• Journal of the Korean Institute of Landscape Architecture
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• v.34 no.5 s.118
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• pp.32-38
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• 2006

Roof greening in a city can contributes to not only providing network opportunities for dispersed greenspace patches but also bringing more greenspaces into a city. In addition, it can help to flooding and microclimate control in the city. Recently, a number of roof greening projects have been introduced, mainly to public buildings and schools. Roof peening need to offers both ecological functions and convenience and satisfaction for urban residents. This study aims to provide directions for improving ecological benefits and visual preference of roof greening. Twelve scene slides were adopted to measure people's visual preference. The survey results show that landscape images can be categorized into naturalness, visual diversity, uniqueness, and spatial flexibility. Physical scenes can be classified into type I mostly greened by plants, type II mixed between convenience facilities and plants, and type III constructed with pond. People show high preferences to type I and type II when visual diversity is high. The results of this study suggest to enhance the visual preference by considering visual diversity when applying the ecological design methods to improve naturalness for roof greening.

• Proceedings of the Korean Society of Environment and Ecology Conference
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• 2003.04a
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• pp.75-77
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• 2003

• Korean Journal of Plant Resources
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• v.13 no.3
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• pp.162-170
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• 2000

This study quantified the effects of urban greenspace on microclimate amelioration and atmospheric $CO_2$ reduction for several residential districts selected in Korea and Japan. The study also explored fire obstruction by urban trees to develop systematic planting guidelines. Transpiration by a Zelkova serrata tree (diameter at breast height: 15 cm) in a day of August equaled cooling effect of about 3 air conditioners running for 12 hours. Average air temperature for the growing season was 0.5$^{\circ}C$ and 1.2$^{\circ}C$ cooler, respectively, in districts with 12% and 22% cover of woody plants than in a district with no vegetation. Annual $CO_2$ uptake and $O_2$ production by woody plants were 3 times greater in a district which was 2 times higher in their cover. Woody plants played, in a district with their 22% cover, an important role through offsetting total $CO_2$ emission from the district by about 3% annually, and through producing 10% of annual $O_2$ requirement by all residents within the district. Appropriate planning strategies of residential greenspace, including species selection, planting layout, greenspace enlargement, and maintenance were suggested to improve microclimate amelioration, air purification, and fire obstruction.

• Proceedings of the Korean Society of Environment and Ecology Conference
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• 2011.04a
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• pp.54-56
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• 2011

• Journal of Preventive Medicine and Public Health
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• v.44 no.5
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• pp.201-209
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• 2011

Objectives: This study examined the use of health impact assessment (HIA) as a tool for intersectoral collaboration using the case of an HIA project conducted in Gwang Myeong City, Korea. Methods: A typical procedure for rapid HIA was used. In the screening step, the Aegi-Neung Waterside Park Plan was chosen as the target of the HIA. In the scoping step, the specific methods and tools to assess potential health impacts were chosen. A participatory workshop was held in the assessment step. Various interest groups, including the Department of Parks and Greenspace, the Department of Culture and Sports, the Department of Environment and Cleansing, civil societies, and residents, discussed previously reviewed literature on the potential health impacts of the Aegi-Neung Waterside Park Plan. Results: Potential health impacts and inequality issues were elicited from the workshop, and measures to maximize positive health impacts and minimize negative health impacts were recommended. The priorities among the recommendations were decided by voting. A report on the HIA was submitted to the Department of Parks and Greenspace for their consideration. Conclusions: Although this study examined only one case, it shows the potential usefulness of HIA as a tool for enhancing intersectoral collaboration. Some strategies to formally implement HIA are discussed.

• Journal of the Korean Institute of Landscape Architecture
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• v.38 no.3
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• pp.23-32
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• 2010

