Robinia pseudo-acacia forest and in case of Namsan-mountain area it was distributed mainly in the lower layer of the Pinus densiflora forest especially. In case of the whole sites, the distribution ratio of Ageratina altissima community was highest in the Pinus koraiensis forest; on the other hand, it was highest in the Robinia pseudo-acacia forest with planted area excepting the Namsan-mountain. As a result of correlation between Ageratina altissima community and Green Covered Ratio(GCR), the more the distribution ratio of Ageratina altissima community was heigher, the more GCR was higher in case of canopy and understory layer. Especially the distribution ratio of Ageratina altissima community was most high where GCR was over 50%. As a result of correlation between Ageratina altissima community and aspect, Ageratina altissima community was distributed mainly to the west, so we suppose that Ageratina altissima community was distributed mainly in the lower layer of the Robinia pseudo-acacia forest which has fine canopy in the west. We should improve the Robinia pseudo-acacia forest to multi-layer natural forest to control the flourishing Ageratina altissima community in the long term.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.241-241
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• 2017

Sweet potatoes (Ipomoea batatas (L.) LAMK.,) have been cultivated in Central and South America for about 2000 years and are now grown mainly in Asia and South America. Sweet potatoes are annual in the temperate region, but are classified as perennial in the tropical region. In 2000, the cultivation area of sweet potatoes decreased to about 16,000 ha in 2000, but the cultivation area increased slightly in recent 20,000 ha in Korea. Sweet potatoes do not show higher maximum dry matter production of 120 ~ 150g per plant, and the leaf area index (LAI), which maximizes dry matter production, is known as 3.0 ~ 4.0. As the leaf area increase, the penetration of light into the canopy becomes poor, and sufficient photosynthesis cannot be achieved in the lower leaves, on the other hand the respiration increase, which results in poor dry matter production. This study was conducted to know the responses of sweet potatoes to intensive shading treatment of 80% shading. This experiment was conducted for about 42 days from September 6, 2016 to October 18, 2016 at Gyeongsang National University Experimental Farm, Jinju, Korea. The plant canopy was shaded with black nylon 80% shade cloth suspended 1.2 m above the ground. The photosynthetic rate, stomatal conductance, chlorophyll fluorescence, SPAD and NDVI were measured in 3 replicates every 7 days after shading initiation. After the fresh weight was measured, the samples were dried at $80^{\circ}C$ in a dry oven and measured. By the 80% shading treatment, chlorophyll fluorescence of the treated plants was slightly higher than that of the control, the SPAD value was higher by 3.4 and NDVI value was higher by 0.01. However, photosynthetic rate and stomatal conductance were lower than those of the control. The stomatal conductance of the control were two times higher than those of the control and the photosynthetic rate of the control was four times higher than that of the control. In control, plant showed a tendency to steadily increase in fresh weight and dry weight. However, in the case of shading treatment, the tendency to increase in the fresh and dry weight of tuberous roots was not clear. The fresh weight of shoot showed a tendency to increase steadily while the difference between treatment and control was not large, but tended to decrease after frost.