The purpose of this study is to quantify human energy budgets for different structures of outdoor spatial surfaces affecting thermal comfort, to analyze the impacts of tree shading on building energy savings, and to suggest desirable strategies of urban greenspace planning concerned. Concrete paving and grass spaces without tree shading and compacted-sand spaces with tree shading were selected to reflect archetypal compositional types for outdoor spatial materials. The study then estimated human energy budgets in static activity for the 3 space types. Major determinants of energy budgets were the presence of shading and also the albedo and temperature of base surfaces. The energy budgets for concrete paving and grass spaces without tree shading were $284\;W/m^2$ and $226\;W/m^2$, respectively, and these space types were considerably poor in thermal comfort. Therefore, it is desirable to construct outdoor resting spaces with evapotranspirational shade trees and natural materials for the base plane. Building energy savings from tree shading for the case of Daegu in the southern region were quantified using computer modeling programs and compared with a previous study for Chuncheon in the middle region. Shade trees planted to the west of a building were most effective for annual savings of heating and cooling energy. Plantings of shade trees in the south should be avoided, because they increased heating energy use with cooling energy savings low in both climate regions. A large shade tree in the west and east saved cooling energy by 1~2% across building types and regions. Based on previous studies and these results, some strategies including indicators for urban greenspace planning were suggested to improve thermal comfort of outdoor spaces and to save energy use in indoor spaces. These included thermal comfort in construction materials for outdoor spaces, building energy savings through shading, evapotranspiration and windspeed mitigation by greenspaces, and greenspace areas and volume for air-temperature reductions. In addition, this study explored the application of the strategies to greenspace-related regulations to ensure their effectiveness.

• Journal of Environmental Policy
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• v.9 no.1
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• pp.137-154
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• 2010

These objectives of this study were to compute heavy metal and accumulation carbon dioxide fixing quantity from urban green space(street trees and urban parks) in Cheong-ju city and Chungju-city and thus to estimate the effect of urban green space for improving the urban environment. The results are summarized below. 1. Results of the total accumulation of the carbon dioxide fixing quantity of street trees, Cheong-ju city and Chungju-city street tree was 1, 230,000kg-C, 1,270,000 kg-C, respectively. Total accumulation carbon dioxide fixing quantity of Balssan urban park had a 25,000kg-C in Cheong-ju city, Degami sports park had a 6,400kg-C in Chungju-city. 2. Results of heavy metal for street trees, fell in the order Zn > Cu > Cr > Ni >, the highest accumulated heavy metal was Zn, and the lowest was Ni. Total heavy metal concentration according to land-use area, was observed in order, for residental areas(157.26 mg/kg) > industrial areas(141.71 mg/kg) > commercial areas(118.55 mg/kg) > and greenspace areas(61.95 mg/kg) in Cheong-ju city. 3. Total heavy metal concentration for street trees fell in the order of commercial areas(84.48 mg/kg) > residental areas(83.70 mg/kg) > and greenspace(48.23 mg/kg) according to land-use area in Chungju-city. Comparatively, Cheong-ju city had more total heavy metal concentration than Chungju-city. 4. Heavy metal for soil that planted street trees was observed in order of Zn > Cu > Pb( > Ni > Cr > As > Cd), and Zn was highest, and Cd was lowest. Total heavy metal concentration for soil fell in the order commercial area(91.82mg/kg) > industrial area(85.96mg/kg) > residental area(67.55mg/kg) > greenspace(43.13mg/kg) according to land-use area in Cheong-ju city. 5. Heavy metal for soil that planted street trees was observed in order of Zn > Pb > Cu( > Ni > Cr > As > Cd, and Zn was highest. Total heavy metal concentration for soil fell in the order commercial area(87.66mg/kg) > greenspace(72.73mg/kg) $${\geq_-}$$ residental area(70.10mg/kg) in Chungju-city.

• Journal of Environmental Science International
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• v.25 no.12
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• pp.1689-1699
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• 2016

The growth conditions of planted trees, invasion of nuisance herbaceous species, competition between species, and effects of erosion control were monitored over five years in a riparian greenspace in Gapyeong County that was established through multilayered and grouped ecological planting. Of 156 trees planted in the upper and middle layers, 5.8% died. This tree death was attributed to poor drainage or aeration in the rooting zone from the clay-added root ball and too deep planting as well as a small-sized root ball and scanty fine roots. Of all the trees, 21.6% grew poorly due to transplant stress in the first year after planting, but they started to grow vigorously in the third year. This good growth was largely associated with soil improvement before planting, selection of appropriate tree species based on growth ground, and control of dryness and invasive climbing plants through surface mulching and multilayered/grouped planting. Mixed planting of fast-growing species as temporary trees was desirable for accelerating planting effect and increasing planting density. Thinning of fast-growing trees was required in the fifth year after planting to avoid considerable competition with target species. To reduce the invasion of herbaceous and climbing plants that oppress normal growth of planted trees, higher density planting of trees (crown opening of about 15%), woodchip mulching to a 10-cm depth, and edge planting 2 m wide were more effective than lower density planting (crown opening of 70%), no surface mulching, and no edge planting, respectively. This reduction effect was especially great during the first three years after planting. Nuisance herbaceous plants rarely invaded higher density planting with woodchip mulching over the five years. Higher density planting or woodchip mulching also showed much greater erosion control through rainfall interception and buffering than lower density planting with no mulching did. Based on these results, desirable planting and management strategies are suggested to improve the functions of riparian greenspaces.

• Journal of People, Plants, and Environment
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• v.24 no.2
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• pp.219-227
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• 2021

Background and objective: Urban street trees play an important role in carbon reduction in cities where greenspace is scarce. There are ongoing studies on carbon reduction by street trees. However, information on the carbon reduction capacity of street trees based on field surveys is still limited. This study aimed to quantify carbon uptake and storage by urban street trees and suggest a method to improve planting of trees in order to increase their carbon reduction capacity. Methods: The cities selected were Sejong, Chungju, and Jeonju among cities without research on carbon reduction, considering the regional distribution in Korea. In the cities, 155 sample sites were selected using systematic sampling to conduct a field survey on street environments and planting structures. The surveyed data included tree species, diameter at breast height (DBH), diameter at root collar (DRC), height, crown width, and vertical structures. The carbon uptake and storage per tree were calculated using the quantification models developed for the urban trees of each species. Results: The average carbon uptake and storage of street trees were approximately 7.2 ± 0.6 kg/tree/yr and 87.1 ± 10.2 kg/tree, respectively. The key factors determining carbon uptake and storage were tree size, vertical structure, the composition of tree species, and growth conditions. The annual total carbon uptake and storage were approximately 1,135.8 tons and 22,737.8 tons, respectively. The total carbon uptake was about the same amount as carbon emitted by 2,272 vehicles a year. Conclusion: This study has significance in providing the basic unit to quantify carbon uptake and storage of street trees based on field surveys. To improve the carbon reduction capacity of street trees, it is necessary to consider planning strategies such as securing and extending available grounds and spaces for high-density street trees with a multi-layered structure.

• Journal of the Korean Institute of Landscape Architecture
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• v.43 no.6
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• pp.16-24
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• 2015

This study quantified storage and annual uptake of carbon for riparian greenspaces established in watersheds of four major rivers in South Korea and explored desirable strategies to improve carbon reduction effects of riparian greenspaces. Greenspace structure and planting technique in the 40 study sites sampled were represented by single-layered planting of small trees in low density, with stem diameter at breast height of $6.9{\pm}0.2cm$ and planting density of $10.4{\pm}0.8trees/100m^2$ on average. Storage and annual uptake of carbon per unit area by planted trees averaged $8.2{\pm}0.5t/ha$ and $1.7{\pm}0.1t/ha/yr$, respectively, increasing as planting density got higher. Mean organic matter and carbon storage in soils were $1.4{\pm}0.1%$ and $26.4{\pm}1.5t/ha$, respectively. Planted trees and soils per ha stored the amount of carbon emitted from gasoline consumption of about 61 kL, and the trees per ha annually offset carbon emissions from gasoline use of about 3 kL. These carbon reduction effects are associated with tree growth over five years to fewer than 10 years after planting, and predicted to become much greater as the planted trees grow. This study simulated changes in annual carbon uptake by tree growth over future 30 years for typical planting models selected as different from the planting technique in the study sites. The simulation revealed that cumulative annual carbon uptake for a multilayered and grouped ecological planting model with both larger tree size and higher planting density was approximately 1.9 times greater 10 years after planting and 1.5 times greater 30 years after than that in the study sites. Strategies to improve carbon reduction effects of riparian greenspaces suggest multilayered and grouped planting mixed with relatively large trees, middle/high density planting of native species mixed with fast-growing trees, and securing the soil environment favorable for normal growth of planting tree species. The research findings are expected to be useful as practical guidelines to improve the role of a carbon uptake source, in addition to water quality conservation and wildlife inhabitation, in implementing riparian greenspace projects under the beginning stage.